[turbofan] Support for combining branches with <Operation>WithOverflow.

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 158 matching lines @@
   } else {  // store [%base + %index], %|#value
     Emit(opcode | AddressingModeField::encode(kMode_MR1I), NULL,
          g.UseRegister(base), g.UseRegister(index), val);
   }
   // TODO(turbofan): addressing modes [r+r*{2,4,8}+K]
 }
 
 
 // Shared routine for multiple binary operations.
 static void VisitBinop(InstructionSelector* selector, Node* node,
-                       ArchOpcode opcode, bool commutative) {
-  X64OperandGenerator g(selector);
-  Node* left = node->InputAt(0);
-  Node* right = node->InputAt(1);
-  // TODO(turbofan): match complex addressing modes.
-  // TODO(turbofan): if commutative, pick the non-live-in operand as the left as
-  // this might be the last use and therefore its register can be reused.
-  if (g.CanBeImmediate(right)) {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
-                   g.UseImmediate(right));
-  } else if (commutative && g.CanBeImmediate(left)) {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(right),
-                   g.UseImmediate(left));
-  } else {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
-                   g.Use(right));
-  }
-}
-
-
-static void VisitBinopWithOverflow(InstructionSelector* selector, Node* node,
-                                   InstructionCode opcode) {
+                       InstructionCode opcode, FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   Int32BinopMatcher m(node);
-  InstructionOperand* inputs[2];
+  InstructionOperand* inputs[4];
   size_t input_count = 0;
   InstructionOperand* outputs[2];
   size_t output_count = 0;
 
   // TODO(turbofan): match complex addressing modes.
   // TODO(turbofan): if commutative, pick the non-live-in operand as the left as
   // this might be the last use and therefore its register can be reused.
   if (g.CanBeImmediate(m.right().node())) {
     inputs[input_count++] = g.Use(m.left().node());
     inputs[input_count++] = g.UseImmediate(m.right().node());
   } else {
     inputs[input_count++] = g.UseRegister(m.left().node());
     inputs[input_count++] = g.Use(m.right().node());
   }
 
-  // Define outputs depending on the projections.
-  Node* projections[2];
-  node->CollectProjections(ARRAY_SIZE(projections), projections);
-  if (projections[0]) {
-    outputs[output_count++] = g.DefineSameAsFirst(projections[0]);
+  if (cont->IsBranch()) {
+    inputs[input_count++] = g.Label(cont->true_block());
+    inputs[input_count++] = g.Label(cont->false_block());
   }
-  if (projections[1]) {
-    opcode |= FlagsModeField::encode(kFlags_set);
-    opcode |= FlagsConditionField::encode(kOverflow);
-    outputs[output_count++] =
-        (projections[0] ? g.DefineAsRegister(projections[1])
-                        : g.DefineSameAsFirst(projections[1]));
+
+  outputs[output_count++] = g.DefineSameAsFirst(node);
+  if (cont->IsSet()) {
+    outputs[output_count++] = g.DefineAsRegister(cont->result());
   }
 
   ASSERT_NE(0, input_count);
   ASSERT_NE(0, output_count);
   ASSERT_GE(ARRAY_SIZE(inputs), input_count);
   ASSERT_GE(ARRAY_SIZE(outputs), output_count);
 
-  selector->Emit(opcode, output_count, outputs, input_count, inputs);
+  Instruction* instr = selector->Emit(cont->Encode(opcode), output_count,
+                                      outputs, input_count, inputs);
+  if (cont->IsBranch()) instr->MarkAsControl();
+}
+
+
+// Shared routine for multiple binary operations.
+static void VisitBinop(InstructionSelector* selector, Node* node,
+                       InstructionCode opcode) {
+  FlagsContinuation cont;
+  VisitBinop(selector, node, opcode, &cont);
 }
 
 
 void InstructionSelector::VisitWord32And(Node* node) {
-  VisitBinop(this, node, kX64And32, true);
+  VisitBinop(this, node, kX64And32);
 }
 
 
 void InstructionSelector::VisitWord64And(Node* node) {
-  VisitBinop(this, node, kX64And, true);
+  VisitBinop(this, node, kX64And);
 }
 
 
 void InstructionSelector::VisitWord32Or(Node* node) {
-  VisitBinop(this, node, kX64Or32, true);
+  VisitBinop(this, node, kX64Or32);
 }
 
