src/v8/src/s390/assembler-s390-inl.h - cobalt - 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 2014 the V8 project authors. All rights reserved.

 #ifndef V8_S390_ASSEMBLER_S390_INL_H_
 #define V8_S390_ASSEMBLER_S390_INL_H_

 #include "src/s390/assembler-s390.h"

 #include "src/assembler.h"
 #include "src/debug/debug.h"
 #include "src/objects-inl.h"

 namespace v8 {
 namespace internal {

 bool CpuFeatures::SupportsCrankshaft() { return true; }

 bool CpuFeatures::SupportsWasmSimd128() { return false; }

 void RelocInfo::apply(intptr_t delta) {
   // Absolute code pointer inside code object moves with the code object.
   if (IsInternalReference(rmode_)) {
     // Jump table entry
     Address target = Memory::Address_at(pc_);
     Memory::Address_at(pc_) = target + delta;
   } else if (IsCodeTarget(rmode_)) {
     SixByteInstr instr =
         Instruction::InstructionBits(reinterpret_cast<const byte*>(pc_));
     int32_t dis = static_cast<int32_t>(instr & 0xFFFFFFFF) * 2  // halfwords
                   - static_cast<int32_t>(delta);
     instr >>= 32;  // Clear the 4-byte displacement field.
     instr <<= 32;
     instr |= static_cast<uint32_t>(dis / 2);
     Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc_),
                                                   instr);
   } else {
     // mov sequence
     DCHECK(IsInternalReferenceEncoded(rmode_));
     Address target = Assembler::target_address_at(pc_, constant_pool_);
     Assembler::set_target_address_at(nullptr, pc_, constant_pool_,
                                      target + delta, SKIP_ICACHE_FLUSH);
   }
 }

 Address RelocInfo::target_internal_reference() {
   if (IsInternalReference(rmode_)) {
     // Jump table entry
     return Memory::Address_at(pc_);
   } else {
     // mov sequence
     DCHECK(IsInternalReferenceEncoded(rmode_));
     return Assembler::target_address_at(pc_, constant_pool_);
   }
 }

 Address RelocInfo::target_internal_reference_address() {
   DCHECK(IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_));
   return reinterpret_cast<Address>(pc_);
 }

 Address RelocInfo::target_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
   return Assembler::target_address_at(pc_, constant_pool_);
 }

 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_) ||
          rmode_ == EMBEDDED_OBJECT || rmode_ == EXTERNAL_REFERENCE);

   // Read the address of the word containing the target_address in an
   // instruction stream.
   // The only architecture-independent user of this function is the serializer.
   // The serializer uses it to find out how many raw bytes of instruction to
   // output before the next target.
   // For an instruction like LIS/ORI where the target bits are mixed into the
   // instruction bits, the size of the target will be zero, indicating that the
   // serializer should not step forward in memory after a target is resolved
   // and written.
   return reinterpret_cast<Address>(pc_);
 }

 Address RelocInfo::constant_pool_entry_address() {
   UNREACHABLE();
 }

 int RelocInfo::target_address_size() { return Assembler::kSpecialTargetSize; }

 Address Assembler::target_address_from_return_address(Address pc) {
   // Returns the address of the call target from the return address that will
   // be returned to after a call.
   // Sequence is:
   //    BRASL r14, RI
   return pc - kCallTargetAddressOffset;
 }

 Address Assembler::return_address_from_call_start(Address pc) {
   // Sequence is:
   //    BRASL r14, RI
   return pc + kCallTargetAddressOffset;
 }

 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
   SixByteInstr instr =
       Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
   int index = instr & 0xFFFFFFFF;
   return code_targets_[index];
 }

 HeapObject* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   return HeapObject::cast(reinterpret_cast<Object*>(
       Assembler::target_address_at(pc_, constant_pool_)));
 }

 Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   if (rmode_ == EMBEDDED_OBJECT) {
     return Handle<HeapObject>(reinterpret_cast<HeapObject**>(
         Assembler::target_address_at(pc_, constant_pool_)));
   } else {
     return Handle<HeapObject>::cast(origin->code_target_object_handle_at(pc_));
   }
 }

 void RelocInfo::set_target_object(HeapObject* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   Assembler::set_target_address_at(target->GetIsolate(), pc_, constant_pool_,
                                    reinterpret_cast<Address>(target),
                                    icache_flush_mode);
   if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != nullptr) {
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
                                                                   target);
     host()->GetHeap()->RecordWriteIntoCode(host(), this, target);
   }
 }

