[intrinsics] Kill the %_IsMinusZero intrinsic.

src/crankshaft/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 2203 matching lines @@
 
   DoubleRegister input_reg = ToDoubleRegister(instr->object());
   EmitFalseBranchF(instr, eq, input_reg, input_reg);
 
   Register scratch = scratch0();
   __ FmoveHigh(scratch, input_reg);
   EmitBranch(instr, eq, scratch, Operand(kHoleNanUpper32));
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    DoubleRegister value = ToDoubleRegister(instr->value());
-    EmitFalseBranchF(instr, ne, value, kDoubleRegZero);
-    __ FmoveHigh(scratch, value);
-    __ li(at, 0x80000000);
-  } else {
-    Register value = ToRegister(instr->value());
-    __ CheckMap(value,
-                scratch,
-                Heap::kHeapNumberMapRootIndex,
-                instr->FalseLabel(chunk()),
-                DO_SMI_CHECK);
-    __ lw(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
-    EmitFalseBranch(instr, ne, scratch, Operand(0x80000000));
-    __ lw(scratch, FieldMemOperand(value, HeapNumber::kMantissaOffset));
-    __ mov(at, zero_reg);
-  }
-  EmitBranch(instr, eq, scratch, Operand(at));
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,
                                  SmiCheck check_needed = INLINE_SMI_CHECK) {
   if (check_needed == INLINE_SMI_CHECK) {
     __ JumpIfSmi(input, is_not_string);
   }
   __ GetObjectType(input, temp1, temp1);
 
   return lt;
@@ skipping 3338 matching lines @@
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8