[turbofan] Unify Int32Add/Sub representation selection rules.

src/compiler/simplified-lowering.cc

Index: src/compiler/simplified-lowering.cc
diff --git a/src/compiler/simplified-lowering.cc b/src/compiler/simplified-lowering.cc
index cc226447c21542b22e69689c1f119e2410180c6e..96ca2a273b7d249e1ecb3bbe978f123d024bc799 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -1124,20 +1124,12 @@ class RepresentationSelector {
     if (BothInputsAre(node, Type::PlainPrimitive())) {
       if (truncation.IsUnused()) return VisitUnused(node);
     }
-    if (BothInputsAre(node, Type::Signed32OrMinusZero()) &&
-        NodeProperties::GetType(node)->Is(Type::Signed32())) {
-      // int32 + int32 = int32   ==>   signed Int32Add/Sub
-      VisitInt32Binop(node);
-      if (lower()) ChangeToPureOp(node, Int32Op(node));
-      return;
-    }
-
-    // Use truncation if available.
     if (BothInputsAre(node, type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
-        truncation.IsUsedAsWord32()) {
-      // safe-int + safe-int = x (truncated to int32)
-      // => signed Int32Add/Sub (truncated)
-      VisitWord32TruncatingBinop(node);
+        (GetUpperBound(node)->Is(Type::Signed32()) ||
+         GetUpperBound(node)->Is(Type::Unsigned32()) ||
+         truncation.IsUsedAsWord32())) {
+      // => Int32Add/Sub
+      VisitInt32Binop(node);

[Jarin, 2016/08/19 08:41:07]

Use VisitWord32TuncatingBinop here, please.

(Eventually, we should get rid of VisitInt32Binop because it is misleading.)

[Benedikt Meurer, 2016/08/19 09:16:02]

Done.

       if (lower()) ChangeToPureOp(node, Int32Op(node));
       return;
     }
@@ -1387,23 +1379,17 @@ class RepresentationSelector {
 
       case IrOpcode::kNumberAdd:
       case IrOpcode::kNumberSubtract: {
-        if (BothInputsAre(node, Type::Signed32()) &&
-            NodeProperties::GetType(node)->Is(Type::Signed32())) {
-          // int32 + int32 = int32
-          // => signed Int32Add/Sub
+        if (BothInputsAre(node, type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
+            (GetUpperBound(node)->Is(Type::Signed32()) ||
+             GetUpperBound(node)->Is(Type::Unsigned32()) ||
+             truncation.IsUsedAsWord32())) {
+          // => Int32Add/Sub
           VisitInt32Binop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
-        } else if (BothInputsAre(node,
-                                 type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
-                   truncation.IsUsedAsWord32()) {
-          // safe-int + safe-int = x (truncated to int32)
-          // => signed Int32Add/Sub (truncated)
-          VisitWord32TruncatingBinop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
+          if (lower()) ChangeToPureOp(node, Int32Op(node));
         } else {
           // => Float64Add/Sub
           VisitFloat64Binop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
+          if (lower()) ChangeToPureOp(node, Float64Op(node));
         }
         return;
       }