1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CGCXXABI.h"
16#include "CGDebugInfo.h"
17#include "CGObjCRuntime.h"
18#include "CodeGenModule.h"
19#include "TargetInfo.h"
20#include "clang/AST/ASTContext.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/AST/StmtVisitor.h"
24#include "clang/Basic/TargetInfo.h"
25#include "clang/Frontend/CodeGenOptions.h"
26#include "llvm/IR/CFG.h"
27#include "llvm/IR/Constants.h"
28#include "llvm/IR/DataLayout.h"
29#include "llvm/IR/Function.h"
30#include "llvm/IR/GlobalVariable.h"
31#include "llvm/IR/Intrinsics.h"
32#include "llvm/IR/Module.h"
33#include <cstdarg>
34
35using namespace clang;
36using namespace CodeGen;
37using llvm::Value;
38
39//===----------------------------------------------------------------------===//
40//                         Scalar Expression Emitter
41//===----------------------------------------------------------------------===//
42
43namespace {
44struct BinOpInfo {
45  Value *LHS;
46  Value *RHS;
47  QualType Ty;  // Computation Type.
48  BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform
49  bool FPContractable;
50  const Expr *E;      // Entire expr, for error unsupported.  May not be binop.
51};
52
53static bool MustVisitNullValue(const Expr *E) {
54  // If a null pointer expression's type is the C++0x nullptr_t, then
55  // it's not necessarily a simple constant and it must be evaluated
56  // for its potential side effects.
57  return E->getType()->isNullPtrType();
58}
59
60class ScalarExprEmitter
61  : public StmtVisitor<ScalarExprEmitter, Value*> {
62  CodeGenFunction &CGF;
63  CGBuilderTy &Builder;
64  bool IgnoreResultAssign;
65  llvm::LLVMContext &VMContext;
66public:
67
68  ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
69    : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
70      VMContext(cgf.getLLVMContext()) {
71  }
72
73  //===--------------------------------------------------------------------===//
74  //                               Utilities
75  //===--------------------------------------------------------------------===//
76
77  bool TestAndClearIgnoreResultAssign() {
78    bool I = IgnoreResultAssign;
79    IgnoreResultAssign = false;
80    return I;
81  }
82
83  llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
84  LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
85  LValue EmitCheckedLValue(const Expr *E, CodeGenFunction::TypeCheckKind TCK) {
86    return CGF.EmitCheckedLValue(E, TCK);
87  }
88
89  void EmitBinOpCheck(ArrayRef<std::pair<Value *, SanitizerMask>> Checks,
90                      const BinOpInfo &Info);
91
92  Value *EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
93    return CGF.EmitLoadOfLValue(LV, Loc).getScalarVal();
94  }
95
96  void EmitLValueAlignmentAssumption(const Expr *E, Value *V) {
97    const AlignValueAttr *AVAttr = nullptr;
98    if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
99      const ValueDecl *VD = DRE->getDecl();
100
101      if (VD->getType()->isReferenceType()) {
102        if (const auto *TTy =
103            dyn_cast<TypedefType>(VD->getType().getNonReferenceType()))
104          AVAttr = TTy->getDecl()->getAttr<AlignValueAttr>();
105      } else {
106        // Assumptions for function parameters are emitted at the start of the
107        // function, so there is no need to repeat that here.
108        if (isa<ParmVarDecl>(VD))
109          return;
110
111        AVAttr = VD->getAttr<AlignValueAttr>();
112      }
113    }
114
115    if (!AVAttr)
116      if (const auto *TTy =
117          dyn_cast<TypedefType>(E->getType()))
118        AVAttr = TTy->getDecl()->getAttr<AlignValueAttr>();
119
120    if (!AVAttr)
121      return;
122
123    Value *AlignmentValue = CGF.EmitScalarExpr(AVAttr->getAlignment());
124    llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(AlignmentValue);
125    CGF.EmitAlignmentAssumption(V, AlignmentCI->getZExtValue());
126  }
127
128  /// EmitLoadOfLValue - Given an expression with complex type that represents a
129  /// value l-value, this method emits the address of the l-value, then loads
130  /// and returns the result.
131  Value *EmitLoadOfLValue(const Expr *E) {
132    Value *V = EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load),
133                                E->getExprLoc());
134
135    EmitLValueAlignmentAssumption(E, V);
136    return V;
137  }
138
139  /// EmitConversionToBool - Convert the specified expression value to a
140  /// boolean (i1) truth value.  This is equivalent to "Val != 0".
141  Value *EmitConversionToBool(Value *Src, QualType DstTy);
142
143  /// Emit a check that a conversion to or from a floating-point type does not
144  /// overflow.
145  void EmitFloatConversionCheck(Value *OrigSrc, QualType OrigSrcType,
146                                Value *Src, QualType SrcType, QualType DstType,
147                                llvm::Type *DstTy, SourceLocation Loc);
148
149  /// Emit a conversion from the specified type to the specified destination
150  /// type, both of which are LLVM scalar types.
151  Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy,
152                              SourceLocation Loc);
153
154  Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy,
155                              SourceLocation Loc, bool TreatBooleanAsSigned);
156
157  /// Emit a conversion from the specified complex type to the specified
158  /// destination type, where the destination type is an LLVM scalar type.
159  Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
160                                       QualType SrcTy, QualType DstTy,
161                                       SourceLocation Loc);
162
163  /// EmitNullValue - Emit a value that corresponds to null for the given type.
164  Value *EmitNullValue(QualType Ty);
165
166  /// EmitFloatToBoolConversion - Perform an FP to boolean conversion.
167  Value *EmitFloatToBoolConversion(Value *V) {
168    // Compare against 0.0 for fp scalars.
169    llvm::Value *Zero = llvm::Constant::getNullValue(V->getType());
170    return Builder.CreateFCmpUNE(V, Zero, "tobool");
171  }
172
173  /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion.
174  Value *EmitPointerToBoolConversion(Value *V) {
175    Value *Zero = llvm::ConstantPointerNull::get(
176                                      cast<llvm::PointerType>(V->getType()));
177    return Builder.CreateICmpNE(V, Zero, "tobool");
178  }
179
180  Value *EmitIntToBoolConversion(Value *V) {
181    // Because of the type rules of C, we often end up computing a
182    // logical value, then zero extending it to int, then wanting it
183    // as a logical value again.  Optimize this common case.
184    if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) {
185      if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) {
186        Value *Result = ZI->getOperand(0);
187        // If there aren't any more uses, zap the instruction to save space.
188        // Note that there can be more uses, for example if this
189        // is the result of an assignment.
190        if (ZI->use_empty())
191          ZI->eraseFromParent();
192        return Result;
193      }
194    }
195
196    return Builder.CreateIsNotNull(V, "tobool");
197  }
198
199  //===--------------------------------------------------------------------===//
200  //                            Visitor Methods
201  //===--------------------------------------------------------------------===//
202
203  Value *Visit(Expr *E) {
204    ApplyDebugLocation DL(CGF, E);
205    return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
206  }
207
208  Value *VisitStmt(Stmt *S) {
209    S->dump(CGF.getContext().getSourceManager());
210    llvm_unreachable("Stmt can't have complex result type!");
211  }
212  Value *VisitExpr(Expr *S);
213
214  Value *VisitParenExpr(ParenExpr *PE) {
215    return Visit(PE->getSubExpr());
216  }
217  Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
218    return Visit(E->getReplacement());
219  }
220  Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
221    return Visit(GE->getResultExpr());
222  }
223
224  // Leaves.
225  Value *VisitIntegerLiteral(const IntegerLiteral *E) {
226    return Builder.getInt(E->getValue());
227  }
228  Value *VisitFloatingLiteral(const FloatingLiteral *E) {
229    return llvm::ConstantFP::get(VMContext, E->getValue());
230  }
231  Value *VisitCharacterLiteral(const CharacterLiteral *E) {
232    return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
233  }
234  Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
235    return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
236  }
237  Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
238    return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
239  }
240  Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
241    return EmitNullValue(E->getType());
242  }
243  Value *VisitGNUNullExpr(const GNUNullExpr *E) {
244    return EmitNullValue(E->getType());
245  }
246  Value *VisitOffsetOfExpr(OffsetOfExpr *E);
247  Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
248  Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
249    llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
250    return Builder.CreateBitCast(V, ConvertType(E->getType()));
251  }
252
253  Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) {
254    return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength());
255  }
256
257  Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) {
258    return CGF.EmitPseudoObjectRValue(E).getScalarVal();
259  }
260
261  Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) {
262    if (E->isGLValue())
263      return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
264
265    // Otherwise, assume the mapping is the scalar directly.
266    return CGF.getOpaqueRValueMapping(E).getScalarVal();
267  }
268
269  // l-values.
270  Value *VisitDeclRefExpr(DeclRefExpr *E) {
271    if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
272      if (result.isReference())
273        return EmitLoadOfLValue(result.getReferenceLValue(CGF, E),
274                                E->getExprLoc());
275      return result.getValue();
276    }
277    return EmitLoadOfLValue(E);
278  }
279
280  Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
281    return CGF.EmitObjCSelectorExpr(E);
282  }
283  Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
284    return CGF.EmitObjCProtocolExpr(E);
285  }
286  Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
287    return EmitLoadOfLValue(E);
288  }
289  Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
290    if (E->getMethodDecl() &&
291        E->getMethodDecl()->getReturnType()->isReferenceType())
292      return EmitLoadOfLValue(E);
293    return CGF.EmitObjCMessageExpr(E).getScalarVal();
294  }
295
296  Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
297    LValue LV = CGF.EmitObjCIsaExpr(E);
298    Value *V = CGF.EmitLoadOfLValue(LV, E->getExprLoc()).getScalarVal();
299    return V;
300  }
301
302  Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
303  Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
304  Value *VisitConvertVectorExpr(ConvertVectorExpr *E);
305  Value *VisitMemberExpr(MemberExpr *E);
306  Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
307  Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
308    return EmitLoadOfLValue(E);
309  }
310
311  Value *VisitInitListExpr(InitListExpr *E);
312
313  Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
314    return EmitNullValue(E->getType());
315  }
316  Value *VisitExplicitCastExpr(ExplicitCastExpr *E) {
317    CGF.CGM.EmitExplicitCastExprType(E, &CGF);
318    return VisitCastExpr(E);
319  }
320  Value *VisitCastExpr(CastExpr *E);
321
322  Value *VisitCallExpr(const CallExpr *E) {
323    if (E->getCallReturnType(CGF.getContext())->isReferenceType())
324      return EmitLoadOfLValue(E);
325
326    Value *V = CGF.EmitCallExpr(E).getScalarVal();
327
328    EmitLValueAlignmentAssumption(E, V);
329    return V;
330  }
331
332  Value *VisitStmtExpr(const StmtExpr *E);
333
334  // Unary Operators.
335  Value *VisitUnaryPostDec(const UnaryOperator *E) {
336    LValue LV = EmitLValue(E->getSubExpr());
337    return EmitScalarPrePostIncDec(E, LV, false, false);
338  }
339  Value *VisitUnaryPostInc(const UnaryOperator *E) {
340    LValue LV = EmitLValue(E->getSubExpr());
341    return EmitScalarPrePostIncDec(E, LV, true, false);
342  }
343  Value *VisitUnaryPreDec(const UnaryOperator *E) {
344    LValue LV = EmitLValue(E->getSubExpr());
345    return EmitScalarPrePostIncDec(E, LV, false, true);
346  }
347  Value *VisitUnaryPreInc(const UnaryOperator *E) {
348    LValue LV = EmitLValue(E->getSubExpr());
349    return EmitScalarPrePostIncDec(E, LV, true, true);
350  }
351
352  llvm::Value *EmitIncDecConsiderOverflowBehavior(const UnaryOperator *E,
353                                                  llvm::Value *InVal,
354                                                  bool IsInc);
355
356  llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
357                                       bool isInc, bool isPre);
358
359
360  Value *VisitUnaryAddrOf(const UnaryOperator *E) {
361    if (isa<MemberPointerType>(E->getType())) // never sugared
362      return CGF.CGM.getMemberPointerConstant(E);
363
364    return EmitLValue(E->getSubExpr()).getPointer();
365  }
366  Value *VisitUnaryDeref(const UnaryOperator *E) {
367    if (E->getType()->isVoidType())
368      return Visit(E->getSubExpr()); // the actual value should be unused
369    return EmitLoadOfLValue(E);
370  }
371  Value *VisitUnaryPlus(const UnaryOperator *E) {
372    // This differs from gcc, though, most likely due to a bug in gcc.
373    TestAndClearIgnoreResultAssign();
374    return Visit(E->getSubExpr());
375  }
376  Value *VisitUnaryMinus    (const UnaryOperator *E);
377  Value *VisitUnaryNot      (const UnaryOperator *E);
378  Value *VisitUnaryLNot     (const UnaryOperator *E);
379  Value *VisitUnaryReal     (const UnaryOperator *E);
380  Value *VisitUnaryImag     (const UnaryOperator *E);
381  Value *VisitUnaryExtension(const UnaryOperator *E) {
382    return Visit(E->getSubExpr());
383  }
384
385  // C++
386  Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) {
387    return EmitLoadOfLValue(E);
388  }
389
390  Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
391    return Visit(DAE->getExpr());
392  }
393  Value *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
394    CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
395    return Visit(DIE->getExpr());
396  }
397  Value *VisitCXXThisExpr(CXXThisExpr *TE) {
398    return CGF.LoadCXXThis();
399  }
400
401  Value *VisitExprWithCleanups(ExprWithCleanups *E) {
402    CGF.enterFullExpression(E);
403    CodeGenFunction::RunCleanupsScope Scope(CGF);
404    return Visit(E->getSubExpr());
405  }
406  Value *VisitCXXNewExpr(const CXXNewExpr *E) {
407    return CGF.EmitCXXNewExpr(E);
408  }
409  Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
410    CGF.EmitCXXDeleteExpr(E);
411    return nullptr;
412  }
413
414  Value *VisitTypeTraitExpr(const TypeTraitExpr *E) {
415    return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
416  }
417
418  Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
419    return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue());
420  }
421
422  Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
423    return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue());
424  }
425
426  Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
427    // C++ [expr.pseudo]p1:
428    //   The result shall only be used as the operand for the function call
429    //   operator (), and the result of such a call has type void. The only
430    //   effect is the evaluation of the postfix-expression before the dot or
431    //   arrow.
432    CGF.EmitScalarExpr(E->getBase());
433    return nullptr;
434  }
435
436  Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
437    return EmitNullValue(E->getType());
438  }
439
440  Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
441    CGF.EmitCXXThrowExpr(E);
442    return nullptr;
443  }
444
445  Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
446    return Builder.getInt1(E->getValue());
447  }
448
449  // Binary Operators.
450  Value *EmitMul(const BinOpInfo &Ops) {
451    if (Ops.Ty->isSignedIntegerOrEnumerationType()) {
452      switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
453      case LangOptions::SOB_Defined:
454        return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
455      case LangOptions::SOB_Undefined:
456        if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
457          return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
458        // Fall through.
459      case LangOptions::SOB_Trapping:
460        return EmitOverflowCheckedBinOp(Ops);
461      }
462    }
463
464    if (Ops.Ty->isUnsignedIntegerType() &&
465        CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow))
466      return EmitOverflowCheckedBinOp(Ops);
467
468    if (Ops.LHS->getType()->isFPOrFPVectorTy())
469      return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
470    return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
471  }
472  /// Create a binary op that checks for overflow.
473  /// Currently only supports +, - and *.
474  Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
475
476  // Check for undefined division and modulus behaviors.
477  void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops,
478                                                  llvm::Value *Zero,bool isDiv);
479  // Common helper for getting how wide LHS of shift is.
480  static Value *GetWidthMinusOneValue(Value* LHS,Value* RHS);
481  Value *EmitDiv(const BinOpInfo &Ops);
482  Value *EmitRem(const BinOpInfo &Ops);
483  Value *EmitAdd(const BinOpInfo &Ops);
484  Value *EmitSub(const BinOpInfo &Ops);
485  Value *EmitShl(const BinOpInfo &Ops);
486  Value *EmitShr(const BinOpInfo &Ops);
487  Value *EmitAnd(const BinOpInfo &Ops) {
488    return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
489  }
490  Value *EmitXor(const BinOpInfo &Ops) {
491    return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
492  }
493  Value *EmitOr (const BinOpInfo &Ops) {
494    return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
495  }
496
497  BinOpInfo EmitBinOps(const BinaryOperator *E);
498  LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
499                            Value *(ScalarExprEmitter::*F)(const BinOpInfo &),
500                                  Value *&Result);
501
502  Value *EmitCompoundAssign(const CompoundAssignOperator *E,
503                            Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
504
505  // Binary operators and binary compound assignment operators.
506#define HANDLEBINOP(OP) \
507  Value *VisitBin ## OP(const BinaryOperator *E) {                         \
508    return Emit ## OP(EmitBinOps(E));                                      \
509  }                                                                        \
510  Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) {       \
511    return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP);          \
512  }
513  HANDLEBINOP(Mul)
514  HANDLEBINOP(Div)
515  HANDLEBINOP(Rem)
516  HANDLEBINOP(Add)
517  HANDLEBINOP(Sub)
518  HANDLEBINOP(Shl)
519  HANDLEBINOP(Shr)
520  HANDLEBINOP(And)
521  HANDLEBINOP(Xor)
522  HANDLEBINOP(Or)
523#undef HANDLEBINOP
524
525  // Comparisons.
