Add Uint32AddWithOverflow and Uint32SubWithOverflow machine operators.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index bd23dfd17e2a6fc9d7a85181df26f2c8a46a55c3..29f219cec819e95e226e07c91e4b97d00ef2a61f 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -106,7 +106,6 @@ static void VisitRRO(InstructionSelector* selector, ArchOpcode opcode,
 }
 
 
-// Shared routine for multiple binary operations.
 static void VisitBinop(InstructionSelector* selector, Node* node,
                        InstructionCode opcode, ImmediateMode operand_mode,
                        FlagsContinuation* cont) {
@@ -141,7 +140,6 @@ static void VisitBinop(InstructionSelector* selector, Node* node,
 }
 
 
-// Shared routine for multiple binary operations.
 static void VisitBinop(InstructionSelector* selector, Node* node,
                        ArchOpcode opcode, ImmediateMode operand_mode) {
   FlagsContinuation cont;
@@ -149,6 +147,18 @@ static void VisitBinop(InstructionSelector* selector, Node* node,
 }
 
 
+static void VisitBinop(InstructionSelector* selector, Node* node,
+                       InstructionCode opcode,
+                       FlagsCondition overflow_condition) {
+  if (Node* overflow = node->FindProjection(1)) {
+    FlagsContinuation cont(overflow_condition, overflow);
+    return VisitBinop(selector, node, opcode, kArithimeticImm, &cont);
+  }
+  FlagsContinuation cont;
+  return VisitBinop(selector, node, opcode, kArithimeticImm, &cont);
+}
+
+
 void InstructionSelector::VisitLoad(Node* node) {
   MachineRepresentation rep = OpParameter<MachineRepresentation>(node);
   Arm64OperandGenerator g(this);
@@ -334,6 +344,16 @@ void InstructionSelector::VisitInt32Add(Node* node) {
 }
 
 
+void InstructionSelector::VisitInt32AddWithOverflow(Node* node) {
+  VisitBinop(this, node, kArm64Add32, kOverflow);
+}
+
+
+void InstructionSelector::VisitUint32AddWithOverflow(Node* node) {
+  VisitBinop(this, node, kArm64Add32, kUnsignedGreaterThanOrEqual);
+}
+
+
 void InstructionSelector::VisitInt64Add(Node* node) {
   VisitBinop(this, node, kArm64Add, kArithimeticImm);
 }
@@ -358,6 +378,16 @@ void InstructionSelector::VisitInt32Sub(Node* node) {
 }
 
 
+void InstructionSelector::VisitInt32SubWithOverflow(Node* node) {
+  VisitBinop(this, node, kArm64Sub32, kOverflow);
+}
+
+
+void InstructionSelector::VisitUint32SubWithOverflow(Node* node) {
+  VisitBinop(this, node, kArm64Sub32, kUnsignedLessThan);
+}
+
+
 void InstructionSelector::VisitInt64Sub(Node* node) {
   VisitSub<int64_t>(this, node, kArm64Sub, kArm64Neg);
 }
@@ -479,18 +509,6 @@ void InstructionSelector::VisitFloat64Mod(Node* node) {
 }
 
 
-void InstructionSelector::VisitInt32AddWithOverflow(Node* node,
-                                                    FlagsContinuation* cont) {
-  VisitBinop(this, node, kArm64Add32, kArithimeticImm, cont);
-}
-
-
-void InstructionSelector::VisitInt32SubWithOverflow(Node* node,
-                                                    FlagsContinuation* cont) {
-  VisitBinop(this, node, kArm64Sub32, kArithimeticImm, cont);
-}
-
-
 // Shared routine for multiple compare operations.
 static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                          InstructionOperand* left, InstructionOperand* right,
@@ -579,6 +597,126 @@ void InstructionSelector::VisitFloat64Compare(Node* node,
 }
 
