[wasm] Remove -0 -x = -x folding because of signalling NaNs.

test/mjsunit/wasm/float-constant-folding.js

 // Copyright 2017 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.
 
 // Flags: --expose-wasm
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 (function() {
   print("F32: sNaN - 0 = qNaN");
   var builder = new WasmModuleBuilder();
   builder.addFunction("F32Sub0", kSig_i_i)
     .addBody([
       kExprGetLocal, 0,
       kExprF32ReinterpretI32,
       kExprF32Const, 0x00, 0x00, 0x00, 0x00, // 0.0
       kExprF32Sub,
       kExprI32ReinterpretF32,
             ])
             .exportFunc();
   var module = builder.instantiate();
   // F32Sub0(signalling_NaN)
   assertEquals(0x7fe00000, module.exports.F32Sub0(0x7fa00000));
 })();
 
 (function() {
+  print("F32: -0 sNaN = qNaN");
+  var builder = new WasmModuleBuilder();
+  builder.addFunction("F32Sub0", kSig_i_i)
+    .addBody([
+      kExprF32Const, 0x00, 0x00, 0x00, 0x80, // 0.0
+      kExprGetLocal, 0,
+      kExprF32ReinterpretI32,
+      kExprF32Sub,
+      kExprI32ReinterpretF32,
+            ])
+            .exportFunc();
+  var module = builder.instantiate();
+  // F32Sub0(signalling_NaN)
+  assertEquals(0x7fe00000, module.exports.F32Sub0(0x7fa00000));
+})();
+
+(function() {
   print("F32: sNaN - X = qNaN");
   var builder = new WasmModuleBuilder();
   builder.addFunction("F32NaNSubX", kSig_i_i)
     .addBody([
       kExprF32Const, 0x00, 0x00, 0xa0, 0x7f,
       kExprF32Const, 0x12, 0x34, 0x56, 0x78,
       kExprF32Sub,
       kExprI32ReinterpretF32,
             ])
             .exportFunc();
@@ skipping 47 matching lines @@
       kExprI64Const, 32,
       kExprI64ShrU,
       kExprI32ConvertI64,
             ])
             .exportFunc();
   var module = builder.instantiate();
   assertEquals(0x7ffa0000, module.exports.F64Sub0());
 })();
 
 (function() {
+  print("F64: -0 - sNaN = qNaN");
+  var builder = new WasmModuleBuilder();
+  builder.addFunction("F64Sub0", kSig_i_i)
+    .addBody([
+      kExprF64Const, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, // 0.0
+      kExprI64Const, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0xf9, 0xff, 0x00,
+      kExprF64ReinterpretI64,
+      kExprF64Sub,
+      kExprI64ReinterpretF64,
+      kExprI64Const, 32,
+      kExprI64ShrU,
+      kExprI32ConvertI64,
+            ])
+            .exportFunc();
+  var module = builder.instantiate();
+  assertEquals(0x7ffa0000, module.exports.F64Sub0());
+})();
+
+(function() {
   print("F64: sNaN - X = qNaN");
   var builder = new WasmModuleBuilder();
   builder.addFunction("F64NaNSubX", kSig_i_i)
     .addBody([
       kExprF64Const, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x7f,
       kExprF64Const, 0xde, 0xbc, 0x0a, 0x89, 0x67, 0x45, 0x23, 0x01,
       kExprF64Sub,
       kExprI64ReinterpretF64,
       kExprI64Const, 32,
       kExprI64ShrU,
@@ skipping 72 matching lines @@
       kExprI64Const, 32,
       kExprI64ShrU,
       kExprI32ConvertI64,
             ])
             .exportFunc();
   var module = builder.instantiate();
   assertEquals(0x7ffa0000, module.exports.F64Div1());
 })();
 
 (function() {
+  print("F64: sNaN / -1 = qNaN");
+  var builder = new WasmModuleBuilder();
+  builder.addFunction("F64Div1", kSig_i_i)
+    .addBody([
+      kExprI64Const, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0xf9, 0xff, 0x00,
+      kExprF64ReinterpretI64,
+      kExprF64Const, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0, 0xbf,
+      kExprF64Div,
+      kExprI64ReinterpretF64,
+      kExprI64Const, 32,
+      kExprI64ShrU,
+      kExprI32ConvertI64,
+            ])
+            .exportFunc();
+  var module = builder.instantiate();
+  assertEquals(0x7ffa0000, module.exports.F64Div1());
+})();
+
+(function() {
   print("F64: X / sNaN = qNaN");
   var builder = new WasmModuleBuilder();
   builder.addFunction("F64XDivNaN", kSig_i_i)
     .addBody([
       kExprF64Const, 0xde, 0xbc, 0x0a, 0x89, 0x67, 0x45, 0x23, 0x01,
       kExprF64Const, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x7f,
       kExprF64Div,
       kExprI64ReinterpretF64,
       kExprI64Const, 32,
       kExprI64ShrU,
@@ skipping 14 matching lines @@
       kExprF64Div,
       kExprI64ReinterpretF64,
       kExprI64Const, 32,
       kExprI64ShrU,
       kExprI32ConvertI64,
             ])
             .exportFunc();
   var module = builder.instantiate();
   assertEquals(0x7ffa0000, module.exports.F64NaNDivX());
 })();