Implement clearing of CompareICs.

src/ia32/ic-ia32.cc

 // Copyright 2012 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
@@ skipping 1717 matching lines @@
   if (FLAG_trace_ic) {
     PrintF("[CompareIC (%s->%s)#%s]\n",
            GetStateName(previous_state),
            GetStateName(state),
            Token::Name(op_));
   }
 #endif
 
   // Activate inlined smi code.
   if (previous_state == UNINITIALIZED) {
-    PatchInlinedSmiCode(address());
+    PatchInlinedSmiCode(address(), ENABLE_INLINED_SMI_CHECK);
   }
 }
 
 
-void PatchInlinedSmiCode(Address address) {
+void PatchInlinedSmiCode(Address address, InlinedSmiCheck check) {
   // The address of the instruction following the call.
   Address test_instruction_address =
       address + Assembler::kCallTargetAddressOffset;
 
   // If the instruction following the call is not a test al, nothing
   // was inlined.
   if (*test_instruction_address != Assembler::kTestAlByte) {
     ASSERT(*test_instruction_address == Assembler::kNopByte);
     return;
   }
 
   Address delta_address = test_instruction_address + 1;
   // The delta to the start of the map check instruction and the
   // condition code uses at the patched jump.
   int8_t delta = *reinterpret_cast<int8_t*>(delta_address);
   if (FLAG_trace_ic) {
     PrintF("[  patching ic at %p, test=%p, delta=%d\n",
            address, test_instruction_address, delta);
   }
 
-  // Patch with a short conditional jump. There must be a
-  // short jump-if-carry/not-carry at this position.
+  // Patch with a short conditional jump. Enabling means switching from a short
+  // jump-if-carry/not-carry to jump-if-zero/not-zero, whereas disabling is the
+  // reverse operation of that.
   Address jmp_address = test_instruction_address - delta;
-  ASSERT(*jmp_address == Assembler::kJncShortOpcode ||
-         *jmp_address == Assembler::kJcShortOpcode);
-  Condition cc = *jmp_address == Assembler::kJncShortOpcode
-      ? not_zero
-      : zero;
+  ASSERT((check == ENABLE_INLINED_SMI_CHECK)
+         ? (*jmp_address == Assembler::kJncShortOpcode ||
+            *jmp_address == Assembler::kJcShortOpcode)
+         : (*jmp_address == Assembler::kJnzShortOpcode ||
+            *jmp_address == Assembler::kJzShortOpcode));
+  Condition cc = (check == ENABLE_INLINED_SMI_CHECK)
+      ? (*jmp_address == Assembler::kJncShortOpcode ? not_zero : zero)
+      : (*jmp_address == Assembler::kJnzShortOpcode ? not_carry : carry);
   *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32