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

src/mips/lithium-codegen-mips.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 4877 matching lines @@
   // The input is a tagged HeapObject.
   // Heap number map check.
   __ lw(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   // This 'at' value and scratch1 map value are used for tests in both clauses
   // of the if.
 
   if (instr->truncating()) {
     // Performs a truncating conversion of a floating point number as used by
     // the JS bitwise operations.
-    Label heap_number;
-    __ Branch(&heap_number, eq, scratch1, Operand(at));  // HeapNumber map?
-    // Check for undefined. Undefined is converted to zero for truncating
-    // conversions.
-    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
-    DeoptimizeIf(ne, instr->environment(), input_reg, Operand(at));
-    ASSERT(ToRegister(instr->result()).is(input_reg));
-    __ mov(input_reg, zero_reg);
+    Label no_heap_number, check_bools, check_false;
+    __ Branch(&no_heap_number, ne, scratch1, Operand(at));  // HeapNumber map?
+    __ mov(scratch2, input_reg);
+    __ TruncateHeapNumberToI(input_reg, scratch2);
     __ Branch(&done);
 
-    __ bind(&heap_number);
-    __ mov(scratch2, input_reg);
-    __ TruncateHeapNumberToI(input_reg, scratch2);
+    // Check for Oddballs. Undefined/False is converted to zero and True to one
+    // for truncating conversions.
+    __ bind(&no_heap_number);
+    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
+    __ Branch(&check_bools, ne, input_reg, Operand(at));
+    ASSERT(ToRegister(instr->result()).is(input_reg));
+    __ Branch(USE_DELAY_SLOT, &done);
+    __ mov(input_reg, zero_reg);  // In delay slot.
+
+    __ bind(&check_bools);
+    __ LoadRoot(at, Heap::kTrueValueRootIndex);
+    __ Branch(&check_false, ne, scratch2, Operand(at));
+    __ Branch(USE_DELAY_SLOT, &done);
+    __ li(input_reg, Operand(1));  // In delay slot.
+
+    __ bind(&check_false);
+    __ LoadRoot(at, Heap::kFalseValueRootIndex);
+    DeoptimizeIf(ne, instr->environment(), scratch2, Operand(at));
+    __ Branch(USE_DELAY_SLOT, &done);
+    __ mov(input_reg, zero_reg);  // In delay slot.
   } else {
     // Deoptimize if we don't have a heap number.
     DeoptimizeIf(ne, instr->environment(), scratch1, Operand(at));
 
     // Load the double value.
     __ ldc1(double_scratch,
             FieldMemOperand(input_reg, HeapNumber::kValueOffset));
 
     Register except_flag = scratch2;
     __ EmitFPUTruncate(kRoundToZero,
@@ skipping 891 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal