diff options
Diffstat (limited to 'deps/v8/src/arm/stub-cache-arm.cc')
| -rw-r--r-- | deps/v8/src/arm/stub-cache-arm.cc | 62 |
1 files changed, 46 insertions, 16 deletions
diff --git a/deps/v8/src/arm/stub-cache-arm.cc b/deps/v8/src/arm/stub-cache-arm.cc index 33fbee52d6..15c5f4edef 100644 --- a/deps/v8/src/arm/stub-cache-arm.cc +++ b/deps/v8/src/arm/stub-cache-arm.cc @@ -45,6 +45,7 @@ static void ProbeTable(Isolate* isolate, StubCache::Table table, Register name, Register offset, + int offset_shift_bits, Register scratch, Register scratch2) { ExternalReference key_offset(isolate->stub_cache()->key_reference(table)); @@ -63,23 +64,34 @@ static void ProbeTable(Isolate* isolate, // Check that the key in the entry matches the name. __ mov(offsets_base_addr, Operand(key_offset)); - __ ldr(ip, MemOperand(offsets_base_addr, offset, LSL, 1)); + __ ldr(ip, MemOperand(offsets_base_addr, offset, LSL, 1 + offset_shift_bits)); __ cmp(name, ip); __ b(ne, &miss); // Get the code entry from the cache. __ add(offsets_base_addr, offsets_base_addr, Operand(value_off_addr - key_off_addr)); - __ ldr(scratch2, MemOperand(offsets_base_addr, offset, LSL, 1)); + __ ldr(scratch2, + MemOperand(offsets_base_addr, offset, LSL, 1 + offset_shift_bits)); // Check that the flags match what we're looking for. __ ldr(scratch2, FieldMemOperand(scratch2, Code::kFlagsOffset)); - __ bic(scratch2, scratch2, Operand(Code::kFlagsNotUsedInLookup)); - __ cmp(scratch2, Operand(flags)); + // It's a nice optimization if this constant is encodable in the bic insn. + + uint32_t mask = Code::kFlagsNotUsedInLookup; + ASSERT(__ ImmediateFitsAddrMode1Instruction(mask)); + __ bic(scratch2, scratch2, Operand(mask)); + // Using cmn and the negative instead of cmp means we can use movw. + if (flags < 0) { + __ cmn(scratch2, Operand(-flags)); + } else { + __ cmp(scratch2, Operand(flags)); + } __ b(ne, &miss); // Re-load code entry from cache. - __ ldr(offset, MemOperand(offsets_base_addr, offset, LSL, 1)); + __ ldr(offset, + MemOperand(offsets_base_addr, offset, LSL, 1 + offset_shift_bits)); // Jump to the first instruction in the code stub. __ add(offset, offset, Operand(Code::kHeaderSize - kHeapObjectTag)); @@ -189,23 +201,41 @@ void StubCache::GenerateProbe(MacroAssembler* masm, __ ldr(scratch, FieldMemOperand(name, String::kHashFieldOffset)); __ ldr(ip, FieldMemOperand(receiver, HeapObject::kMapOffset)); __ add(scratch, scratch, Operand(ip)); - __ eor(scratch, scratch, Operand(flags)); - __ and_(scratch, - scratch, - Operand((kPrimaryTableSize - 1) << kHeapObjectTagSize)); + uint32_t mask = (kPrimaryTableSize - 1) << kHeapObjectTagSize; + // Mask down the eor argument to the minimum to keep the immediate + // ARM-encodable. + __ eor(scratch, scratch, Operand(flags & mask)); + // Prefer and_ to ubfx here because ubfx takes 2 cycles. + __ and_(scratch, scratch, Operand(mask)); + __ mov(scratch, Operand(scratch, LSR, 1)); // Probe the primary table. - ProbeTable(isolate, masm, flags, kPrimary, name, scratch, extra, extra2); + ProbeTable(isolate, + masm, + flags, + kPrimary, + name, + scratch, + 1, + extra, + extra2); // Primary miss: Compute hash for secondary probe. - __ sub(scratch, scratch, Operand(name)); - __ add(scratch, scratch, Operand(flags)); - __ and_(scratch, - scratch, - Operand((kSecondaryTableSize - 1) << kHeapObjectTagSize)); + __ sub(scratch, scratch, Operand(name, LSR, 1)); + uint32_t mask2 = (kSecondaryTableSize - 1) << (kHeapObjectTagSize - 1); + __ add(scratch, scratch, Operand((flags >> 1) & mask2)); + __ and_(scratch, scratch, Operand(mask2)); // Probe the secondary table. - ProbeTable(isolate, masm, flags, kSecondary, name, scratch, extra, extra2); + ProbeTable(isolate, + masm, + flags, + kSecondary, + name, + scratch, + 1, + extra, + extra2); // Cache miss: Fall-through and let caller handle the miss by // entering the runtime system. |