src/arm/assembler-arm-inl.h - platform/external/v8 - Git at Google

 // 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_));
 }


 Handle<JSGlobalPropertyCell> RelocInfo::target_cell_handle() {
   ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
   Address address = Memory::Address_at(pc_);
   return Handle<JSGlobalPropertyCell>(
       reinterpret_cast<JSGlobalPropertyCell**>(address));
 }


 JSGlobalPropertyCell* RelocInfo::target_cell() {
   ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
   Address address = Memory::Address_at(pc_);
   Object* object = HeapObject::FromAddress(
       address - JSGlobalPropertyCell::kValueOffset);
   return reinterpret_cast<JSGlobalPropertyCell*>(object);
 }


 void RelocInfo::set_target_cell(JSGlobalPropertyCell* cell) {
   ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
   Address address = cell->address() + JSGlobalPropertyCell::kValueOffset;
   Memory::Address_at(pc_) = address;
 }


 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, Assembler::DEBUG_BREAK_NOP);
 }


 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::GLOBAL_PROPERTY_CELL) {
     visitor->VisitGlobalPropertyCell(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::GLOBAL_PROPERTY_CELL) {
     StaticVisitor::VisitGlobalPropertyCell(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

   ASSERT(IsLdrPcImmediateOffset(instr));
   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_
	// 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_));
	}


	Handle<JSGlobalPropertyCell> RelocInfo::target_cell_handle() {
	ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
	Address address = Memory::Address_at(pc_);
	return Handle<JSGlobalPropertyCell>(
	reinterpret_cast<JSGlobalPropertyCell**>(address));
	}


	JSGlobalPropertyCell* RelocInfo::target_cell() {
	ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
	Address address = Memory::Address_at(pc_);
	Object* object = HeapObject::FromAddress(
	address - JSGlobalPropertyCell::kValueOffset);
	return reinterpret_cast<JSGlobalPropertyCell*>(object);
	}


	void RelocInfo::set_target_cell(JSGlobalPropertyCell* cell) {
	ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
	Address address = cell->address() + JSGlobalPropertyCell::kValueOffset;
	Memory::Address_at(pc_) = address;
	}


	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, Assembler::DEBUG_BREAK_NOP);
	}


	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::GLOBAL_PROPERTY_CELL) {
	visitor->VisitGlobalPropertyCell(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::GLOBAL_PROPERTY_CELL) {
	StaticVisitor::VisitGlobalPropertyCell(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

	ASSERT(IsLdrPcImmediateOffset(instr));
	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_