 Address RelocInfo::target_external_reference() {
   DCHECK(rmode_ == EXTERNAL_REFERENCE);
   return Assembler::target_address_at(pc_, constant_pool_);
 }

 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();
 }

 void RelocInfo::set_target_runtime_entry(Isolate* isolate, Address target,
                                          WriteBarrierMode write_barrier_mode,
                                          ICacheFlushMode icache_flush_mode) {
   DCHECK(IsRuntimeEntry(rmode_));
   if (target_address() != target)
     set_target_address(isolate, target, write_barrier_mode, icache_flush_mode);
 }

 void RelocInfo::WipeOut(Isolate* isolate) {
   DCHECK(IsEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
          IsRuntimeEntry(rmode_) || IsExternalReference(rmode_) ||
          IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_));
   if (IsInternalReference(rmode_)) {
     // Jump table entry
     Memory::Address_at(pc_) = nullptr;
   } else if (IsInternalReferenceEncoded(rmode_)) {
     // mov sequence
     // Currently used only by deserializer, no need to flush.
     Assembler::set_target_address_at(isolate, pc_, constant_pool_, nullptr,
                                      SKIP_ICACHE_FLUSH);
   } else {
     Assembler::set_target_address_at(isolate, pc_, constant_pool_, nullptr);
   }
 }

 template <typename ObjectVisitor>
 void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     visitor->VisitEmbeddedPointer(host(), this);
   } else if (RelocInfo::IsCodeTarget(mode)) {
     visitor->VisitCodeTarget(host(), this);
   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
     visitor->VisitExternalReference(host(), this);
   } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
     visitor->VisitInternalReference(host(), this);
   } else if (IsRuntimeEntry(mode)) {
     visitor->VisitRuntimeEntry(host(), this);
   }
 }

 // Operand constructors
 Operand::Operand(Register rm) : rm_(rm), rmode_(kRelocInfo_NONEPTR) {}

 int32_t Assembler::emit_code_target(Handle<Code> target,
                                     RelocInfo::Mode rmode) {
   DCHECK(RelocInfo::IsCodeTarget(rmode));
   RecordRelocInfo(rmode);

   size_t current = code_targets_.size();
   if (current > 0 && !target.is_null() &&
       code_targets_.back().address() == target.address()) {
     // Optimization if we keep jumping to the same code target.
     current--;
   } else {
     code_targets_.push_back(target);
   }
   return current;
 }


 // Fetch the 32bit value from the FIXED_SEQUENCE IIHF / IILF
 Address Assembler::target_address_at(Address pc, Address constant_pool) {
   // S390 Instruction!
   // We want to check for instructions generated by Asm::mov()
   Opcode op1 = Instruction::S390OpcodeValue(reinterpret_cast<const byte*>(pc));
   SixByteInstr instr_1 =
       Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));

   if (BRASL == op1 || BRCL == op1) {
     int32_t dis = static_cast<int32_t>(instr_1 & 0xFFFFFFFF) * 2;
     return reinterpret_cast<Address>(reinterpret_cast<uint64_t>(pc) + dis);
   }

 #if V8_TARGET_ARCH_S390X
   int instr1_length =
       Instruction::InstructionLength(reinterpret_cast<const byte*>(pc));
   Opcode op2 = Instruction::S390OpcodeValue(
       reinterpret_cast<const byte*>(pc + instr1_length));
   SixByteInstr instr_2 = Instruction::InstructionBits(
       reinterpret_cast<const byte*>(pc + instr1_length));
   // IIHF for hi_32, IILF for lo_32
   if (IIHF == op1 && IILF == op2) {
     return reinterpret_cast<Address>(((instr_1 & 0xFFFFFFFF) << 32) |
                                      ((instr_2 & 0xFFFFFFFF)));
   }
 #else
   // IILF loads 32-bits
   if (IILF == op1 || CFI == op1) {
     return reinterpret_cast<Address>((instr_1 & 0xFFFFFFFF));
   }
 #endif

