Bug 1401675 - Baldr: simplify how function bodies end (r=lth)

--HG--
extra : rebase_source : 419677654d23ba47ba7ce26472cab50826586850

js/src/wasm/WasmBaselineCompile.cpp

@@ -8395,6 +8395,12 @@ bool BaseCompiler::emitEnd() {
   }
 
   switch (kind) {
+    case LabelKind::Body:
+      endBlock(type);
+      iter_.popEnd();
+      MOZ_ASSERT(iter_.controlStackEmpty());
+      doReturn(type, PopStack(false));
+      return iter_.readFunctionEnd(iter_.end());
     case LabelKind::Block:
       endBlock(type);
       break;
@@ -8558,6 +8564,9 @@ bool BaseCompiler::emitDrop() {
 }
 
 void BaseCompiler::doReturn(ExprType type, bool popStack) {
+  if (deadCode_) {
+    return;
+  }
   switch (type.code()) {
     case ExprType::Void: {
       returnCleanup(popStack);
@@ -10944,12 +10953,8 @@ bool BaseCompiler::emitBody() {
         if (!emitEnd()) {
           return false;
         }
-
         if (iter_.controlStackEmpty()) {
-          if (!deadCode_) {
-            doReturn(funcType().ret(), PopStack(false));
-          }
-          return iter_.readFunctionEnd(iter_.end());
+          return true;
         }
         NEXT();
 

js/src/wasm/WasmIonCompile.cpp

@@ -1784,6 +1784,17 @@ static bool EmitEnd(FunctionCompiler& f) {
 
   MDefinition* def = nullptr;
   switch (kind) {
+    case LabelKind::Body:
+      MOZ_ASSERT(f.iter().controlStackEmpty());
+      if (!f.finishBlock(&def)) {
+        return false;
+      }
+      if (f.inDeadCode() || IsVoid(type)) {
+        f.returnVoid();
+      } else {
+        f.returnExpr(def);
+      }
+      return f.iter().readFunctionEnd(f.iter().end());
     case LabelKind::Block:
       if (!f.finishBlock(&def)) {
         return false;
@@ -3109,14 +3120,8 @@ static bool EmitBodyExprs(FunctionCompiler& f) {
         if (!EmitEnd(f)) {
           return false;
         }
-
         if (f.iter().controlStackEmpty()) {
-          if (f.inDeadCode() || IsVoid(f.funcType().ret())) {
-            f.returnVoid();
-          } else {
-            f.returnExpr(f.iter().getResult());
-          }
-          return f.iter().readFunctionEnd(f.iter().end());
+          return true;
         }
         break;
 

js/src/wasm/WasmOpIter.h

@@ -30,7 +30,7 @@ namespace js {
 namespace wasm {
 
 // The kind of a control-flow stack item.
-enum class LabelKind : uint8_t { Block, Loop, Then, Else };
+enum class LabelKind : uint8_t { Body, Block, Loop, Then, Else };
 
 // The type of values on the operand stack during validation. The Any type
 // represents the type of a value produced by an unconditional branch.
@@ -815,7 +815,7 @@ inline bool OpIter<Policy>::readFunctionStart(ExprType ret) {
   MOZ_ASSERT(controlStack_.empty());
   MOZ_ASSERT(op_.b0 == uint16_t(Op::Limit));
 
-  return pushControl(LabelKind::Block, ret);
+  return pushControl(LabelKind::Body, ret);
 }
 
 template <typename Policy>
@@ -840,7 +840,7 @@ inline bool OpIter<Policy>::readReturn(Value* value) {
   MOZ_ASSERT(Classify(op_) == OpKind::Return);
 
   ControlStackEntry<ControlItem>& body = controlStack_[0];
-  MOZ_ASSERT(body.kind() == LabelKind::Block);
+  MOZ_ASSERT(body.kind() == LabelKind::Body);
 
   if (!popWithType(body.resultType(), value)) {
     return false;