X87: [wasm] Use the Float64Max/Min machine operators to implement F64Max/Min.

src/crankshaft/x87/lithium-codegen-x87.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/crankshaft/x87/lithium-codegen-x87.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 4717 matching lines @@
     } else {
       Label heap_number, convert;
       __ j(equal, &heap_number);
 
       // Convert undefined (or hole) to NaN.
       __ cmp(input_reg, factory()->undefined_value());
       DeoptimizeIf(not_equal, instr,
                    DeoptimizeReason::kNotAHeapNumberUndefined);
 
       __ bind(&convert);
-      __ push(Immediate(0xffffffff));
-      __ push(Immediate(0x7fffffff));
+      __ push(Immediate(0xfff80000));

[ahaas, 2016/08/11 08:06:11]

In the old code the low word "0xffffffff" was push first and the high word
"0x7fffffff" was pushed second. It seems to me that in the new code the low word
"0x00000000" is pushed second and the high word "0xfff80000" is pushed first.
Are you sure that you push the words in the right order here?

+      __ push(Immediate(0x00000000));
       __ fld_d(MemOperand(esp, 0));
       __ lea(esp, Operand(esp, kDoubleSize));
       __ jmp(&done, Label::kNear);
 
       __ bind(&heap_number);
     }
     // Heap number to x87 conversion.
     __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
     if (deoptimize_on_minus_zero) {
       __ fldz();
@@ skipping 1021 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87