   UNIMPLEMENTED();
   return (Address)0;
 }

 // This sets the branch destination (which gets loaded at the call address).
 // This is for calls and branches within generated code.  The serializer
 // has already deserialized the mov instructions etc.
 // There is a FIXED_SEQUENCE assumption here
 void Assembler::deserialization_set_special_target_at(
     Isolate* isolate, Address instruction_payload, Code* code, Address target) {
   set_target_address_at(isolate, instruction_payload,
                         code ? code->constant_pool() : nullptr, target);
 }

 void Assembler::deserialization_set_target_internal_reference_at(
     Isolate* isolate, Address pc, Address target, RelocInfo::Mode mode) {
   if (RelocInfo::IsInternalReferenceEncoded(mode)) {
     set_target_address_at(isolate, pc, nullptr, target, SKIP_ICACHE_FLUSH);
   } else {
     Memory::Address_at(pc) = target;
   }
 }

 // This code assumes the FIXED_SEQUENCE of IIHF/IILF
 void Assembler::set_target_address_at(Isolate* isolate, Address pc,
                                       Address constant_pool, Address target,
                                       ICacheFlushMode icache_flush_mode) {
   DCHECK_IMPLIES(isolate == nullptr, icache_flush_mode == SKIP_ICACHE_FLUSH);

   // Check for instructions generated by Asm::mov()
   Opcode op1 = Instruction::S390OpcodeValue(reinterpret_cast<const byte*>(pc));
   SixByteInstr instr_1 =
       Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
   bool patched = false;

   if (BRASL == op1 || BRCL == op1) {
     instr_1 >>= 32;  // Zero out the lower 32-bits
     instr_1 <<= 32;
     int32_t halfwords = (target - pc) / 2;  // number of halfwords
     instr_1 |= static_cast<uint32_t>(halfwords);
     Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
                                                   instr_1);
     if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
       Assembler::FlushICache(isolate, pc, 6);
     }
     patched = true;
   } else {
 #if V8_TARGET_ARCH_S390X
     int instr1_length =
         Instruction::InstructionLength(reinterpret_cast<const byte*>(pc));
     Opcode op2 = Instruction::S390OpcodeValue(
         reinterpret_cast<const byte*>(pc + instr1_length));
     SixByteInstr instr_2 = Instruction::InstructionBits(
         reinterpret_cast<const byte*>(pc + instr1_length));
     // IIHF for hi_32, IILF for lo_32
     if (IIHF == op1 && IILF == op2) {
       // IIHF
       instr_1 >>= 32;  // Zero out the lower 32-bits
       instr_1 <<= 32;
       instr_1 |= reinterpret_cast<uint64_t>(target) >> 32;

       Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
                                                     instr_1);

       // IILF
       instr_2 >>= 32;
       instr_2 <<= 32;
       instr_2 |= reinterpret_cast<uint64_t>(target) & 0xFFFFFFFF;

       Instruction::SetInstructionBits<SixByteInstr>(
           reinterpret_cast<byte*>(pc + instr1_length), instr_2);
       if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
         Assembler::FlushICache(isolate, pc, 12);
       }
       patched = true;
     }
 #else
     // IILF loads 32-bits
     if (IILF == op1 || CFI == op1) {
       instr_1 >>= 32;  // Zero out the lower 32-bits
       instr_1 <<= 32;
       instr_1 |= reinterpret_cast<uint32_t>(target);

       Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
                                                     instr_1);
       if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
         Assembler::FlushICache(isolate, pc, 6);
       }
       patched = true;
     }
 #endif
   }
   if (!patched) UNREACHABLE();
 }

 }  // namespace internal
 }  // namespace v8

 #endif  // V8_S390_ASSEMBLER_S390_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 2014 the V8 project authors. All rights reserved.

	#ifndef V8_S390_ASSEMBLER_S390_INL_H_
	#define V8_S390_ASSEMBLER_S390_INL_H_

	#include "src/s390/assembler-s390.h"

