[wasm-gc] Extend type checks to allow picking branch hints

Bug: v8:7748
Change-Id: I32c87d4e3b98ab44699c1b7bf952aedef3e27002
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2704667
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72890}

src/compiler/graph-assembler.h

@@ -370,6 +370,22 @@ class V8_EXPORT_PRIVATE GraphAssembler {
                       BranchHint hint, Vars...);
 
   // Control helpers.
+
+  // {GotoIf(c, l, h)} is equivalent to {BranchWithHint(c, l, templ, h);
+  // Bind(templ)}.
+  template <typename... Vars>
+  void GotoIf(Node* condition, GraphAssemblerLabel<sizeof...(Vars)>* label,
+              BranchHint hint, Vars...);
+
+  // {GotoIfNot(c, l, h)} is equivalent to {BranchWithHint(c, templ, l, h);
+  // Bind(templ)}.
+  // The branch hint refers to the expected outcome of the provided condition,
+  // so {GotoIfNot(..., BranchHint::kTrue)} means "optimize for the case where
+  // the branch is *not* taken".
+  template <typename... Vars>
+  void GotoIfNot(Node* condition, GraphAssemblerLabel<sizeof...(Vars)>* label,
+                 BranchHint hint, Vars...);
+
   // {GotoIf(c, l)} is equivalent to {Branch(c, l, templ);Bind(templ)}.
   template <typename... Vars>
   void GotoIf(Node* condition, GraphAssemblerLabel<sizeof...(Vars)>* label,
@@ -748,9 +764,7 @@ void GraphAssembler::Goto(GraphAssemblerLabel<sizeof...(Vars)>* label,
 template <typename... Vars>
 void GraphAssembler::GotoIf(Node* condition,
                             GraphAssemblerLabel<sizeof...(Vars)>* label,
-                            Vars... vars) {
-  BranchHint hint =
-      label->IsDeferred() ? BranchHint::kFalse : BranchHint::kNone;
+                            BranchHint hint, Vars... vars) {
   Node* branch = graph()->NewNode(common()->Branch(hint), condition, control());
 
   control_ = graph()->NewNode(common()->IfTrue(), branch);
@@ -763,8 +777,7 @@ void GraphAssembler::GotoIf(Node* condition,
 template <typename... Vars>
 void GraphAssembler::GotoIfNot(Node* condition,
                                GraphAssemblerLabel<sizeof...(Vars)>* label,
-                               Vars... vars) {
-  BranchHint hint = label->IsDeferred() ? BranchHint::kTrue : BranchHint::kNone;
+                               BranchHint hint, Vars... vars) {
   Node* branch = graph()->NewNode(common()->Branch(hint), condition, control());
 
   control_ = graph()->NewNode(common()->IfFalse(), branch);
@@ -774,6 +787,23 @@ void GraphAssembler::GotoIfNot(Node* condition,
   control_ = AddNode(graph()->NewNode(common()->IfTrue(), branch));
 }
 
+template <typename... Vars>
+void GraphAssembler::GotoIf(Node* condition,
+                            GraphAssemblerLabel<sizeof...(Vars)>* label,
+                            Vars... vars) {
+  BranchHint hint =
+      label->IsDeferred() ? BranchHint::kFalse : BranchHint::kNone;
+  return GotoIf(condition, label, hint, vars...);
+}
+
+template <typename... Vars>
+void GraphAssembler::GotoIfNot(Node* condition,
+                               GraphAssemblerLabel<sizeof...(Vars)>* label,
+                               Vars... vars) {
+  BranchHint hint = label->IsDeferred() ? BranchHint::kTrue : BranchHint::kNone;
+  return GotoIfNot(condition, label, hint, vars...);
+}
+
 template <typename... Args>
 TNode<Object> GraphAssembler::Call(const CallDescriptor* call_descriptor,
                                    Node* first_arg, Args... args) {

