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 "ARM/ARMABCCompilerDriver.h"
30
31 namespace {
32
33 class ARMABCExpandVAArg : public bcc::ABCExpandVAArgPass {
34 public:
getPassName() const35 virtual const char *getPassName() const {
36 return "ARM 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 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
51 llvm::Value *va_list_addr_bpp =
52 builder.CreateBitCast(va_list_addr, bpp, "ap");
53 llvm::Value *addr = builder.CreateLoad(va_list_addr_bpp, "ap.cur");
54 // Handle address alignment for type alignment > 32 bits.
55 uint64_t ty_align = td->getABITypeAlignment(ty);
56
57 if (ty_align > 4) {
58 assert((ty_align & (ty_align - 1)) == 0 &&
59 "Alignment is not power of 2!");
60 llvm::Value *addr_as_int =
61 builder.CreatePtrToInt(addr, llvm::Type::getInt32Ty(*mContext));
62 addr_as_int = builder.CreateAdd(addr_as_int,
63 builder.getInt32(ty_align-1));
64 addr_as_int = builder.CreateAnd(addr_as_int,
65 builder.getInt32(~(ty_align-1)));
66 addr = builder.CreateIntToPtr(addr_as_int, bp);
67 }
68 llvm::Value *addr_typed = builder.CreateBitCast(addr, pty);
69
70 uint64_t offset = llvm::RoundUpToAlignment(td->getTypeSizeInBits(ty)/8, 4);
71 llvm::Value *next_addr = builder.CreateGEP(addr,
72 llvm::ConstantInt::get(llvm::Type::getInt32Ty(*mContext), offset),
73 "ap.next");
74 builder.CreateStore(next_addr, va_list_addr_bpp);
75 return addr_typed;
76 }
77
78 };
79
80 } // end anonymous namespace
81
82 namespace bcc {
83
createExpandVAArgPass() const84 ABCExpandVAArgPass *ARMABCCompilerDriver::createExpandVAArgPass() const {
85 return new ARMABCExpandVAArg();
86 }
87
88 } // end namespace bcc
89