[turbofan] Unify Math.floor / Math.ceil optimization.

src/compiler/ia32/instruction-selector-ia32.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"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 101 matching lines @@
       return kMode_MR1;
     }
   }
 
   bool CanBeBetterLeftOperand(Node* node) const {
     return !selector()->IsLive(node);
   }
 };
 
 
-static void VisitRRFloat64(InstructionSelector* selector, ArchOpcode opcode,
-                           Node* node) {
+static void VisitRRFloat64(InstructionSelector* selector,
+                           InstructionCode opcode, Node* node) {
   IA32OperandGenerator g(selector);
   selector->Emit(opcode, g.DefineAsRegister(node),
                  g.UseRegister(node->InputAt(0)));
 }
 
 
 void InstructionSelector::VisitLoad(Node* node) {
   MachineType rep = RepresentationOf(OpParameter<LoadRepresentation>(node));
   MachineType typ = TypeOf(OpParameter<LoadRepresentation>(node));
 
@@ skipping 505 matching lines @@
          g.UseRegister(node->InputAt(0)), g.Use(node->InputAt(1)));
   } else {
     Emit(kSSEFloat64Add, g.DefineSameAsFirst(node),
          g.UseRegister(node->InputAt(0)), g.Use(node->InputAt(1)));
   }
 }
 
 
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   IA32OperandGenerator g(this);
+  Float64BinopMatcher m(node);
+  if (m.left().IsMinusZero() && m.right().IsFloat64RoundDown() &&
+      CanCover(m.node(), m.right().node())) {
+    if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub &&
+        CanCover(m.right().node(), m.right().InputAt(0))) {
+      Float64BinopMatcher mright0(m.right().InputAt(0));
+      if (mright0.left().IsMinusZero()) {
+        Emit(kSSEFloat64Round | MiscField::encode(kRoundUp),
+             g.DefineAsRegister(node), g.UseRegister(mright0.right().node()));
+        return;
+      }
+    }
+  }
   if (IsSupported(AVX)) {
     Emit(kAVXFloat64Sub, g.DefineAsRegister(node),
          g.UseRegister(node->InputAt(0)), g.Use(node->InputAt(1)));
   } else {
     Emit(kSSEFloat64Sub, g.DefineSameAsFirst(node),
          g.UseRegister(node->InputAt(0)), g.Use(node->InputAt(1)));
   }
 }
 
 
@@ skipping 29 matching lines @@
        temps);
 }
 
 
 void InstructionSelector::VisitFloat64Sqrt(Node* node) {
   IA32OperandGenerator g(this);
   Emit(kSSEFloat64Sqrt, g.DefineAsRegister(node), g.Use(node->InputAt(0)));
 }
 
 
-void InstructionSelector::VisitFloat64Floor(Node* node) {
-  DCHECK(CpuFeatures::IsSupported(SSE4_1));
-  VisitRRFloat64(this, kSSEFloat64Floor, node);
-}
-
-
-void InstructionSelector::VisitFloat64Ceil(Node* node) {
-  DCHECK(CpuFeatures::IsSupported(SSE4_1));
-  VisitRRFloat64(this, kSSEFloat64Ceil, node);
+void InstructionSelector::VisitFloat64RoundDown(Node* node) {
+  VisitRRFloat64(this, kSSEFloat64Round | MiscField::encode(kRoundDown), node);
 }
 
 
 void InstructionSelector::VisitFloat64RoundTruncate(Node* node) {
-  DCHECK(CpuFeatures::IsSupported(SSE4_1));
-  VisitRRFloat64(this, kSSEFloat64RoundTruncate, node);
+  VisitRRFloat64(this, kSSEFloat64Round | MiscField::encode(kRoundToZero),
+                 node);
 }
 
 
 void InstructionSelector::VisitFloat64RoundTiesAway(Node* node) {
   UNREACHABLE();
 }
 
 
 void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
   IA32OperandGenerator g(this);
@@ skipping 401 matching lines @@
        g.UseRegister(left), g.Use(right));
 }
 
 
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   MachineOperatorBuilder::Flags flags =
       MachineOperatorBuilder::kWord32ShiftIsSafe;
   if (CpuFeatures::IsSupported(SSE4_1)) {
-    flags |= MachineOperatorBuilder::kFloat64Floor |
-             MachineOperatorBuilder::kFloat64Ceil |
+    flags |= MachineOperatorBuilder::kFloat64RoundDown |
              MachineOperatorBuilder::kFloat64RoundTruncate;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8