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/IR/DerivedTypes.h>
19 #include <llvm/IR/Function.h>
20 #include <llvm/IR/Instructions.h>
21 #include <llvm/IR/IRBuilder.h>
22 #include <llvm/IR/Module.h>
23 #include <llvm/Pass.h>
24 #include <llvm/IR/Type.h>
25 #include <llvm/IR/DataLayout.h>
26
27 #include "bcc/AndroidBitcode/ABCExpandVAArgPass.h"
28
29 #include "Mips/MipsABCCompilerDriver.h"
30
31 namespace {
32
33 class MipsABCExpandVAArg : public bcc::ABCExpandVAArgPass {
34 public:
getPassName() const35 virtual const char *getPassName() const {
36 return "Mips LLVM va_arg Instruction Expansion Pass";
37 }
38
39 private:
40 // Derivative work from external/clang/lib/CodeGen/TargetInfo.cpp.
expandVAArg(llvm::Instruction * pInst)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::DataLayout *dl = getAnalysisIfAvailable<llvm::DataLayout>();
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 = dl->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(dl->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
85 namespace bcc {
86
createExpandVAArgPass() const87 ABCExpandVAArgPass *MipsABCCompilerDriver::createExpandVAArgPass() const {
88 return new MipsABCExpandVAArg();
89 }
90
91 } // end namespace bcc
92