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// Copyright (c) 1994-2006 Sun Microsystems Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// - Redistribution in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the
// distribution.
//
// - Neither the name of Sun Microsystems or the names of contributors may
// be used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
// The original source code covered by the above license above has been modified
// significantly by Google Inc.
// Copyright 2006-2008 the V8 project authors. All rights reserved.
#ifndef V8_ARM_ASSEMBLER_ARM_INL_H_
#define V8_ARM_ASSEMBLER_ARM_INL_H_
#include "arm/assembler-arm.h"
#include "cpu.h"
#include "debug.h"
namespace v8 {
namespace internal {
void RelocInfo::apply(intptr_t delta) {
if (RelocInfo::IsInternalReference(rmode_)) {
// absolute code pointer inside code object moves with the code object.
int32_t* p = reinterpret_cast<int32_t*>(pc_);
*p += delta; // relocate entry
}
// We do not use pc relative addressing on ARM, so there is
// nothing else to do.
}
Address RelocInfo::target_address() {
ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
return Assembler::target_address_at(pc_);
}
Address RelocInfo::target_address_address() {
ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
return reinterpret_cast<Address>(Assembler::target_address_address_at(pc_));
}
int RelocInfo::target_address_size() {
return Assembler::kExternalTargetSize;
}
void RelocInfo::set_target_address(Address target) {
ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
Assembler::set_target_address_at(pc_, target);
}
Object* RelocInfo::target_object() {
ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
return Memory::Object_at(Assembler::target_address_address_at(pc_));
}
Handle<Object> RelocInfo::target_object_handle(Assembler* origin) {
ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
return Memory::Object_Handle_at(Assembler::target_address_address_at(pc_));
}
Object** RelocInfo::target_object_address() {
ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
return reinterpret_cast<Object**>(Assembler::target_address_address_at(pc_));
}
void RelocInfo::set_target_object(Object* target) {
ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
Assembler::set_target_address_at(pc_, reinterpret_cast<Address>(target));
}
Address* RelocInfo::target_reference_address() {
ASSERT(rmode_ == EXTERNAL_REFERENCE);
return reinterpret_cast<Address*>(Assembler::target_address_address_at(pc_));
}
Address RelocInfo::call_address() {
// The 2 instructions offset assumes patched debug break slot or return
// sequence.
ASSERT((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
return Memory::Address_at(pc_ + 2 * Assembler::kInstrSize);
}
void RelocInfo::set_call_address(Address target) {
ASSERT((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
Memory::Address_at(pc_ + 2 * Assembler::kInstrSize) = target;
}
Object* RelocInfo::call_object() {
return *call_object_address();
}
void RelocInfo::set_call_object(Object* target) {
*call_object_address() = target;
}
Object** RelocInfo::call_object_address() {
ASSERT((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
return reinterpret_cast<Object**>(pc_ + 2 * Assembler::kInstrSize);
}
bool RelocInfo::IsPatchedReturnSequence() {
Instr current_instr = Assembler::instr_at(pc_);
Instr next_instr = Assembler::instr_at(pc_ + Assembler::kInstrSize);
#ifdef USE_BLX
// A patched return sequence is:
// ldr ip, [pc, #0]
// blx ip
return ((current_instr & kLdrPCMask) == kLdrPCPattern)
&& ((next_instr & kBlxRegMask) == kBlxRegPattern);
#else
// A patched return sequence is:
// mov lr, pc
// ldr pc, [pc, #-4]
return (current_instr == kMovLrPc)
&& ((next_instr & kLdrPCMask) == kLdrPCPattern);
#endif
}
bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
Instr current_instr = Assembler::instr_at(pc_);
return !Assembler::IsNop(current_instr, 2);
}
void RelocInfo::Visit(ObjectVisitor* visitor) {
RelocInfo::Mode mode = rmode();
if (mode == RelocInfo::EMBEDDED_OBJECT) {
visitor->VisitPointer(target_object_address());
} else if (RelocInfo::IsCodeTarget(mode)) {
visitor->VisitCodeTarget(this);
} else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
visitor->VisitExternalReference(target_reference_address());
#ifdef ENABLE_DEBUGGER_SUPPORT
} else if (Debug::has_break_points() &&
((RelocInfo::IsJSReturn(mode) &&
IsPatchedReturnSequence()) ||
(RelocInfo::IsDebugBreakSlot(mode) &&
IsPatchedDebugBreakSlotSequence()))) {
visitor->VisitDebugTarget(this);
#endif
} else if (mode == RelocInfo::RUNTIME_ENTRY) {
visitor->VisitRuntimeEntry(this);
}
}
template<typename StaticVisitor>
void RelocInfo::Visit() {
RelocInfo::Mode mode = rmode();
if (mode == RelocInfo::EMBEDDED_OBJECT) {
StaticVisitor::VisitPointer(target_object_address());
} else if (RelocInfo::IsCodeTarget(mode)) {
StaticVisitor::VisitCodeTarget(this);
} else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
StaticVisitor::VisitExternalReference(target_reference_address());
#ifdef ENABLE_DEBUGGER_SUPPORT
} else if (Debug::has_break_points() &&
((RelocInfo::IsJSReturn(mode) &&
IsPatchedReturnSequence()) ||
(RelocInfo::IsDebugBreakSlot(mode) &&
IsPatchedDebugBreakSlotSequence()))) {
StaticVisitor::VisitDebugTarget(this);
#endif
} else if (mode == RelocInfo::RUNTIME_ENTRY) {
StaticVisitor::VisitRuntimeEntry(this);
}
}
Operand::Operand(int32_t immediate, RelocInfo::Mode rmode) {
rm_ = no_reg;
imm32_ = immediate;
rmode_ = rmode;
}
Operand::Operand(const ExternalReference& f) {
rm_ = no_reg;
imm32_ = reinterpret_cast<int32_t>(f.address());
rmode_ = RelocInfo::EXTERNAL_REFERENCE;
}
Operand::Operand(Smi* value) {
rm_ = no_reg;
imm32_ = reinterpret_cast<intptr_t>(value);
rmode_ = RelocInfo::NONE;
}
Operand::Operand(Register rm) {
rm_ = rm;
rs_ = no_reg;
shift_op_ = LSL;
shift_imm_ = 0;
}
bool Operand::is_reg() const {
return rm_.is_valid() &&
rs_.is(no_reg) &&
shift_op_ == LSL &&
shift_imm_ == 0;
}
void Assembler::CheckBuffer() {
if (buffer_space() <= kGap) {
GrowBuffer();
}
if (pc_offset() >= next_buffer_check_) {
CheckConstPool(false, true);
}
}
void Assembler::emit(Instr x) {
CheckBuffer();
*reinterpret_cast<Instr*>(pc_) = x;
pc_ += kInstrSize;
}
Address Assembler::target_address_address_at(Address pc) {
Address target_pc = pc;
Instr instr = Memory::int32_at(target_pc);
// If we have a bx instruction, the instruction before the bx is
// what we need to patch.
static const int32_t kBxInstMask = 0x0ffffff0;
static const int32_t kBxInstPattern = 0x012fff10;
if ((instr & kBxInstMask) == kBxInstPattern) {
target_pc -= kInstrSize;
instr = Memory::int32_at(target_pc);
}
#ifdef USE_BLX
// If we have a blx instruction, the instruction before it is
// what needs to be patched.
if ((instr & kBlxRegMask) == kBlxRegPattern) {
target_pc -= kInstrSize;
instr = Memory::int32_at(target_pc);
}
#endif
// Verify that the instruction to patch is a
// ldr<cond> <Rd>, [pc +/- offset_12].
ASSERT((instr & 0x0f7f0000) == 0x051f0000);
int offset = instr & 0xfff; // offset_12 is unsigned
if ((instr & (1 << 23)) == 0) offset = -offset; // U bit defines offset sign
// Verify that the constant pool comes after the instruction referencing it.
ASSERT(offset >= -4);
return target_pc + offset + 8;
}
Address Assembler::target_address_at(Address pc) {
return Memory::Address_at(target_address_address_at(pc));
}
void Assembler::set_target_at(Address constant_pool_entry,
Address target) {
Memory::Address_at(constant_pool_entry) = target;
}
void Assembler::set_target_address_at(Address pc, Address target) {
Memory::Address_at(target_address_address_at(pc)) = target;
// Intuitively, we would think it is necessary to flush the instruction cache
// after patching a target address in the code as follows:
// CPU::FlushICache(pc, sizeof(target));
// However, on ARM, no instruction was actually patched by the assignment
// above; the target address is not part of an instruction, it is patched in
// the constant pool and is read via a data access; the instruction accessing
// this address in the constant pool remains unchanged.
}
} } // namespace v8::internal
#endif // V8_ARM_ASSEMBLER_ARM_INL_H_