1 /*
2 * Copyright (C) 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 "runtime_support_builder_arm.h"
18
19 #include "ir_builder.h"
20 #include "thread.h"
21 #include "utils_llvm.h"
22
23 #include <llvm/IR/DerivedTypes.h>
24 #include <llvm/IR/Function.h>
25 #include <llvm/IR/InlineAsm.h>
26 #include <llvm/IR/Module.h>
27 #include <llvm/IR/Type.h>
28
29 #include <vector>
30
31 using ::llvm::CallInst;
32 using ::llvm::Function;
33 using ::llvm::FunctionType;
34 using ::llvm::InlineAsm;
35 using ::llvm::IntegerType;
36 using ::llvm::Type;
37 using ::llvm::Value;
38
39 namespace {
40
LDRSTRSuffixByType(art::llvm::IRBuilder & irb,Type * type)41 char LDRSTRSuffixByType(art::llvm::IRBuilder& irb, Type* type) {
42 int width = type->isPointerTy() ?
43 irb.getSizeOfPtrEquivInt()*8 :
44 ::llvm::cast<IntegerType>(type)->getBitWidth();
45 switch (width) {
46 case 8: return 'b';
47 case 16: return 'h';
48 case 32: return ' ';
49 default:
50 LOG(FATAL) << "Unsupported width: " << width;
51 return ' ';
52 }
53 }
54
55 } // namespace
56
57 namespace art {
58 namespace llvm {
59
60 /* Thread */
61
EmitGetCurrentThread()62 Value* RuntimeSupportBuilderARM::EmitGetCurrentThread() {
63 Function* ori_func = GetRuntimeSupportFunction(runtime_support::GetCurrentThread);
64 InlineAsm* func = InlineAsm::get(ori_func->getFunctionType(), "mov $0, r9", "=r", false);
65 CallInst* thread = irb_.CreateCall(func);
66 thread->setDoesNotAccessMemory();
67 irb_.SetTBAA(thread, kTBAAConstJObject);
68 return thread;
69 }
70
EmitLoadFromThreadOffset(int64_t offset,::llvm::Type * type,TBAASpecialType s_ty)71 Value* RuntimeSupportBuilderARM::EmitLoadFromThreadOffset(int64_t offset, ::llvm::Type* type,
72 TBAASpecialType s_ty) {
73 FunctionType* func_ty = FunctionType::get(/*Result=*/type,
74 /*isVarArg=*/false);
75 std::string inline_asm(StringPrintf("ldr%c $0, [r9, #%d]",
76 LDRSTRSuffixByType(irb_, type),
77 static_cast<int>(offset)));
78 InlineAsm* func = InlineAsm::get(func_ty, inline_asm, "=r", true);
79 CallInst* result = irb_.CreateCall(func);
80 result->setOnlyReadsMemory();
81 irb_.SetTBAA(result, s_ty);
82 return result;
83 }
84
EmitStoreToThreadOffset(int64_t offset,Value * value,TBAASpecialType s_ty)85 void RuntimeSupportBuilderARM::EmitStoreToThreadOffset(int64_t offset, Value* value,
86 TBAASpecialType s_ty) {
87 FunctionType* func_ty = FunctionType::get(/*Result=*/Type::getVoidTy(context_),
88 /*Params=*/value->getType(),
89 /*isVarArg=*/false);
90 std::string inline_asm(StringPrintf("str%c $0, [r9, #%d]",
91 LDRSTRSuffixByType(irb_, value->getType()),
92 static_cast<int>(offset)));
93 InlineAsm* func = InlineAsm::get(func_ty, inline_asm, "r", true);
94 CallInst* call_inst = irb_.CreateCall(func, value);
95 irb_.SetTBAA(call_inst, s_ty);
96 }
97
EmitSetCurrentThread(Value * thread)98 Value* RuntimeSupportBuilderARM::EmitSetCurrentThread(Value* thread) {
99 // Separate to two InlineAsm: The first one produces the return value, while the second,
100 // sets the current thread.
101 // LLVM can delete the first one if the caller in LLVM IR doesn't use the return value.
102 //
103 // Here we don't call EmitGetCurrentThread, because we mark it as DoesNotAccessMemory and
104 // ConstJObject. We denote side effect to "true" below instead, so LLVM won't
105 // reorder these instructions incorrectly.
106 Function* ori_func = GetRuntimeSupportFunction(runtime_support::GetCurrentThread);
107 InlineAsm* func = InlineAsm::get(ori_func->getFunctionType(), "mov $0, r9", "=r", true);
108 CallInst* old_thread_register = irb_.CreateCall(func);
109 old_thread_register->setOnlyReadsMemory();
110
111 FunctionType* func_ty = FunctionType::get(/*Result=*/Type::getVoidTy(context_),
112 /*Params=*/irb_.getJObjectTy(),
113 /*isVarArg=*/false);
114 func = InlineAsm::get(func_ty, "mov r9, $0", "r", true);
115 irb_.CreateCall(func, thread);
116 return old_thread_register;
117 }
118
119 } // namespace llvm
120 } // namespace art
121