[ptr-compr][turbofan] Specialize Word32 -> CompressedSigned conversion

Reverse specialization of https://chromium-review.googlesource.com/c/v8/v8/+/1684075.
Again, it skips over Tagged to save some instructions.

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:7703
Change-Id: I7fc50e0d8eebfef7a1ba02ce3d687ff808f30680
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1693007Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62645}

src/compiler/effect-control-linearizer.cc

@@ -51,6 +51,7 @@ class EffectControlLinearizer {
   bool TryWireInStateEffect(Node* node, Node* frame_state, Node** effect,
                             Node** control);
   Node* LowerChangeBitToTagged(Node* node);
+  Node* LowerChangeInt31ToCompressedSigned(Node* node);
   Node* LowerChangeInt31ToTaggedSigned(Node* node);
   Node* LowerChangeInt32ToTagged(Node* node);
   Node* LowerChangeInt64ToTagged(Node* node);
@@ -221,6 +222,7 @@ class EffectControlLinearizer {
   Node* LowerStringComparison(Callable const& callable, Node* node);
   Node* IsElementsKindGreaterThan(Node* kind, ElementsKind reference_kind);
 
+  Node* ChangeInt32ToCompressedSmi(Node* value);
   Node* ChangeInt32ToSmi(Node* value);
   Node* ChangeInt32ToIntPtr(Node* value);
   Node* ChangeInt64ToSmi(Node* value);
@@ -835,6 +837,9 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kChangeBitToTagged:
       result = LowerChangeBitToTagged(node);
       break;
+    case IrOpcode::kChangeInt31ToCompressedSigned:
+      result = LowerChangeInt31ToCompressedSigned(node);
+      break;
     case IrOpcode::kChangeInt31ToTaggedSigned:
       result = LowerChangeInt31ToTaggedSigned(node);
       break;
@@ -1386,6 +1391,11 @@ Node* EffectControlLinearizer::LowerChangeBitToTagged(Node* node) {
   return done.PhiAt(0);
 }
 
+Node* EffectControlLinearizer::LowerChangeInt31ToCompressedSigned(Node* node) {
+  Node* value = node->InputAt(0);
+  return ChangeInt32ToCompressedSmi(value);
+}
+
 Node* EffectControlLinearizer::LowerChangeInt31ToTaggedSigned(Node* node) {
   Node* value = node->InputAt(0);
   return ChangeInt32ToSmi(value);
@@ -4420,6 +4430,11 @@ Node* EffectControlLinearizer::ChangeIntPtrToInt32(Node* value) {
   return value;
 }
 
+Node* EffectControlLinearizer::ChangeInt32ToCompressedSmi(Node* value) {
+  CHECK(machine()->Is64() && SmiValuesAre31Bits());
+  return __ Word32Shl(value, SmiShiftBitsConstant());
+}
+
 Node* EffectControlLinearizer::ChangeInt32ToSmi(Node* value) {
   // Do shift on 32bit values if Smis are stored in the lower word.
   if (machine()->Is64() && SmiValuesAre31Bits()) {

src/compiler/opcodes.h

@@ -242,6 +242,7 @@
   V(ChangeTaggedToTaggedSigned)      \
   V(ChangeCompressedToTaggedSigned)  \
   V(ChangeTaggedToCompressedSigned)  \
+  V(ChangeInt31ToCompressedSigned)   \
   V(ChangeInt31ToTaggedSigned)       \
   V(ChangeInt32ToTagged)             \
   V(ChangeInt64ToTagged)             \

src/compiler/representation-change.cc

@@ -634,9 +634,13 @@ Node* RepresentationChanger::GetCompressedSignedRepresentationFor(
                                             use_node, use_info);
     op = machine()->ChangeTaggedSignedToCompressedSigned();
   } else if (IsWord(output_rep)) {
-    node = GetTaggedSignedRepresentationFor(node, output_rep, output_type,
-                                            use_node, use_info);
-    op = machine()->ChangeTaggedSignedToCompressedSigned();
+    if (output_type.Is(Type::Signed31())) {
+      op = simplified()->ChangeInt31ToCompressedSigned();
+    } else {
+      node = GetTaggedSignedRepresentationFor(node, output_rep, output_type,
+                                              use_node, use_info);
+      op = machine()->ChangeTaggedSignedToCompressedSigned();
+    }
   } else if (output_rep == MachineRepresentation::kWord64) {
     node = GetTaggedSignedRepresentationFor(node, output_rep, output_type,
                                             use_node, use_info);

src/compiler/simplified-operator.cc

@@ -731,6 +731,7 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(ChangeCompressedToTaggedSigned, Operator::kNoProperties, 1, 0) \
   V(ChangeTaggedToCompressedSigned, Operator::kNoProperties, 1, 0) \
   V(ChangeFloat64ToTaggedPointer, Operator::kNoProperties, 1, 0)   \
+  V(ChangeInt31ToCompressedSigned, Operator::kNoProperties, 1, 0)  \
   V(ChangeInt31ToTaggedSigned, Operator::kNoProperties, 1, 0)      \
   V(ChangeInt32ToTagged, Operator::kNoProperties, 1, 0)            \
   V(ChangeInt64ToTagged, Operator::kNoProperties, 1, 0)            \

src/compiler/simplified-operator.h

@@ -705,6 +705,7 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* ChangeTaggedToTaggedSigned();
   const Operator* ChangeCompressedToTaggedSigned();
   const Operator* ChangeTaggedToCompressedSigned();
+  const Operator* ChangeInt31ToCompressedSigned();
   const Operator* ChangeInt31ToTaggedSigned();
   const Operator* ChangeInt32ToTagged();
   const Operator* ChangeInt64ToTagged();

src/compiler/verifier.cc

@@ -1375,6 +1375,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, to));
       break;
     }
+    case IrOpcode::kChangeInt31ToCompressedSigned:
     case IrOpcode::kChangeInt31ToTaggedSigned: {
       // Signed31 /\ UntaggedInt32 -> Signed31 /\ Tagged
       // TODO(neis): Activate once ChangeRepresentation works in typer.

test/cctest/compiler/test-representation-change.cc

@@ -522,6 +522,9 @@ TEST(SingleChanges) {
   CheckChange(IrOpcode::kChangeBitToTagged, MachineRepresentation::kBit,
               Type::Boolean(), MachineRepresentation::kTagged);
 
+  CheckChange(IrOpcode::kChangeInt31ToCompressedSigned,
+              MachineRepresentation::kWord32, Type::Signed31(),
+              MachineRepresentation::kCompressedSigned);
   CheckChange(IrOpcode::kChangeInt31ToTaggedSigned,
               MachineRepresentation::kWord32, Type::Signed31(),
               MachineRepresentation::kTagged);