 
 void InstructionSelector::VisitWord64Or(Node* node) {
-  VisitBinop(this, node, kX64Or, true);
+  VisitBinop(this, node, kX64Or);
 }
 
 
 template <typename T>
 static void VisitXor(InstructionSelector* selector, Node* node,
                      ArchOpcode xor_opcode, ArchOpcode not_opcode) {
   X64OperandGenerator g(selector);
   BinopMatcher<IntMatcher<T>, IntMatcher<T> > m(node);
   if (m.right().Is(-1)) {
     selector->Emit(not_opcode, g.DefineSameAsFirst(node),
                    g.Use(m.left().node()));
   } else {
-    VisitBinop(selector, node, xor_opcode, true);
+    VisitBinop(selector, node, xor_opcode);
   }
 }
 
 
 void InstructionSelector::VisitWord32Xor(Node* node) {
   VisitXor<int32_t>(this, node, kX64Xor32, kX64Not32);
 }
 
 
 void InstructionSelector::VisitWord64Xor(Node* node) {
@@ skipping 77 matching lines @@
   VisitWord32Shift(this, node, kX64Sar32);
 }
 
 
 void InstructionSelector::VisitWord64Sar(Node* node) {
   VisitWord64Shift(this, node, kX64Sar);
 }
 
 
 void InstructionSelector::VisitInt32Add(Node* node) {
-  VisitBinop(this, node, kX64Add32, true);
-}
-
-
-void InstructionSelector::VisitInt32AddWithOverflow(Node* node) {
-  VisitBinopWithOverflow(this, node, kX64Add32);
+  VisitBinop(this, node, kX64Add32);
 }
 
 
 void InstructionSelector::VisitInt64Add(Node* node) {
-  VisitBinop(this, node, kX64Add, true);
+  VisitBinop(this, node, kX64Add);
 }
 
 
 template <typename T>
 static void VisitSub(InstructionSelector* selector, Node* node,
                      ArchOpcode sub_opcode, ArchOpcode neg_opcode) {
   X64OperandGenerator g(selector);
   BinopMatcher<IntMatcher<T>, IntMatcher<T> > m(node);
   if (m.left().Is(0)) {
     selector->Emit(neg_opcode, g.DefineSameAsFirst(node),
                    g.Use(m.right().node()));
   } else {
-    VisitBinop(selector, node, sub_opcode, false);
+    VisitBinop(selector, node, sub_opcode);
   }
 }
 
 
 void InstructionSelector::VisitInt32Sub(Node* node) {
   VisitSub<int32_t>(this, node, kX64Sub32, kX64Neg32);
 }
 
 
-void InstructionSelector::VisitInt32SubWithOverflow(Node* node) {
-  VisitBinopWithOverflow(this, node, kX64Sub32);
-}
-
-
 void InstructionSelector::VisitInt64Sub(Node* node) {
   VisitSub<int64_t>(this, node, kX64Sub, kX64Neg);
 }
 
 
 static void VisitMul(InstructionSelector* selector, Node* node,
                      ArchOpcode opcode) {
   X64OperandGenerator g(selector);
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
@@ skipping 160 matching lines @@
 
 
 void InstructionSelector::VisitConvertInt32ToInt64(Node* node) {
   X64OperandGenerator g(this);
   // TODO(dcarney): other modes
   Emit(kX64Int32ToInt64, g.DefineAsRegister(node),
        g.UseRegister(node->InputAt(0)));
 }
 
 
+void InstructionSelector::VisitInt32AddWithOverflow(Node* node,
+                                                    FlagsContinuation* cont) {
+  VisitBinop(this, node, kX64Add32, cont);
+}
+
+
+void InstructionSelector::VisitInt32SubWithOverflow(Node* node,
+                                                    FlagsContinuation* cont) {
+  VisitBinop(this, node, kX64Sub32, cont);
+}
+
+
 // Shared routine for multiple compare operations.
 static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                          InstructionOperand* left, InstructionOperand* right,
                          FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   opcode = cont->Encode(opcode);
   if (cont->IsBranch()) {
     selector->Emit(opcode, NULL, left, right, g.Label(cont->true_block()),
                    g.Label(cont->false_block()))->MarkAsControl();
   } else {
@@ skipping 133 matching lines @@
     ASSERT(deoptimization == NULL && continuation == NULL);
     Emit(kPopStack | MiscField::encode(buffer.pushed_count), NULL);
   }
 }
 
 #endif
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8