1/*
2 * Copyright 2012, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <llvm/ADT/Triple.h>
18#include <llvm/DerivedTypes.h>
19#include <llvm/Function.h>
20#include <llvm/Instructions.h>
21#include <llvm/IRBuilder.h>
22#include <llvm/Module.h>
23#include <llvm/Pass.h>
24#include <llvm/Type.h>
25#include <llvm/Target/TargetData.h>
26
27#include "bcc/AndroidBitcode/ABCExpandVAArgPass.h"
28
29#include "Mips/MipsABCCompilerDriver.h"
30
31namespace {
32
33class MipsABCExpandVAArg : public bcc::ABCExpandVAArgPass {
34public:
35  virtual const char *getPassName() const {
36    return "Mips LLVM va_arg Instruction Expansion Pass";
37  }
38
39private:
40  // Derivative work from external/clang/lib/CodeGen/TargetInfo.cpp.
41  virtual llvm::Value *expandVAArg(llvm::Instruction *pInst) {
42    llvm::Type *pty = pInst->getType();
43    llvm::Type *ty = pty->getContainedType(0);
44    llvm::Value *va_list_addr = pInst->getOperand(0);
45    llvm::IRBuilder<> builder(pInst);
46    const llvm::TargetData *td = getAnalysisIfAvailable<llvm::TargetData>();
47
48    llvm::Type *bp = llvm::Type::getInt8PtrTy(*mContext);
49    llvm::Type *bpp = bp->getPointerTo(0);
50    llvm::Value *va_list_addr_bpp = builder.CreateBitCast(va_list_addr,
51                                                          bpp, "ap");
52    llvm::Value *addr = builder.CreateLoad(va_list_addr_bpp, "ap.cur");
53    int64_t type_align = td->getABITypeAlignment(ty);
54    llvm::Value *addr_typed;
55    llvm::IntegerType *int_ty = llvm::Type::getInt32Ty(*mContext);
56
57    if (type_align > 4) {
58      llvm::Value *addr_as_int = builder.CreatePtrToInt(addr, int_ty);
59      llvm::Value *inc = llvm::ConstantInt::get(int_ty, type_align - 1);
60      llvm::Value *mask = llvm::ConstantInt::get(int_ty, -type_align);
61      llvm::Value *add_v = builder.CreateAdd(addr_as_int, inc);
62      llvm::Value *and_v = builder.CreateAnd(add_v, mask);
63      addr_typed = builder.CreateIntToPtr(and_v, pty);
64    }
65    else {
66      addr_typed = builder.CreateBitCast(addr, pty);
67    }
68
69    llvm::Value *aligned_addr = builder.CreateBitCast(addr_typed, bp);
70    type_align = std::max((unsigned)type_align, (unsigned) 4);
71    uint64_t offset =
72      llvm::RoundUpToAlignment(td->getTypeSizeInBits(ty) / 8, type_align);
73    llvm::Value *next_addr =
74      builder.CreateGEP(aligned_addr, llvm::ConstantInt::get(int_ty, offset),
75                        "ap.next");
76    builder.CreateStore(next_addr, va_list_addr_bpp);
77
78    return addr_typed;
79  }
80
81};
82
83} // end anonymous namespace
84
85namespace bcc {
86
87ABCExpandVAArgPass *MipsABCCompilerDriver::createExpandVAArgPass() const {
88  return new MipsABCExpandVAArg();
89}
90
91} // end namespace bcc
92