MIPS64: Fix r6 boolean materializations after a float32 compare.

src/compiler/mips/code-generator-mips.cc

 // Copyright 2014 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/compiler/code-generator.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
 #include "src/mips/macro-assembler-mips.h"
@@ skipping 1083 matching lines @@
       } else {
         __ Movt(result, zero_reg);
       }
     } else {
       if (instr->arch_opcode() == kMipsCmpD) {
         __ cmp(cc, L, kDoubleCompareReg, left, right);
       } else {
         DCHECK(instr->arch_opcode() == kMipsCmpS);
         __ cmp(cc, W, kDoubleCompareReg, left, right);
       }
-      __ mfc1(at, kDoubleCompareReg);
-      __ srl(result, at, 31);  // Cmp returns all 1s for true.
+      __ mfc1(result, kDoubleCompareReg);
+      __ andi(result, result, 1);  // Cmp returns all 1's/0's, use only LSB.
       if (!predicate)          // Toggle result for not equal.
         __ xori(result, result, 1);
     }
     return;
   } else {
     PrintF("AssembleArchBranch Unimplemented arch_opcode is : %d\n",
            instr->arch_opcode());
     TRACE_UNIMPL();
     UNIMPLEMENTED();
   }
@@ skipping 344 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8