526  Value *EmitCompare(const BinaryOperator *E, llvm::CmpInst::Predicate UICmpOpc,
527                     llvm::CmpInst::Predicate SICmpOpc,
528                     llvm::CmpInst::Predicate FCmpOpc);
529#define VISITCOMP(CODE, UI, SI, FP) \
530    Value *VisitBin##CODE(const BinaryOperator *E) { \
531      return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
532                         llvm::FCmpInst::FP); }
533  VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
534  VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
535  VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
536  VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
537  VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
538  VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
539#undef VISITCOMP
540
541  Value *VisitBinAssign     (const BinaryOperator *E);
542
543  Value *VisitBinLAnd       (const BinaryOperator *E);
544  Value *VisitBinLOr        (const BinaryOperator *E);
545  Value *VisitBinComma      (const BinaryOperator *E);
546
547  Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
548  Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
549
550  // Other Operators.
551  Value *VisitBlockExpr(const BlockExpr *BE);
552  Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *);
553  Value *VisitChooseExpr(ChooseExpr *CE);
554  Value *VisitVAArgExpr(VAArgExpr *VE);
555  Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
556    return CGF.EmitObjCStringLiteral(E);
557  }
558  Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) {
559    return CGF.EmitObjCBoxedExpr(E);
560  }
561  Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) {
562    return CGF.EmitObjCArrayLiteral(E);
563  }
564  Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
565    return CGF.EmitObjCDictionaryLiteral(E);
566  }
567  Value *VisitAsTypeExpr(AsTypeExpr *CE);
568  Value *VisitAtomicExpr(AtomicExpr *AE);
569};
570}  // end anonymous namespace.
571
572//===----------------------------------------------------------------------===//
573//                                Utilities
574//===----------------------------------------------------------------------===//
575
576/// EmitConversionToBool - Convert the specified expression value to a
577/// boolean (i1) truth value.  This is equivalent to "Val != 0".
578Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) {
579  assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs");
580
581  if (SrcType->isRealFloatingType())
582    return EmitFloatToBoolConversion(Src);
583
584  if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType))
585    return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT);
586
587  assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
588         "Unknown scalar type to convert");
589
590  if (isa<llvm::IntegerType>(Src->getType()))
591    return EmitIntToBoolConversion(Src);
592
593  assert(isa<llvm::PointerType>(Src->getType()));
594  return EmitPointerToBoolConversion(Src);
595}
596
597void ScalarExprEmitter::EmitFloatConversionCheck(
598    Value *OrigSrc, QualType OrigSrcType, Value *Src, QualType SrcType,
599    QualType DstType, llvm::Type *DstTy, SourceLocation Loc) {
600  CodeGenFunction::SanitizerScope SanScope(&CGF);
601  using llvm::APFloat;
602  using llvm::APSInt;
603
604  llvm::Type *SrcTy = Src->getType();
605
606  llvm::Value *Check = nullptr;
607  if (llvm::IntegerType *IntTy = dyn_cast<llvm::IntegerType>(SrcTy)) {
608    // Integer to floating-point. This can fail for unsigned short -> __half
609    // or unsigned __int128 -> float.
610    assert(DstType->isFloatingType());
611    bool SrcIsUnsigned = OrigSrcType->isUnsignedIntegerOrEnumerationType();
612
613    APFloat LargestFloat =
614      APFloat::getLargest(CGF.getContext().getFloatTypeSemantics(DstType));
615    APSInt LargestInt(IntTy->getBitWidth(), SrcIsUnsigned);
616
617    bool IsExact;
618    if (LargestFloat.convertToInteger(LargestInt, APFloat::rmTowardZero,
619                                      &IsExact) != APFloat::opOK)
620      // The range of representable values of this floating point type includes
621      // all values of this integer type. Don't need an overflow check.
622      return;
623
624    llvm::Value *Max = llvm::ConstantInt::get(VMContext, LargestInt);
625    if (SrcIsUnsigned)
626      Check = Builder.CreateICmpULE(Src, Max);
627    else {
628      llvm::Value *Min = llvm::ConstantInt::get(VMContext, -LargestInt);
629      llvm::Value *GE = Builder.CreateICmpSGE(Src, Min);
630      llvm::Value *LE = Builder.CreateICmpSLE(Src, Max);
631      Check = Builder.CreateAnd(GE, LE);
632    }
633  } else {
634    const llvm::fltSemantics &SrcSema =
635      CGF.getContext().getFloatTypeSemantics(OrigSrcType);
636    if (isa<llvm::IntegerType>(DstTy)) {
637      // Floating-point to integer. This has undefined behavior if the source is
638      // +-Inf, NaN, or doesn't fit into the destination type (after truncation
639      // to an integer).
640      unsigned Width = CGF.getContext().getIntWidth(DstType);
641      bool Unsigned = DstType->isUnsignedIntegerOrEnumerationType();
642
643      APSInt Min = APSInt::getMinValue(Width, Unsigned);
644      APFloat MinSrc(SrcSema, APFloat::uninitialized);
645      if (MinSrc.convertFromAPInt(Min, !Unsigned, APFloat::rmTowardZero) &
646          APFloat::opOverflow)
647        // Don't need an overflow check for lower bound. Just check for
648        // -Inf/NaN.
649        MinSrc = APFloat::getInf(SrcSema, true);
650      else
651        // Find the largest value which is too small to represent (before
652        // truncation toward zero).
653        MinSrc.subtract(APFloat(SrcSema, 1), APFloat::rmTowardNegative);
654
655      APSInt Max = APSInt::getMaxValue(Width, Unsigned);
656      APFloat MaxSrc(SrcSema, APFloat::uninitialized);
657      if (MaxSrc.convertFromAPInt(Max, !Unsigned, APFloat::rmTowardZero) &
658          APFloat::opOverflow)
659        // Don't need an overflow check for upper bound. Just check for
660        // +Inf/NaN.
661        MaxSrc = APFloat::getInf(SrcSema, false);
662      else
663        // Find the smallest value which is too large to represent (before
664        // truncation toward zero).
665        MaxSrc.add(APFloat(SrcSema, 1), APFloat::rmTowardPositive);
666
667      // If we're converting from __half, convert the range to float to match
668      // the type of src.
669      if (OrigSrcType->isHalfType()) {
670        const llvm::fltSemantics &Sema =
671          CGF.getContext().getFloatTypeSemantics(SrcType);
672        bool IsInexact;
673        MinSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact);
674        MaxSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact);
675      }
676
677      llvm::Value *GE =
678        Builder.CreateFCmpOGT(Src, llvm::ConstantFP::get(VMContext, MinSrc));
679      llvm::Value *LE =
680        Builder.CreateFCmpOLT(Src, llvm::ConstantFP::get(VMContext, MaxSrc));
681      Check = Builder.CreateAnd(GE, LE);
682    } else {
683      // FIXME: Maybe split this sanitizer out from float-cast-overflow.
684      //
685      // Floating-point to floating-point. This has undefined behavior if the
686      // source is not in the range of representable values of the destination
687      // type. The C and C++ standards are spectacularly unclear here. We
688      // diagnose finite out-of-range conversions, but allow infinities and NaNs
689      // to convert to the corresponding value in the smaller type.
690      //
691      // C11 Annex F gives all such conversions defined behavior for IEC 60559
692      // conforming implementations. Unfortunately, LLVM's fptrunc instruction
693      // does not.
694
695      // Converting from a lower rank to a higher rank can never have
696      // undefined behavior, since higher-rank types must have a superset
697      // of values of lower-rank types.
698      if (CGF.getContext().getFloatingTypeOrder(OrigSrcType, DstType) != 1)
699        return;
700
701      assert(!OrigSrcType->isHalfType() &&
702             "should not check conversion from __half, it has the lowest rank");
703
704      const llvm::fltSemantics &DstSema =
705        CGF.getContext().getFloatTypeSemantics(DstType);
706      APFloat MinBad = APFloat::getLargest(DstSema, false);
707      APFloat MaxBad = APFloat::getInf(DstSema, false);
708
709      bool IsInexact;
710      MinBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact);
711      MaxBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact);
712
713      Value *AbsSrc = CGF.EmitNounwindRuntimeCall(
714        CGF.CGM.getIntrinsic(llvm::Intrinsic::fabs, Src->getType()), Src);
715      llvm::Value *GE =
716        Builder.CreateFCmpOGT(AbsSrc, llvm::ConstantFP::get(VMContext, MinBad));
717      llvm::Value *LE =
718        Builder.CreateFCmpOLT(AbsSrc, llvm::ConstantFP::get(VMContext, MaxBad));
719      Check = Builder.CreateNot(Builder.CreateAnd(GE, LE));
720    }
721  }
722
723  llvm::Constant *StaticArgs[] = {CGF.EmitCheckSourceLocation(Loc),
724                                  CGF.EmitCheckTypeDescriptor(OrigSrcType),
725                                  CGF.EmitCheckTypeDescriptor(DstType)};
726  CGF.EmitCheck(std::make_pair(Check, SanitizerKind::FloatCastOverflow),
727                "float_cast_overflow", StaticArgs, OrigSrc);
728}
729
730/// Emit a conversion from the specified type to the specified destination type,
731/// both of which are LLVM scalar types.
732Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
733                                               QualType DstType,
734                                               SourceLocation Loc) {
735  return EmitScalarConversion(Src, SrcType, DstType, Loc, false);
736}
737
738Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
739                                               QualType DstType,
740                                               SourceLocation Loc,
741                                               bool TreatBooleanAsSigned) {
742  SrcType = CGF.getContext().getCanonicalType(SrcType);
743  DstType = CGF.getContext().getCanonicalType(DstType);
744  if (SrcType == DstType) return Src;
745
746  if (DstType->isVoidType()) return nullptr;
747
748  llvm::Value *OrigSrc = Src;
749  QualType OrigSrcType = SrcType;
750  llvm::Type *SrcTy = Src->getType();
751
752  // Handle conversions to bool first, they are special: comparisons against 0.
753  if (DstType->isBooleanType())
754    return EmitConversionToBool(Src, SrcType);
755
756  llvm::Type *DstTy = ConvertType(DstType);
757
758  // Cast from half through float if half isn't a native type.
759  if (SrcType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
760    // Cast to FP using the intrinsic if the half type itself isn't supported.
761    if (DstTy->isFloatingPointTy()) {
762      if (!CGF.getContext().getLangOpts().HalfArgsAndReturns)
763        return Builder.CreateCall(
764            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16, DstTy),
765            Src);
766    } else {
767      // Cast to other types through float, using either the intrinsic or FPExt,
768      // depending on whether the half type itself is supported
769      // (as opposed to operations on half, available with NativeHalfType).
770      if (!CGF.getContext().getLangOpts().HalfArgsAndReturns) {
771        Src = Builder.CreateCall(
772            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
773                                 CGF.CGM.FloatTy),
774            Src);
775      } else {
776        Src = Builder.CreateFPExt(Src, CGF.CGM.FloatTy, "conv");
777      }
778      SrcType = CGF.getContext().FloatTy;
779      SrcTy = CGF.FloatTy;
780    }
781  }
782
783  // Ignore conversions like int -> uint.
784  if (SrcTy == DstTy)
785    return Src;
786
787  // Handle pointer conversions next: pointers can only be converted to/from
788  // other pointers and integers. Check for pointer types in terms of LLVM, as
789  // some native types (like Obj-C id) may map to a pointer type.
790  if (isa<llvm::PointerType>(DstTy)) {
791    // The source value may be an integer, or a pointer.
792    if (isa<llvm::PointerType>(SrcTy))
793      return Builder.CreateBitCast(Src, DstTy, "conv");
794
795    assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
796    // First, convert to the correct width so that we control the kind of
797    // extension.
798    llvm::Type *MiddleTy = CGF.IntPtrTy;
799    bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
800    llvm::Value* IntResult =
801        Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
802    // Then, cast to pointer.
803    return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
804  }
805
806  if (isa<llvm::PointerType>(SrcTy)) {
807    // Must be an ptr to int cast.
808    assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
809    return Builder.CreatePtrToInt(Src, DstTy, "conv");
810  }
811
812  // A scalar can be splatted to an extended vector of the same element type
813  if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
814    // Cast the scalar to element type
815    QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType();
816    llvm::Value *Elt = EmitScalarConversion(
817        Src, SrcType, EltTy, Loc, CGF.getContext().getLangOpts().OpenCL);
818
819    // Splat the element across to all elements
820    unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
821    return Builder.CreateVectorSplat(NumElements, Elt, "splat");
822  }
823
824  // Allow bitcast from vector to integer/fp of the same size.
825  if (isa<llvm::VectorType>(SrcTy) ||
826      isa<llvm::VectorType>(DstTy))
827    return Builder.CreateBitCast(Src, DstTy, "conv");
828
829  // Finally, we have the arithmetic types: real int/float.
830  Value *Res = nullptr;
831  llvm::Type *ResTy = DstTy;
832
833  // An overflowing conversion has undefined behavior if either the source type
834  // or the destination type is a floating-point type.
835  if (CGF.SanOpts.has(SanitizerKind::FloatCastOverflow) &&
836      (OrigSrcType->isFloatingType() || DstType->isFloatingType()))
837    EmitFloatConversionCheck(OrigSrc, OrigSrcType, Src, SrcType, DstType, DstTy,
838                             Loc);
839
840  // Cast to half through float if half isn't a native type.
841  if (DstType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
842    // Make sure we cast in a single step if from another FP type.
843    if (SrcTy->isFloatingPointTy()) {
844      // Use the intrinsic if the half type itself isn't supported
845      // (as opposed to operations on half, available with NativeHalfType).
846      if (!CGF.getContext().getLangOpts().HalfArgsAndReturns)
847        return Builder.CreateCall(
848            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, SrcTy), Src);
849      // If the half type is supported, just use an fptrunc.
850      return Builder.CreateFPTrunc(Src, DstTy);
851    }
852    DstTy = CGF.FloatTy;
853  }
854
855  if (isa<llvm::IntegerType>(SrcTy)) {
856    bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
857    if (SrcType->isBooleanType() && TreatBooleanAsSigned) {
858      InputSigned = true;
859    }
860    if (isa<llvm::IntegerType>(DstTy))
861      Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
862    else if (InputSigned)
863      Res = Builder.CreateSIToFP(Src, DstTy, "conv");
864    else
865      Res = Builder.CreateUIToFP(Src, DstTy, "conv");
866  } else if (isa<llvm::IntegerType>(DstTy)) {
867    assert(SrcTy->isFloatingPointTy() && "Unknown real conversion");
868    if (DstType->isSignedIntegerOrEnumerationType())
869      Res = Builder.CreateFPToSI(Src, DstTy, "conv");
870    else
871      Res = Builder.CreateFPToUI(Src, DstTy, "conv");
872  } else {
873    assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() &&
874           "Unknown real conversion");
875    if (DstTy->getTypeID() < SrcTy->getTypeID())
876      Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
877    else
878      Res = Builder.CreateFPExt(Src, DstTy, "conv");
879  }
880
881  if (DstTy != ResTy) {
882    if (!CGF.getContext().getLangOpts().HalfArgsAndReturns) {
883      assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion");
884      Res = Builder.CreateCall(
885        CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, CGF.CGM.FloatTy),
886        Res);
887    } else {
888      Res = Builder.CreateFPTrunc(Res, ResTy, "conv");
889    }
890  }
891
892  return Res;
893}
894
895/// Emit a conversion from the specified complex type to the specified
896/// destination type, where the destination type is an LLVM scalar type.
897Value *ScalarExprEmitter::EmitComplexToScalarConversion(
898    CodeGenFunction::ComplexPairTy Src, QualType SrcTy, QualType DstTy,
899    SourceLocation Loc) {
900  // Get the source element type.
901  SrcTy = SrcTy->castAs<ComplexType>()->getElementType();
902
903  // Handle conversions to bool first, they are special: comparisons against 0.
904  if (DstTy->isBooleanType()) {
905    //  Complex != 0  -> (Real != 0) | (Imag != 0)
906    Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy, Loc);
907    Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy, Loc);
908    return Builder.CreateOr(Src.first, Src.second, "tobool");
909  }
910
911  // C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
912  // the imaginary part of the complex value is discarded and the value of the
913  // real part is converted according to the conversion rules for the
914  // corresponding real type.
915  return EmitScalarConversion(Src.first, SrcTy, DstTy, Loc);
916}
917
918Value *ScalarExprEmitter::EmitNullValue(QualType Ty) {
919  return CGF.EmitFromMemory(CGF.CGM.EmitNullConstant(Ty), Ty);
920}
921
922/// \brief Emit a sanitization check for the given "binary" operation (which
923/// might actually be a unary increment which has been lowered to a binary
924/// operation). The check passes if all values in \p Checks (which are \c i1),
925/// are \c true.
