| // 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/v8.h" |
| |
| #if V8_TARGET_ARCH_X64 |
| |
| #include "src/codegen.h" |
| #include "src/ic/ic.h" |
| #include "src/ic/stub-cache.h" |
| #include "src/interface-descriptors.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| #define __ ACCESS_MASM(masm) |
| |
| |
| static void ProbeTable(Isolate* isolate, MacroAssembler* masm, |
| Code::Kind ic_kind, Code::Flags flags, bool leave_frame, |
| StubCache::Table table, Register receiver, Register name, |
| // The offset is scaled by 4, based on |
| // kCacheIndexShift, which is two bits |
| Register offset) { |
| // We need to scale up the pointer by 2 when the offset is scaled by less |
| // than the pointer size. |
| DCHECK(kPointerSize == kInt64Size |
| ? kPointerSizeLog2 == StubCache::kCacheIndexShift + 1 |
| : kPointerSizeLog2 == StubCache::kCacheIndexShift); |
| ScaleFactor scale_factor = kPointerSize == kInt64Size ? times_2 : times_1; |
| |
| DCHECK_EQ(3 * kPointerSize, sizeof(StubCache::Entry)); |
| // The offset register holds the entry offset times four (due to masking |
| // and shifting optimizations). |
| ExternalReference key_offset(isolate->stub_cache()->key_reference(table)); |
| ExternalReference value_offset(isolate->stub_cache()->value_reference(table)); |
| Label miss; |
| |
| // Multiply by 3 because there are 3 fields per entry (name, code, map). |
| __ leap(offset, Operand(offset, offset, times_2, 0)); |
| |
| __ LoadAddress(kScratchRegister, key_offset); |
| |
| // Check that the key in the entry matches the name. |
| __ cmpp(name, Operand(kScratchRegister, offset, scale_factor, 0)); |
| __ j(not_equal, &miss); |
| |
| // Get the map entry from the cache. |
| // Use key_offset + kPointerSize * 2, rather than loading map_offset. |
| DCHECK(isolate->stub_cache()->map_reference(table).address() - |
| isolate->stub_cache()->key_reference(table).address() == |
| kPointerSize * 2); |
| __ movp(kScratchRegister, |
| Operand(kScratchRegister, offset, scale_factor, kPointerSize * 2)); |
| __ cmpp(kScratchRegister, FieldOperand(receiver, HeapObject::kMapOffset)); |
| __ j(not_equal, &miss); |
| |
| // Get the code entry from the cache. |
| __ LoadAddress(kScratchRegister, value_offset); |
| __ movp(kScratchRegister, Operand(kScratchRegister, offset, scale_factor, 0)); |
| |
| // Check that the flags match what we're looking for. |
| __ movl(offset, FieldOperand(kScratchRegister, Code::kFlagsOffset)); |
| __ andp(offset, Immediate(~Code::kFlagsNotUsedInLookup)); |
| __ cmpl(offset, Immediate(flags)); |
| __ j(not_equal, &miss); |
| |
| #ifdef DEBUG |
| if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) { |
| __ jmp(&miss); |
| } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) { |
| __ jmp(&miss); |
| } |
| #endif |
| |
| if (leave_frame) __ leave(); |
| |
| // Jump to the first instruction in the code stub. |
| __ addp(kScratchRegister, Immediate(Code::kHeaderSize - kHeapObjectTag)); |
| __ jmp(kScratchRegister); |
| |
| __ bind(&miss); |
| } |
| |
| |
| void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind, |
| Code::Flags flags, bool leave_frame, |
| Register receiver, Register name, |
| Register scratch, Register extra, Register extra2, |
| Register extra3) { |
| Isolate* isolate = masm->isolate(); |
| Label miss; |
| USE(extra); // The register extra is not used on the X64 platform. |
| USE(extra2); // The register extra2 is not used on the X64 platform. |
| USE(extra3); // The register extra2 is not used on the X64 platform. |
| // Make sure that code is valid. The multiplying code relies on the |
| // entry size being 3 * kPointerSize. |
| DCHECK(sizeof(Entry) == 3 * kPointerSize); |
| |
| // Make sure the flags do not name a specific type. |
| DCHECK(Code::ExtractTypeFromFlags(flags) == 0); |
| |
| // Make sure that there are no register conflicts. |
| DCHECK(!scratch.is(receiver)); |
| DCHECK(!scratch.is(name)); |
| |
| // Check scratch register is valid, extra and extra2 are unused. |
| DCHECK(!scratch.is(no_reg)); |
| DCHECK(extra2.is(no_reg)); |
| DCHECK(extra3.is(no_reg)); |
| |
| #ifdef DEBUG |
| // If vector-based ics are in use, ensure that scratch doesn't conflict with |
| // the vector and slot registers, which need to be preserved for a handler |
| // call or miss. |
| if (IC::ICUseVector(ic_kind)) { |
| Register vector = VectorLoadICDescriptor::VectorRegister(); |
| Register slot = VectorLoadICDescriptor::SlotRegister(); |
| DCHECK(!AreAliased(vector, slot, scratch)); |
| } |
| #endif |
| |
| Counters* counters = masm->isolate()->counters(); |
| __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1); |
| |
| // Check that the receiver isn't a smi. |
| __ JumpIfSmi(receiver, &miss); |
| |
| // Get the map of the receiver and compute the hash. |
| __ movl(scratch, FieldOperand(name, Name::kHashFieldOffset)); |
| // Use only the low 32 bits of the map pointer. |
| __ addl(scratch, FieldOperand(receiver, HeapObject::kMapOffset)); |
| __ xorp(scratch, Immediate(flags)); |
| // We mask out the last two bits because they are not part of the hash and |
| // they are always 01 for maps. Also in the two 'and' instructions below. |
| __ andp(scratch, Immediate((kPrimaryTableSize - 1) << kCacheIndexShift)); |
| |
| // Probe the primary table. |
| ProbeTable(isolate, masm, ic_kind, flags, leave_frame, kPrimary, receiver, |
| name, scratch); |
| |
| // Primary miss: Compute hash for secondary probe. |
| __ movl(scratch, FieldOperand(name, Name::kHashFieldOffset)); |
| __ addl(scratch, FieldOperand(receiver, HeapObject::kMapOffset)); |
| __ xorp(scratch, Immediate(flags)); |
| __ andp(scratch, Immediate((kPrimaryTableSize - 1) << kCacheIndexShift)); |
| __ subl(scratch, name); |
| __ addl(scratch, Immediate(flags)); |
| __ andp(scratch, Immediate((kSecondaryTableSize - 1) << kCacheIndexShift)); |
| |
| // Probe the secondary table. |
| ProbeTable(isolate, masm, ic_kind, flags, leave_frame, kSecondary, receiver, |
| name, scratch); |
| |
| // Cache miss: Fall-through and let caller handle the miss by |
| // entering the runtime system. |
| __ bind(&miss); |
| __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1); |
| } |
| |
| |
| #undef __ |
| } |
| } // namespace v8::internal |
| |
| #endif // V8_TARGET_ARCH_X64 |