	#include "src/assembler.h"
	#include "src/debug/debug.h"
	#include "src/objects-inl.h"

	namespace v8 {
	namespace internal {

	bool CpuFeatures::SupportsCrankshaft() { return true; }

	bool CpuFeatures::SupportsWasmSimd128() { return false; }

	void RelocInfo::apply(intptr_t delta) {
	// Absolute code pointer inside code object moves with the code object.
	if (IsInternalReference(rmode_)) {
	// Jump table entry
	Address target = Memory::Address_at(pc_);
	Memory::Address_at(pc_) = target + delta;
	} else if (IsCodeTarget(rmode_)) {
	SixByteInstr instr =
	Instruction::InstructionBits(reinterpret_cast<const byte*>(pc_));
	int32_t dis = static_cast<int32_t>(instr & 0xFFFFFFFF) * 2 // halfwords
	- static_cast<int32_t>(delta);
	instr >>= 32; // Clear the 4-byte displacement field.
	instr <<= 32;
	instr \|= static_cast<uint32_t>(dis / 2);
	Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc_),
	instr);
	} else {
	// mov sequence
	DCHECK(IsInternalReferenceEncoded(rmode_));
	Address target = Assembler::target_address_at(pc_, constant_pool_);
	Assembler::set_target_address_at(nullptr, pc_, constant_pool_,
	target + delta, SKIP_ICACHE_FLUSH);
	}
	}

	Address RelocInfo::target_internal_reference() {
	if (IsInternalReference(rmode_)) {
	// Jump table entry
	return Memory::Address_at(pc_);
	} else {
	// mov sequence
	DCHECK(IsInternalReferenceEncoded(rmode_));
	return Assembler::target_address_at(pc_, constant_pool_);
	}
	}

	Address RelocInfo::target_internal_reference_address() {
	DCHECK(IsInternalReference(rmode_) \|\| IsInternalReferenceEncoded(rmode_));
	return reinterpret_cast<Address>(pc_);
	}

	Address RelocInfo::target_address() {
	DCHECK(IsCodeTarget(rmode_) \|\| IsRuntimeEntry(rmode_) \|\| IsWasmCall(rmode_));
	return Assembler::target_address_at(pc_, constant_pool_);
	}

	Address RelocInfo::target_address_address() {
	DCHECK(IsCodeTarget(rmode_) \|\| IsRuntimeEntry(rmode_) \|\| IsWasmCall(rmode_) \|\|
	rmode_ == EMBEDDED_OBJECT \|\| rmode_ == EXTERNAL_REFERENCE);

	// Read the address of the word containing the target_address in an
	// instruction stream.
	// The only architecture-independent user of this function is the serializer.
	// The serializer uses it to find out how many raw bytes of instruction to
	// output before the next target.
	// For an instruction like LIS/ORI where the target bits are mixed into the
	// instruction bits, the size of the target will be zero, indicating that the
	// serializer should not step forward in memory after a target is resolved
	// and written.
	return reinterpret_cast<Address>(pc_);
	}

	Address RelocInfo::constant_pool_entry_address() {
	UNREACHABLE();
	}

	int RelocInfo::target_address_size() { return Assembler::kSpecialTargetSize; }

	Address Assembler::target_address_from_return_address(Address pc) {
	// Returns the address of the call target from the return address that will
	// be returned to after a call.
	// Sequence is:
	// BRASL r14, RI
	return pc - kCallTargetAddressOffset;
	}

	Address Assembler::return_address_from_call_start(Address pc) {
	// Sequence is:
	// BRASL r14, RI
	return pc + kCallTargetAddressOffset;
	}

	Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
	SixByteInstr instr =
	Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
	int index = instr & 0xFFFFFFFF;
	return code_targets_[index];
	}

	HeapObject* RelocInfo::target_object() {
	DCHECK(IsCodeTarget(rmode_) \|\| rmode_ == EMBEDDED_OBJECT);
	return HeapObject::cast(reinterpret_cast<Object*>(
	Assembler::target_address_at(pc_, constant_pool_)));
	}

	Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
	DCHECK(IsCodeTarget(rmode_) \|\| rmode_ == EMBEDDED_OBJECT);
	if (rmode_ == EMBEDDED_OBJECT) {
	return Handle<HeapObject>(reinterpret_cast<HeapObject**>(
	Assembler::target_address_at(pc_, constant_pool_)));
	} else {
	return Handle<HeapObject>::cast(origin->code_target_object_handle_at(pc_));
	}
	}

	void RelocInfo::set_target_object(HeapObject* target,
	WriteBarrierMode write_barrier_mode,
	ICacheFlushMode icache_flush_mode) {
	DCHECK(IsCodeTarget(rmode_) \|\| rmode_ == EMBEDDED_OBJECT);
	Assembler::set_target_address_at(target->GetIsolate(), pc_, constant_pool_,
	reinterpret_cast<Address>(target),
	icache_flush_mode);
	if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != nullptr) {
	host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
	target);
	host()->GetHeap()->RecordWriteIntoCode(host(), this, target);
	}
	}

