1//===- CodeGen/Analysis.h - CodeGen LLVM IR Analysis Utilities --*- C++ -*-===//
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 file declares several CodeGen-specific LLVM IR analysis utilities.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CODEGEN_ANALYSIS_H
15#define LLVM_CODEGEN_ANALYSIS_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/CodeGen/ISDOpcodes.h"
20#include "llvm/IR/CallSite.h"
21#include "llvm/IR/InlineAsm.h"
22#include "llvm/IR/Instructions.h"
23
24namespace llvm {
25class GlobalValue;
26class TargetLoweringBase;
27class TargetLowering;
28class TargetMachine;
29class SDNode;
30class SDValue;
31class SelectionDAG;
32struct EVT;
33
34/// \brief Compute the linearized index of a member in a nested
35/// aggregate/struct/array.
36///
37/// Given an LLVM IR aggregate type and a sequence of insertvalue or
38/// extractvalue indices that identify a member, return the linearized index of
39/// the start of the member, i.e the number of element in memory before the
40/// seeked one. This is disconnected from the number of bytes.
41///
42/// \param Ty is the type indexed by \p Indices.
43/// \param Indices is an optional pointer in the indices list to the current
44/// index.
45/// \param IndicesEnd is the end of the indices list.
46/// \param CurIndex is the current index in the recursion.
47///
48/// \returns \p CurIndex plus the linear index in \p Ty  the indices list.
49unsigned ComputeLinearIndex(Type *Ty,
50                            const unsigned *Indices,
51                            const unsigned *IndicesEnd,
52                            unsigned CurIndex = 0);
53
54inline unsigned ComputeLinearIndex(Type *Ty,
55                                   ArrayRef<unsigned> Indices,
56                                   unsigned CurIndex = 0) {
57  return ComputeLinearIndex(Ty, Indices.begin(), Indices.end(), CurIndex);
58}
59
60/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of
61/// EVTs that represent all the individual underlying
62/// non-aggregate types that comprise it.
63///
64/// If Offsets is non-null, it points to a vector to be filled in
65/// with the in-memory offsets of each of the individual values.
66///
67void ComputeValueVTs(const TargetLowering &TLI, Type *Ty,
68                     SmallVectorImpl<EVT> &ValueVTs,
69                     SmallVectorImpl<uint64_t> *Offsets = nullptr,
70                     uint64_t StartingOffset = 0);
71
72/// ExtractTypeInfo - Returns the type info, possibly bitcast, encoded in V.
73GlobalValue *ExtractTypeInfo(Value *V);
74
75/// hasInlineAsmMemConstraint - Return true if the inline asm instruction being
76/// processed uses a memory 'm' constraint.
77bool hasInlineAsmMemConstraint(InlineAsm::ConstraintInfoVector &CInfos,
78                               const TargetLowering &TLI);
79
80/// getFCmpCondCode - Return the ISD condition code corresponding to
81/// the given LLVM IR floating-point condition code.  This includes
82/// consideration of global floating-point math flags.
83///
84ISD::CondCode getFCmpCondCode(FCmpInst::Predicate Pred);
85
86/// getFCmpCodeWithoutNaN - Given an ISD condition code comparing floats,
87/// return the equivalent code if we're allowed to assume that NaNs won't occur.
88ISD::CondCode getFCmpCodeWithoutNaN(ISD::CondCode CC);
89
90/// getICmpCondCode - Return the ISD condition code corresponding to
91/// the given LLVM IR integer condition code.
92///
93ISD::CondCode getICmpCondCode(ICmpInst::Predicate Pred);
94
95/// Test if the given instruction is in a position to be optimized
96/// with a tail-call. This roughly means that it's in a block with
97/// a return and there's nothing that needs to be scheduled
98/// between it and the return.
99///
100/// This function only tests target-independent requirements.
101bool isInTailCallPosition(ImmutableCallSite CS, const TargetMachine &TM);
102
103/// Test if given that the input instruction is in the tail call position if the
104/// return type or any attributes of the function will inhibit tail call
105/// optimization.
106bool returnTypeIsEligibleForTailCall(const Function *F,
107                                     const Instruction *I,
108                                     const ReturnInst *Ret,
109                                     const TargetLoweringBase &TLI);
110
111// True if GV can be left out of the object symbol table. This is the case
112// for linkonce_odr values whose address is not significant. While legal, it is
113// not normally profitable to omit them from the .o symbol table. Using this
114// analysis makes sense when the information can be passed down to the linker
115// or we are in LTO.
116bool canBeOmittedFromSymbolTable(const GlobalValue *GV);
117
118} // End llvm namespace
119
120#endif
121