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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/codegen/assembler-inl.h"
#include "src/codegen/macro-assembler.h"
#include "src/codegen/register-configuration.h"
#include "src/codegen/safepoint-table.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/objects/objects-inl.h"
namespace v8 {
namespace internal {
const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
const int Deoptimizer::kDeoptExitSize = 0;
#define __ masm->
// This code tries to be close to ia32 code so that any changes can be
// easily ported.
void Deoptimizer::GenerateDeoptimizationEntries(MacroAssembler* masm,
Isolate* isolate,
DeoptimizeKind deopt_kind) {
NoRootArrayScope no_root_array(masm);
// Save all general purpose registers before messing with them.
const int kNumberOfRegisters = Register::kNumRegisters;
// Everything but pc, lr and ip which will be saved but not restored.
RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
const int kDoubleRegsSize = kDoubleSize * DwVfpRegister::kNumRegisters;
// Save all allocatable VFP registers before messing with them.
{
// We use a run-time check for VFP32DREGS.
CpuFeatureScope scope(masm, VFP32DREGS,
CpuFeatureScope::kDontCheckSupported);
UseScratchRegisterScope temps(masm);
Register scratch = temps.Acquire();
// Check CPU flags for number of registers, setting the Z condition flag.
__ CheckFor32DRegs(scratch);
// Push registers d0-d15, and possibly d16-d31, on the stack.
// If d16-d31 are not pushed, decrease the stack pointer instead.
__ vstm(db_w, sp, d16, d31, ne);
// Okay to not call AllocateStackSpace here because the size is a known
// small number and we need to use condition codes.
__ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
__ vstm(db_w, sp, d0, d15);
}
// Push all 16 registers (needed to populate FrameDescription::registers_).
// TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
// handle this a bit differently.
__ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
{
UseScratchRegisterScope temps(masm);
Register scratch = temps.Acquire();
__ mov(scratch, Operand(ExternalReference::Create(
IsolateAddressId::kCEntryFPAddress, isolate)));
__ str(fp, MemOperand(scratch));
}
const int kSavedRegistersAreaSize =
(kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
// Get the bailout id is passed as r10 by the caller.
__ mov(r2, r10);
// Get the address of the location in the code object (r3) (return
// address for lazy deoptimization) and compute the fp-to-sp delta in
// register r4.
__ mov(r3, lr);
__ add(r4, sp, Operand(kSavedRegistersAreaSize));
__ sub(r4, fp, r4);
// Allocate a new deoptimizer object.
// Pass four arguments in r0 to r3 and fifth argument on stack.
__ PrepareCallCFunction(6);
__ mov(r0, Operand(0));
Label context_check;
__ ldr(r1, MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
__ JumpIfSmi(r1, &context_check);
__ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
__ bind(&context_check);
__ mov(r1, Operand(static_cast<int>(deopt_kind)));
// r2: bailout id already loaded.
// r3: code address or 0 already loaded.
__ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
__ mov(r5, Operand(ExternalReference::isolate_address(isolate)));
__ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
// Call Deoptimizer::New().
{
AllowExternalCallThatCantCauseGC scope(masm);
__ CallCFunction(ExternalReference::new_deoptimizer_function(), 6);
}
// Preserve "deoptimizer" object in register r0 and get the input
// frame descriptor pointer to r1 (deoptimizer->input_);
__ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
// Copy core registers into FrameDescription::registers_[kNumRegisters].
DCHECK_EQ(Register::kNumRegisters, kNumberOfRegisters);
for (int i = 0; i < kNumberOfRegisters; i++) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
__ ldr(r2, MemOperand(sp, i * kPointerSize));
__ str(r2, MemOperand(r1, offset));
}
// Copy VFP registers to
// double_registers_[DoubleRegister::kNumAllocatableRegisters]
int double_regs_offset = FrameDescription::double_registers_offset();
const RegisterConfiguration* config = RegisterConfiguration::Default();
for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
int code = config->GetAllocatableDoubleCode(i);
int dst_offset = code * kDoubleSize + double_regs_offset;
int src_offset = code * kDoubleSize + kNumberOfRegisters * kPointerSize;
__ vldr(d0, sp, src_offset);
__ vstr(d0, r1, dst_offset);
}
// Remove the saved registers from the stack.
