[turbofan] Improve code generation for unordered comparisons.

src/compiler/x64/instruction-selector-x64.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/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 1009 matching lines @@
 
 
 // Shared routine for comparison with zero.
 static void VisitCompareZero(InstructionSelector* selector, Node* node,
                              InstructionCode opcode, FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   VisitCompare(selector, opcode, g.Use(node), g.TempImmediate(0), cont);
 }
 
 
-// Shared routine for multiple float64 compare operations.
+// Shared routine for multiple float64 compare operations (inputs commuted).
 static void VisitFloat64Compare(InstructionSelector* selector, Node* node,
                                 FlagsContinuation* cont) {
-  VisitCompare(selector, kSSEFloat64Cmp, node->InputAt(0), node->InputAt(1),
-               cont, node->op()->HasProperty(Operator::kCommutative));
+  Node* const left = node->InputAt(0);
+  Node* const right = node->InputAt(1);
+  VisitCompare(selector, kSSEFloat64Cmp, right, left, cont, false);
 }
 
 
 void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
                                       BasicBlock* fbranch) {
   X64OperandGenerator g(this);
   Node* user = branch;
   Node* value = branch->InputAt(0);
 
   FlagsContinuation cont(kNotEqual, tbranch, fbranch);
@@ skipping 50 matching lines @@
       case IrOpcode::kInt64LessThanOrEqual:
         cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
         return VisitWordCompare(this, value, kX64Cmp, &cont);
       case IrOpcode::kUint64LessThan:
         cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
         return VisitWordCompare(this, value, kX64Cmp, &cont);
       case IrOpcode::kFloat64Equal:
         cont.OverwriteAndNegateIfEqual(kUnorderedEqual);
         return VisitFloat64Compare(this, value, &cont);
       case IrOpcode::kFloat64LessThan:
-        cont.OverwriteAndNegateIfEqual(kUnorderedLessThan);
+        cont.OverwriteAndNegateIfEqual(kUnsignedGreaterThan);
         return VisitFloat64Compare(this, value, &cont);
       case IrOpcode::kFloat64LessThanOrEqual:
-        cont.OverwriteAndNegateIfEqual(kUnorderedLessThanOrEqual);
+        cont.OverwriteAndNegateIfEqual(kUnsignedGreaterThanOrEqual);
         return VisitFloat64Compare(this, value, &cont);
       case IrOpcode::kProjection:
         // Check if this is the overflow output projection of an
         // <Operation>WithOverflow node.
         if (OpParameter<size_t>(value) == 1u) {
           // We cannot combine the <Operation>WithOverflow with this branch
           // unless the 0th projection (the use of the actual value of the
           // <Operation> is either NULL, which means there's no use of the
           // actual value, or was already defined, which means it is scheduled
           // *AFTER* this branch).
@@ skipping 165 matching lines @@
 }
 
 
 void InstructionSelector::VisitFloat64Equal(Node* node) {
   FlagsContinuation cont(kUnorderedEqual, node);
   VisitFloat64Compare(this, node, &cont);
 }
 
 
 void InstructionSelector::VisitFloat64LessThan(Node* node) {
-  FlagsContinuation cont(kUnorderedLessThan, node);
+  FlagsContinuation cont(kUnsignedGreaterThan, node);
   VisitFloat64Compare(this, node, &cont);
 }
 
 
 void InstructionSelector::VisitFloat64LessThanOrEqual(Node* node) {
-  FlagsContinuation cont(kUnorderedLessThanOrEqual, node);
+  FlagsContinuation cont(kUnsignedGreaterThanOrEqual, node);
   VisitFloat64Compare(this, node, &cont);
 }
 
 
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   if (CpuFeatures::IsSupported(SSE4_1)) {
     return MachineOperatorBuilder::kFloat64Floor |
            MachineOperatorBuilder::kFloat64Ceil |
            MachineOperatorBuilder::kFloat64RoundTruncate |
            MachineOperatorBuilder::kWord32ShiftIsSafe;
   }
   return MachineOperatorBuilder::kNoFlags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8