Truncate booleans to 0/1 in truncating t-to-i.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 4594 matching lines @@
 
   // Smi to XMM conversion
   __ bind(&load_smi);
   __ SmiToInteger32(kScratchRegister, input_reg);
   __ Cvtlsi2sd(result_reg, kScratchRegister);
   __ bind(&done);
 }
 
 
 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr, Label* done) {
-  Label heap_number;
   Register input_reg = ToRegister(instr->value());
 
+  if (instr->truncating()) {
+    Label no_heap_number, check_bools, check_false;
 
-  if (instr->truncating()) {
     // Heap number map check.
     __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                    Heap::kHeapNumberMapRootIndex);
-    __ j(equal, &heap_number, Label::kNear);
-    // Check for undefined. Undefined is converted to zero for truncating
-    // conversions.
+    __ j(not_equal, &no_heap_number, Label::kNear);
+    __ TruncateHeapNumberToI(input_reg, input_reg);
+    __ jmp(done);
+
+    __ bind(&no_heap_number);
+    // Check for Oddballs. Undefined/False is converted to zero and True to one
+    // for truncating conversions.
     __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
+    __ j(not_equal, &check_bools, Label::kNear);
+    __ Set(input_reg, 0);
+    __ jmp(done);
+
+    __ bind(&check_bools);
+    __ CompareRoot(input_reg, Heap::kTrueValueRootIndex);
+    __ j(not_equal, &check_false, Label::kNear);
+    __ Set(input_reg, 1);
+    __ jmp(done);
+
+    __ bind(&check_false);
+    __ CompareRoot(input_reg, Heap::kFalseValueRootIndex);
+    __ RecordComment("Deferred TaggedToI: cannot truncate");
     DeoptimizeIf(not_equal, instr->environment());
     __ Set(input_reg, 0);
     __ jmp(done);
-
-    __ bind(&heap_number);
-    __ TruncateHeapNumberToI(input_reg, input_reg);
   } else {
     Label bailout;
     XMMRegister xmm_temp = ToDoubleRegister(instr->temp());
     __ TaggedToI(input_reg, input_reg, xmm_temp,
         instr->hydrogen()->GetMinusZeroMode(), &bailout, Label::kNear);
 
     __ jmp(done);
     __ bind(&bailout);
     DeoptimizeIf(no_condition, instr->environment());
   }
@@ skipping 795 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64