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// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/globals.h" // Needed here to get TARGET_ARCH_ARM.
#if defined(TARGET_ARCH_ARM)
#include "vm/code_patcher.h"
#include "vm/flow_graph_compiler.h"
#include "vm/instructions.h"
#include "vm/object.h"
namespace dart {
uword CodePatcher::GetStaticCallTargetAt(uword return_address,
const Code& code) {
ASSERT(code.ContainsInstructionAt(return_address));
CallPattern call(return_address, code);
return call.TargetAddress();
}
void CodePatcher::PatchStaticCallAt(uword return_address,
const Code& code,
uword new_target) {
ASSERT(code.ContainsInstructionAt(return_address));
CallPattern call(return_address, code);
call.SetTargetAddress(new_target);
}
void CodePatcher::PatchInstanceCallAt(uword return_address,
const Code& code,
uword new_target) {
ASSERT(code.ContainsInstructionAt(return_address));
CallPattern call(return_address, code);
call.SetTargetAddress(new_target);
}
int32_t CodePatcher::GetPoolOffsetAt(uword return_address) {
UNIMPLEMENTED();
return 0;
}
void CodePatcher::SetPoolOffsetAt(uword return_address, int32_t offset) {
UNIMPLEMENTED();
}
void CodePatcher::InsertCallAt(uword start, uword target) {
// The inserted call should not overlap the lazy deopt jump code.
ASSERT(start + CallPattern::LengthInBytes() <= target);
CallPattern::InsertAt(start, target);
}
uword CodePatcher::GetInstanceCallAt(uword return_address,
const Code& code,
ICData* ic_data) {
ASSERT(code.ContainsInstructionAt(return_address));
CallPattern call(return_address, code);
if (ic_data != NULL) {
*ic_data = call.IcData();
}
return call.TargetAddress();
}
intptr_t CodePatcher::InstanceCallSizeInBytes() {
// The instance call instruction sequence has a variable size on ARM.
UNREACHABLE();
return 0;
}
RawFunction* CodePatcher::GetUnoptimizedStaticCallAt(
uword return_address, const Code& code, ICData* ic_data_result) {
ASSERT(code.ContainsInstructionAt(return_address));
CallPattern static_call(return_address, code);
ICData& ic_data = ICData::Handle();
ic_data ^= static_call.IcData();
if (ic_data_result != NULL) {
*ic_data_result = ic_data.raw();
}
return ic_data.GetTargetAt(0);
}
// This class pattern matches on a load from the object pool. Loading on
// ARM is complicated because it can take four possible different forms. We
// match backwards from the end of the sequence so we can reuse the code for
// matching object pool loads at calls.
class EdgeCounter : public ValueObject {
public:
EdgeCounter(uword pc, const Code& code)
: end_(pc - FlowGraphCompiler::EdgeCounterIncrementSizeInBytes()),
object_pool_(Array::Handle(code.ObjectPool())) {
// An IsValid predicate is complicated and duplicates the code in the
// decoding function. Instead we rely on decoding the pattern which
// will assert partial validity.
}
RawObject* edge_counter() const {
Register ignored;
intptr_t index;
InstructionPattern::DecodeLoadWordFromPool(end_, &ignored, &index);
ASSERT(ignored == R0);
return object_pool_.At(index);
}
private:
// The object pool load is followed by the fixed-size edge counter
// incrementing code:
// ldr ip, [r0, #+11]
// adds ip, ip, #2
// str ip, [r0, #+11]
static const intptr_t kAdjust = 3 * Instr::kInstrSize;
uword end_;
const Array& object_pool_;
};
RawObject* CodePatcher::GetEdgeCounterAt(uword pc, const Code& code) {
ASSERT(code.ContainsInstructionAt(pc));
EdgeCounter counter(pc, code);
return counter.edge_counter();
}
} // namespace dart
#endif // defined TARGET_ARCH_ARM