[turbofan] Introduce integer multiplication with overflow.

src/compiler/arm64/instruction-selector-arm64.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 1252 matching lines @@
            g.UseRegister(mright.left().node()),
            g.UseRegister(mright.right().node()),
            g.UseRegister(m.left().node()));
       return;
     }
   }
 
   VisitAddSub<Int64BinopMatcher>(this, node, kArm64Sub, kArm64Add);
 }
 
+void VisitInt32MulWithOverflowImpl(InstructionSelector* selector, Node* node,

[Benedikt Meurer, 2016/07/12 04:09:28]

Put this into an anonymous namespace and remove the Impl suffix.

[mvstanton, 2016/07/12 08:52:49]

Done.

+                                   FlagsContinuation* cont) {
+  Arm64OperandGenerator g(selector);
+  Int32BinopMatcher m(node);
+  InstructionOperand result = g.DefineAsRegister(node);
+  InstructionOperand left = g.UseRegister(m.left().node());
+  InstructionOperand right = g.UseRegister(m.right().node());
+  selector->Emit(kArm64Smull, result, left, right);
+
+  InstructionCode opcode = cont->Encode(kArm64Cmp) |
+                           AddressingModeField::encode(kMode_Operand2_R_SXTW);
+  if (cont->IsBranch()) {
+    selector->Emit(opcode, g.NoOutput(), result, result,
+                   g.Label(cont->true_block()), g.Label(cont->false_block()));
+  } else if (cont->IsDeoptimize()) {
+    InstructionOperand in[] = {result, result};
+    selector->EmitDeoptimize(opcode, 0, nullptr, 2, in, cont->frame_state());
+  } else {
+    DCHECK(cont->IsSet());
+    selector->Emit(opcode, g.DefineAsRegister(cont->result()), result, result);
+  }
+}
 
 void InstructionSelector::VisitInt32Mul(Node* node) {
   Arm64OperandGenerator g(this);
   Int32BinopMatcher m(node);
 
   // First, try to reduce the multiplication to addition with left shift.
   // x * (2^k + 1) -> x + (x << k)
   int32_t shift = LeftShiftForReducedMultiply(&m);
   if (shift > 0) {
     Emit(kArm64Add32 | AddressingModeField::encode(kMode_Operand2_R_LSL_I),
@@ skipping 63 matching lines @@
     if (mright.left().Is(0)) {
       Emit(kArm64Mneg, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
            g.UseRegister(mright.right().node()));
       return;
     }
   }
 
   VisitRRR(this, kArm64Mul, node);
 }
 
-
 void InstructionSelector::VisitInt32MulHigh(Node* node) {
   Arm64OperandGenerator g(this);
   InstructionOperand const smull_operand = g.TempRegister();
   Emit(kArm64Smull, smull_operand, g.UseRegister(node->InputAt(0)),
        g.UseRegister(node->InputAt(1)));
   Emit(kArm64Asr, g.DefineAsRegister(node), smull_operand, g.TempImmediate(32));
 }
 
 
 void InstructionSelector::VisitUint32MulHigh(Node* node) {
@@ skipping 874 matching lines @@
           if (result == nullptr || selector->IsDefined(result)) {
             switch (node->opcode()) {
               case IrOpcode::kInt32AddWithOverflow:
                 cont->OverwriteAndNegateIfEqual(kOverflow);
                 return VisitBinop<Int32BinopMatcher>(
                     selector, node, kArm64Add32, kArithmeticImm, cont);
               case IrOpcode::kInt32SubWithOverflow:
                 cont->OverwriteAndNegateIfEqual(kOverflow);
                 return VisitBinop<Int32BinopMatcher>(
                     selector, node, kArm64Sub32, kArithmeticImm, cont);
+              case IrOpcode::kInt32MulWithOverflow:
+                // ARM64 doesn't set the overflow flag for multiplication, so we
+                // need to test on kNotEqual. Here is the code sequence used:
+                //   smull result, left, right
+                //   cmp result.X(), Operand(result, SXTW)
+                cont->OverwriteAndNegateIfEqual(kNotEqual);
+                return VisitInt32MulWithOverflowImpl(selector, node, cont);
               case IrOpcode::kInt64AddWithOverflow:
                 cont->OverwriteAndNegateIfEqual(kOverflow);
                 return VisitBinop<Int64BinopMatcher>(selector, node, kArm64Add,
                                                      kArithmeticImm, cont);
               case IrOpcode::kInt64SubWithOverflow:
                 cont->OverwriteAndNegateIfEqual(kOverflow);
                 return VisitBinop<Int64BinopMatcher>(selector, node, kArm64Sub,
                                                      kArithmeticImm, cont);
               default:
                 break;
@@ skipping 187 matching lines @@
 void InstructionSelector::VisitInt32SubWithOverflow(Node* node) {
   if (Node* ovf = NodeProperties::FindProjection(node, 1)) {
     FlagsContinuation cont = FlagsContinuation::ForSet(kOverflow, ovf);
     return VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32,
                                          kArithmeticImm, &cont);
   }
   FlagsContinuation cont;
   VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32, kArithmeticImm, &cont);
 }
 
+void InstructionSelector::VisitInt32MulWithOverflow(Node* node) {
+  if (Node* ovf = NodeProperties::FindProjection(node, 1)) {
+    // ARM64 doesn't set the overflow flag for multiplication, so we need to
+    // test on kNotEqual. Here is the code sequence used:
+    //   smull result, left, right
+    //   cmp result.X(), Operand(result, SXTW)
+    FlagsContinuation cont = FlagsContinuation::ForSet(kNotEqual, ovf);
+    return VisitInt32MulWithOverflowImpl(this, node, &cont);
+  }
+  FlagsContinuation cont;
+  VisitInt32MulWithOverflowImpl(this, node, &cont);
+}
 
 void InstructionSelector::VisitInt64AddWithOverflow(Node* node) {
   if (Node* ovf = NodeProperties::FindProjection(node, 1)) {
     FlagsContinuation cont = FlagsContinuation::ForSet(kOverflow, ovf);
     return VisitBinop<Int64BinopMatcher>(this, node, kArm64Add, kArithmeticImm,
                                          &cont);
   }
   FlagsContinuation cont;
   VisitBinop<Int64BinopMatcher>(this, node, kArm64Add, kArithmeticImm, &cont);
 }
@@ skipping 210 matching lines @@
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8