| Index: src/a64/codegen-a64.cc
|
| diff --git a/src/a64/codegen-a64.cc b/src/a64/codegen-a64.cc
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..7ce1bfae09e960f9ff807bda3c46d2ca5f0adbdf
|
| --- /dev/null
|
| +++ b/src/a64/codegen-a64.cc
|
| @@ -0,0 +1,614 @@
|
| +// Copyright 2013 the V8 project authors. 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.
|
| +// * Redistributions 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 Google Inc. nor the names of its
|
| +// 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.
|
| +
|
| +#include "v8.h"
|
| +
|
| +#if V8_TARGET_ARCH_A64
|
| +
|
| +#include "codegen.h"
|
| +#include "macro-assembler.h"
|
| +#include "simulator-a64.h"
|
| +
|
| +namespace v8 {
|
| +namespace internal {
|
| +
|
| +#define __ ACCESS_MASM(masm)
|
| +
|
| +#if defined(USE_SIMULATOR)
|
| +byte* fast_exp_a64_machine_code = NULL;
|
| +double fast_exp_simulator(double x) {
|
| + Simulator * simulator = Simulator::current(Isolate::Current());
|
| + return simulator->CallDouble(fast_exp_a64_machine_code,
|
| + Simulator::CallArgument(x),
|
| + Simulator::CallArgument::End());
|
| +}
|
| +#endif
|
| +
|
| +
|
| +UnaryMathFunction CreateExpFunction() {
|
| + if (!FLAG_fast_math) return &std::exp;
|
| +
|
| + // Use the Math.exp implemetation in MathExpGenerator::EmitMathExp() to create
|
| + // an AAPCS64-compliant exp() function. This will be faster than the C
|
| + // library's exp() function, but probably less accurate.
|
| + size_t actual_size;
|
| + byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
|
| + if (buffer == NULL) return &std::exp;
|
| +
|
| + ExternalReference::InitializeMathExpData();
|
| + MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
|
| + masm.SetStackPointer(csp);
|
| +
|
| + // The argument will be in d0 on entry.
|
| + DoubleRegister input = d0;
|
| + // Use other caller-saved registers for all other values.
|
| + DoubleRegister result = d1;
|
| + DoubleRegister double_temp1 = d2;
|
| + DoubleRegister double_temp2 = d3;
|
| + Register temp1 = x10;
|
| + Register temp2 = x11;
|
| + Register temp3 = x12;
|
| +
|
| + MathExpGenerator::EmitMathExp(&masm, input, result,
|
| + double_temp1, double_temp2,
|
| + temp1, temp2, temp3);
|
| + // Move the result to the return register.
|
| + masm.Fmov(d0, result);
|
| + masm.Ret();
|
| +
|
| + CodeDesc desc;
|
| + masm.GetCode(&desc);
|
| + ASSERT(!RelocInfo::RequiresRelocation(desc));
|
| +
|
| + CPU::FlushICache(buffer, actual_size);
|
| + OS::ProtectCode(buffer, actual_size);
|
| +
|
| +#if !defined(USE_SIMULATOR)
|
| + return FUNCTION_CAST<UnaryMathFunction>(buffer);
|
| +#else
|
| + fast_exp_a64_machine_code = buffer;
|
| + return &fast_exp_simulator;
|
| +#endif
|
| +}
|
| +
|
| +
|
| +UnaryMathFunction CreateSqrtFunction() {
|
| + return &std::sqrt;
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------------
|
| +// Platform-specific RuntimeCallHelper functions.