	Address RelocInfo::target_external_reference() {
	DCHECK(rmode_ == EXTERNAL_REFERENCE);
	return Assembler::target_address_at(pc_, constant_pool_);
	}

	Address RelocInfo::target_runtime_entry(Assembler* origin) {
	DCHECK(IsRuntimeEntry(rmode_));
	return target_address();
	}

	void RelocInfo::set_target_runtime_entry(Isolate* isolate, Address target,
	WriteBarrierMode write_barrier_mode,
	ICacheFlushMode icache_flush_mode) {
	DCHECK(IsRuntimeEntry(rmode_));
	if (target_address() != target)
	set_target_address(isolate, target, write_barrier_mode, icache_flush_mode);
	}

	void RelocInfo::WipeOut(Isolate* isolate) {
	DCHECK(IsEmbeddedObject(rmode_) \|\| IsCodeTarget(rmode_) \|\|
	IsRuntimeEntry(rmode_) \|\| IsExternalReference(rmode_) \|\|
	IsInternalReference(rmode_) \|\| IsInternalReferenceEncoded(rmode_));
	if (IsInternalReference(rmode_)) {
	// Jump table entry
	Memory::Address_at(pc_) = nullptr;
	} else if (IsInternalReferenceEncoded(rmode_)) {
	// mov sequence
	// Currently used only by deserializer, no need to flush.
	Assembler::set_target_address_at(isolate, pc_, constant_pool_, nullptr,
	SKIP_ICACHE_FLUSH);
	} else {
	Assembler::set_target_address_at(isolate, pc_, constant_pool_, nullptr);
	}
	}

	template <typename ObjectVisitor>
	void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
	RelocInfo::Mode mode = rmode();
	if (mode == RelocInfo::EMBEDDED_OBJECT) {
	visitor->VisitEmbeddedPointer(host(), this);
	} else if (RelocInfo::IsCodeTarget(mode)) {
	visitor->VisitCodeTarget(host(), this);
	} else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
	visitor->VisitExternalReference(host(), this);
	} else if (mode == RelocInfo::INTERNAL_REFERENCE) {
	visitor->VisitInternalReference(host(), this);
	} else if (IsRuntimeEntry(mode)) {
	visitor->VisitRuntimeEntry(host(), this);
	}
	}

	// Operand constructors
	Operand::Operand(Register rm) : rm_(rm), rmode_(kRelocInfo_NONEPTR) {}

	int32_t Assembler::emit_code_target(Handle<Code> target,
	RelocInfo::Mode rmode) {
	DCHECK(RelocInfo::IsCodeTarget(rmode));
	RecordRelocInfo(rmode);

	size_t current = code_targets_.size();
	if (current > 0 && !target.is_null() &&
	code_targets_.back().address() == target.address()) {
	// Optimization if we keep jumping to the same code target.
	current--;
	} else {
	code_targets_.push_back(target);
	}
	return current;
	}


	// Fetch the 32bit value from the FIXED_SEQUENCE IIHF / IILF
	Address Assembler::target_address_at(Address pc, Address constant_pool) {
	// S390 Instruction!
	// We want to check for instructions generated by Asm::mov()
	Opcode op1 = Instruction::S390OpcodeValue(reinterpret_cast<const byte*>(pc));
	SixByteInstr instr_1 =
	Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));

	if (BRASL == op1 \|\| BRCL == op1) {
	int32_t dis = static_cast<int32_t>(instr_1 & 0xFFFFFFFF) * 2;
	return reinterpret_cast<Address>(reinterpret_cast<uint64_t>(pc) + dis);
	}