926void ScalarExprEmitter::EmitBinOpCheck(
927    ArrayRef<std::pair<Value *, SanitizerMask>> Checks, const BinOpInfo &Info) {
928  assert(CGF.IsSanitizerScope);
929  StringRef CheckName;
930  SmallVector<llvm::Constant *, 4> StaticData;
931  SmallVector<llvm::Value *, 2> DynamicData;
932
933  BinaryOperatorKind Opcode = Info.Opcode;
934  if (BinaryOperator::isCompoundAssignmentOp(Opcode))
935    Opcode = BinaryOperator::getOpForCompoundAssignment(Opcode);
936
937  StaticData.push_back(CGF.EmitCheckSourceLocation(Info.E->getExprLoc()));
938  const UnaryOperator *UO = dyn_cast<UnaryOperator>(Info.E);
939  if (UO && UO->getOpcode() == UO_Minus) {
940    CheckName = "negate_overflow";
941    StaticData.push_back(CGF.EmitCheckTypeDescriptor(UO->getType()));
942    DynamicData.push_back(Info.RHS);
943  } else {
944    if (BinaryOperator::isShiftOp(Opcode)) {
945      // Shift LHS negative or too large, or RHS out of bounds.
946      CheckName = "shift_out_of_bounds";
947      const BinaryOperator *BO = cast<BinaryOperator>(Info.E);
948      StaticData.push_back(
949        CGF.EmitCheckTypeDescriptor(BO->getLHS()->getType()));
950      StaticData.push_back(
951        CGF.EmitCheckTypeDescriptor(BO->getRHS()->getType()));
952    } else if (Opcode == BO_Div || Opcode == BO_Rem) {
953      // Divide or modulo by zero, or signed overflow (eg INT_MAX / -1).
954      CheckName = "divrem_overflow";
955      StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty));
956    } else {
957      // Arithmetic overflow (+, -, *).
958      switch (Opcode) {
959      case BO_Add: CheckName = "add_overflow"; break;
960      case BO_Sub: CheckName = "sub_overflow"; break;
961      case BO_Mul: CheckName = "mul_overflow"; break;
962      default: llvm_unreachable("unexpected opcode for bin op check");
963      }
964      StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty));
965    }
966    DynamicData.push_back(Info.LHS);
967    DynamicData.push_back(Info.RHS);
968  }
969
970  CGF.EmitCheck(Checks, CheckName, StaticData, DynamicData);
971}
972
973//===----------------------------------------------------------------------===//
974//                            Visitor Methods
975//===----------------------------------------------------------------------===//
976
977Value *ScalarExprEmitter::VisitExpr(Expr *E) {
978  CGF.ErrorUnsupported(E, "scalar expression");
979  if (E->getType()->isVoidType())
980    return nullptr;
981  return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
982}
983
984Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
985  // Vector Mask Case
986  if (E->getNumSubExprs() == 2 ||
987      (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) {
988    Value *LHS = CGF.EmitScalarExpr(E->getExpr(0));
989    Value *RHS = CGF.EmitScalarExpr(E->getExpr(1));
990    Value *Mask;
991
992    llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
993    unsigned LHSElts = LTy->getNumElements();
994
995    if (E->getNumSubExprs() == 3) {
996      Mask = CGF.EmitScalarExpr(E->getExpr(2));
997
998      // Shuffle LHS & RHS into one input vector.
999      SmallVector<llvm::Constant*, 32> concat;
1000      for (unsigned i = 0; i != LHSElts; ++i) {
1001        concat.push_back(Builder.getInt32(2*i));
1002        concat.push_back(Builder.getInt32(2*i+1));
1003      }
1004
1005      Value* CV = llvm::ConstantVector::get(concat);
1006      LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat");
1007      LHSElts *= 2;
1008    } else {
1009      Mask = RHS;
1010    }
1011
1012    llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
1013
1014    // Mask off the high bits of each shuffle index.
1015    Value *MaskBits =
1016        llvm::ConstantInt::get(MTy, llvm::NextPowerOf2(LHSElts - 1) - 1);
1017    Mask = Builder.CreateAnd(Mask, MaskBits, "mask");
1018
1019    // newv = undef
1020    // mask = mask & maskbits
1021    // for each elt
1022    //   n = extract mask i
1023    //   x = extract val n
1024    //   newv = insert newv, x, i
1025    llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(),
1026                                                  MTy->getNumElements());
1027    Value* NewV = llvm::UndefValue::get(RTy);
1028    for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) {
1029      Value *IIndx = llvm::ConstantInt::get(CGF.SizeTy, i);
1030      Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx");
1031
1032      Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt");
1033      NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins");
1034    }
1035    return NewV;
1036  }
1037
1038  Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
1039  Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
1040
1041  SmallVector<llvm::Constant*, 32> indices;
1042  for (unsigned i = 2; i < E->getNumSubExprs(); ++i) {
1043    llvm::APSInt Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2);
1044    // Check for -1 and output it as undef in the IR.
1045    if (Idx.isSigned() && Idx.isAllOnesValue())
1046      indices.push_back(llvm::UndefValue::get(CGF.Int32Ty));
1047    else
1048      indices.push_back(Builder.getInt32(Idx.getZExtValue()));
1049  }
1050
1051  Value *SV = llvm::ConstantVector::get(indices);
1052  return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
1053}
1054
1055Value *ScalarExprEmitter::VisitConvertVectorExpr(ConvertVectorExpr *E) {
1056  QualType SrcType = E->getSrcExpr()->getType(),
1057           DstType = E->getType();
1058
1059  Value *Src  = CGF.EmitScalarExpr(E->getSrcExpr());
1060
1061  SrcType = CGF.getContext().getCanonicalType(SrcType);
1062  DstType = CGF.getContext().getCanonicalType(DstType);
1063  if (SrcType == DstType) return Src;
1064
1065  assert(SrcType->isVectorType() &&
1066         "ConvertVector source type must be a vector");
1067  assert(DstType->isVectorType() &&
1068         "ConvertVector destination type must be a vector");
1069
1070  llvm::Type *SrcTy = Src->getType();
1071  llvm::Type *DstTy = ConvertType(DstType);
1072
1073  // Ignore conversions like int -> uint.
1074  if (SrcTy == DstTy)
1075    return Src;
1076
1077  QualType SrcEltType = SrcType->getAs<VectorType>()->getElementType(),
1078           DstEltType = DstType->getAs<VectorType>()->getElementType();
1079
1080  assert(SrcTy->isVectorTy() &&
1081         "ConvertVector source IR type must be a vector");
1082  assert(DstTy->isVectorTy() &&
1083         "ConvertVector destination IR type must be a vector");
1084
1085  llvm::Type *SrcEltTy = SrcTy->getVectorElementType(),
1086             *DstEltTy = DstTy->getVectorElementType();
1087
1088  if (DstEltType->isBooleanType()) {
1089    assert((SrcEltTy->isFloatingPointTy() ||
1090            isa<llvm::IntegerType>(SrcEltTy)) && "Unknown boolean conversion");
1091
1092    llvm::Value *Zero = llvm::Constant::getNullValue(SrcTy);
1093    if (SrcEltTy->isFloatingPointTy()) {
1094      return Builder.CreateFCmpUNE(Src, Zero, "tobool");
1095    } else {
1096      return Builder.CreateICmpNE(Src, Zero, "tobool");
1097    }
1098  }
1099
1100  // We have the arithmetic types: real int/float.
1101  Value *Res = nullptr;
1102
1103  if (isa<llvm::IntegerType>(SrcEltTy)) {
1104    bool InputSigned = SrcEltType->isSignedIntegerOrEnumerationType();
1105    if (isa<llvm::IntegerType>(DstEltTy))
1106      Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
1107    else if (InputSigned)
1108      Res = Builder.CreateSIToFP(Src, DstTy, "conv");
1109    else
1110      Res = Builder.CreateUIToFP(Src, DstTy, "conv");
1111  } else if (isa<llvm::IntegerType>(DstEltTy)) {
1112    assert(SrcEltTy->isFloatingPointTy() && "Unknown real conversion");
1113    if (DstEltType->isSignedIntegerOrEnumerationType())
1114      Res = Builder.CreateFPToSI(Src, DstTy, "conv");
1115    else
1116      Res = Builder.CreateFPToUI(Src, DstTy, "conv");
1117  } else {
1118    assert(SrcEltTy->isFloatingPointTy() && DstEltTy->isFloatingPointTy() &&
1119           "Unknown real conversion");
1120    if (DstEltTy->getTypeID() < SrcEltTy->getTypeID())
1121      Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
1122    else
1123      Res = Builder.CreateFPExt(Src, DstTy, "conv");
1124  }
1125
1126  return Res;
1127}
1128
1129Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
1130  llvm::APSInt Value;
1131  if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) {
1132    if (E->isArrow())
1133      CGF.EmitScalarExpr(E->getBase());
1134    else
1135      EmitLValue(E->getBase());
1136    return Builder.getInt(Value);
1137  }
1138
1139  return EmitLoadOfLValue(E);
1140}
1141
1142Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
1143  TestAndClearIgnoreResultAssign();
1144
1145  // Emit subscript expressions in rvalue context's.  For most cases, this just
1146  // loads the lvalue formed by the subscript expr.  However, we have to be
1147  // careful, because the base of a vector subscript is occasionally an rvalue,
1148  // so we can't get it as an lvalue.
1149  if (!E->getBase()->getType()->isVectorType())
1150    return EmitLoadOfLValue(E);
1151
1152  // Handle the vector case.  The base must be a vector, the index must be an
1153  // integer value.
1154  Value *Base = Visit(E->getBase());
1155  Value *Idx  = Visit(E->getIdx());
1156  QualType IdxTy = E->getIdx()->getType();
1157
1158  if (CGF.SanOpts.has(SanitizerKind::ArrayBounds))
1159    CGF.EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, /*Accessed*/true);
1160
1161  return Builder.CreateExtractElement(Base, Idx, "vecext");
1162}
1163
1164static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
1165                                  unsigned Off, llvm::Type *I32Ty) {
1166  int MV = SVI->getMaskValue(Idx);
1167  if (MV == -1)
1168    return llvm::UndefValue::get(I32Ty);
1169  return llvm::ConstantInt::get(I32Ty, Off+MV);
1170}
1171
1172static llvm::Constant *getAsInt32(llvm::ConstantInt *C, llvm::Type *I32Ty) {
1173  if (C->getBitWidth() != 32) {
1174      assert(llvm::ConstantInt::isValueValidForType(I32Ty,
1175                                                    C->getZExtValue()) &&
1176             "Index operand too large for shufflevector mask!");
1177      return llvm::ConstantInt::get(I32Ty, C->getZExtValue());
1178  }
1179  return C;
1180}
1181
1182Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
1183  bool Ignore = TestAndClearIgnoreResultAssign();
1184  (void)Ignore;
1185  assert (Ignore == false && "init list ignored");
1186  unsigned NumInitElements = E->getNumInits();
1187
1188  if (E->hadArrayRangeDesignator())
1189    CGF.ErrorUnsupported(E, "GNU array range designator extension");
1190
1191  llvm::VectorType *VType =
1192    dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
1193
1194  if (!VType) {
1195    if (NumInitElements == 0) {
1196      // C++11 value-initialization for the scalar.
1197      return EmitNullValue(E->getType());
1198    }
1199    // We have a scalar in braces. Just use the first element.
1200    return Visit(E->getInit(0));
1201  }
1202
1203  unsigned ResElts = VType->getNumElements();
1204
1205  // Loop over initializers collecting the Value for each, and remembering
1206  // whether the source was swizzle (ExtVectorElementExpr).  This will allow
1207  // us to fold the shuffle for the swizzle into the shuffle for the vector
1208  // initializer, since LLVM optimizers generally do not want to touch
1209  // shuffles.
1210  unsigned CurIdx = 0;
1211  bool VIsUndefShuffle = false;
1212  llvm::Value *V = llvm::UndefValue::get(VType);
1213  for (unsigned i = 0; i != NumInitElements; ++i) {
1214    Expr *IE = E->getInit(i);
1215    Value *Init = Visit(IE);
1216    SmallVector<llvm::Constant*, 16> Args;
1217
1218    llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
1219
1220    // Handle scalar elements.  If the scalar initializer is actually one
1221    // element of a different vector of the same width, use shuffle instead of
1222    // extract+insert.
1223    if (!VVT) {
1224      if (isa<ExtVectorElementExpr>(IE)) {
1225        llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
1226
1227        if (EI->getVectorOperandType()->getNumElements() == ResElts) {
1228          llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
1229          Value *LHS = nullptr, *RHS = nullptr;
1230          if (CurIdx == 0) {
1231            // insert into undef -> shuffle (src, undef)
1232            // shufflemask must use an i32
1233            Args.push_back(getAsInt32(C, CGF.Int32Ty));
1234            Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1235
1236            LHS = EI->getVectorOperand();
1237            RHS = V;
1238            VIsUndefShuffle = true;
1239          } else if (VIsUndefShuffle) {
1240            // insert into undefshuffle && size match -> shuffle (v, src)
1241            llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
1242            for (unsigned j = 0; j != CurIdx; ++j)
1243              Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty));
1244            Args.push_back(Builder.getInt32(ResElts + C->getZExtValue()));
1245            Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1246
1247            LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
1248            RHS = EI->getVectorOperand();
1249            VIsUndefShuffle = false;
1250          }
1251          if (!Args.empty()) {
1252            llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1253            V = Builder.CreateShuffleVector(LHS, RHS, Mask);
1254            ++CurIdx;
1255            continue;
1256          }
1257        }
1258      }
1259      V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx),
1260                                      "vecinit");
1261      VIsUndefShuffle = false;
1262      ++CurIdx;
1263      continue;
1264    }
1265
1266    unsigned InitElts = VVT->getNumElements();
1267
1268    // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
1269    // input is the same width as the vector being constructed, generate an
1270    // optimized shuffle of the swizzle input into the result.
1271    unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
1272    if (isa<ExtVectorElementExpr>(IE)) {
1273      llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
1274      Value *SVOp = SVI->getOperand(0);
1275      llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
1276
1277      if (OpTy->getNumElements() == ResElts) {
1278        for (unsigned j = 0; j != CurIdx; ++j) {
1279          // If the current vector initializer is a shuffle with undef, merge
1280          // this shuffle directly into it.
1281          if (VIsUndefShuffle) {
1282            Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
1283                                      CGF.Int32Ty));
1284          } else {
1285            Args.push_back(Builder.getInt32(j));
1286          }
1287        }
1288        for (unsigned j = 0, je = InitElts; j != je; ++j)
1289          Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty));
1290        Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1291
1292        if (VIsUndefShuffle)
1293          V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
1294
1295        Init = SVOp;
1296      }
1297    }
1298
1299    // Extend init to result vector length, and then shuffle its contribution
1300    // to the vector initializer into V.
1301    if (Args.empty()) {
1302      for (unsigned j = 0; j != InitElts; ++j)
1303        Args.push_back(Builder.getInt32(j));
1304      Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1305      llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1306      Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
1307                                         Mask, "vext");
1308
1309      Args.clear();
1310      for (unsigned j = 0; j != CurIdx; ++j)
1311        Args.push_back(Builder.getInt32(j));
1312      for (unsigned j = 0; j != InitElts; ++j)
1313        Args.push_back(Builder.getInt32(j+Offset));
1314      Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1315    }
1316
1317    // If V is undef, make sure it ends up on the RHS of the shuffle to aid
1318    // merging subsequent shuffles into this one.
1319    if (CurIdx == 0)
1320      std::swap(V, Init);
1321    llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1322    V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
1323    VIsUndefShuffle = isa<llvm::UndefValue>(Init);
1324    CurIdx += InitElts;
1325  }
1326
1327  // FIXME: evaluate codegen vs. shuffling against constant null vector.
1328  // Emit remaining default initializers.
1329  llvm::Type *EltTy = VType->getElementType();
1330
1331  // Emit remaining default initializers
1332  for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
1333    Value *Idx = Builder.getInt32(CurIdx);
1334    llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
1335    V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
1336  }
1337  return V;
1338}
1339
1340bool CodeGenFunction::ShouldNullCheckClassCastValue(const CastExpr *CE) {
1341  const Expr *E = CE->getSubExpr();
1342
1343  if (CE->getCastKind() == CK_UncheckedDerivedToBase)
1344    return false;
1345
1346  if (isa<CXXThisExpr>(E->IgnoreParens())) {
1347    // We always assume that 'this' is never null.
1348    return false;
1349  }
1350
1351  if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
1352    // And that glvalue casts are never null.
1353    if (ICE->getValueKind() != VK_RValue)
1354      return false;
1355  }
1356
1357  return true;
1358}
1359
1360// VisitCastExpr - Emit code for an explicit or implicit cast.  Implicit casts
1361// have to handle a more broad range of conversions than explicit casts, as they
1362// handle things like function to ptr-to-function decay etc.
1363Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
1364  Expr *E = CE->getSubExpr();
1365  QualType DestTy = CE->getType();
1366  CastKind Kind = CE->getCastKind();
1367
1368  if (!DestTy->isVoidType())
1369    TestAndClearIgnoreResultAssign();
1370
1371  // Since almost all cast kinds apply to scalars, this switch doesn't have
1372  // a default case, so the compiler will warn on a missing case.  The cases
1373  // are in the same order as in the CastKind enum.
1374  switch (Kind) {
1375  case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
1376  case CK_BuiltinFnToFnPtr:
1377    llvm_unreachable("builtin functions are handled elsewhere");
1378
1379  case CK_LValueBitCast:
1380  case CK_ObjCObjectLValueCast: {
1381    Address Addr = EmitLValue(E).getAddress();
1382    Addr = Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(DestTy));
1383    LValue LV = CGF.MakeAddrLValue(Addr, DestTy);
1384    return EmitLoadOfLValue(LV, CE->getExprLoc());
1385  }
1386
1387  case CK_CPointerToObjCPointerCast:
1388  case CK_BlockPointerToObjCPointerCast:
1389  case CK_AnyPointerToBlockPointerCast:
1390  case CK_BitCast: {
1391    Value *Src = Visit(const_cast<Expr*>(E));
1392    llvm::Type *SrcTy = Src->getType();
1393    llvm::Type *DstTy = ConvertType(DestTy);
1394    if (SrcTy->isPtrOrPtrVectorTy() && DstTy->isPtrOrPtrVectorTy() &&
1395        SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace()) {
1396      llvm_unreachable("wrong cast for pointers in different address spaces"
1397                       "(must be an address space cast)!");
1398    }
1399
1400    if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast)) {
1401      if (auto PT = DestTy->getAs<PointerType>())
1402        CGF.EmitVTablePtrCheckForCast(PT->getPointeeType(), Src,
1403                                      /*MayBeNull=*/true,
1404                                      CodeGenFunction::CFITCK_UnrelatedCast,
1405                                      CE->getLocStart());
1406    }
1407
1408    return Builder.CreateBitCast(Src, DstTy);
1409  }
1410  case CK_AddressSpaceConversion: {
1411    Value *Src = Visit(const_cast<Expr*>(E));
1412    return Builder.CreateAddrSpaceCast(Src, ConvertType(DestTy));
1413  }
1414  case CK_AtomicToNonAtomic:
1415  case CK_NonAtomicToAtomic:
1416  case CK_NoOp:
1417  case CK_UserDefinedConversion:
1418    return Visit(const_cast<Expr*>(E));
1419
1420  case CK_BaseToDerived: {
1421    const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl();
1422    assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!");
1423
1424    Address Base = CGF.EmitPointerWithAlignment(E);
1425    Address Derived =
1426      CGF.GetAddressOfDerivedClass(Base, DerivedClassDecl,
1427                                   CE->path_begin(), CE->path_end(),
1428                                   CGF.ShouldNullCheckClassCastValue(CE));
1429
1430    // C++11 [expr.static.cast]p11: Behavior is undefined if a downcast is
1431    // performed and the object is not of the derived type.
1432    if (CGF.sanitizePerformTypeCheck())
1433      CGF.EmitTypeCheck(CodeGenFunction::TCK_DowncastPointer, CE->getExprLoc(),
1434                        Derived.getPointer(), DestTy->getPointeeType());
1435
1436    if (CGF.SanOpts.has(SanitizerKind::CFIDerivedCast))
1437      CGF.EmitVTablePtrCheckForCast(DestTy->getPointeeType(),
1438                                    Derived.getPointer(),
1439                                    /*MayBeNull=*/true,
1440                                    CodeGenFunction::CFITCK_DerivedCast,
1441                                    CE->getLocStart());
1442
1443    return Derived.getPointer();
1444  }
1445  case CK_UncheckedDerivedToBase:
1446  case CK_DerivedToBase: {
1447    // The EmitPointerWithAlignment path does this fine; just discard
1448    // the alignment.
1449    return CGF.EmitPointerWithAlignment(CE).getPointer();
1450  }
1451
1452  case CK_Dynamic: {
1453    Address V = CGF.EmitPointerWithAlignment(E);
1454    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
1455    return CGF.EmitDynamicCast(V, DCE);
1456  }
1457
1458  case CK_ArrayToPointerDecay:
1459    return CGF.EmitArrayToPointerDecay(E).getPointer();
1460  case CK_FunctionToPointerDecay:
1461    return EmitLValue(E).getPointer();
1462
1463  case CK_NullToPointer:
1464    if (MustVisitNullValue(E))
1465      (void) Visit(E);
1466
1467    return llvm::ConstantPointerNull::get(
1468                               cast<llvm::PointerType>(ConvertType(DestTy)));
1469
1470  case CK_NullToMemberPointer: {
1471    if (MustVisitNullValue(E))
1472      (void) Visit(E);
1473
1474    const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>();
1475    return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
1476  }
1477
1478  case CK_ReinterpretMemberPointer:
1479  case CK_BaseToDerivedMemberPointer:
1480  case CK_DerivedToBaseMemberPointer: {
1481    Value *Src = Visit(E);
1482
1483    // Note that the AST doesn't distinguish between checked and
1484    // unchecked member pointer conversions, so we always have to
1485    // implement checked conversions here.  This is inefficient when
1486    // actual control flow may be required in order to perform the
1487    // check, which it is for data member pointers (but not member
1488    // function pointers on Itanium and ARM).
1489    return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src);
1490  }
1491
1492  case CK_ARCProduceObject:
1493    return CGF.EmitARCRetainScalarExpr(E);
1494  case CK_ARCConsumeObject:
1495    return CGF.EmitObjCConsumeObject(E->getType(), Visit(E));
1496  case CK_ARCReclaimReturnedObject: {
1497    llvm::Value *value = Visit(E);
1498    value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
1499    return CGF.EmitObjCConsumeObject(E->getType(), value);
1500  }
1501  case CK_ARCExtendBlockObject:
1502    return CGF.EmitARCExtendBlockObject(E);
1503
1504  case CK_CopyAndAutoreleaseBlockObject:
1505    return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType());
1506
1507  case CK_FloatingRealToComplex:
1508  case CK_FloatingComplexCast:
1509  case CK_IntegralRealToComplex:
1510  case CK_IntegralComplexCast:
1511  case CK_IntegralComplexToFloatingComplex:
1512  case CK_FloatingComplexToIntegralComplex:
1513  case CK_ConstructorConversion:
1514  case CK_ToUnion:
1515    llvm_unreachable("scalar cast to non-scalar value");
1516
1517  case CK_LValueToRValue:
1518    assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
1519    assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!");
1520    return Visit(const_cast<Expr*>(E));
1521
1522  case CK_IntegralToPointer: {
1523    Value *Src = Visit(const_cast<Expr*>(E));
1524
1525    // First, convert to the correct width so that we control the kind of
1526    // extension.
1527    llvm::Type *MiddleTy = CGF.IntPtrTy;
1528    bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType();
1529    llvm::Value* IntResult =
1530      Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
1531
1532    return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
1533  }
1534  case CK_PointerToIntegral:
1535    assert(!DestTy->isBooleanType() && "bool should use PointerToBool");
1536    return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy));
1537
1538  case CK_ToVoid: {
1539    CGF.EmitIgnoredExpr(E);
1540    return nullptr;
1541  }
1542  case CK_VectorSplat: {
1543    llvm::Type *DstTy = ConvertType(DestTy);
1544    // Need an IgnoreImpCasts here as by default a boolean will be promoted to
1545    // an int, which will not perform the sign extension, so if we know we are
1546    // going to cast to a vector we have to strip the implicit cast off.
1547    Value *Elt = Visit(const_cast<Expr*>(E->IgnoreImpCasts()));
1548    Elt = EmitScalarConversion(Elt, E->IgnoreImpCasts()->getType(),
1549                               DestTy->getAs<VectorType>()->getElementType(),
1550                               CE->getExprLoc(),
1551                               CGF.getContext().getLangOpts().OpenCL);
1552
1553    // Splat the element across to all elements
1554    unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
1555    return Builder.CreateVectorSplat(NumElements, Elt, "splat");
1556  }
1557
1558  case CK_IntegralCast:
1559  case CK_IntegralToFloating:
1560  case CK_FloatingToIntegral:
1561  case CK_FloatingCast:
1562    return EmitScalarConversion(Visit(E), E->getType(), DestTy,
1563                                CE->getExprLoc());
1564  case CK_IntegralToBoolean:
1565    return EmitIntToBoolConversion(Visit(E));
1566  case CK_PointerToBoolean:
1567    return EmitPointerToBoolConversion(Visit(E));
1568  case CK_FloatingToBoolean:
1569    return EmitFloatToBoolConversion(Visit(E));
1570  case CK_MemberPointerToBoolean: {
1571    llvm::Value *MemPtr = Visit(E);
1572    const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
1573    return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
1574  }
1575
1576  case CK_FloatingComplexToReal:
1577  case CK_IntegralComplexToReal:
1578    return CGF.EmitComplexExpr(E, false, true).first;
1579
1580  case CK_FloatingComplexToBoolean:
1581  case CK_IntegralComplexToBoolean: {
1582    CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E);
1583
1584    // TODO: kill this function off, inline appropriate case here
1585    return EmitComplexToScalarConversion(V, E->getType(), DestTy,
1586                                         CE->getExprLoc());
1587  }
1588
1589  case CK_ZeroToOCLEvent: {
1590    assert(DestTy->isEventT() && "CK_ZeroToOCLEvent cast on non-event type");
1591    return llvm::Constant::getNullValue(ConvertType(DestTy));
1592  }
1593
1594  }
1595
1596  llvm_unreachable("unknown scalar cast");
1597}
1598
1599Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
1600  CodeGenFunction::StmtExprEvaluation eval(CGF);
1601  Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(),
1602                                           !E->getType()->isVoidType());
1603  if (!RetAlloca.isValid())
1604    return nullptr;
1605  return CGF.EmitLoadOfScalar(CGF.MakeAddrLValue(RetAlloca, E->getType()),
1606                              E->getExprLoc());
1607}
1608
1609//===----------------------------------------------------------------------===//
1610//                             Unary Operators
1611//===----------------------------------------------------------------------===//
1612
1613static BinOpInfo createBinOpInfoFromIncDec(const UnaryOperator *E,
1614                                           llvm::Value *InVal, bool IsInc) {
1615  BinOpInfo BinOp;
1616  BinOp.LHS = InVal;
1617  BinOp.RHS = llvm::ConstantInt::get(InVal->getType(), 1, false);
1618  BinOp.Ty = E->getType();
1619  BinOp.Opcode = IsInc ? BO_Add : BO_Sub;
1620  BinOp.FPContractable = false;
1621  BinOp.E = E;
1622  return BinOp;
1623}
1624
1625llvm::Value *ScalarExprEmitter::EmitIncDecConsiderOverflowBehavior(
1626    const UnaryOperator *E, llvm::Value *InVal, bool IsInc) {
1627  llvm::Value *Amount =
1628      llvm::ConstantInt::get(InVal->getType(), IsInc ? 1 : -1, true);
1629  StringRef Name = IsInc ? "inc" : "dec";
1630  switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
1631  case LangOptions::SOB_Defined:
1632    return Builder.CreateAdd(InVal, Amount, Name);
1633  case LangOptions::SOB_Undefined:
1634    if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
1635      return Builder.CreateNSWAdd(InVal, Amount, Name);
1636    // Fall through.
1637  case LangOptions::SOB_Trapping:
1638    return EmitOverflowCheckedBinOp(createBinOpInfoFromIncDec(E, InVal, IsInc));
1639  }
1640  llvm_unreachable("Unknown SignedOverflowBehaviorTy");
1641}
1642
1643llvm::Value *
1644ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
1645                                           bool isInc, bool isPre) {
1646
1647  QualType type = E->getSubExpr()->getType();
1648  llvm::PHINode *atomicPHI = nullptr;
1649  llvm::Value *value;
1650  llvm::Value *input;
1651
1652  int amount = (isInc ? 1 : -1);
1653
1654  if (const AtomicType *atomicTy = type->getAs<AtomicType>()) {
1655    type = atomicTy->getValueType();
1656    if (isInc && type->isBooleanType()) {
1657      llvm::Value *True = CGF.EmitToMemory(Builder.getTrue(), type);
1658      if (isPre) {
1659        Builder.CreateStore(True, LV.getAddress(), LV.isVolatileQualified())
1660          ->setAtomic(llvm::SequentiallyConsistent);
1661        return Builder.getTrue();
1662      }
1663      // For atomic bool increment, we just store true and return it for
1664      // preincrement, do an atomic swap with true for postincrement
1665        return Builder.CreateAtomicRMW(llvm::AtomicRMWInst::Xchg,
1666            LV.getPointer(), True, llvm::SequentiallyConsistent);
1667    }
1668    // Special case for atomic increment / decrement on integers, emit
1669    // atomicrmw instructions.  We skip this if we want to be doing overflow
1670    // checking, and fall into the slow path with the atomic cmpxchg loop.
1671    if (!type->isBooleanType() && type->isIntegerType() &&
1672        !(type->isUnsignedIntegerType() &&
1673          CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) &&
1674        CGF.getLangOpts().getSignedOverflowBehavior() !=
1675            LangOptions::SOB_Trapping) {
1676      llvm::AtomicRMWInst::BinOp aop = isInc ? llvm::AtomicRMWInst::Add :
1677        llvm::AtomicRMWInst::Sub;
1678      llvm::Instruction::BinaryOps op = isInc ? llvm::Instruction::Add :
1679        llvm::Instruction::Sub;
1680      llvm::Value *amt = CGF.EmitToMemory(
1681          llvm::ConstantInt::get(ConvertType(type), 1, true), type);
1682      llvm::Value *old = Builder.CreateAtomicRMW(aop,
1683          LV.getPointer(), amt, llvm::SequentiallyConsistent);
1684      return isPre ? Builder.CreateBinOp(op, old, amt) : old;
1685    }
1686    value = EmitLoadOfLValue(LV, E->getExprLoc());
1687    input = value;
1688    // For every other atomic operation, we need to emit a load-op-cmpxchg loop
1689    llvm::BasicBlock *startBB = Builder.GetInsertBlock();
1690    llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
1691    value = CGF.EmitToMemory(value, type);
1692    Builder.CreateBr(opBB);
1693    Builder.SetInsertPoint(opBB);
1694    atomicPHI = Builder.CreatePHI(value->getType(), 2);
1695    atomicPHI->addIncoming(value, startBB);
1696    value = atomicPHI;
1697  } else {
1698    value = EmitLoadOfLValue(LV, E->getExprLoc());
1699    input = value;
1700  }
1701
1702  // Special case of integer increment that we have to check first: bool++.
1703  // Due to promotion rules, we get:
1704  //   bool++ -> bool = bool + 1
1705  //          -> bool = (int)bool + 1
1706  //          -> bool = ((int)bool + 1 != 0)
1707  // An interesting aspect of this is that increment is always true.
1708  // Decrement does not have this property.
1709  if (isInc && type->isBooleanType()) {
1710    value = Builder.getTrue();
1711
1712  // Most common case by far: integer increment.
1713  } else if (type->isIntegerType()) {
1714    // Note that signed integer inc/dec with width less than int can't
1715    // overflow because of promotion rules; we're just eliding a few steps here.
1716    bool CanOverflow = value->getType()->getIntegerBitWidth() >=
1717                       CGF.IntTy->getIntegerBitWidth();
1718    if (CanOverflow && type->isSignedIntegerOrEnumerationType()) {
1719      value = EmitIncDecConsiderOverflowBehavior(E, value, isInc);
1720    } else if (CanOverflow && type->isUnsignedIntegerType() &&
1721               CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) {
1722      value =
1723          EmitOverflowCheckedBinOp(createBinOpInfoFromIncDec(E, value, isInc));
1724    } else {
1725      llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true);
1726      value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
1727    }
1728
1729  // Next most common: pointer increment.
1730  } else if (const PointerType *ptr = type->getAs<PointerType>()) {
1731    QualType type = ptr->getPointeeType();
1732
1733    // VLA types don't have constant size.
1734    if (const VariableArrayType *vla
1735          = CGF.getContext().getAsVariableArrayType(type)) {
1736      llvm::Value *numElts = CGF.getVLASize(vla).first;
1737      if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize");
1738      if (CGF.getLangOpts().isSignedOverflowDefined())
1739        value = Builder.CreateGEP(value, numElts, "vla.inc");
1740      else
1741        value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc");
1742
1743    // Arithmetic on function pointers (!) is just +-1.
1744    } else if (type->isFunctionType()) {
1745      llvm::Value *amt = Builder.getInt32(amount);
1746
1747      value = CGF.EmitCastToVoidPtr(value);
1748      if (CGF.getLangOpts().isSignedOverflowDefined())
1749        value = Builder.CreateGEP(value, amt, "incdec.funcptr");
1750      else
1751        value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr");
1752      value = Builder.CreateBitCast(value, input->getType());
1753
1754    // For everything else, we can just do a simple increment.
1755    } else {
1756      llvm::Value *amt = Builder.getInt32(amount);
1757      if (CGF.getLangOpts().isSignedOverflowDefined())
1758        value = Builder.CreateGEP(value, amt, "incdec.ptr");
1759      else
1760        value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr");
1761    }
1762
1763  // Vector increment/decrement.
1764  } else if (type->isVectorType()) {
1765    if (type->hasIntegerRepresentation()) {
1766      llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
1767
1768      value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
1769    } else {
1770      value = Builder.CreateFAdd(
1771                  value,
1772                  llvm::ConstantFP::get(value->getType(), amount),
1773                  isInc ? "inc" : "dec");
1774    }
1775
1776  // Floating point.
1777  } else if (type->isRealFloatingType()) {
1778    // Add the inc/dec to the real part.
1779    llvm::Value *amt;
1780
1781    if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
1782      // Another special case: half FP increment should be done via float
1783      if (!CGF.getContext().getLangOpts().HalfArgsAndReturns) {
1784        value = Builder.CreateCall(
1785            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
1786                                 CGF.CGM.FloatTy),
1787            input, "incdec.conv");
1788      } else {
1789        value = Builder.CreateFPExt(input, CGF.CGM.FloatTy, "incdec.conv");
1790      }
1791    }
1792
1793    if (value->getType()->isFloatTy())
1794      amt = llvm::ConstantFP::get(VMContext,
1795                                  llvm::APFloat(static_cast<float>(amount)));
1796    else if (value->getType()->isDoubleTy())
1797      amt = llvm::ConstantFP::get(VMContext,
1798                                  llvm::APFloat(static_cast<double>(amount)));
1799    else {
1800      // Remaining types are either Half or LongDouble.  Convert from float.
1801      llvm::APFloat F(static_cast<float>(amount));
1802      bool ignored;
1803      // Don't use getFloatTypeSemantics because Half isn't
1804      // necessarily represented using the "half" LLVM type.
1805      F.convert(value->getType()->isHalfTy()
1806                    ? CGF.getTarget().getHalfFormat()
1807                    : CGF.getTarget().getLongDoubleFormat(),
1808                llvm::APFloat::rmTowardZero, &ignored);
1809      amt = llvm::ConstantFP::get(VMContext, F);
1810    }
1811    value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec");
1812
1813    if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
1814      if (!CGF.getContext().getLangOpts().HalfArgsAndReturns) {
1815        value = Builder.CreateCall(
1816            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16,
1817                                 CGF.CGM.FloatTy),
1818            value, "incdec.conv");
1819      } else {
1820        value = Builder.CreateFPTrunc(value, input->getType(), "incdec.conv");
1821      }
1822    }
1823
1824  // Objective-C pointer types.
1825  } else {
1826    const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>();
1827    value = CGF.EmitCastToVoidPtr(value);
1828
1829    CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType());
1830    if (!isInc) size = -size;
1831    llvm::Value *sizeValue =
1832      llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity());
1833
1834    if (CGF.getLangOpts().isSignedOverflowDefined())
1835      value = Builder.CreateGEP(value, sizeValue, "incdec.objptr");
1836    else
1837      value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr");
1838    value = Builder.CreateBitCast(value, input->getType());
1839  }
1840
1841  if (atomicPHI) {
1842    llvm::BasicBlock *opBB = Builder.GetInsertBlock();
1843    llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
1844    auto Pair = CGF.EmitAtomicCompareExchange(
1845        LV, RValue::get(atomicPHI), RValue::get(value), E->getExprLoc());
1846    llvm::Value *old = CGF.EmitToMemory(Pair.first.getScalarVal(), type);
1847    llvm::Value *success = Pair.second;
1848    atomicPHI->addIncoming(old, opBB);
1849    Builder.CreateCondBr(success, contBB, opBB);
1850    Builder.SetInsertPoint(contBB);
1851    return isPre ? value : input;
1852  }
1853
1854  // Store the updated result through the lvalue.
1855  if (LV.isBitField())
1856    CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value);
1857  else
1858    CGF.EmitStoreThroughLValue(RValue::get(value), LV);
1859
1860  // If this is a postinc, return the value read from memory, otherwise use the
1861  // updated value.
1862  return isPre ? value : input;
1863}
1864
1865
1866
1867Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
1868  TestAndClearIgnoreResultAssign();
1869  // Emit unary minus with EmitSub so we handle overflow cases etc.
1870  BinOpInfo BinOp;
1871  BinOp.RHS = Visit(E->getSubExpr());
1872
1873  if (BinOp.RHS->getType()->isFPOrFPVectorTy())
1874    BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType());
1875  else
1876    BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
1877  BinOp.Ty = E->getType();
1878  BinOp.Opcode = BO_Sub;
1879  BinOp.FPContractable = false;
1880  BinOp.E = E;
1881  return EmitSub(BinOp);
1882}
1883
1884Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
1885  TestAndClearIgnoreResultAssign();
1886  Value *Op = Visit(E->getSubExpr());
1887  return Builder.CreateNot(Op, "neg");
1888}
1889
1890Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
1891  // Perform vector logical not on comparison with zero vector.
1892  if (E->getType()->isExtVectorType()) {
1893    Value *Oper = Visit(E->getSubExpr());
1894    Value *Zero = llvm::Constant::getNullValue(Oper->getType());
1895    Value *Result;
1896    if (Oper->getType()->isFPOrFPVectorTy())
1897      Result = Builder.CreateFCmp(llvm::CmpInst::FCMP_OEQ, Oper, Zero, "cmp");
1898    else
1899      Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp");
1900    return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
1901  }
1902
1903  // Compare operand to zero.
1904  Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
1905
1906  // Invert value.
1907  // TODO: Could dynamically modify easy computations here.  For example, if
1908  // the operand is an icmp ne, turn into icmp eq.
1909  BoolVal = Builder.CreateNot(BoolVal, "lnot");
1910
1911  // ZExt result to the expr type.
1912  return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
1913}
1914
1915Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) {
1916  // Try folding the offsetof to a constant.
1917  llvm::APSInt Value;
1918  if (E->EvaluateAsInt(Value, CGF.getContext()))
1919    return Builder.getInt(Value);
1920
1921  // Loop over the components of the offsetof to compute the value.
1922  unsigned n = E->getNumComponents();
1923  llvm::Type* ResultType = ConvertType(E->getType());
1924  llvm::Value* Result = llvm::Constant::getNullValue(ResultType);
1925  QualType CurrentType = E->getTypeSourceInfo()->getType();
1926  for (unsigned i = 0; i != n; ++i) {
1927    OffsetOfExpr::OffsetOfNode ON = E->getComponent(i);
1928    llvm::Value *Offset = nullptr;
1929    switch (ON.getKind()) {
1930    case OffsetOfExpr::OffsetOfNode::Array: {
1931      // Compute the index
1932      Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex());
1933      llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr);
1934      bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType();
1935      Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv");
1936
1937      // Save the element type
1938      CurrentType =
1939          CGF.getContext().getAsArrayType(CurrentType)->getElementType();
1940
1941      // Compute the element size
1942      llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType,
1943          CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity());
1944
1945      // Multiply out to compute the result
1946      Offset = Builder.CreateMul(Idx, ElemSize);
1947      break;
1948    }
1949
1950    case OffsetOfExpr::OffsetOfNode::Field: {
1951      FieldDecl *MemberDecl = ON.getField();
1952      RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
1953      const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
1954
1955      // Compute the index of the field in its parent.
1956      unsigned i = 0;
1957      // FIXME: It would be nice if we didn't have to loop here!
1958      for (RecordDecl::field_iterator Field = RD->field_begin(),
1959                                      FieldEnd = RD->field_end();
1960           Field != FieldEnd; ++Field, ++i) {
1961        if (*Field == MemberDecl)
1962          break;
1963      }
1964      assert(i < RL.getFieldCount() && "offsetof field in wrong type");
1965
1966      // Compute the offset to the field
1967      int64_t OffsetInt = RL.getFieldOffset(i) /
1968                          CGF.getContext().getCharWidth();
1969      Offset = llvm::ConstantInt::get(ResultType, OffsetInt);
1970
1971      // Save the element type.
1972      CurrentType = MemberDecl->getType();
1973      break;
1974    }
1975
1976    case OffsetOfExpr::OffsetOfNode::Identifier:
1977      llvm_unreachable("dependent __builtin_offsetof");
1978
1979    case OffsetOfExpr::OffsetOfNode::Base: {
1980      if (ON.getBase()->isVirtual()) {
1981        CGF.ErrorUnsupported(E, "virtual base in offsetof");
1982        continue;
1983      }
1984
1985      RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
1986      const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
1987
1988      // Save the element type.
1989      CurrentType = ON.getBase()->getType();
1990
1991      // Compute the offset to the base.
1992      const RecordType *BaseRT = CurrentType->getAs<RecordType>();
1993      CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
1994      CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD);
1995      Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity());
1996      break;
1997    }
1998    }
1999    Result = Builder.CreateAdd(Result, Offset);
2000  }
2001  return Result;
2002}
2003
2004/// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of
2005/// argument of the sizeof expression as an integer.
2006Value *
2007ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
2008                              const UnaryExprOrTypeTraitExpr *E) {
2009  QualType TypeToSize = E->getTypeOfArgument();
2010  if (E->getKind() == UETT_SizeOf) {
2011    if (const VariableArrayType *VAT =
2012          CGF.getContext().getAsVariableArrayType(TypeToSize)) {
2013      if (E->isArgumentType()) {
2014        // sizeof(type) - make sure to emit the VLA size.
2015        CGF.EmitVariablyModifiedType(TypeToSize);
2016      } else {
2017        // C99 6.5.3.4p2: If the argument is an expression of type
2018        // VLA, it is evaluated.
2019        CGF.EmitIgnoredExpr(E->getArgumentExpr());
2020      }
2021
2022      QualType eltType;
2023      llvm::Value *numElts;
2024      std::tie(numElts, eltType) = CGF.getVLASize(VAT);
2025
2026      llvm::Value *size = numElts;
2027
2028      // Scale the number of non-VLA elements by the non-VLA element size.
2029      CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
2030      if (!eltSize.isOne())
2031        size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts);
2032
2033      return size;
2034    }
2035  } else if (E->getKind() == UETT_OpenMPRequiredSimdAlign) {
2036    auto Alignment =
2037        CGF.getContext()
2038            .toCharUnitsFromBits(CGF.getContext().getOpenMPDefaultSimdAlign(
2039                E->getTypeOfArgument()->getPointeeType()))
2040            .getQuantity();
2041    return llvm::ConstantInt::get(CGF.SizeTy, Alignment);
2042  }
2043
2044  // If this isn't sizeof(vla), the result must be constant; use the constant
2045  // folding logic so we don't have to duplicate it here.
2046  return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext()));
2047}
2048
2049Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
2050  Expr *Op = E->getSubExpr();
2051  if (Op->getType()->isAnyComplexType()) {
2052    // If it's an l-value, load through the appropriate subobject l-value.
2053    // Note that we have to ask E because Op might be an l-value that
2054    // this won't work for, e.g. an Obj-C property.
2055    if (E->isGLValue())
2056      return CGF.EmitLoadOfLValue(CGF.EmitLValue(E),
2057                                  E->getExprLoc()).getScalarVal();
2058
2059    // Otherwise, calculate and project.
2060    return CGF.EmitComplexExpr(Op, false, true).first;
2061  }
2062
2063  return Visit(Op);
2064}
2065
2066Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
2067  Expr *Op = E->getSubExpr();
2068  if (Op->getType()->isAnyComplexType()) {
2069    // If it's an l-value, load through the appropriate subobject l-value.
2070    // Note that we have to ask E because Op might be an l-value that
2071    // this won't work for, e.g. an Obj-C property.
2072    if (Op->isGLValue())
2073      return CGF.EmitLoadOfLValue(CGF.EmitLValue(E),
2074                                  E->getExprLoc()).getScalarVal();
2075
2076    // Otherwise, calculate and project.
2077    return CGF.EmitComplexExpr(Op, true, false).second;
2078  }
2079
2080  // __imag on a scalar returns zero.  Emit the subexpr to ensure side
2081  // effects are evaluated, but not the actual value.
2082  if (Op->isGLValue())
2083    CGF.EmitLValue(Op);
2084  else
2085    CGF.EmitScalarExpr(Op, true);
2086  return llvm::Constant::getNullValue(ConvertType(E->getType()));
2087}
2088
2089//===----------------------------------------------------------------------===//
2090//                           Binary Operators
2091//===----------------------------------------------------------------------===//
2092
2093BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
2094  TestAndClearIgnoreResultAssign();
2095  BinOpInfo Result;
2096  Result.LHS = Visit(E->getLHS());
2097  Result.RHS = Visit(E->getRHS());
2098  Result.Ty  = E->getType();
2099  Result.Opcode = E->getOpcode();
2100  Result.FPContractable = E->isFPContractable();
2101  Result.E = E;
2102  return Result;
2103}
2104
2105LValue ScalarExprEmitter::EmitCompoundAssignLValue(
2106                                              const CompoundAssignOperator *E,
2107                        Value *(ScalarExprEmitter::*Func)(const BinOpInfo &),
2108                                                   Value *&Result) {
2109  QualType LHSTy = E->getLHS()->getType();
2110  BinOpInfo OpInfo;
2111
2112  if (E->getComputationResultType()->isAnyComplexType())
2113    return CGF.EmitScalarCompoundAssignWithComplex(E, Result);
2114
2115  // Emit the RHS first.  __block variables need to have the rhs evaluated
2116  // first, plus this should improve codegen a little.
2117  OpInfo.RHS = Visit(E->getRHS());
2118  OpInfo.Ty = E->getComputationResultType();
2119  OpInfo.Opcode = E->getOpcode();
2120  OpInfo.FPContractable = E->isFPContractable();
2121  OpInfo.E = E;
2122  // Load/convert the LHS.
2123  LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
2124
2125  llvm::PHINode *atomicPHI = nullptr;
2126  if (const AtomicType *atomicTy = LHSTy->getAs<AtomicType>()) {
2127    QualType type = atomicTy->getValueType();
2128    if (!type->isBooleanType() && type->isIntegerType() &&
2129        !(type->isUnsignedIntegerType() &&
2130          CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) &&
2131        CGF.getLangOpts().getSignedOverflowBehavior() !=
2132            LangOptions::SOB_Trapping) {
2133      llvm::AtomicRMWInst::BinOp aop = llvm::AtomicRMWInst::BAD_BINOP;
2134      switch (OpInfo.Opcode) {
2135        // We don't have atomicrmw operands for *, %, /, <<, >>
2136        case BO_MulAssign: case BO_DivAssign:
2137        case BO_RemAssign:
2138        case BO_ShlAssign:
2139        case BO_ShrAssign:
2140          break;
2141        case BO_AddAssign:
2142          aop = llvm::AtomicRMWInst::Add;
2143          break;
2144        case BO_SubAssign:
2145          aop = llvm::AtomicRMWInst::Sub;
2146          break;
2147        case BO_AndAssign:
2148          aop = llvm::AtomicRMWInst::And;
2149          break;
2150        case BO_XorAssign:
2151          aop = llvm::AtomicRMWInst::Xor;
2152          break;
2153        case BO_OrAssign:
2154          aop = llvm::AtomicRMWInst::Or;
2155          break;
2156        default:
2157          llvm_unreachable("Invalid compound assignment type");
2158      }
2159      if (aop != llvm::AtomicRMWInst::BAD_BINOP) {
2160        llvm::Value *amt = CGF.EmitToMemory(
2161            EmitScalarConversion(OpInfo.RHS, E->getRHS()->getType(), LHSTy,
2162                                 E->getExprLoc()),
2163            LHSTy);
2164        Builder.CreateAtomicRMW(aop, LHSLV.getPointer(), amt,
2165            llvm::SequentiallyConsistent);
2166        return LHSLV;
2167      }
2168    }
2169    // FIXME: For floating point types, we should be saving and restoring the
2170    // floating point environment in the loop.
2171    llvm::BasicBlock *startBB = Builder.GetInsertBlock();
2172    llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
2173    OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc());
2174    OpInfo.LHS = CGF.EmitToMemory(OpInfo.LHS, type);
2175    Builder.CreateBr(opBB);
2176    Builder.SetInsertPoint(opBB);
2177    atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2);
2178    atomicPHI->addIncoming(OpInfo.LHS, startBB);
2179    OpInfo.LHS = atomicPHI;
2180  }
2181  else
2182    OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc());
2183
2184  SourceLocation Loc = E->getExprLoc();
2185  OpInfo.LHS =
2186      EmitScalarConversion(OpInfo.LHS, LHSTy, E->getComputationLHSType(), Loc);
2187
2188  // Expand the binary operator.
2189  Result = (this->*Func)(OpInfo);
2190
2191  // Convert the result back to the LHS type.
2192  Result =
2193      EmitScalarConversion(Result, E->getComputationResultType(), LHSTy, Loc);
2194
2195  if (atomicPHI) {
2196    llvm::BasicBlock *opBB = Builder.GetInsertBlock();
2197    llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
2198    auto Pair = CGF.EmitAtomicCompareExchange(
2199        LHSLV, RValue::get(atomicPHI), RValue::get(Result), E->getExprLoc());
2200    llvm::Value *old = CGF.EmitToMemory(Pair.first.getScalarVal(), LHSTy);
2201    llvm::Value *success = Pair.second;
2202    atomicPHI->addIncoming(old, opBB);
2203    Builder.CreateCondBr(success, contBB, opBB);
2204    Builder.SetInsertPoint(contBB);
2205    return LHSLV;
2206  }
2207
2208  // Store the result value into the LHS lvalue. Bit-fields are handled
2209  // specially because the result is altered by the store, i.e., [C99 6.5.16p1]
2210  // 'An assignment expression has the value of the left operand after the
2211  // assignment...'.