|
| +
|
| +void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
|
| + masm->EnterFrame(StackFrame::INTERNAL);
|
| + ASSERT(!masm->has_frame());
|
| + masm->set_has_frame(true);
|
| +}
|
| +
|
| +
|
| +void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
|
| + masm->LeaveFrame(StackFrame::INTERNAL);
|
| + ASSERT(masm->has_frame());
|
| + masm->set_has_frame(false);
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------------
|
| +// Code generators
|
| +
|
| +void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
|
| + MacroAssembler* masm, AllocationSiteMode mode,
|
| + Label* allocation_memento_found) {
|
| + // ----------- S t a t e -------------
|
| + // -- x2 : receiver
|
| + // -- x3 : target map
|
| + // -----------------------------------
|
| + Register receiver = x2;
|
| + Register map = x3;
|
| +
|
| + if (mode == TRACK_ALLOCATION_SITE) {
|
| + ASSERT(allocation_memento_found != NULL);
|
| + __ JumpIfJSArrayHasAllocationMemento(receiver, x10, x11,
|
| + allocation_memento_found);
|
| + }
|
| +
|
| + // Set transitioned map.
|
| + __ Str(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
|
| + __ RecordWriteField(receiver,
|
| + HeapObject::kMapOffset,
|
| + map,
|
| + x10,
|
| + kLRHasNotBeenSaved,
|
| + kDontSaveFPRegs,
|
| + EMIT_REMEMBERED_SET,
|
| + OMIT_SMI_CHECK);
|
| +}
|
| +
|
| +
|
| +void ElementsTransitionGenerator::GenerateSmiToDouble(
|
| + MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
|
| + ASM_LOCATION("ElementsTransitionGenerator::GenerateSmiToDouble");
|
| + // ----------- S t a t e -------------
|
| + // -- lr : return address
|
| + // -- x0 : value
|
| + // -- x1 : key
|
| + // -- x2 : receiver
|
| + // -- x3 : target map, scratch for subsequent call
|
| + // -----------------------------------
|
| + Register receiver = x2;
|
| + Register target_map = x3;
|
| +
|
| + Label gc_required, only_change_map;
|
| +
|
| + if (mode == TRACK_ALLOCATION_SITE) {
|
| + __ JumpIfJSArrayHasAllocationMemento(receiver, x10, x11, fail);
|
| + }
|
| +
|
| + // Check for empty arrays, which only require a map transition and no changes
|
| + // to the backing store.
|
| + Register elements = x4;
|
| + __ Ldr(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
|
| + __ JumpIfRoot(elements, Heap::kEmptyFixedArrayRootIndex, &only_change_map);
|
| +
|
| + __ Push(lr);
|
| + Register length = x5;
|
| + __ Ldrsw(length, UntagSmiFieldMemOperand(elements,
|
| + FixedArray::kLengthOffset));
|
| +
|
| + // Allocate new FixedDoubleArray.
|
| + Register array_size = x6;
|
| + Register array = x7;
|
| + __ Lsl(array_size, length, kDoubleSizeLog2);
|
| + __ Add(array_size, array_size, FixedDoubleArray::kHeaderSize);
|
| + __ Allocate(array_size, array, x10, x11, &gc_required, DOUBLE_ALIGNMENT);
|
| + // Register array is non-tagged heap object.
|
| +
|
| + // Set the destination FixedDoubleArray's length and map.
|
| + Register map_root = x6;
|
| + __ LoadRoot(map_root, Heap::kFixedDoubleArrayMapRootIndex);
|
| + __ SmiTag(x11, length);
|
| + __ Str(x11, MemOperand(array, FixedDoubleArray::kLengthOffset));
|
| + __ Str(map_root, MemOperand(array, HeapObject::kMapOffset));
|
| +
|
| + __ Str(target_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
|
| + __ RecordWriteField(receiver, HeapObject::kMapOffset, target_map, x6,
|
| + kLRHasBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
|
| + OMIT_SMI_CHECK);
|
| +
|
| + // Replace receiver's backing store with newly created FixedDoubleArray.
|
| + __ Add(x10, array, kHeapObjectTag);
|
| + __ Str(x10, FieldMemOperand(receiver, JSObject::kElementsOffset));
|
| + __ RecordWriteField(receiver, JSObject::kElementsOffset, x10,
|
| + x6, kLRHasBeenSaved, kDontSaveFPRegs,
|
| + EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
|
| +
|
| + // Prepare for conversion loop.