__ add(sp, sp, Operand(kSavedRegistersAreaSize));
// Compute a pointer to the unwinding limit in register r2; that is
// the first stack slot not part of the input frame.
__ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
__ add(r2, r2, sp);
// Unwind the stack down to - but not including - the unwinding
// limit and copy the contents of the activation frame to the input
// frame description.
__ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
Label pop_loop;
Label pop_loop_header;
__ b(&pop_loop_header);
__ bind(&pop_loop);
__ pop(r4);
__ str(r4, MemOperand(r3, 0));
__ add(r3, r3, Operand(sizeof(uint32_t)));
__ bind(&pop_loop_header);
__ cmp(r2, sp);
__ b(ne, &pop_loop);
// Compute the output frame in the deoptimizer.
__ push(r0); // Preserve deoptimizer object across call.
// r0: deoptimizer object; r1: scratch.
__ PrepareCallCFunction(1);
// Call Deoptimizer::ComputeOutputFrames().
{
AllowExternalCallThatCantCauseGC scope(masm);
__ CallCFunction(ExternalReference::compute_output_frames_function(), 1);
}
__ pop(r0); // Restore deoptimizer object (class Deoptimizer).
__ ldr(sp, MemOperand(r0, Deoptimizer::caller_frame_top_offset()));
// Replace the current (input) frame with the output frames.
Label outer_push_loop, inner_push_loop, outer_loop_header, inner_loop_header;
// Outer loop state: r4 = current "FrameDescription** output_",
// r1 = one past the last FrameDescription**.
__ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
__ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
__ add(r1, r4, Operand(r1, LSL, 2));
__ jmp(&outer_loop_header);
__ bind(&outer_push_loop);
// Inner loop state: r2 = current FrameDescription*, r3 = loop index.
__ ldr(r2, MemOperand(r4, 0)); // output_[ix]
__ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
__ jmp(&inner_loop_header);
__ bind(&inner_push_loop);
__ sub(r3, r3, Operand(sizeof(uint32_t)));
__ add(r6, r2, Operand(r3));
__ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
__ push(r6);
__ bind(&inner_loop_header);
__ cmp(r3, Operand::Zero());
__ b(ne, &inner_push_loop); // test for gt?
__ add(r4, r4, Operand(kPointerSize));
__ bind(&outer_loop_header);
__ cmp(r4, r1);
__ b(lt, &outer_push_loop);
__ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
int code = config->GetAllocatableDoubleCode(i);
DwVfpRegister reg = DwVfpRegister::from_code(code);
int src_offset = code * kDoubleSize + double_regs_offset;
__ vldr(reg, r1, src_offset);
}
// Push pc and continuation from the last output frame.
__ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
__ push(r6);
__ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
__ push(r6);
// Push the registers from the last output frame.
for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
__ ldr(r6, MemOperand(r2, offset));
__ push(r6);
}
// Restore the registers from the stack.
__ ldm(ia_w, sp, restored_regs); // all but pc registers.
// Remove sp, lr and pc.
__ Drop(3);
{
UseScratchRegisterScope temps(masm);
Register scratch = temps.Acquire();
__ pop(scratch); // get continuation, leave pc on stack
__ pop(lr);
__ Jump(scratch);
}
__ stop();
}
Float32 RegisterValues::GetFloatRegister(unsigned n) const {
const int kShift = n % 2 == 0 ? 0 : 32;
return Float32::FromBits(
static_cast<uint32_t>(double_registers_[n / 2].get_bits() >> kShift));
}
void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
SetFrameSlot(offset, value);
}
void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
SetFrameSlot(offset, value);
}
void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
// No embedded constant pool support.
UNREACHABLE();
}
#undef __
} // namespace internal
} // namespace v8