 
+void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
+                                      BasicBlock* fbranch) {
+  OperandGenerator g(this);
+  Node* user = branch;
+  Node* value = branch->InputAt(0);
+
+  FlagsContinuation cont(kNotEqual, tbranch, fbranch);
+
+  // If we can fall through to the true block, invert the branch.
+  if (IsNextInAssemblyOrder(tbranch)) {
+    cont.Negate();
+    cont.SwapBlocks();
+  }
+
+  // Try to combine with comparisons against 0 by simply inverting the branch.
+  while (CanCover(user, value)) {
+    if (value->opcode() == IrOpcode::kWord32Equal) {
+      Int32BinopMatcher m(value);
+      if (m.right().Is(0)) {
+        user = value;
+        value = m.left().node();
+        cont.Negate();
+      } else {
+        break;
+      }
+    } else if (value->opcode() == IrOpcode::kWord64Equal) {
+      Int64BinopMatcher m(value);
+      if (m.right().Is(0)) {
+        user = value;
+        value = m.left().node();
+        cont.Negate();
+      } else {
+        break;
+      }
+    } else {
+      break;
+    }
+  }
+
+  // Try to combine the branch with a comparison.
+  if (CanCover(user, value)) {
+    switch (value->opcode()) {
+      case IrOpcode::kWord32Equal:
+        cont.OverwriteAndNegateIfEqual(kEqual);
+        return VisitWord32Compare(value, &cont);
+      case IrOpcode::kInt32LessThan:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThan);
+        return VisitWord32Compare(value, &cont);
+      case IrOpcode::kInt32LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
+        return VisitWord32Compare(value, &cont);
+      case IrOpcode::kUint32LessThan:
+        cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
+        return VisitWord32Compare(value, &cont);
+      case IrOpcode::kUint32LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kUnsignedLessThanOrEqual);
+        return VisitWord32Compare(value, &cont);
+      case IrOpcode::kWord64Equal:
+        cont.OverwriteAndNegateIfEqual(kEqual);
+        return VisitWord64Compare(value, &cont);
+      case IrOpcode::kInt64LessThan:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThan);
+        return VisitWord64Compare(value, &cont);
+      case IrOpcode::kInt64LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
+        return VisitWord64Compare(value, &cont);
+      case IrOpcode::kFloat64Equal:
+        cont.OverwriteAndNegateIfEqual(kUnorderedEqual);
+        return VisitFloat64Compare(value, &cont);
+      case IrOpcode::kFloat64LessThan:
+        cont.OverwriteAndNegateIfEqual(kUnorderedLessThan);
+        return VisitFloat64Compare(value, &cont);
+      case IrOpcode::kFloat64LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kUnorderedLessThanOrEqual);
+        return VisitFloat64Compare(value, &cont);
+      case IrOpcode::kProjection:
+        // Check if this is the overflow output projection of an
+        // <Operation>WithOverflow node.
+        if (OpParameter<int32_t>(value) == 1) {
+          // 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).
+          Node* node = value->InputAt(0);
+          Node* result = node->FindProjection(0);
+          if (result == NULL || IsDefined(result)) {
+            switch (node->opcode()) {
+              case IrOpcode::kInt32AddWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kOverflow);
+                return VisitBinop(this, node, kArm64Add32, kArithimeticImm,
+                                  &cont);
+              case IrOpcode::kUint32AddWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kUnsignedGreaterThanOrEqual);
+                return VisitBinop(this, node, kArm64Add32, kArithimeticImm,
+                                  &cont);
+              case IrOpcode::kInt32SubWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kOverflow);
+                return VisitBinop(this, node, kArm64Sub32, kArithimeticImm,
+                                  &cont);
+              case IrOpcode::kUint32SubWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
+                return VisitBinop(this, node, kArm64Sub32, kArithimeticImm,
+                                  &cont);
+              default:
+                break;
+            }
+          }
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  // Branch could not be combined with a compare, emit compare against 0.
+  VisitWord32Test(value, &cont);
+}
+
+
 void InstructionSelector::VisitCall(Node* call, BasicBlock* continuation,
                                     BasicBlock* deoptimization) {
   Arm64OperandGenerator g(this);