|
| + Register src_elements = x10;
|
| + Register dst_elements = x11;
|
| + Register dst_end = x12;
|
| + __ Add(src_elements, elements, FixedArray::kHeaderSize - kHeapObjectTag);
|
| + __ Add(dst_elements, array, FixedDoubleArray::kHeaderSize);
|
| + __ Add(dst_end, dst_elements, Operand(length, LSL, kDoubleSizeLog2));
|
| +
|
| + FPRegister nan_d = d1;
|
| + __ Fmov(nan_d, rawbits_to_double(kHoleNanInt64));
|
| +
|
| + Label entry, done;
|
| + __ B(&entry);
|
| +
|
| + __ Bind(&only_change_map);
|
| + __ Str(target_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
|
| + __ RecordWriteField(receiver, HeapObject::kMapOffset, target_map, x6,
|
| + kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
|
| + OMIT_SMI_CHECK);
|
| + __ B(&done);
|
| +
|
| + // Call into runtime if GC is required.
|
| + __ Bind(&gc_required);
|
| + __ Pop(lr);
|
| + __ B(fail);
|
| +
|
| + // Iterate over the array, copying and coverting smis to doubles. If an
|
| + // element is non-smi, write a hole to the destination.
|
| + {
|
| + Label loop;
|
| + __ Bind(&loop);
|
| + __ Ldr(x13, MemOperand(src_elements, kPointerSize, PostIndex));
|
| + __ SmiUntagToDouble(d0, x13, kSpeculativeUntag);
|
| + __ Tst(x13, kSmiTagMask);
|
| + __ Fcsel(d0, d0, nan_d, eq);
|
| + __ Str(d0, MemOperand(dst_elements, kDoubleSize, PostIndex));
|
| +
|
| + __ Bind(&entry);
|
| + __ Cmp(dst_elements, dst_end);
|
| + __ B(lt, &loop);
|
| + }
|
| +
|
| + __ Pop(lr);
|
| + __ Bind(&done);
|
| +}
|
| +
|
| +
|
| +void ElementsTransitionGenerator::GenerateDoubleToObject(
|
| + MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
|
| + ASM_LOCATION("ElementsTransitionGenerator::GenerateDoubleToObject");
|
| + // ----------- S t a t e -------------
|
| + // -- x0 : value
|
| + // -- x1 : key
|
| + // -- x2 : receiver
|
| + // -- lr : return address
|
| + // -- x3 : target map, scratch for subsequent call
|
| + // -- x4 : scratch (elements)
|
| + // -----------------------------------
|
| + Register value = x0;
|
| + Register key = x1;
|
| + Register receiver = x2;
|
| + Register target_map = x3;
|
| +
|
| + if (mode == TRACK_ALLOCATION_SITE) {
|
| + __ JumpIfJSArrayHasAllocationMemento(receiver, x10, x11, fail);
|
| + }
|
| +
|
| + // Check for empty arrays, which only require a map transition and no changes
|
| + // to the backing store.
|
| + Label only_change_map;
|
| + Register elements = x4;
|
| + __ Ldr(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
|
| + __ JumpIfRoot(elements, Heap::kEmptyFixedArrayRootIndex, &only_change_map);
|
| +
|
| + __ Push(lr);
|
| + // TODO(all): These registers may not need to be pushed. Examine
|
| + // RecordWriteStub and check whether it's needed.
|
| + __ Push(target_map, receiver, key, value);
|
| + Register length = x5;
|
| + __ Ldrsw(length, UntagSmiFieldMemOperand(elements,
|
| + FixedArray::kLengthOffset));
|
| +
|
| + // Allocate new FixedArray.
|
| + Register array_size = x6;
|
| + Register array = x7;
|
| + Label gc_required;
|
| + __ Mov(array_size, FixedDoubleArray::kHeaderSize);
|
| + __ Add(array_size, array_size, Operand(length, LSL, kPointerSizeLog2));
|
| + __ Allocate(array_size, array, x10, x11, &gc_required, NO_ALLOCATION_FLAGS);
|
| +
|
| + // Set destination FixedDoubleArray's length and map.
|
| + Register map_root = x6;
|
| + __ LoadRoot(map_root, Heap::kFixedArrayMapRootIndex);
|
| + __ SmiTag(x11, length);
|
| + __ Str(x11, MemOperand(array, FixedDoubleArray::kLengthOffset));
|
| + __ Str(map_root, MemOperand(array, HeapObject::kMapOffset));
|
| +
|
| + // Prepare for conversion loop.
|
| + Register src_elements = x10;
|
| + Register dst_elements = x11;
|
| + Register dst_end = x12;
|
| + __ Add(src_elements, elements,
|
| + FixedDoubleArray::kHeaderSize - kHeapObjectTag);
|
| + __ Add(dst_elements, array, FixedArray::kHeaderSize);
|
| + __ Add(array, array, kHeapObjectTag);
|
| + __ Add(dst_end, dst_elements, Operand(length, LSL, kPointerSizeLog2));
|
| +
|
| + Register the_hole = x14;
|
| + Register heap_num_map = x15;
|
| + __ LoadRoot(the_hole, Heap::kTheHoleValueRootIndex);
|
| + __ LoadRoot(heap_num_map, Heap::kHeapNumberMapRootIndex);
|
| +
|
| + Label entry;
|
| + __ B(&entry);
|
| +
|
| + // Call into runtime if GC is required.
|
| + __ Bind(&gc_required);
|
| + __ Pop(value, key, receiver, target_map);
|
| + __ Pop(lr);
|
| + __ B(fail);
|
| +
|
| + {
|
| + Label loop, convert_hole;
|
| + __ Bind(&loop);
|
| + __ Ldr(x13, MemOperand(src_elements, kPointerSize, PostIndex));
|
| + __ Cmp(x13, kHoleNanInt64);
|
| + __ B(eq, &convert_hole);
|
| +
|
| + // Non-hole double, copy value into a heap number.
|
| + Register heap_num = x5;
|
| + __ AllocateHeapNumber(heap_num, &gc_required, x6, x4, heap_num_map);
|
| + __ Str(x13, FieldMemOperand(heap_num, HeapNumber::kValueOffset));
|
| + __ Mov(x13, dst_elements);
|
| + __ Str(heap_num, MemOperand(dst_elements, kPointerSize, PostIndex));
|
| + __ RecordWrite(array, x13, heap_num, kLRHasBeenSaved, kDontSaveFPRegs,
|
| + EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
|
| +
|
| + __ B(&entry);
|
| +
|
| + // Replace the-hole NaN with the-hole pointer.
|
| + __ Bind(&convert_hole);
|
| + __ Str(the_hole, MemOperand(dst_elements, kPointerSize, PostIndex));
|
| +
|
| + __ Bind(&entry);
|
| + __ Cmp(dst_elements, dst_end);
|
| + __ B(lt, &loop);
|
| + }
|
| +
|
| + __ Pop(value, key, receiver, target_map);
|
| + // Replace receiver's backing store with newly created and filled FixedArray.