	#if V8_TARGET_ARCH_S390X
	int instr1_length =
	Instruction::InstructionLength(reinterpret_cast<const byte*>(pc));
	Opcode op2 = Instruction::S390OpcodeValue(
	reinterpret_cast<const byte*>(pc + instr1_length));
	SixByteInstr instr_2 = Instruction::InstructionBits(
	reinterpret_cast<const byte*>(pc + instr1_length));
	// IIHF for hi_32, IILF for lo_32
	if (IIHF == op1 && IILF == op2) {
	return reinterpret_cast<Address>(((instr_1 & 0xFFFFFFFF) << 32) \|
	((instr_2 & 0xFFFFFFFF)));
	}
	#else
	// IILF loads 32-bits
	if (IILF == op1 \|\| CFI == op1) {
	return reinterpret_cast<Address>((instr_1 & 0xFFFFFFFF));
	}
	#endif

	UNIMPLEMENTED();
	return (Address)0;
	}

	// This sets the branch destination (which gets loaded at the call address).
	// This is for calls and branches within generated code. The serializer
	// has already deserialized the mov instructions etc.
	// There is a FIXED_SEQUENCE assumption here
	void Assembler::deserialization_set_special_target_at(
	Isolate* isolate, Address instruction_payload, Code* code, Address target) {
	set_target_address_at(isolate, instruction_payload,
	code ? code->constant_pool() : nullptr, target);
	}

	void Assembler::deserialization_set_target_internal_reference_at(
	Isolate* isolate, Address pc, Address target, RelocInfo::Mode mode) {
	if (RelocInfo::IsInternalReferenceEncoded(mode)) {
	set_target_address_at(isolate, pc, nullptr, target, SKIP_ICACHE_FLUSH);
	} else {
	Memory::Address_at(pc) = target;
	}
	}

	// This code assumes the FIXED_SEQUENCE of IIHF/IILF
	void Assembler::set_target_address_at(Isolate* isolate, Address pc,
	Address constant_pool, Address target,
	ICacheFlushMode icache_flush_mode) {
	DCHECK_IMPLIES(isolate == nullptr, icache_flush_mode == SKIP_ICACHE_FLUSH);

	// Check for instructions generated by Asm::mov()
	Opcode op1 = Instruction::S390OpcodeValue(reinterpret_cast<const byte*>(pc));
	SixByteInstr instr_1 =
	Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
	bool patched = false;

	if (BRASL == op1 \|\| BRCL == op1) {
	instr_1 >>= 32; // Zero out the lower 32-bits
	instr_1 <<= 32;
	int32_t halfwords = (target - pc) / 2; // number of halfwords
	instr_1 \|= static_cast<uint32_t>(halfwords);
	Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
	instr_1);
	if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
	Assembler::FlushICache(isolate, pc, 6);
	}
	patched = true;
	} else {
	#if V8_TARGET_ARCH_S390X
	int instr1_length =
	Instruction::InstructionLength(reinterpret_cast<const byte*>(pc));
	Opcode op2 = Instruction::S390OpcodeValue(
	reinterpret_cast<const byte*>(pc + instr1_length));
	SixByteInstr instr_2 = Instruction::InstructionBits(
	reinterpret_cast<const byte*>(pc + instr1_length));
	// IIHF for hi_32, IILF for lo_32
	if (IIHF == op1 && IILF == op2) {
	// IIHF
	instr_1 >>= 32; // Zero out the lower 32-bits
	instr_1 <<= 32;
	instr_1 \|= reinterpret_cast<uint64_t>(target) >> 32;

	Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
	instr_1);

	// IILF
	instr_2 >>= 32;
	instr_2 <<= 32;
	instr_2 \|= reinterpret_cast<uint64_t>(target) & 0xFFFFFFFF;

	Instruction::SetInstructionBits<SixByteInstr>(
	reinterpret_cast<byte*>(pc + instr1_length), instr_2);
	if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
	Assembler::FlushICache(isolate, pc, 12);
	}
	patched = true;
	}
	#else
	// IILF loads 32-bits
	if (IILF == op1 \|\| CFI == op1) {
	instr_1 >>= 32; // Zero out the lower 32-bits
	instr_1 <<= 32;
	instr_1 \|= reinterpret_cast<uint32_t>(target);

	Instruction::SetInstructionBits<SixByteInstr>(reinterpret_cast<byte*>(pc),
	instr_1);
	if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
	Assembler::FlushICache(isolate, pc, 6);
	}
	patched = true;
	}
	#endif
	}
	if (!patched) UNREACHABLE();
	}

	} // namespace internal
	} // namespace v8

	#endif // V8_S390_ASSEMBLER_S390_INL_H_