// Copyright 2014 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/assembler-inl.h" #include "src/codegen.h" #include "src/deoptimizer.h" #include "src/register-configuration.h" #include "src/safepoint-table.h" namespace v8 { namespace internal { const int Deoptimizer::table_entry_size_ = 8; #define __ masm()-> // This code tries to be close to ia32 code so that any changes can be // easily ported. void Deoptimizer::TableEntryGenerator::Generate() { GeneratePrologue(); // Unlike on ARM we don't save all the registers, just the useful ones. // For the rest, there are gaps on the stack, so the offsets remain the same. const int kNumberOfRegisters = Register::kNumRegisters; RegList restored_regs = kJSCallerSaved | kCalleeSaved; RegList saved_regs = restored_regs | sp.bit(); const int kDoubleRegsSize = kDoubleSize * DoubleRegister::kNumRegisters; const int kFloatRegsSize = kFloatSize * FloatRegister::kNumRegisters; // Save all double registers before messing with them. __ subi(sp, sp, Operand(kDoubleRegsSize)); const RegisterConfiguration* config = RegisterConfiguration::Default(); for (int i = 0; i < config->num_allocatable_double_registers(); ++i) { int code = config->GetAllocatableDoubleCode(i); const DoubleRegister dreg = DoubleRegister::from_code(code); int offset = code * kDoubleSize; __ stfd(dreg, MemOperand(sp, offset)); } // Save all float registers before messing with them. __ subi(sp, sp, Operand(kFloatRegsSize)); for (int i = 0; i < config->num_allocatable_float_registers(); ++i) { int code = config->GetAllocatableFloatCode(i); const FloatRegister freg = FloatRegister::from_code(code); int offset = code * kFloatSize; __ stfs(freg, MemOperand(sp, offset)); } // Push saved_regs (needed to populate FrameDescription::registers_). // Leave gaps for other registers. __ subi(sp, sp, Operand(kNumberOfRegisters * kPointerSize)); for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) { if ((saved_regs & (1 << i)) != 0) { __ StoreP(ToRegister(i), MemOperand(sp, kPointerSize * i)); } } __ mov(ip, Operand(ExternalReference(IsolateAddressId::kCEntryFPAddress, isolate()))); __ StoreP(fp, MemOperand(ip)); const int kSavedRegistersAreaSize = (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize + kFloatRegsSize; // Get the bailout id from the stack. __ LoadP(r5, MemOperand(sp, kSavedRegistersAreaSize)); // Get the address of the location in the code object (r6) (return // address for lazy deoptimization) and compute the fp-to-sp delta in // register r7. __ mflr(r6); // Correct one word for bailout id. __ addi(r7, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize))); __ sub(r7, fp, r7); // Allocate a new deoptimizer object. // Pass six arguments in r3 to r8. __ PrepareCallCFunction(6, r8); __ li(r3, Operand::Zero()); Label context_check; __ LoadP(r4, MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset)); __ JumpIfSmi(r4, &context_check); __ LoadP(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset)); __ bind(&context_check); __ li(r4, Operand(type())); // bailout type, // r5: bailout id already loaded. // r6: code address or 0 already loaded. // r7: Fp-to-sp delta. __ mov(r8, Operand(ExternalReference::isolate_address(isolate()))); // Call Deoptimizer::New(). { AllowExternalCallThatCantCauseGC scope(masm()); __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); } // Preserve "deoptimizer" object in register r3 and get the input // frame descriptor pointer to r4 (deoptimizer->input_); __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset())); // Copy core registers into FrameDescription::registers_[kNumRegisters]. DCHECK(Register::kNumRegisters == kNumberOfRegisters); for (int i = 0; i < kNumberOfRegisters; i++) { int offset = (i * kPointerSize) + FrameDescription::registers_offset(); __ LoadP(r5, MemOperand(sp, i * kPointerSize)); __ StoreP(r5, MemOperand(r4, offset)); } int double_regs_offset = FrameDescription::double_registers_offset(); // Copy double registers to // double_registers_[DoubleRegister::kNumRegisters] 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 + kFloatRegsSize; __ lfd(d0, MemOperand(sp, src_offset)); __ stfd(d0, MemOperand(r4, dst_offset)); } int float_regs_offset = FrameDescription::float_registers_offset(); // Copy float registers to // float_registers_[FloatRegister::kNumRegisters] for (int i = 0; i < config->num_allocatable_float_registers(); ++i) { int code = config->GetAllocatableFloatCode(i); int dst_offset = code * kFloatSize + float_regs_offset; int src_offset = code * kFloatSize + kNumberOfRegisters * kPointerSize; __ lfs(d0, MemOperand(sp, src_offset)); __ stfs(d0, MemOperand(r4, dst_offset)); } // Remove the bailout id and the saved registers from the stack. __ addi(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize))); // Compute a pointer to the unwinding limit in register r5; that is // the first stack slot not part of the input frame. __ LoadP(r5, MemOperand(r4, FrameDescription::frame_size_offset())); __ add(r5, r5, 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. __ addi(r6, r4, Operand(FrameDescription::frame_content_offset())); Label pop_loop; Label pop_loop_header; __ b(&pop_loop_header); __ bind(&pop_loop); __ pop(r7); __ StoreP(r7, MemOperand(r6, 0)); __ addi(r6, r6, Operand(kPointerSize)); __ bind(&pop_loop_header); __ cmp(r5, sp); __ bne(&pop_loop); // Compute the output frame in the deoptimizer. __ push(r3); // Preserve deoptimizer object across call. // r3: deoptimizer object; r4: scratch. __ PrepareCallCFunction(1, r4); // Call Deoptimizer::ComputeOutputFrames(). { AllowExternalCallThatCantCauseGC scope(masm()); __ CallCFunction( ExternalReference::compute_output_frames_function(isolate()), 1); } __ pop(r3); // Restore deoptimizer object (class Deoptimizer). __ LoadP(sp, MemOperand(r3, 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: r7 = current "FrameDescription** output_", // r4 = one past the last FrameDescription**. __ lwz(r4, MemOperand(r3, Deoptimizer::output_count_offset())); __ LoadP(r7, MemOperand(r3, Deoptimizer::output_offset())); // r7 is output_. __ ShiftLeftImm(r4, r4, Operand(kPointerSizeLog2)); __ add(r4, r7, r4); __ b(&outer_loop_header); __ bind(&outer_push_loop); // Inner loop state: r5 = current FrameDescription*, r6 = loop index. __ LoadP(r5, MemOperand(r7, 0)); // output_[ix] __ LoadP(r6, MemOperand(r5, FrameDescription::frame_size_offset())); __ b(&inner_loop_header); __ bind(&inner_push_loop); __ addi(r6, r6, Operand(-sizeof(intptr_t))); __ add(r9, r5, r6); __ LoadP(r9, MemOperand(r9, FrameDescription::frame_content_offset())); __ push(r9); __ bind(&inner_loop_header); __ cmpi(r6, Operand::Zero()); __ bne(&inner_push_loop); // test for gt? __ addi(r7, r7, Operand(kPointerSize)); __ bind(&outer_loop_header); __ cmp(r7, r4); __ blt(&outer_push_loop); __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset())); for (int i = 0; i < config->num_allocatable_double_registers(); ++i) { int code = config->GetAllocatableDoubleCode(i); const DoubleRegister dreg = DoubleRegister::from_code(code); int src_offset = code * kDoubleSize + double_regs_offset; __ lfd(dreg, MemOperand(r4, src_offset)); } // Push state, pc, and continuation from the last output frame. __ LoadP(r9, MemOperand(r5, FrameDescription::state_offset())); __ push(r9); __ LoadP(r9, MemOperand(r5, FrameDescription::pc_offset())); __ push(r9); __ LoadP(r9, MemOperand(r5, FrameDescription::continuation_offset())); __ push(r9); // Restore the registers from the last output frame. DCHECK(!(ip.bit() & restored_regs)); __ mr(ip, r5); for (int i = kNumberOfRegisters - 1; i >= 0; i--) { int offset = (i * kPointerSize) + FrameDescription::registers_offset(); if ((restored_regs & (1 << i)) != 0) { __ LoadP(ToRegister(i), MemOperand(ip, offset)); } } __ InitializeRootRegister(); __ pop(ip); // get continuation, leave pc on stack __ pop(r0); __ mtlr(r0); __ Jump(ip); __ stop("Unreachable."); } void Deoptimizer::TableEntryGenerator::GeneratePrologue() { Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm()); // Create a sequence of deoptimization entries. // Note that registers are still live when jumping to an entry. Label done; for (int i = 0; i < count(); i++) { int start = masm()->pc_offset(); USE(start); __ li(ip, Operand(i)); __ b(&done); DCHECK(masm()->pc_offset() - start == table_entry_size_); } __ bind(&done); __ push(ip); } 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) { DCHECK(FLAG_enable_embedded_constant_pool); SetFrameSlot(offset, value); } #undef __ } // namespace internal } // namespace v8