2212  if (LHSLV.isBitField())
2213    CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result);
2214  else
2215    CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV);
2216
2217  return LHSLV;
2218}
2219
2220Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
2221                      Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
2222  bool Ignore = TestAndClearIgnoreResultAssign();
2223  Value *RHS;
2224  LValue LHS = EmitCompoundAssignLValue(E, Func, RHS);
2225
2226  // If the result is clearly ignored, return now.
2227  if (Ignore)
2228    return nullptr;
2229
2230  // The result of an assignment in C is the assigned r-value.
2231  if (!CGF.getLangOpts().CPlusPlus)
2232    return RHS;
2233
2234  // If the lvalue is non-volatile, return the computed value of the assignment.
2235  if (!LHS.isVolatileQualified())
2236    return RHS;
2237
2238  // Otherwise, reload the value.
2239  return EmitLoadOfLValue(LHS, E->getExprLoc());
2240}
2241
2242void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck(
2243    const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) {
2244  SmallVector<std::pair<llvm::Value *, SanitizerMask>, 2> Checks;
2245
2246  if (CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero)) {
2247    Checks.push_back(std::make_pair(Builder.CreateICmpNE(Ops.RHS, Zero),
2248                                    SanitizerKind::IntegerDivideByZero));
2249  }
2250
2251  if (CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow) &&
2252      Ops.Ty->hasSignedIntegerRepresentation()) {
2253    llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType());
2254
2255    llvm::Value *IntMin =
2256      Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth()));
2257    llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL);
2258
2259    llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin);
2260    llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne);
2261    llvm::Value *NotOverflow = Builder.CreateOr(LHSCmp, RHSCmp, "or");
2262    Checks.push_back(
2263        std::make_pair(NotOverflow, SanitizerKind::SignedIntegerOverflow));
2264  }
2265
2266  if (Checks.size() > 0)
2267    EmitBinOpCheck(Checks, Ops);
2268}
2269
2270Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
2271  {
2272    CodeGenFunction::SanitizerScope SanScope(&CGF);
2273    if ((CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero) ||
2274         CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow)) &&
2275        Ops.Ty->isIntegerType()) {
2276      llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2277      EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true);
2278    } else if (CGF.SanOpts.has(SanitizerKind::FloatDivideByZero) &&
2279               Ops.Ty->isRealFloatingType()) {
2280      llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2281      llvm::Value *NonZero = Builder.CreateFCmpUNE(Ops.RHS, Zero);
2282      EmitBinOpCheck(std::make_pair(NonZero, SanitizerKind::FloatDivideByZero),
2283                     Ops);
2284    }
2285  }
2286
2287  if (Ops.LHS->getType()->isFPOrFPVectorTy()) {
2288    llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
2289    if (CGF.getLangOpts().OpenCL) {
2290      // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp
2291      llvm::Type *ValTy = Val->getType();
2292      if (ValTy->isFloatTy() ||
2293          (isa<llvm::VectorType>(ValTy) &&
2294           cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy()))
2295        CGF.SetFPAccuracy(Val, 2.5);
2296    }
2297    return Val;
2298  }
2299  else if (Ops.Ty->hasUnsignedIntegerRepresentation())
2300    return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div");
2301  else
2302    return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div");
2303}
2304
2305Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
2306  // Rem in C can't be a floating point type: C99 6.5.5p2.
2307  if (CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero)) {
2308    CodeGenFunction::SanitizerScope SanScope(&CGF);
2309    llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2310
2311    if (Ops.Ty->isIntegerType())
2312      EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false);
2313  }
2314
2315  if (Ops.Ty->hasUnsignedIntegerRepresentation())
2316    return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem");
2317  else
2318    return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
2319}
2320
2321Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
2322  unsigned IID;
2323  unsigned OpID = 0;
2324
2325  bool isSigned = Ops.Ty->isSignedIntegerOrEnumerationType();
2326  switch (Ops.Opcode) {
2327  case BO_Add:
2328  case BO_AddAssign:
2329    OpID = 1;
2330    IID = isSigned ? llvm::Intrinsic::sadd_with_overflow :
2331                     llvm::Intrinsic::uadd_with_overflow;
2332    break;
2333  case BO_Sub:
2334  case BO_SubAssign:
2335    OpID = 2;
2336    IID = isSigned ? llvm::Intrinsic::ssub_with_overflow :
2337                     llvm::Intrinsic::usub_with_overflow;
2338    break;
2339  case BO_Mul:
2340  case BO_MulAssign:
2341    OpID = 3;
2342    IID = isSigned ? llvm::Intrinsic::smul_with_overflow :
2343                     llvm::Intrinsic::umul_with_overflow;
2344    break;
2345  default:
2346    llvm_unreachable("Unsupported operation for overflow detection");
2347  }
2348  OpID <<= 1;
2349  if (isSigned)
2350    OpID |= 1;
2351
2352  llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
2353
2354  llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy);
2355
2356  Value *resultAndOverflow = Builder.CreateCall(intrinsic, {Ops.LHS, Ops.RHS});
2357  Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
2358  Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
2359
2360  // Handle overflow with llvm.trap if no custom handler has been specified.
2361  const std::string *handlerName =
2362    &CGF.getLangOpts().OverflowHandler;
2363  if (handlerName->empty()) {
2364    // If the signed-integer-overflow sanitizer is enabled, emit a call to its
2365    // runtime. Otherwise, this is a -ftrapv check, so just emit a trap.
2366    if (!isSigned || CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow)) {
2367      CodeGenFunction::SanitizerScope SanScope(&CGF);
2368      llvm::Value *NotOverflow = Builder.CreateNot(overflow);
2369      SanitizerMask Kind = isSigned ? SanitizerKind::SignedIntegerOverflow
2370                              : SanitizerKind::UnsignedIntegerOverflow;
2371      EmitBinOpCheck(std::make_pair(NotOverflow, Kind), Ops);
2372    } else
2373      CGF.EmitTrapCheck(Builder.CreateNot(overflow));
2374    return result;
2375  }
2376
2377  // Branch in case of overflow.
2378  llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
2379  llvm::Function::iterator insertPt = initialBB->getIterator();
2380  llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn,
2381                                                      &*std::next(insertPt));
2382  llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn);
2383
2384  Builder.CreateCondBr(overflow, overflowBB, continueBB);
2385
2386  // If an overflow handler is set, then we want to call it and then use its
2387  // result, if it returns.
2388  Builder.SetInsertPoint(overflowBB);
2389
2390  // Get the overflow handler.
2391  llvm::Type *Int8Ty = CGF.Int8Ty;
2392  llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty };
2393  llvm::FunctionType *handlerTy =
2394      llvm::FunctionType::get(CGF.Int64Ty, argTypes, true);
2395  llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName);
2396
2397  // Sign extend the args to 64-bit, so that we can use the same handler for
2398  // all types of overflow.
2399  llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty);
2400  llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty);
2401
2402  // Call the handler with the two arguments, the operation, and the size of
2403  // the result.
2404  llvm::Value *handlerArgs[] = {
2405    lhs,
2406    rhs,
2407    Builder.getInt8(OpID),
2408    Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())
2409  };
2410  llvm::Value *handlerResult =
2411    CGF.EmitNounwindRuntimeCall(handler, handlerArgs);
2412
2413  // Truncate the result back to the desired size.
2414  handlerResult = Builder.CreateTrunc(handlerResult, opTy);
2415  Builder.CreateBr(continueBB);
2416
2417  Builder.SetInsertPoint(continueBB);
2418  llvm::PHINode *phi = Builder.CreatePHI(opTy, 2);
2419  phi->addIncoming(result, initialBB);
2420  phi->addIncoming(handlerResult, overflowBB);
2421
2422  return phi;
2423}
2424
2425/// Emit pointer + index arithmetic.
2426static Value *emitPointerArithmetic(CodeGenFunction &CGF,
2427                                    const BinOpInfo &op,
2428                                    bool isSubtraction) {
2429  // Must have binary (not unary) expr here.  Unary pointer
2430  // increment/decrement doesn't use this path.
2431  const BinaryOperator *expr = cast<BinaryOperator>(op.E);
2432
2433  Value *pointer = op.LHS;
2434  Expr *pointerOperand = expr->getLHS();
2435  Value *index = op.RHS;
2436  Expr *indexOperand = expr->getRHS();
2437
2438  // In a subtraction, the LHS is always the pointer.
2439  if (!isSubtraction && !pointer->getType()->isPointerTy()) {
2440    std::swap(pointer, index);
2441    std::swap(pointerOperand, indexOperand);
2442  }
2443
2444  unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
2445  if (width != CGF.PointerWidthInBits) {
2446    // Zero-extend or sign-extend the pointer value according to
2447    // whether the index is signed or not.
2448    bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
2449    index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned,
2450                                      "idx.ext");
2451  }
2452
2453  // If this is subtraction, negate the index.
2454  if (isSubtraction)
2455    index = CGF.Builder.CreateNeg(index, "idx.neg");
2456
2457  if (CGF.SanOpts.has(SanitizerKind::ArrayBounds))
2458    CGF.EmitBoundsCheck(op.E, pointerOperand, index, indexOperand->getType(),
2459                        /*Accessed*/ false);
2460
2461  const PointerType *pointerType
2462    = pointerOperand->getType()->getAs<PointerType>();
2463  if (!pointerType) {
2464    QualType objectType = pointerOperand->getType()
2465                                        ->castAs<ObjCObjectPointerType>()
2466                                        ->getPointeeType();
2467    llvm::Value *objectSize
2468      = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType));
2469
2470    index = CGF.Builder.CreateMul(index, objectSize);
2471
2472    Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
2473    result = CGF.Builder.CreateGEP(result, index, "add.ptr");
2474    return CGF.Builder.CreateBitCast(result, pointer->getType());
2475  }
2476
2477  QualType elementType = pointerType->getPointeeType();
2478  if (const VariableArrayType *vla
2479        = CGF.getContext().getAsVariableArrayType(elementType)) {
2480    // The element count here is the total number of non-VLA elements.
2481    llvm::Value *numElements = CGF.getVLASize(vla).first;
2482
2483    // Effectively, the multiply by the VLA size is part of the GEP.
2484    // GEP indexes are signed, and scaling an index isn't permitted to
2485    // signed-overflow, so we use the same semantics for our explicit
2486    // multiply.  We suppress this if overflow is not undefined behavior.
2487    if (CGF.getLangOpts().isSignedOverflowDefined()) {
2488      index = CGF.Builder.CreateMul(index, numElements, "vla.index");
2489      pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr");
2490    } else {
2491      index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index");
2492      pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
2493    }
2494    return pointer;
2495  }
2496
2497  // Explicitly handle GNU void* and function pointer arithmetic extensions. The
2498  // GNU void* casts amount to no-ops since our void* type is i8*, but this is
2499  // future proof.
2500  if (elementType->isVoidType() || elementType->isFunctionType()) {
2501    Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
2502    result = CGF.Builder.CreateGEP(result, index, "add.ptr");
2503    return CGF.Builder.CreateBitCast(result, pointer->getType());
2504  }
2505
2506  if (CGF.getLangOpts().isSignedOverflowDefined())
2507    return CGF.Builder.CreateGEP(pointer, index, "add.ptr");
2508
2509  return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
2510}
2511
2512// Construct an fmuladd intrinsic to represent a fused mul-add of MulOp and
2513// Addend. Use negMul and negAdd to negate the first operand of the Mul or
2514// the add operand respectively. This allows fmuladd to represent a*b-c, or
2515// c-a*b. Patterns in LLVM should catch the negated forms and translate them to
2516// efficient operations.
2517static Value* buildFMulAdd(llvm::BinaryOperator *MulOp, Value *Addend,
2518                           const CodeGenFunction &CGF, CGBuilderTy &Builder,
2519                           bool negMul, bool negAdd) {
2520  assert(!(negMul && negAdd) && "Only one of negMul and negAdd should be set.");
2521
2522  Value *MulOp0 = MulOp->getOperand(0);
2523  Value *MulOp1 = MulOp->getOperand(1);
2524  if (negMul) {
2525    MulOp0 =
2526      Builder.CreateFSub(
2527        llvm::ConstantFP::getZeroValueForNegation(MulOp0->getType()), MulOp0,
2528        "neg");
2529  } else if (negAdd) {
2530    Addend =
2531      Builder.CreateFSub(
2532        llvm::ConstantFP::getZeroValueForNegation(Addend->getType()), Addend,
2533        "neg");
2534  }
2535
2536  Value *FMulAdd = Builder.CreateCall(
2537      CGF.CGM.getIntrinsic(llvm::Intrinsic::fmuladd, Addend->getType()),
2538      {MulOp0, MulOp1, Addend});
2539   MulOp->eraseFromParent();
2540
2541   return FMulAdd;
2542}
2543
2544// Check whether it would be legal to emit an fmuladd intrinsic call to
2545// represent op and if so, build the fmuladd.
2546//
2547// Checks that (a) the operation is fusable, and (b) -ffp-contract=on.
2548// Does NOT check the type of the operation - it's assumed that this function
2549// will be called from contexts where it's known that the type is contractable.
2550static Value* tryEmitFMulAdd(const BinOpInfo &op,
2551                         const CodeGenFunction &CGF, CGBuilderTy &Builder,
2552                         bool isSub=false) {
2553
2554  assert((op.Opcode == BO_Add || op.Opcode == BO_AddAssign ||
2555          op.Opcode == BO_Sub || op.Opcode == BO_SubAssign) &&
2556         "Only fadd/fsub can be the root of an fmuladd.");
2557
2558  // Check whether this op is marked as fusable.
2559  if (!op.FPContractable)
2560    return nullptr;
2561
2562  // Check whether -ffp-contract=on. (If -ffp-contract=off/fast, fusing is
2563  // either disabled, or handled entirely by the LLVM backend).
2564  if (CGF.CGM.getCodeGenOpts().getFPContractMode() != CodeGenOptions::FPC_On)
2565    return nullptr;
2566
2567  // We have a potentially fusable op. Look for a mul on one of the operands.
2568  // Also, make sure that the mul result isn't used directly. In that case,
2569  // there's no point creating a muladd operation.
2570  if (auto *LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS)) {
2571    if (LHSBinOp->getOpcode() == llvm::Instruction::FMul &&
2572        LHSBinOp->use_empty())
2573      return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub);
2574  }
2575  if (auto *RHSBinOp = dyn_cast<llvm::BinaryOperator>(op.RHS)) {
2576    if (RHSBinOp->getOpcode() == llvm::Instruction::FMul &&
2577        RHSBinOp->use_empty())
2578      return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false);
2579  }
2580
2581  return nullptr;
2582}
2583
2584Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) {
2585  if (op.LHS->getType()->isPointerTy() ||
2586      op.RHS->getType()->isPointerTy())
2587    return emitPointerArithmetic(CGF, op, /*subtraction*/ false);
2588
2589  if (op.Ty->isSignedIntegerOrEnumerationType()) {
2590    switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
2591    case LangOptions::SOB_Defined:
2592      return Builder.CreateAdd(op.LHS, op.RHS, "add");
2593    case LangOptions::SOB_Undefined:
2594      if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
2595        return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
2596      // Fall through.
2597    case LangOptions::SOB_Trapping:
2598      return EmitOverflowCheckedBinOp(op);
2599    }
2600  }
2601
2602  if (op.Ty->isUnsignedIntegerType() &&
2603      CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow))
2604    return EmitOverflowCheckedBinOp(op);
2605
2606  if (op.LHS->getType()->isFPOrFPVectorTy()) {
2607    // Try to form an fmuladd.
2608    if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder))
2609      return FMulAdd;
2610
2611    return Builder.CreateFAdd(op.LHS, op.RHS, "add");
2612  }
2613
2614  return Builder.CreateAdd(op.LHS, op.RHS, "add");
2615}
2616
2617Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) {
2618  // The LHS is always a pointer if either side is.
2619  if (!op.LHS->getType()->isPointerTy()) {
2620    if (op.Ty->isSignedIntegerOrEnumerationType()) {
2621      switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
2622      case LangOptions::SOB_Defined:
2623        return Builder.CreateSub(op.LHS, op.RHS, "sub");
2624      case LangOptions::SOB_Undefined:
2625        if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
2626          return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
2627        // Fall through.
2628      case LangOptions::SOB_Trapping:
2629        return EmitOverflowCheckedBinOp(op);
2630      }
2631    }
2632
2633    if (op.Ty->isUnsignedIntegerType() &&
2634        CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow))
2635      return EmitOverflowCheckedBinOp(op);
2636
2637    if (op.LHS->getType()->isFPOrFPVectorTy()) {
2638      // Try to form an fmuladd.
2639      if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder, true))
2640        return FMulAdd;
2641      return Builder.CreateFSub(op.LHS, op.RHS, "sub");
2642    }
2643
2644    return Builder.CreateSub(op.LHS, op.RHS, "sub");
2645  }
2646
2647  // If the RHS is not a pointer, then we have normal pointer
2648  // arithmetic.
2649  if (!op.RHS->getType()->isPointerTy())
2650    return emitPointerArithmetic(CGF, op, /*subtraction*/ true);
2651
2652  // Otherwise, this is a pointer subtraction.
2653
2654  // Do the raw subtraction part.
2655  llvm::Value *LHS
2656    = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast");
2657  llvm::Value *RHS
2658    = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast");
2659  Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
2660
2661  // Okay, figure out the element size.