src/compiler/wasm-compiler.cc

@@ -5754,29 +5754,31 @@ void AssertFalse(MachineGraph* mcgraph, GraphAssembler* gasm, Node* condition) {
 WasmGraphBuilder::Callbacks WasmGraphBuilder::TestCallbacks(
     GraphAssemblerLabel<1>* label) {
   return {// succeed_if
-          [=](Node* condition) -> void {
-            gasm_->GotoIf(condition, label, gasm_->Int32Constant(1));
+          [=](Node* condition, BranchHint hint) -> void {
+            gasm_->GotoIf(condition, label, hint, gasm_->Int32Constant(1));
           },
           // fail_if
-          [=](Node* condition) -> void {
-            gasm_->GotoIf(condition, label, gasm_->Int32Constant(0));
+          [=](Node* condition, BranchHint hint) -> void {
+            gasm_->GotoIf(condition, label, hint, gasm_->Int32Constant(0));
           },
           // fail_if_not
-          [=](Node* condition) -> void {
-            gasm_->GotoIfNot(condition, label, gasm_->Int32Constant(0));
+          [=](Node* condition, BranchHint hint) -> void {
+            gasm_->GotoIfNot(condition, label, hint, gasm_->Int32Constant(0));
           }};
 }
 
 WasmGraphBuilder::Callbacks WasmGraphBuilder::CastCallbacks(
     GraphAssemblerLabel<0>* label, wasm::WasmCodePosition position) {
   return {// succeed_if
-          [=](Node* condition) -> void { gasm_->GotoIf(condition, label); },
+          [=](Node* condition, BranchHint hint) -> void {
+            gasm_->GotoIf(condition, label, hint);
+          },
           // fail_if
-          [=](Node* condition) -> void {
+          [=](Node* condition, BranchHint hint) -> void {
             TrapIfTrue(wasm::kTrapIllegalCast, condition, position);
           },
           // fail_if_not
-          [=](Node* condition) -> void {
+          [=](Node* condition, BranchHint hint) -> void {
             TrapIfFalse(wasm::kTrapIllegalCast, condition, position);
           }};
 }
@@ -5786,30 +5788,27 @@ WasmGraphBuilder::Callbacks WasmGraphBuilder::BranchCallbacks(
     SmallNodeVector& match_controls, SmallNodeVector& match_effects) {
   return {
       // succeed_if
-      [&](Node* condition) -> void {
-        Node* branch =
-            graph()->NewNode(mcgraph()->common()->Branch(BranchHint::kTrue),
-                             condition, control());
+      [&](Node* condition, BranchHint hint) -> void {
+        Node* branch = graph()->NewNode(mcgraph()->common()->Branch(hint),
+                                        condition, control());
         match_controls.emplace_back(
             graph()->NewNode(mcgraph()->common()->IfTrue(), branch));
         match_effects.emplace_back(effect());
         SetControl(graph()->NewNode(mcgraph()->common()->IfFalse(), branch));
       },
       // fail_if
-      [&](Node* condition) -> void {
-        Node* branch =
-            graph()->NewNode(mcgraph()->common()->Branch(BranchHint::kFalse),
-                             condition, control());
+      [&](Node* condition, BranchHint hint) -> void {
+        Node* branch = graph()->NewNode(mcgraph()->common()->Branch(hint),
+                                        condition, control());
         no_match_controls.emplace_back(
             graph()->NewNode(mcgraph()->common()->IfTrue(), branch));
         no_match_effects.emplace_back(effect());
         SetControl(graph()->NewNode(mcgraph()->common()->IfFalse(), branch));
       },
       // fail_if_not
-      [&](Node* condition) -> void {
-        Node* branch =
-            graph()->NewNode(mcgraph()->common()->Branch(BranchHint::kTrue),
-                             condition, control());
+      [&](Node* condition, BranchHint hint) -> void {
+        Node* branch = graph()->NewNode(mcgraph()->common()->Branch(hint),
+                                        condition, control());
         no_match_controls.emplace_back(
             graph()->NewNode(mcgraph()->common()->IfFalse(), branch));
         no_match_effects.emplace_back(effect());
@@ -5821,8 +5820,8 @@ void WasmGraphBuilder::TypeCheck(
     Node* object, Node* rtt, WasmGraphBuilder::ObjectReferenceKnowledge config,
     bool null_succeeds, Callbacks callbacks) {
   if (config.object_can_be_null) {
-    (null_succeeds ? callbacks.succeed_if
-                   : callbacks.fail_if)(gasm_->WordEqual(object, RefNull()));
+    (null_succeeds ? callbacks.succeed_if : callbacks.fail_if)(
+        gasm_->WordEqual(object, RefNull()), BranchHint::kFalse);
   }
 
