Handle negative number in Math.floor,ia32,non-SSE4.1 code path.

src/ia32/lithium-codegen-ia32.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 2906 matching lines @@
       __ test(output_reg, Immediate(1));
       DeoptimizeIf(not_zero, instr->environment());
       __ bind(&non_zero);
     }
     __ roundsd(xmm_scratch, input_reg, Assembler::kRoundDown);
     __ cvttsd2si(output_reg, Operand(xmm_scratch));
     // Overflow is signalled with minint.
     __ cmp(output_reg, 0x80000000u);
     DeoptimizeIf(equal, instr->environment());
   } else {
+    Label negative_sign;
     Label done;
-    // Deoptimize on negative numbers.
+    // Deoptimize on unordered.
     __ xorps(xmm_scratch, xmm_scratch);  // Zero the register.
     __ ucomisd(input_reg, xmm_scratch);
-    DeoptimizeIf(below, instr->environment());
+    DeoptimizeIf(parity_even, instr->environment());
+    __ j(below, &negative_sign, Label::kNear);
 
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       // Check for negative zero.
       Label positive_sign;
       __ j(above, &positive_sign, Label::kNear);
       __ movmskpd(output_reg, input_reg);
       __ test(output_reg, Immediate(1));
       DeoptimizeIf(not_zero, instr->environment());
       __ Set(output_reg, Immediate(0));
       __ jmp(&done, Label::kNear);
       __ bind(&positive_sign);
     }
 
     // Use truncating instruction (OK because input is positive).
     __ cvttsd2si(output_reg, Operand(input_reg));
-
     // Overflow is signalled with minint.
     __ cmp(output_reg, 0x80000000u);
     DeoptimizeIf(equal, instr->environment());
+    __ jmp(&done, Label::kNear);
+
+    // Non-zero negative reaches here
+    __ bind(&negative_sign);
+    // Truncate, then compare and compensate
+    __ cvttsd2si(output_reg, Operand(input_reg));
+    __ cvtsi2sd(xmm_scratch, output_reg);
+    __ ucomisd(input_reg, xmm_scratch);
+    __ j(equal, &done, Label::kNear);
+    __ sub(output_reg, Immediate(1));
+    DeoptimizeIf(overflow, instr->environment());
+
     __ bind(&done);
   }
 }
 
 void LCodeGen::DoMathRound(LUnaryMathOperation* instr) {
   XMMRegister xmm_scratch = xmm0;
   Register output_reg = ToRegister(instr->result());
   XMMRegister input_reg = ToDoubleRegister(instr->value());
 
   Label below_half, done;
@@ skipping 2064 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32