Implement clearing of CompareICs.

src/arm/ic-arm.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 1672 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) {
   Address cmp_instruction_address =
       address + Assembler::kCallTargetAddressOffset;
 
   // If the instruction following the call is not a cmp rx, #yyy, nothing
   // was inlined.
   Instr instr = Assembler::instr_at(cmp_instruction_address);
   if (!Assembler::IsCmpImmediate(instr)) {
     return;
   }
 
@@ skipping 13 matching lines @@
     PrintF("[  patching ic at %p, cmp=%p, delta=%d\n",
            address, cmp_instruction_address, delta);
   }
 #endif
 
   Address patch_address =
       cmp_instruction_address - delta * Instruction::kInstrSize;
   Instr instr_at_patch = Assembler::instr_at(patch_address);
   Instr branch_instr =
       Assembler::instr_at(patch_address + Instruction::kInstrSize);
-  ASSERT(Assembler::IsCmpRegister(instr_at_patch));
-  ASSERT_EQ(Assembler::GetRn(instr_at_patch).code(),
-            Assembler::GetRm(instr_at_patch).code());
+  // This is patching a conditional "jump if not smi/jump if smi" site.
+  // Enabling by changing from
+  //   cmp rx, rx
+  //   b eq/ne, <target>
+  // to
+  //   tst rx, #kSmiTagMask
+  //   b ne/eq, <target>
+  // and vice-versa to be disabled again.
+  CodePatcher patcher(patch_address, 2);
+  Register reg = Assembler::GetRn(instr_at_patch);
+  if (check == ENABLE_INLINED_SMI_CHECK) {
+    ASSERT(Assembler::IsCmpRegister(instr_at_patch));
+    ASSERT_EQ(Assembler::GetRn(instr_at_patch).code(),
+              Assembler::GetRm(instr_at_patch).code());
+    patcher.masm()->tst(reg, Operand(kSmiTagMask));
+  } else {
+    ASSERT(check == DISABLE_INLINED_SMI_CHECK);
+    ASSERT(Assembler::IsTstImmediate(instr_at_patch));
+    patcher.masm()->cmp(reg, reg);
+  }
   ASSERT(Assembler::IsBranch(branch_instr));
   if (Assembler::GetCondition(branch_instr) == eq) {
-    // This is patching a "jump if not smi" site to be active.
-    // Changing
-    //   cmp rx, rx
-    //   b eq, <target>
-    // to
-    //   tst rx, #kSmiTagMask
-    //   b ne, <target>
-    CodePatcher patcher(patch_address, 2);
-    Register reg = Assembler::GetRn(instr_at_patch);
-    patcher.masm()->tst(reg, Operand(kSmiTagMask));
     patcher.EmitCondition(ne);
   } else {
     ASSERT(Assembler::GetCondition(branch_instr) == ne);
-    // This is patching a "jump if smi" site to be active.
-    // Changing
-    //   cmp rx, rx
-    //   b ne, <target>
-    // to
-    //   tst rx, #kSmiTagMask
-    //   b eq, <target>
-    CodePatcher patcher(patch_address, 2);
-    Register reg = Assembler::GetRn(instr_at_patch);
-    patcher.masm()->tst(reg, Operand(kSmiTagMask));
     patcher.EmitCondition(eq);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM