Improve our type feedback by recogizining never-executed IC calls for binary ...

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
===================================================================
--- src/ia32/ic-ia32.cc	(revision 5952)
+++ src/ia32/ic-ia32.cc	(working copy)
@@ -2076,6 +2076,34 @@
 }
 
 
+void TRBinaryOpIC::PatchInlinedSmiCode(Address address) {
+  // 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 eax, nothing
+  // was inlined.
+  if (*test_instruction_address != Assembler::kTestEaxByte) 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.
+  int delta_and_condition = *reinterpret_cast<int*>(delta_address);
+  int condition = delta_and_condition & 0xffff;
+  int delta = delta_and_condition >> 16;
+  if (FLAG_trace_ic) {
+    PrintF("[TRBinaryOpIC patching ic at %p, test=%p, delta=%d, cc=%d\n",
+           address, test_instruction_address, delta, condition);
+  }
+
+  // Patch with a short conditional jump. There must be an unconditional
+  // short jump at this position.
+  Address jmp_address = test_instruction_address - delta;
+  ASSERT(*jmp_address == Assembler::kJmpShortOpcode);
+  *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | condition);
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32