2662  const BinaryOperator *expr = cast<BinaryOperator>(op.E);
2663  QualType elementType = expr->getLHS()->getType()->getPointeeType();
2664
2665  llvm::Value *divisor = nullptr;
2666
2667  // For a variable-length array, this is going to be non-constant.
2668  if (const VariableArrayType *vla
2669        = CGF.getContext().getAsVariableArrayType(elementType)) {
2670    llvm::Value *numElements;
2671    std::tie(numElements, elementType) = CGF.getVLASize(vla);
2672
2673    divisor = numElements;
2674
2675    // Scale the number of non-VLA elements by the non-VLA element size.
2676    CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType);
2677    if (!eltSize.isOne())
2678      divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor);
2679
2680  // For everything elese, we can just compute it, safe in the
2681  // assumption that Sema won't let anything through that we can't
2682  // safely compute the size of.
2683  } else {
2684    CharUnits elementSize;
2685    // Handle GCC extension for pointer arithmetic on void* and
2686    // function pointer types.
2687    if (elementType->isVoidType() || elementType->isFunctionType())
2688      elementSize = CharUnits::One();
2689    else
2690      elementSize = CGF.getContext().getTypeSizeInChars(elementType);
2691
2692    // Don't even emit the divide for element size of 1.
2693    if (elementSize.isOne())
2694      return diffInChars;
2695
2696    divisor = CGF.CGM.getSize(elementSize);
2697  }
2698
2699  // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since
2700  // pointer difference in C is only defined in the case where both operands
2701  // are pointing to elements of an array.
2702  return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div");
2703}
2704
2705Value *ScalarExprEmitter::GetWidthMinusOneValue(Value* LHS,Value* RHS) {
2706  llvm::IntegerType *Ty;
2707  if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(LHS->getType()))
2708    Ty = cast<llvm::IntegerType>(VT->getElementType());
2709  else
2710    Ty = cast<llvm::IntegerType>(LHS->getType());
2711  return llvm::ConstantInt::get(RHS->getType(), Ty->getBitWidth() - 1);
2712}
2713
2714Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
2715  // LLVM requires the LHS and RHS to be the same type: promote or truncate the
2716  // RHS to the same size as the LHS.
2717  Value *RHS = Ops.RHS;
2718  if (Ops.LHS->getType() != RHS->getType())
2719    RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
2720
2721  bool SanitizeBase = CGF.SanOpts.has(SanitizerKind::ShiftBase) &&
2722                      Ops.Ty->hasSignedIntegerRepresentation();
2723  bool SanitizeExponent = CGF.SanOpts.has(SanitizerKind::ShiftExponent);
2724  // OpenCL 6.3j: shift values are effectively % word size of LHS.
2725  if (CGF.getLangOpts().OpenCL)
2726    RHS =
2727        Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shl.mask");
2728  else if ((SanitizeBase || SanitizeExponent) &&
2729           isa<llvm::IntegerType>(Ops.LHS->getType())) {
2730    CodeGenFunction::SanitizerScope SanScope(&CGF);
2731    SmallVector<std::pair<Value *, SanitizerMask>, 2> Checks;
2732    llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, RHS);
2733    llvm::Value *ValidExponent = Builder.CreateICmpULE(RHS, WidthMinusOne);
2734
2735    if (SanitizeExponent) {
2736      Checks.push_back(
2737          std::make_pair(ValidExponent, SanitizerKind::ShiftExponent));
2738    }
2739
2740    if (SanitizeBase) {
2741      // Check whether we are shifting any non-zero bits off the top of the
2742      // integer. We only emit this check if exponent is valid - otherwise
2743      // instructions below will have undefined behavior themselves.
2744      llvm::BasicBlock *Orig = Builder.GetInsertBlock();
2745      llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
2746      llvm::BasicBlock *CheckShiftBase = CGF.createBasicBlock("check");
2747      Builder.CreateCondBr(ValidExponent, CheckShiftBase, Cont);
2748      CGF.EmitBlock(CheckShiftBase);
2749      llvm::Value *BitsShiftedOff =
2750        Builder.CreateLShr(Ops.LHS,
2751                           Builder.CreateSub(WidthMinusOne, RHS, "shl.zeros",
2752                                             /*NUW*/true, /*NSW*/true),
2753                           "shl.check");
2754      if (CGF.getLangOpts().CPlusPlus) {
2755        // In C99, we are not permitted to shift a 1 bit into the sign bit.
2756        // Under C++11's rules, shifting a 1 bit into the sign bit is
2757        // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't
2758        // define signed left shifts, so we use the C99 and C++11 rules there).
2759        llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1);
2760        BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One);
2761      }
2762      llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0);
2763      llvm::Value *ValidBase = Builder.CreateICmpEQ(BitsShiftedOff, Zero);
2764      CGF.EmitBlock(Cont);
2765      llvm::PHINode *BaseCheck = Builder.CreatePHI(ValidBase->getType(), 2);
2766      BaseCheck->addIncoming(Builder.getTrue(), Orig);
2767      BaseCheck->addIncoming(ValidBase, CheckShiftBase);
2768      Checks.push_back(std::make_pair(BaseCheck, SanitizerKind::ShiftBase));
2769    }
2770
2771    assert(!Checks.empty());
2772    EmitBinOpCheck(Checks, Ops);
2773  }
2774
2775  return Builder.CreateShl(Ops.LHS, RHS, "shl");
2776}
2777
2778Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
2779  // LLVM requires the LHS and RHS to be the same type: promote or truncate the
2780  // RHS to the same size as the LHS.
2781  Value *RHS = Ops.RHS;
2782  if (Ops.LHS->getType() != RHS->getType())
2783    RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
2784
2785  // OpenCL 6.3j: shift values are effectively % word size of LHS.
2786  if (CGF.getLangOpts().OpenCL)
2787    RHS =
2788        Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shr.mask");
2789  else if (CGF.SanOpts.has(SanitizerKind::ShiftExponent) &&
2790           isa<llvm::IntegerType>(Ops.LHS->getType())) {
2791    CodeGenFunction::SanitizerScope SanScope(&CGF);
2792    llvm::Value *Valid =
2793        Builder.CreateICmpULE(RHS, GetWidthMinusOneValue(Ops.LHS, RHS));
2794    EmitBinOpCheck(std::make_pair(Valid, SanitizerKind::ShiftExponent), Ops);
2795  }
2796
2797  if (Ops.Ty->hasUnsignedIntegerRepresentation())
2798    return Builder.CreateLShr(Ops.LHS, RHS, "shr");
2799  return Builder.CreateAShr(Ops.LHS, RHS, "shr");
2800}
2801
2802enum IntrinsicType { VCMPEQ, VCMPGT };
2803// return corresponding comparison intrinsic for given vector type
2804static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT,
2805                                        BuiltinType::Kind ElemKind) {
2806  switch (ElemKind) {
2807  default: llvm_unreachable("unexpected element type");
2808  case BuiltinType::Char_U:
2809  case BuiltinType::UChar:
2810    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
2811                            llvm::Intrinsic::ppc_altivec_vcmpgtub_p;
2812  case BuiltinType::Char_S:
2813  case BuiltinType::SChar:
2814    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
2815                            llvm::Intrinsic::ppc_altivec_vcmpgtsb_p;
2816  case BuiltinType::UShort:
2817    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
2818                            llvm::Intrinsic::ppc_altivec_vcmpgtuh_p;
2819  case BuiltinType::Short:
2820    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
2821                            llvm::Intrinsic::ppc_altivec_vcmpgtsh_p;
2822  case BuiltinType::UInt:
2823  case BuiltinType::ULong:
2824    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
2825                            llvm::Intrinsic::ppc_altivec_vcmpgtuw_p;
2826  case BuiltinType::Int:
2827  case BuiltinType::Long:
2828    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
2829                            llvm::Intrinsic::ppc_altivec_vcmpgtsw_p;
2830  case BuiltinType::Float:
2831    return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p :
2832                            llvm::Intrinsic::ppc_altivec_vcmpgtfp_p;
2833  }
2834}
2835
2836Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,
2837                                      llvm::CmpInst::Predicate UICmpOpc,
2838                                      llvm::CmpInst::Predicate SICmpOpc,
2839                                      llvm::CmpInst::Predicate FCmpOpc) {
2840  TestAndClearIgnoreResultAssign();
2841  Value *Result;
2842  QualType LHSTy = E->getLHS()->getType();
2843  QualType RHSTy = E->getRHS()->getType();
2844  if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) {
2845    assert(E->getOpcode() == BO_EQ ||
2846           E->getOpcode() == BO_NE);
2847    Value *LHS = CGF.EmitScalarExpr(E->getLHS());
2848    Value *RHS = CGF.EmitScalarExpr(E->getRHS());
2849    Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison(
2850                   CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE);
2851  } else if (!LHSTy->isAnyComplexType() && !RHSTy->isAnyComplexType()) {
2852    Value *LHS = Visit(E->getLHS());
2853    Value *RHS = Visit(E->getRHS());
2854
2855    // If AltiVec, the comparison results in a numeric type, so we use
2856    // intrinsics comparing vectors and giving 0 or 1 as a result
2857    if (LHSTy->isVectorType() && !E->getType()->isVectorType()) {
2858      // constants for mapping CR6 register bits to predicate result
2859      enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6;
2860
2861      llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic;
2862
2863      // in several cases vector arguments order will be reversed
2864      Value *FirstVecArg = LHS,
2865            *SecondVecArg = RHS;
2866
2867      QualType ElTy = LHSTy->getAs<VectorType>()->getElementType();
2868      const BuiltinType *BTy = ElTy->getAs<BuiltinType>();
2869      BuiltinType::Kind ElementKind = BTy->getKind();
2870
2871      switch(E->getOpcode()) {
2872      default: llvm_unreachable("is not a comparison operation");
2873      case BO_EQ:
2874        CR6 = CR6_LT;
2875        ID = GetIntrinsic(VCMPEQ, ElementKind);
2876        break;
2877      case BO_NE:
2878        CR6 = CR6_EQ;
2879        ID = GetIntrinsic(VCMPEQ, ElementKind);
2880        break;
2881      case BO_LT:
2882        CR6 = CR6_LT;
2883        ID = GetIntrinsic(VCMPGT, ElementKind);
2884        std::swap(FirstVecArg, SecondVecArg);
2885        break;
2886      case BO_GT:
2887        CR6 = CR6_LT;
2888        ID = GetIntrinsic(VCMPGT, ElementKind);
2889        break;
2890      case BO_LE:
2891        if (ElementKind == BuiltinType::Float) {
2892          CR6 = CR6_LT;
2893          ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
2894          std::swap(FirstVecArg, SecondVecArg);
2895        }
2896        else {
2897          CR6 = CR6_EQ;
2898          ID = GetIntrinsic(VCMPGT, ElementKind);
2899        }
2900        break;
2901      case BO_GE:
2902        if (ElementKind == BuiltinType::Float) {
2903          CR6 = CR6_LT;
2904          ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
2905        }
2906        else {
2907          CR6 = CR6_EQ;
2908          ID = GetIntrinsic(VCMPGT, ElementKind);
2909          std::swap(FirstVecArg, SecondVecArg);
2910        }
2911        break;
2912      }
2913
2914      Value *CR6Param = Builder.getInt32(CR6);
2915      llvm::Function *F = CGF.CGM.getIntrinsic(ID);
2916      Result = Builder.CreateCall(F, {CR6Param, FirstVecArg, SecondVecArg});
2917      return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(),
2918                                  E->getExprLoc());
2919    }
2920
2921    if (LHS->getType()->isFPOrFPVectorTy()) {
2922      Result = Builder.CreateFCmp(FCmpOpc, LHS, RHS, "cmp");
2923    } else if (LHSTy->hasSignedIntegerRepresentation()) {
2924      Result = Builder.CreateICmp(SICmpOpc, LHS, RHS, "cmp");
2925    } else {
2926      // Unsigned integers and pointers.
2927      Result = Builder.CreateICmp(UICmpOpc, LHS, RHS, "cmp");
2928    }
2929
2930    // If this is a vector comparison, sign extend the result to the appropriate
2931    // vector integer type and return it (don't convert to bool).
2932    if (LHSTy->isVectorType())
2933      return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
2934
2935  } else {
2936    // Complex Comparison: can only be an equality comparison.
2937    CodeGenFunction::ComplexPairTy LHS, RHS;
2938    QualType CETy;
2939    if (auto *CTy = LHSTy->getAs<ComplexType>()) {
2940      LHS = CGF.EmitComplexExpr(E->getLHS());
2941      CETy = CTy->getElementType();
2942    } else {
2943      LHS.first = Visit(E->getLHS());
2944      LHS.second = llvm::Constant::getNullValue(LHS.first->getType());
2945      CETy = LHSTy;
2946    }
2947    if (auto *CTy = RHSTy->getAs<ComplexType>()) {
2948      RHS = CGF.EmitComplexExpr(E->getRHS());
2949      assert(CGF.getContext().hasSameUnqualifiedType(CETy,
2950                                                     CTy->getElementType()) &&
2951             "The element types must always match.");
2952      (void)CTy;
2953    } else {
2954      RHS.first = Visit(E->getRHS());
2955      RHS.second = llvm::Constant::getNullValue(RHS.first->getType());
2956      assert(CGF.getContext().hasSameUnqualifiedType(CETy, RHSTy) &&
2957             "The element types must always match.");
2958    }
2959
2960    Value *ResultR, *ResultI;
2961    if (CETy->isRealFloatingType()) {
2962      ResultR = Builder.CreateFCmp(FCmpOpc, LHS.first, RHS.first, "cmp.r");
2963      ResultI = Builder.CreateFCmp(FCmpOpc, LHS.second, RHS.second, "cmp.i");
2964    } else {
2965      // Complex comparisons can only be equality comparisons.  As such, signed
2966      // and unsigned opcodes are the same.
2967      ResultR = Builder.CreateICmp(UICmpOpc, LHS.first, RHS.first, "cmp.r");
2968      ResultI = Builder.CreateICmp(UICmpOpc, LHS.second, RHS.second, "cmp.i");
2969    }
2970
2971    if (E->getOpcode() == BO_EQ) {
2972      Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
2973    } else {
2974      assert(E->getOpcode() == BO_NE &&
2975             "Complex comparison other than == or != ?");
2976      Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
2977    }
2978  }
2979
2980  return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(),
2981                              E->getExprLoc());
2982}
2983
2984Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
2985  bool Ignore = TestAndClearIgnoreResultAssign();
2986
2987  Value *RHS;
2988  LValue LHS;
2989
2990  switch (E->getLHS()->getType().getObjCLifetime()) {
2991  case Qualifiers::OCL_Strong:
2992    std::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore);
2993    break;
2994
2995  case Qualifiers::OCL_Autoreleasing:
2996    std::tie(LHS, RHS) = CGF.EmitARCStoreAutoreleasing(E);
2997    break;
2998
2999  case Qualifiers::OCL_Weak:
3000    RHS = Visit(E->getRHS());
3001    LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
3002    RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore);
3003    break;
3004
3005  // No reason to do any of these differently.
3006  case Qualifiers::OCL_None:
3007  case Qualifiers::OCL_ExplicitNone:
3008    // __block variables need to have the rhs evaluated first, plus
3009    // this should improve codegen just a little.
3010    RHS = Visit(E->getRHS());
3011    LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
3012
3013    // Store the value into the LHS.  Bit-fields are handled specially
3014    // because the result is altered by the store, i.e., [C99 6.5.16p1]
3015    // 'An assignment expression has the value of the left operand after
3016    // the assignment...'.
3017    if (LHS.isBitField())
3018      CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS);
3019    else
3020      CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS);
3021  }
3022
3023  // If the result is clearly ignored, return now.
3024  if (Ignore)
3025    return nullptr;
3026
3027  // The result of an assignment in C is the assigned r-value.
3028  if (!CGF.getLangOpts().CPlusPlus)
3029    return RHS;
3030
3031  // If the lvalue is non-volatile, return the computed value of the assignment.
3032  if (!LHS.isVolatileQualified())
3033    return RHS;
3034
3035  // Otherwise, reload the value.
3036  return EmitLoadOfLValue(LHS, E->getExprLoc());
3037}
3038
3039Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
3040  // Perform vector logical and on comparisons with zero vectors.
3041  if (E->getType()->isVectorType()) {
3042    CGF.incrementProfileCounter(E);
3043
3044    Value *LHS = Visit(E->getLHS());
3045    Value *RHS = Visit(E->getRHS());
3046    Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
3047    if (LHS->getType()->isFPOrFPVectorTy()) {
3048      LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp");
3049      RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp");
3050    } else {
3051      LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
3052      RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
3053    }
3054    Value *And = Builder.CreateAnd(LHS, RHS);
3055    return Builder.CreateSExt(And, ConvertType(E->getType()), "sext");
3056  }
3057
3058  llvm::Type *ResTy = ConvertType(E->getType());
3059
3060  // If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
3061  // If we have 1 && X, just emit X without inserting the control flow.
3062  bool LHSCondVal;
3063  if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
3064    if (LHSCondVal) { // If we have 1 && X, just emit X.
3065      CGF.incrementProfileCounter(E);
3066
3067      Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3068      // ZExt result to int or bool.