|
| + __ Str(array, FieldMemOperand(receiver, JSObject::kElementsOffset));
|
| + __ RecordWriteField(receiver, JSObject::kElementsOffset, array, x13,
|
| + kLRHasBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
|
| + OMIT_SMI_CHECK);
|
| + __ Pop(lr);
|
| +
|
| + __ Bind(&only_change_map);
|
| + __ Str(target_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
|
| + __ RecordWriteField(receiver, HeapObject::kMapOffset, target_map, x13,
|
| + kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
|
| + OMIT_SMI_CHECK);
|
| +}
|
| +
|
| +
|
| +bool Code::IsYoungSequence(byte* sequence) {
|
| + return MacroAssembler::IsYoungSequence(sequence);
|
| +}
|
| +
|
| +
|
| +void Code::GetCodeAgeAndParity(byte* sequence, Age* age,
|
| + MarkingParity* parity) {
|
| + if (IsYoungSequence(sequence)) {
|
| + *age = kNoAgeCodeAge;
|
| + *parity = NO_MARKING_PARITY;
|
| + } else {
|
| + byte* target = sequence + kCodeAgeStubEntryOffset;
|
| + Code* stub = GetCodeFromTargetAddress(Memory::Address_at(target));
|
| + GetCodeAgeAndParity(stub, age, parity);
|
| + }
|
| +}
|
| +
|
| +
|
| +void Code::PatchPlatformCodeAge(Isolate* isolate,
|
| + byte* sequence,
|
| + Code::Age age,
|
| + MarkingParity parity) {
|
| + PatchingAssembler patcher(sequence, kCodeAgeSequenceSize / kInstructionSize);
|
| + if (age == kNoAgeCodeAge) {
|
| + MacroAssembler::EmitFrameSetupForCodeAgePatching(&patcher);
|
| + } else {
|
| + Code * stub = GetCodeAgeStub(isolate, age, parity);
|
| + MacroAssembler::EmitCodeAgeSequence(&patcher, stub);
|
| + }
|
| +}
|
| +
|
| +
|
| +void StringCharLoadGenerator::Generate(MacroAssembler* masm,
|
| + Register string,
|
| + Register index,
|
| + Register result,
|
| + Label* call_runtime) {
|
| + // Fetch the instance type of the receiver into result register.
|
| + __ Ldr(result, FieldMemOperand(string, HeapObject::kMapOffset));
|
| + __ Ldrb(result, FieldMemOperand(result, Map::kInstanceTypeOffset));
|
| +
|
| + // We need special handling for indirect strings.
|
| + Label check_sequential;
|
| + __ TestAndBranchIfAllClear(result, kIsIndirectStringMask, &check_sequential);
|
| +
|
| + // Dispatch on the indirect string shape: slice or cons.
|
| + Label cons_string;
|
| + __ TestAndBranchIfAllClear(result, kSlicedNotConsMask, &cons_string);
|
| +
|
| + // Handle slices.
|
| + Label indirect_string_loaded;
|
| + __ Ldrsw(result,
|
| + UntagSmiFieldMemOperand(string, SlicedString::kOffsetOffset));
|
| + __ Ldr(string, FieldMemOperand(string, SlicedString::kParentOffset));
|
| + __ Add(index, index, result);
|
| + __ B(&indirect_string_loaded);
|
| +
|
| + // Handle cons strings.
|
| + // Check whether the right hand side is the empty string (i.e. if
|
| + // this is really a flat string in a cons string). If that is not
|
| + // the case we would rather go to the runtime system now to flatten
|
| + // the string.
|
| + __ Bind(&cons_string);
|
| + __ Ldr(result, FieldMemOperand(string, ConsString::kSecondOffset));
|
| + __ JumpIfNotRoot(result, Heap::kempty_stringRootIndex, call_runtime);
|
| + // Get the first of the two strings and load its instance type.
|
| + __ Ldr(string, FieldMemOperand(string, ConsString::kFirstOffset));
|
| +
|
| + __ Bind(&indirect_string_loaded);
|
| + __ Ldr(result, FieldMemOperand(string, HeapObject::kMapOffset));
|
| + __ Ldrb(result, FieldMemOperand(result, Map::kInstanceTypeOffset));
|
| +
|
| + // Distinguish sequential and external strings. Only these two string
|
| + // representations can reach here (slices and flat cons strings have been
|
| + // reduced to the underlying sequential or external string).
|
| + Label external_string, check_encoding;
|
| + __ Bind(&check_sequential);
|
| + STATIC_ASSERT(kSeqStringTag == 0);
|
| + __ TestAndBranchIfAnySet(result, kStringRepresentationMask, &external_string);
|
| +
|
| + // Prepare sequential strings
|
| + STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
|
| + __ Add(string, string, SeqTwoByteString::kHeaderSize - kHeapObjectTag);
|
| + __ B(&check_encoding);
|
| +
|
| + // Handle external strings.
|
| + __ Bind(&external_string);
|
| + if (FLAG_debug_code) {
|
| + // Assert that we do not have a cons or slice (indirect strings) here.
|
| + // Sequential strings have already been ruled out.
|
| + __ Tst(result, kIsIndirectStringMask);
|
| + __ Assert(eq, kExternalStringExpectedButNotFound);
|
| + }
|
| + // Rule out short external strings.
|
| + STATIC_CHECK(kShortExternalStringTag != 0);
|
| + // TestAndBranchIfAnySet can emit Tbnz. Do not use it because call_runtime
|
| + // can be bound far away in deferred code.
|
| + __ Tst(result, kShortExternalStringMask);
|
| + __ B(ne, call_runtime);
|
| + __ Ldr(string, FieldMemOperand(string, ExternalString::kResourceDataOffset));
|
| +
|
| + Label ascii, done;
|
| + __ Bind(&check_encoding);
|
| + STATIC_ASSERT(kTwoByteStringTag == 0);
|
| + __ TestAndBranchIfAnySet(result, kStringEncodingMask, &ascii);
|
| + // Two-byte string.
|
| + __ Ldrh(result, MemOperand(string, index, LSL, 1));
|
| + __ B(&done);
|
| + __ Bind(&ascii);
|
| + // Ascii string.
|
| + __ Ldrb(result, MemOperand(string, index));
|
| + __ Bind(&done);
|
| +}
|
| +
|
| +
|
| +static MemOperand ExpConstant(Register base, int index) {
|
| + return MemOperand(base, index * kDoubleSize);
|
| +}
|
| +
|
| +
|
| +void MathExpGenerator::EmitMathExp(MacroAssembler* masm,
|
| + DoubleRegister input,
|
| + DoubleRegister result,
|
| + DoubleRegister double_temp1,
|
| + DoubleRegister double_temp2,
|
| + Register temp1,
|
| + Register temp2,
|
| + Register temp3) {
|
| + // TODO(jbramley): There are several instances where fnmsub could be used
|
| + // instead of fmul and fsub. Doing this changes the result, but since this is
|
| + // an estimation anyway, does it matter?
|
| +
|
| + ASSERT(!AreAliased(input, result,
|
| + double_temp1, double_temp2,
|
| + temp1, temp2, temp3));
|
| + ASSERT(ExternalReference::math_exp_constants(0).address() != NULL);
|
| +
|
| + Label done;
|
| + DoubleRegister double_temp3 = result;
|
| + Register constants = temp3;
|
| +
|
| + // The algorithm used relies on some magic constants which are initialized in
|
| + // ExternalReference::InitializeMathExpData().
|
| +
|
| + // Load the address of the start of the array.
|
| + __ Mov(constants, Operand(ExternalReference::math_exp_constants(0)));
|
| +
|
| + // We have to do a four-way split here:
|
| + // - If input <= about -708.4, the output always rounds to zero.
|
| + // - If input >= about 709.8, the output always rounds to +infinity.
|
| + // - If the input is NaN, the output is NaN.
|
| + // - Otherwise, the result needs to be calculated.
|
| + Label result_is_finite_non_zero;
|
| + // Assert that we can load offset 0 (the small input threshold) and offset 1
|
| + // (the large input threshold) with a single ldp.
|
| + ASSERT(kDRegSizeInBytes == (ExpConstant(constants, 1).offset() -
|
| + ExpConstant(constants, 0).offset()));
|
| + __ Ldp(double_temp1, double_temp2, ExpConstant(constants, 0));
|
| +
|
| + __ Fcmp(input, double_temp1);
|
| + __ Fccmp(input, double_temp2, NoFlag, hi);
|
| + // At this point, the condition flags can be in one of five states:
|
| + // NZCV
|
| + // 1000 -708.4 < input < 709.8 result = exp(input)
|
| + // 0110 input == 709.8 result = +infinity
|
| + // 0010 input > 709.8 result = +infinity
|
| + // 0011 input is NaN result = input
|
| + // 0000 input <= -708.4 result = +0.0
|
| +
|
| + // Continue the common case first. 'mi' tests N == 1.
|
| + __ B(&result_is_finite_non_zero, mi);
|
| +
|
| + // TODO(jbramley): Add (and use) a zero D register for A64.
|
| + // TODO(jbramley): Consider adding a +infinity register for A64.
|
| + __ Ldr(double_temp2, ExpConstant(constants, 2)); // Synthesize +infinity.
|
| + __ Fsub(double_temp1, double_temp1, double_temp1); // Synthesize +0.0.
|
| +
|
| + // Select between +0.0 and +infinity. 'lo' tests C == 0.
|
| + __ Fcsel(result, double_temp1, double_temp2, lo);
|
| + // Select between {+0.0 or +infinity} and input. 'vc' tests V == 0.
|
| + __ Fcsel(result, result, input, vc);
|
| + __ B(&done);
|
| +
|
| + // The rest is magic, as described in InitializeMathExpData().
|
| + __ Bind(&result_is_finite_non_zero);
|
| +
|
| + // Assert that we can load offset 3 and offset 4 with a single ldp.
|
| + ASSERT(kDRegSizeInBytes == (ExpConstant(constants, 4).offset() -
|
| + ExpConstant(constants, 3).offset()));
|
| + __ Ldp(double_temp1, double_temp3, ExpConstant(constants, 3));
|
| + __ Fmadd(double_temp1, double_temp1, input, double_temp3);
|
| + __ Fmov(temp2.W(), double_temp1.S());
|
| + __ Fsub(double_temp1, double_temp1, double_temp3);
|
| +
|
| + // Assert that we can load offset 5 and offset 6 with a single ldp.
|
| + ASSERT(kDRegSizeInBytes == (ExpConstant(constants, 6).offset() -
|
| + ExpConstant(constants, 5).offset()));
|
| + __ Ldp(double_temp2, double_temp3, ExpConstant(constants, 5));
|
| + // TODO(jbramley): Consider using Fnmsub here.
|
| + __ Fmul(double_temp1, double_temp1, double_temp2);
|
| + __ Fsub(double_temp1, double_temp1, input);
|
| +
|
| + __ Fmul(double_temp2, double_temp1, double_temp1);
|
| + __ Fsub(double_temp3, double_temp3, double_temp1);
|
| + __ Fmul(double_temp3, double_temp3, double_temp2);
|
| +
|
| + __ Mov(temp1.W(), Operand(temp2.W(), LSR, 11));
|
| +
|
| + __ Ldr(double_temp2, ExpConstant(constants, 7));
|
| + // TODO(jbramley): Consider using Fnmsub here.
|
| + __ Fmul(double_temp3, double_temp3, double_temp2);
|
| + __ Fsub(double_temp3, double_temp3, double_temp1);
|
| +
|
| + // The 8th constant is 1.0, so use an immediate move rather than a load.
|
| + // We can't generate a runtime assertion here as we would need to call Abort
|
| + // in the runtime and we don't have an Isolate when we generate this code.
|
| + __ Fmov(double_temp2, 1.0);
|
| + __ Fadd(double_temp3, double_temp3, double_temp2);
|
| +
|
| + __ And(temp2, temp2, 0x7ff);
|
| + __ Add(temp1, temp1, 0x3ff);
|
| +
|
| + // Do the final table lookup.
|
| + __ Mov(temp3, Operand(ExternalReference::math_exp_log_table()));
|
| +
|
| + __ Add(temp3, temp3, Operand(temp2, LSL, kDRegSizeInBytesLog2));
|
| + __ Ldp(temp2.W(), temp3.W(), MemOperand(temp3));
|
| + __ Orr(temp1.W(), temp3.W(), Operand(temp1.W(), LSL, 20));
|
| + __ Bfi(temp2, temp1, 32, 32);
|
| + __ Fmov(double_temp1, temp2);
|
| +
|
| + __ Fmul(result, double_temp3, double_temp1);
|
| +
|
| + __ Bind(&done);
|
| +}
|
| +
|
| +#undef __
|
| +
|
| +} } // namespace v8::internal
|
| +
|
| +#endif // V8_TARGET_ARCH_A64
|
|
|