| // 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. |
| |
| #if V8_TARGET_ARCH_ARM |
| |
| #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, |
| StubCache::Table table, Register receiver, Register name, |
| // Number of the cache entry, not scaled. |
| Register offset, Register scratch, Register scratch2, |
| Register offset_scratch) { |
| ExternalReference key_offset(isolate->stub_cache()->key_reference(table)); |
| ExternalReference value_offset(isolate->stub_cache()->value_reference(table)); |
| ExternalReference map_offset(isolate->stub_cache()->map_reference(table)); |
| |
| uint32_t key_off_addr = reinterpret_cast<uint32_t>(key_offset.address()); |
| uint32_t value_off_addr = reinterpret_cast<uint32_t>(value_offset.address()); |
| uint32_t map_off_addr = reinterpret_cast<uint32_t>(map_offset.address()); |
| |
| // Check the relative positions of the address fields. |
| DCHECK(value_off_addr > key_off_addr); |
| DCHECK((value_off_addr - key_off_addr) % 4 == 0); |
| DCHECK((value_off_addr - key_off_addr) < (256 * 4)); |
| DCHECK(map_off_addr > key_off_addr); |
| DCHECK((map_off_addr - key_off_addr) % 4 == 0); |
| DCHECK((map_off_addr - key_off_addr) < (256 * 4)); |
| |
| Label miss; |
| Register base_addr = scratch; |
| scratch = no_reg; |
| |
| // Multiply by 3 because there are 3 fields per entry (name, code, map). |
| __ add(offset_scratch, offset, Operand(offset, LSL, 1)); |
| |
| // Calculate the base address of the entry. |
| __ mov(base_addr, Operand(key_offset)); |
| __ add(base_addr, base_addr, Operand(offset_scratch, LSL, kPointerSizeLog2)); |
| |
| // Check that the key in the entry matches the name. |
| __ ldr(ip, MemOperand(base_addr, 0)); |
| __ cmp(name, ip); |
| __ b(ne, &miss); |
| |
| // Check the map matches. |
| __ ldr(ip, MemOperand(base_addr, map_off_addr - key_off_addr)); |
| __ ldr(scratch2, FieldMemOperand(receiver, HeapObject::kMapOffset)); |
| __ cmp(ip, scratch2); |
| __ b(ne, &miss); |
| |
| // Get the code entry from the cache. |
| Register code = scratch2; |
| scratch2 = no_reg; |
| __ ldr(code, MemOperand(base_addr, value_off_addr - key_off_addr)); |
| |
| // Check that the flags match what we're looking for. |
| Register flags_reg = base_addr; |
| base_addr = no_reg; |
| __ ldr(flags_reg, FieldMemOperand(code, Code::kFlagsOffset)); |
| // It's a nice optimization if this constant is encodable in the bic insn. |
| |
| uint32_t mask = Code::kFlagsNotUsedInLookup; |
| DCHECK(__ ImmediateFitsAddrMode1Instruction(mask)); |
| __ bic(flags_reg, flags_reg, Operand(mask)); |
| __ cmp(flags_reg, Operand(flags)); |
| __ b(ne, &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 |
| |
| // Jump to the first instruction in the code stub. |
| __ add(pc, code, Operand(Code::kHeaderSize - kHeapObjectTag)); |
| |
| // Miss: fall through. |
| __ bind(&miss); |
| } |
| |
| |
| void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind, |
| Code::Flags flags, Register receiver, |
| Register name, Register scratch, Register extra, |
| Register extra2, Register extra3) { |
| Isolate* isolate = masm->isolate(); |
| Label miss; |
| |
| // Make sure that code is valid. The multiplying code relies on the |
| // entry size being 12. |
| DCHECK(sizeof(Entry) == 12); |
| |
| // Make sure the flags does not name a specific type. |
| DCHECK(Code::ExtractTypeFromFlags(flags) == 0); |
| |
| // Make sure that there are no register conflicts. |
| DCHECK(!AreAliased(receiver, name, scratch, extra, extra2, extra3)); |
| |
| // Check scratch, extra and extra2 registers are valid. |
| DCHECK(!scratch.is(no_reg)); |
| DCHECK(!extra.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, extra, extra2 and |
| // extra3 don'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, slot; |
| if (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC) { |
| vector = VectorStoreICDescriptor::VectorRegister(); |
| slot = VectorStoreICDescriptor::SlotRegister(); |
| } else { |
| vector = LoadWithVectorDescriptor::VectorRegister(); |
| slot = LoadWithVectorDescriptor::SlotRegister(); |
| } |
| DCHECK(!AreAliased(vector, slot, scratch, extra, extra2, extra3)); |
| } |
| #endif |
| |
| Counters* counters = masm->isolate()->counters(); |
| __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2, |
| extra3); |
| |
| // Check that the receiver isn't a smi. |
| __ JumpIfSmi(receiver, &miss); |
| |
| // Get the map of the receiver and compute the hash. |
| __ ldr(scratch, FieldMemOperand(name, Name::kHashFieldOffset)); |
| __ ldr(ip, FieldMemOperand(receiver, HeapObject::kMapOffset)); |
| __ add(scratch, scratch, Operand(ip)); |
| uint32_t mask = kPrimaryTableSize - 1; |
| // We shift out the last two bits because they are not part of the hash and |
| // they are always 01 for maps. |
| __ mov(scratch, Operand(scratch, LSR, kCacheIndexShift)); |
| // Mask down the eor argument to the minimum to keep the immediate |
| // ARM-encodable. |
| __ eor(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask)); |
| // Prefer and_ to ubfx here because ubfx takes 2 cycles. |
| __ and_(scratch, scratch, Operand(mask)); |
| |
| // Probe the primary table. |
| ProbeTable(isolate, masm, ic_kind, flags, kPrimary, receiver, name, scratch, |
| extra, extra2, extra3); |
| |
| // Primary miss: Compute hash for secondary probe. |
| __ sub(scratch, scratch, Operand(name, LSR, kCacheIndexShift)); |
| uint32_t mask2 = kSecondaryTableSize - 1; |
| __ add(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask2)); |
| __ and_(scratch, scratch, Operand(mask2)); |
| |
| // Probe the secondary table. |
| ProbeTable(isolate, masm, ic_kind, flags, kSecondary, receiver, name, scratch, |
| extra, extra2, extra3); |
| |
| // Cache miss: Fall-through and let caller handle the miss by |
| // entering the runtime system. |
| __ bind(&miss); |
| __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1, extra2, |
| extra3); |
| } |
| |
| |
| #undef __ |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_TARGET_ARCH_ARM |