Revert of [ic] [stubs] Don't use Code::flags in megamorphic stub cache hash computations.

src/ic/x64/stub-cache-x64.cc

 // 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_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(StubCache* stub_cache, MacroAssembler* masm,
-                       StubCache::Table table, Register receiver, Register name,
+                       Code::Flags flags, 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;
 
@@ skipping 20 matching lines @@
          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));
 
-#ifdef DEBUG
   // Check that the flags match what we're looking for.
-  Code::Flags flags = Code::RemoveHolderFromFlags(
-      Code::ComputeHandlerFlags(stub_cache->ic_kind()));
   __ movl(offset, FieldOperand(kScratchRegister, Code::kFlagsOffset));
   __ andp(offset, Immediate(~Code::kFlagsNotUsedInLookup));
   __ cmpl(offset, Immediate(flags));
-  __ Check(equal, kUnexpectedValue);
+  __ 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
 
   // Jump to the first instruction in the code stub.
   __ addp(kScratchRegister, Immediate(Code::kHeaderSize - kHeapObjectTag));
   __ jmp(kScratchRegister);
 
   __ bind(&miss);
 }
 
 void StubCache::GenerateProbe(MacroAssembler* masm, Register receiver,
                               Register name, Register scratch, Register extra,
                               Register extra2, Register extra3) {
+  Code::Flags flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(ic_kind_));
+
   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 that there are no register conflicts.
   DCHECK(!scratch.is(receiver));
@@ skipping 25 matching lines @@
   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(this, masm, kPrimary, receiver, name, scratch);
+  ProbeTable(this, masm, flags, 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(this, masm, kSecondary, receiver, name, scratch);
+  ProbeTable(this, masm, flags, 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 internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64