A64: Truncate booleans to 0 or 1 in LTaggedToI.

src/a64/lithium-codegen-a64.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 5100 matching lines @@
   DoubleRegister dbl_scratch1 = double_scratch();
 
   Label done;
 
   // Load heap object map.
   __ Ldr(scratch1, FieldMemOperand(input, HeapObject::kMapOffset));
 
   if (instr->truncating()) {
     Register output = ToRegister(instr->result());
     Register scratch2 = ToRegister(temp2);
-    Label check_bools, undefined;
+    Label check_bools;
 
     // If it's not a heap number, jump to undefined check.
     __ JumpIfNotRoot(scratch1, Heap::kHeapNumberMapRootIndex, &check_bools);
 
     // A heap number: load value and convert to int32 using truncating function.
     __ Ldr(dbl_scratch1, FieldMemOperand(input, HeapNumber::kValueOffset));
     __ ECMA262ToInt32(output, dbl_scratch1, scratch1, scratch2);
     __ B(&done);
 
     __ Bind(&check_bools);
 
-    TODO_UNIMPLEMENTED("LTaggedToI: Truncate booleans to 0 or 1.");
+    Register true_root = output;
+    Register false_root = scratch2;
+    __ LoadTrueFalseRoots(true_root, false_root);
+    __ Cmp(scratch1, true_root);
+    __ Cset(output, eq);
+    __ Ccmp(scratch1, false_root, ZFlag, ne);
+    __ B(eq, &done);
 
-    // Check for undefined. Undefined is converted to zero for truncating
+    // Output contains zero, undefined is converted to zero for truncating
     // conversions.
-    __ Bind(&undefined);
-
     DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex,
                         instr->environment());
-    __ Mov(output, 0);
   } else {
     Register output = ToRegister32(instr->result());
 
     DoubleRegister dbl_scratch2 = ToDoubleRegister(temp2);
     Label converted;
 
     // Deoptimized if it's not a heap number.
     DeoptimizeIfNotRoot(scratch1, Heap::kHeapNumberMapRootIndex,
                         instr->environment());
 
@@ skipping 392 matching lines @@
   __ Bind(&out_of_object);
   __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   // Index is equal to negated out of object property index plus 1.
   __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
   __ Ldr(result, FieldMemOperand(result,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ Bind(&done);
 }
 
 } }  // namespace v8::internal