   Node* map = gasm_->LoadMap(object);
@@ -5830,13 +5829,13 @@ void WasmGraphBuilder::TypeCheck(
   if (config.reference_kind == kFunction) {
     // Currently, the only way for a function to match an rtt is if its map
     // is equal to that rtt.
-    callbacks.fail_if_not(gasm_->TaggedEqual(map, rtt));
+    callbacks.fail_if_not(gasm_->TaggedEqual(map, rtt), BranchHint::kTrue);
     return;
   }
 
   DCHECK(config.reference_kind == kArrayOrStruct);
 
-  callbacks.succeed_if(gasm_->TaggedEqual(map, rtt));
+  callbacks.succeed_if(gasm_->TaggedEqual(map, rtt), BranchHint::kTrue);
 
   Node* type_info = gasm_->LoadWasmTypeInfo(map);
   Node* supertypes = gasm_->LoadSupertypes(type_info);
@@ -5847,30 +5846,33 @@ void WasmGraphBuilder::TypeCheck(
           ? gasm_->Int32Constant(config.rtt_depth)
           : BuildChangeSmiToInt32(gasm_->LoadFixedArrayLengthAsSmi(
                 gasm_->LoadSupertypes(gasm_->LoadWasmTypeInfo(rtt))));
-  callbacks.fail_if_not(gasm_->Uint32LessThan(rtt_depth, supertypes_length));
+  callbacks.fail_if_not(gasm_->Uint32LessThan(rtt_depth, supertypes_length),
+                        BranchHint::kTrue);
   Node* maybe_match = gasm_->LoadFixedArrayElement(
       supertypes, rtt_depth, MachineType::TaggedPointer());
 
-  callbacks.fail_if_not(gasm_->TaggedEqual(maybe_match, rtt));
+  callbacks.fail_if_not(gasm_->TaggedEqual(maybe_match, rtt),
+                        BranchHint::kTrue);
 }
 
 void WasmGraphBuilder::DataCheck(Node* object, bool object_can_be_null,
                                  Callbacks callbacks) {
   if (object_can_be_null) {
-    callbacks.fail_if(gasm_->WordEqual(object, RefNull()));
+    callbacks.fail_if(gasm_->WordEqual(object, RefNull()), BranchHint::kFalse);
   }
-  callbacks.fail_if(gasm_->IsI31(object));
+  callbacks.fail_if(gasm_->IsI31(object), BranchHint::kFalse);
   Node* map = gasm_->LoadMap(object);
-  callbacks.fail_if_not(gasm_->IsDataRefMap(map));
+  callbacks.fail_if_not(gasm_->IsDataRefMap(map), BranchHint::kTrue);
 }
 
 void WasmGraphBuilder::FuncCheck(Node* object, bool object_can_be_null,
                                  Callbacks callbacks) {
   if (object_can_be_null) {
-    callbacks.fail_if(gasm_->WordEqual(object, RefNull()));
+    callbacks.fail_if(gasm_->WordEqual(object, RefNull()), BranchHint::kFalse);
   }
-  callbacks.fail_if(gasm_->IsI31(object));
-  callbacks.fail_if_not(gasm_->HasInstanceType(object, JS_FUNCTION_TYPE));
+  callbacks.fail_if(gasm_->IsI31(object), BranchHint::kFalse);
+  callbacks.fail_if_not(gasm_->HasInstanceType(object, JS_FUNCTION_TYPE),
+                        BranchHint::kTrue);
 }
 
 Node* WasmGraphBuilder::BrOnCastAbs(

src/compiler/wasm-compiler.h

@@ -39,6 +39,7 @@ enum class TrapId : uint32_t;
 struct Int64LoweringSpecialCase;
 template <size_t VarCount>
 class GraphAssemblerLabel;
+enum class BranchHint : uint8_t;
 }  // namespace compiler
 
 namespace wasm {
@@ -621,11 +622,11 @@ class WasmGraphBuilder {
   // generates {index > max ? Smi(max) : Smi(index)}
   Node* BuildConvertUint32ToSmiWithSaturation(Node* index, uint32_t maxval);
 
-  using NodeConsumer = std::function<void(Node*)>;
+  using BranchBuilder = std::function<void(Node*, BranchHint)>;
   struct Callbacks {
-    NodeConsumer succeed_if;
-    NodeConsumer fail_if;
-    NodeConsumer fail_if_not;
+    BranchBuilder succeed_if;
+    BranchBuilder fail_if;
+    BranchBuilder fail_if_not;
   };
 
   // This type is used to collect control/effect nodes we need to merge at the