3069      return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
3070    }
3071
3072    // 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
3073    if (!CGF.ContainsLabel(E->getRHS()))
3074      return llvm::Constant::getNullValue(ResTy);
3075  }
3076
3077  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
3078  llvm::BasicBlock *RHSBlock  = CGF.createBasicBlock("land.rhs");
3079
3080  CodeGenFunction::ConditionalEvaluation eval(CGF);
3081
3082  // Branch on the LHS first.  If it is false, go to the failure (cont) block.
3083  CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock,
3084                           CGF.getProfileCount(E->getRHS()));
3085
3086  // Any edges into the ContBlock are now from an (indeterminate number of)
3087  // edges from this first condition.  All of these values will be false.  Start
3088  // setting up the PHI node in the Cont Block for this.
3089  llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
3090                                            "", ContBlock);
3091  for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
3092       PI != PE; ++PI)
3093    PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
3094
3095  eval.begin(CGF);
3096  CGF.EmitBlock(RHSBlock);
3097  CGF.incrementProfileCounter(E);
3098  Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3099  eval.end(CGF);
3100
3101  // Reaquire the RHS block, as there may be subblocks inserted.
3102  RHSBlock = Builder.GetInsertBlock();
3103
3104  // Emit an unconditional branch from this block to ContBlock.
3105  {
3106    // There is no need to emit line number for unconditional branch.
3107    auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3108    CGF.EmitBlock(ContBlock);
3109  }
3110  // Insert an entry into the phi node for the edge with the value of RHSCond.
3111  PN->addIncoming(RHSCond, RHSBlock);
3112
3113  // ZExt result to int.
3114  return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
3115}
3116
3117Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
3118  // Perform vector logical or on comparisons with zero vectors.
3119  if (E->getType()->isVectorType()) {
3120    CGF.incrementProfileCounter(E);
3121
3122    Value *LHS = Visit(E->getLHS());
3123    Value *RHS = Visit(E->getRHS());
3124    Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
3125    if (LHS->getType()->isFPOrFPVectorTy()) {
3126      LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp");
3127      RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp");
3128    } else {
3129      LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
3130      RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
3131    }
3132    Value *Or = Builder.CreateOr(LHS, RHS);
3133    return Builder.CreateSExt(Or, ConvertType(E->getType()), "sext");
3134  }
3135
3136  llvm::Type *ResTy = ConvertType(E->getType());
3137
3138  // If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
3139  // If we have 0 || X, just emit X without inserting the control flow.
3140  bool LHSCondVal;
3141  if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
3142    if (!LHSCondVal) { // If we have 0 || X, just emit X.
3143      CGF.incrementProfileCounter(E);
3144
3145      Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3146      // ZExt result to int or bool.
3147      return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
3148    }
3149
3150    // 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
3151    if (!CGF.ContainsLabel(E->getRHS()))
3152      return llvm::ConstantInt::get(ResTy, 1);
3153  }
3154
3155  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
3156  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
3157
3158  CodeGenFunction::ConditionalEvaluation eval(CGF);
3159
3160  // Branch on the LHS first.  If it is true, go to the success (cont) block.
3161  CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock,
3162                           CGF.getCurrentProfileCount() -
3163                               CGF.getProfileCount(E->getRHS()));
3164
3165  // Any edges into the ContBlock are now from an (indeterminate number of)
3166  // edges from this first condition.  All of these values will be true.  Start
3167  // setting up the PHI node in the Cont Block for this.
3168  llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
3169                                            "", ContBlock);
3170  for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
3171       PI != PE; ++PI)
3172    PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
3173
3174  eval.begin(CGF);
3175
3176  // Emit the RHS condition as a bool value.
3177  CGF.EmitBlock(RHSBlock);
3178  CGF.incrementProfileCounter(E);
3179  Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3180
3181  eval.end(CGF);
3182
3183  // Reaquire the RHS block, as there may be subblocks inserted.
3184  RHSBlock = Builder.GetInsertBlock();
3185
3186  // Emit an unconditional branch from this block to ContBlock.  Insert an entry
3187  // into the phi node for the edge with the value of RHSCond.
3188  CGF.EmitBlock(ContBlock);
3189  PN->addIncoming(RHSCond, RHSBlock);
3190
3191  // ZExt result to int.
3192  return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
3193}
3194
3195Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
3196  CGF.EmitIgnoredExpr(E->getLHS());
3197  CGF.EnsureInsertPoint();
3198  return Visit(E->getRHS());
3199}
3200
3201//===----------------------------------------------------------------------===//
3202//                             Other Operators
3203//===----------------------------------------------------------------------===//
3204
3205/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
3206/// expression is cheap enough and side-effect-free enough to evaluate
3207/// unconditionally instead of conditionally.  This is used to convert control
3208/// flow into selects in some cases.
3209static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
3210                                                   CodeGenFunction &CGF) {
3211  // Anything that is an integer or floating point constant is fine.
3212  return E->IgnoreParens()->isEvaluatable(CGF.getContext());
3213
3214  // Even non-volatile automatic variables can't be evaluated unconditionally.
3215  // Referencing a thread_local may cause non-trivial initialization work to
3216  // occur. If we're inside a lambda and one of the variables is from the scope
3217  // outside the lambda, that function may have returned already. Reading its
3218  // locals is a bad idea. Also, these reads may introduce races there didn't
3219  // exist in the source-level program.
3220}
3221
3222
3223Value *ScalarExprEmitter::
3224VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
3225  TestAndClearIgnoreResultAssign();
3226
3227  // Bind the common expression if necessary.
3228  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
3229
3230  Expr *condExpr = E->getCond();
3231  Expr *lhsExpr = E->getTrueExpr();
3232  Expr *rhsExpr = E->getFalseExpr();
3233
3234  // If the condition constant folds and can be elided, try to avoid emitting
3235  // the condition and the dead arm.
3236  bool CondExprBool;
3237  if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3238    Expr *live = lhsExpr, *dead = rhsExpr;
3239    if (!CondExprBool) std::swap(live, dead);
3240
3241    // If the dead side doesn't have labels we need, just emit the Live part.
3242    if (!CGF.ContainsLabel(dead)) {
3243      if (CondExprBool)
3244        CGF.incrementProfileCounter(E);
3245      Value *Result = Visit(live);
3246
3247      // If the live part is a throw expression, it acts like it has a void
3248      // type, so evaluating it returns a null Value*.  However, a conditional
3249      // with non-void type must return a non-null Value*.
3250      if (!Result && !E->getType()->isVoidType())
3251        Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
3252
3253      return Result;
3254    }
3255  }
3256
3257  // OpenCL: If the condition is a vector, we can treat this condition like
3258  // the select function.
3259  if (CGF.getLangOpts().OpenCL
3260      && condExpr->getType()->isVectorType()) {
3261    CGF.incrementProfileCounter(E);
3262
3263    llvm::Value *CondV = CGF.EmitScalarExpr(condExpr);
3264    llvm::Value *LHS = Visit(lhsExpr);
3265    llvm::Value *RHS = Visit(rhsExpr);
3266
3267    llvm::Type *condType = ConvertType(condExpr->getType());
3268    llvm::VectorType *vecTy = cast<llvm::VectorType>(condType);
3269
3270    unsigned numElem = vecTy->getNumElements();
3271    llvm::Type *elemType = vecTy->getElementType();
3272
3273    llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy);
3274    llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec);
3275    llvm::Value *tmp = Builder.CreateSExt(TestMSB,
3276                                          llvm::VectorType::get(elemType,
3277                                                                numElem),
3278                                          "sext");
3279    llvm::Value *tmp2 = Builder.CreateNot(tmp);
3280
3281    // Cast float to int to perform ANDs if necessary.
3282    llvm::Value *RHSTmp = RHS;
3283    llvm::Value *LHSTmp = LHS;
3284    bool wasCast = false;
3285    llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType());
3286    if (rhsVTy->getElementType()->isFloatingPointTy()) {
3287      RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType());
3288      LHSTmp = Builder.CreateBitCast(LHS, tmp->getType());
3289      wasCast = true;
3290    }
3291
3292    llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2);
3293    llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp);
3294    llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond");
3295    if (wasCast)
3296      tmp5 = Builder.CreateBitCast(tmp5, RHS->getType());
3297
3298    return tmp5;
3299  }
3300
3301  // If this is a really simple expression (like x ? 4 : 5), emit this as a
3302  // select instead of as control flow.  We can only do this if it is cheap and
3303  // safe to evaluate the LHS and RHS unconditionally.
3304  if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) &&
3305      isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) {
3306    CGF.incrementProfileCounter(E);
3307
3308    llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr);
3309    llvm::Value *LHS = Visit(lhsExpr);
3310    llvm::Value *RHS = Visit(rhsExpr);
3311    if (!LHS) {
3312      // If the conditional has void type, make sure we return a null Value*.
3313      assert(!RHS && "LHS and RHS types must match");
3314      return nullptr;
3315    }
3316    return Builder.CreateSelect(CondV, LHS, RHS, "cond");
3317  }
3318
3319  llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
3320  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
3321  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
3322
3323  CodeGenFunction::ConditionalEvaluation eval(CGF);
3324  CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock,
3325                           CGF.getProfileCount(lhsExpr));
3326
3327  CGF.EmitBlock(LHSBlock);
3328  CGF.incrementProfileCounter(E);
3329  eval.begin(CGF);
3330  Value *LHS = Visit(lhsExpr);
3331  eval.end(CGF);
3332
3333  LHSBlock = Builder.GetInsertBlock();
3334  Builder.CreateBr(ContBlock);
3335
3336  CGF.EmitBlock(RHSBlock);
3337  eval.begin(CGF);
3338  Value *RHS = Visit(rhsExpr);
3339  eval.end(CGF);
3340
3341  RHSBlock = Builder.GetInsertBlock();
3342  CGF.EmitBlock(ContBlock);
3343
3344  // If the LHS or RHS is a throw expression, it will be legitimately null.
3345  if (!LHS)
3346    return RHS;
3347  if (!RHS)
3348    return LHS;
3349
3350  // Create a PHI node for the real part.
3351  llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond");
3352  PN->addIncoming(LHS, LHSBlock);
3353  PN->addIncoming(RHS, RHSBlock);
3354  return PN;
3355}
3356
3357Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) {
3358  return Visit(E->getChosenSubExpr());
3359}
3360
3361Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
3362  QualType Ty = VE->getType();
3363
3364  if (Ty->isVariablyModifiedType())
3365    CGF.EmitVariablyModifiedType(Ty);
3366
3367  Address ArgValue = Address::invalid();
3368  Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
3369
3370  llvm::Type *ArgTy = ConvertType(VE->getType());
3371
3372  // If EmitVAArg fails, we fall back to the LLVM instruction.
3373  if (!ArgPtr.isValid())
3374    return Builder.CreateVAArg(ArgValue.getPointer(), ArgTy);
3375
3376  // FIXME Volatility.
3377  llvm::Value *Val = Builder.CreateLoad(ArgPtr);
3378
3379  // If EmitVAArg promoted the type, we must truncate it.
3380  if (ArgTy != Val->getType()) {
3381    if (ArgTy->isPointerTy() && !Val->getType()->isPointerTy())
3382      Val = Builder.CreateIntToPtr(Val, ArgTy);
3383    else
3384      Val = Builder.CreateTrunc(Val, ArgTy);
3385  }
3386
3387  return Val;
3388}
3389
3390Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) {
3391  return CGF.EmitBlockLiteral(block);
3392}
3393
3394Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) {
3395  Value *Src  = CGF.EmitScalarExpr(E->getSrcExpr());
3396  llvm::Type *DstTy = ConvertType(E->getType());
3397
3398  // Going from vec4->vec3 or vec3->vec4 is a special case and requires
3399  // a shuffle vector instead of a bitcast.
3400  llvm::Type *SrcTy = Src->getType();
3401  if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) {
3402    unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements();
3403    unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements();
3404    if ((numElementsDst == 3 && numElementsSrc == 4)
3405        || (numElementsDst == 4 && numElementsSrc == 3)) {
3406
3407
3408      // In the case of going from int4->float3, a bitcast is needed before
3409      // doing a shuffle.
3410      llvm::Type *srcElemTy =
3411      cast<llvm::VectorType>(SrcTy)->getElementType();
3412      llvm::Type *dstElemTy =
3413      cast<llvm::VectorType>(DstTy)->getElementType();
3414
3415      if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy())
3416          || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) {
3417        // Create a float type of the same size as the source or destination.
3418        llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy,
3419                                                                 numElementsSrc);
3420
3421        Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast");
3422      }
3423
3424      llvm::Value *UnV = llvm::UndefValue::get(Src->getType());
3425
3426      SmallVector<llvm::Constant*, 3> Args;
3427      Args.push_back(Builder.getInt32(0));
3428      Args.push_back(Builder.getInt32(1));
3429      Args.push_back(Builder.getInt32(2));
3430
3431      if (numElementsDst == 4)
3432        Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
3433
3434      llvm::Constant *Mask = llvm::ConstantVector::get(Args);
3435
3436      return Builder.CreateShuffleVector(Src, UnV, Mask, "astype");
3437    }
3438  }
3439
3440  return Builder.CreateBitCast(Src, DstTy, "astype");
3441}
3442
3443Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) {
3444  return CGF.EmitAtomicExpr(E).getScalarVal();
3445}
3446
3447//===----------------------------------------------------------------------===//
3448//                         Entry Point into this File
3449//===----------------------------------------------------------------------===//
3450
3451/// Emit the computation of the specified expression of scalar type, ignoring
3452/// the result.
3453Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) {
3454  assert(E && hasScalarEvaluationKind(E->getType()) &&
3455         "Invalid scalar expression to emit");
3456
3457  return ScalarExprEmitter(*this, IgnoreResultAssign)
3458      .Visit(const_cast<Expr *>(E));
3459}
3460
3461/// Emit a conversion from the specified type to the specified destination type,
3462/// both of which are LLVM scalar types.
3463Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy,
3464                                             QualType DstTy,
3465                                             SourceLocation Loc) {
3466  assert(hasScalarEvaluationKind(SrcTy) && hasScalarEvaluationKind(DstTy) &&
3467         "Invalid scalar expression to emit");
3468  return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy, Loc);
3469}
3470
3471/// Emit a conversion from the specified complex type to the specified
3472/// destination type, where the destination type is an LLVM scalar type.
3473Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src,
3474                                                      QualType SrcTy,
3475                                                      QualType DstTy,
3476                                                      SourceLocation Loc) {
3477  assert(SrcTy->isAnyComplexType() && hasScalarEvaluationKind(DstTy) &&
3478         "Invalid complex -> scalar conversion");
3479  return ScalarExprEmitter(*this)
3480      .EmitComplexToScalarConversion(Src, SrcTy, DstTy, Loc);
3481}
3482
3483
3484llvm::Value *CodeGenFunction::
3485EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
3486                        bool isInc, bool isPre) {
3487  return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre);
3488}
3489
3490LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
3491  // object->isa or (*object).isa
3492  // Generate code as for: *(Class*)object
3493
3494  Expr *BaseExpr = E->getBase();
3495  Address Addr = Address::invalid();
3496  if (BaseExpr->isRValue()) {
3497    Addr = Address(EmitScalarExpr(BaseExpr), getPointerAlign());
3498  } else {
3499    Addr = EmitLValue(BaseExpr).getAddress();
3500  }
3501
3502  // Cast the address to Class*.
3503  Addr = Builder.CreateElementBitCast(Addr, ConvertType(E->getType()));
3504  return MakeAddrLValue(Addr, E->getType());
3505}
3506
3507
3508LValue CodeGenFunction::EmitCompoundAssignmentLValue(
3509                                            const CompoundAssignOperator *E) {
3510  ScalarExprEmitter Scalar(*this);
3511  Value *Result = nullptr;
3512  switch (E->getOpcode()) {
3513#define COMPOUND_OP(Op)                                                       \
3514    case BO_##Op##Assign:                                                     \
3515      return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \
3516                                             Result)
3517  COMPOUND_OP(Mul);
3518  COMPOUND_OP(Div);
3519  COMPOUND_OP(Rem);
3520  COMPOUND_OP(Add);
3521  COMPOUND_OP(Sub);
3522  COMPOUND_OP(Shl);
3523  COMPOUND_OP(Shr);
3524  COMPOUND_OP(And);
3525  COMPOUND_OP(Xor);
3526  COMPOUND_OP(Or);
3527#undef COMPOUND_OP
3528
3529  case BO_PtrMemD:
3530  case BO_PtrMemI:
3531  case BO_Mul:
3532  case BO_Div:
3533  case BO_Rem:
3534  case BO_Add:
3535  case BO_Sub:
3536  case BO_Shl:
3537  case BO_Shr:
3538  case BO_LT:
3539  case BO_GT:
3540  case BO_LE:
3541  case BO_GE:
3542  case BO_EQ:
3543  case BO_NE:
3544  case BO_And:
3545  case BO_Xor:
3546  case BO_Or:
3547  case BO_LAnd:
3548  case BO_LOr:
3549  case BO_Assign:
3550  case BO_Comma:
3551    llvm_unreachable("Not valid compound assignment operators");
3552  }
3553
3554  llvm_unreachable("Unhandled compound assignment operator");
3555}
3556