Fixed deopt reasons in TaggedToI.

src/arm/lithium-codegen-arm.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.
 
 #include "src/v8.h"
 
 #include "src/arm/lithium-codegen-arm.h"
 #include "src/arm/lithium-gap-resolver-arm.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 4957 matching lines @@
     __ bind(&check_bools);
     __ LoadRoot(ip, Heap::kTrueValueRootIndex);
     __ cmp(scratch2, Operand(ip));
     __ b(ne, &check_false);
     __ mov(input_reg, Operand(1));
     __ b(&done);
 
     __ bind(&check_false);
     __ LoadRoot(ip, Heap::kFalseValueRootIndex);
     __ cmp(scratch2, Operand(ip));
+    __ RecordComment("Deferred TaggedToI: cannot truncate");
     DeoptimizeIf(ne, instr->environment());
     __ mov(input_reg, Operand::Zero());
-    __ b(&done);
   } else {
-    // Deoptimize if we don't have a heap number.
+    __ RecordComment("Deferred TaggedToI: not a heap number");
     DeoptimizeIf(ne, instr->environment());
 
     __ sub(ip, scratch2, Operand(kHeapObjectTag));
     __ vldr(double_scratch2, ip, HeapNumber::kValueOffset);
     __ TryDoubleToInt32Exact(input_reg, double_scratch2, double_scratch);
+    __ RecordComment("Deferred TaggedToI: lost precision or NaN");
     DeoptimizeIf(ne, instr->environment());
 
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       __ cmp(input_reg, Operand::Zero());
       __ b(ne, &done);
       __ VmovHigh(scratch1, double_scratch2);
       __ tst(scratch1, Operand(HeapNumber::kSignMask));
+      __ RecordComment("Deferred TaggedToI: minus zero");
       DeoptimizeIf(ne, instr->environment());
     }
   }
   __ bind(&done);
 }
 
 
 void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
   class DeferredTaggedToI FINAL : public LDeferredCode {
    public:
@@ skipping 907 matching lines @@
   __ Push(scope_info);
   __ push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal