[clang][bytecode] jumpcase

tbaederr · tbaederr · commit ea4398fc19df · 2026-06-05T16:36:24.000+02:00
diff --git a/clang/lib/AST/ByteCode/ByteCodeEmitter.cpp b/clang/lib/AST/ByteCode/ByteCodeEmitter.cpp
@@ -225,6 +225,10 @@ bool ByteCodeEmitter::jumpTrue(const LabelTy &Label, SourceInfo SI) {
   return emitJt(getOffset(Label), SI);
 }
 
+bool ByteCodeEmitter::jumpCase(const LabelTy &Label, SourceInfo SI) {
+  return emitJc(getOffset(Label), SI);
+}
+
 bool ByteCodeEmitter::jumpFalse(const LabelTy &Label, SourceInfo SI) {
   return emitJf(getOffset(Label), SI);
 }
diff --git a/clang/lib/AST/ByteCode/ByteCodeEmitter.h b/clang/lib/AST/ByteCode/ByteCodeEmitter.h
@@ -55,6 +55,7 @@ class ByteCodeEmitter {
 
   /// Emits jumps.
   bool jumpTrue(const LabelTy &Label, SourceInfo SI);
+  bool jumpCase(const LabelTy &Label, SourceInfo SI);
   bool jumpFalse(const LabelTy &Label, SourceInfo SI);
   bool jump(const LabelTy &Label, SourceInfo SI);
   bool fallthrough(const LabelTy &Label);
diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -6675,7 +6675,7 @@ bool Compiler<Emitter>::visitSwitchStmt(const SwitchStmt *S) {
       // Compare and jump to the case label.
       if (!this->emitEQ(ValueT, S))
         return false;
-      if (!this->jumpTrue(CaseLabels[CS], S))
+      if (!this->jumpCase(CaseLabels[CS], S))
         return false;
     } else {
       assert(!DefaultLabel);
diff --git a/clang/lib/AST/ByteCode/EvalEmitter.cpp b/clang/lib/AST/ByteCode/EvalEmitter.cpp
@@ -161,6 +161,10 @@ bool EvalEmitter::jumpTrue(const LabelTy &Label, SourceInfo SI) {
   return true;
 }
 
+bool EvalEmitter::jumpCase(const LabelTy &Label, SourceInfo SI) {
+  return jumpTrue(Label, SI);
+}
+
 bool EvalEmitter::jumpFalse(const LabelTy &Label, SourceInfo SI) {
   if (isActive()) {
     CurrentSource = SI;
diff --git a/clang/lib/AST/ByteCode/EvalEmitter.h b/clang/lib/AST/ByteCode/EvalEmitter.h
@@ -73,6 +73,7 @@ class EvalEmitter : public SourceMapper {
 
   /// Emits jumps.
   bool jumpTrue(const LabelTy &Label, SourceInfo SI);
+  bool jumpCase(const LabelTy &Label, SourceInfo SI);
   bool jumpFalse(const LabelTy &Label, SourceInfo SI);
   bool jump(const LabelTy &Label, SourceInfo SI);
   bool fallthrough(const LabelTy &Label);
diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
@@ -62,10 +62,15 @@ static bool Jmp(InterpState &S, CodePtr &PC, int32_t Offset) {
   return S.noteStep(PC);
 }
 
-static bool Jt(InterpState &S, CodePtr &PC, int32_t Offset) {
-  if (S.Stk.pop<bool>()) {
+/// jumpCase - like jumpTrue, but we do not note a step.
+static bool Jc(InterpState &S, CodePtr &PC, int32_t Offset) {
+  if (S.Stk.pop<bool>())
     PC += Offset;
-  }
+  return true;
+}
+
+static bool Jt(InterpState &S, CodePtr &PC, int32_t Offset) {
+  Jc(S, PC, Offset);
   return S.noteStep(PC);
 }
 
diff --git a/clang/lib/AST/ByteCode/Opcodes.td b/clang/lib/AST/ByteCode/Opcodes.td
@@ -175,6 +175,8 @@ class JumpOpcode : Opcode {
 def Jmp : JumpOpcode;
 // [Bool] -> [], jumps if true.
 def Jt : JumpOpcode;
+// [Bool] -> [], jumps if true. Does NOT count as a step.
+def Jc : JumpOpcode;
 // [Bool] -> [], jumps if false.
 def Jf : JumpOpcode;
 

Original file line number	Diff line number	Diff line change
`@@ -225,6 +225,10 @@ bool ByteCodeEmitter::jumpTrue(const LabelTy &Label, SourceInfo SI) {`
`225`	`225`	`return emitJt(getOffset(Label), SI);`
`226`	`226`	`}`
`227`	`227`
	`228`	`+bool ByteCodeEmitter::jumpCase(const LabelTy &Label, SourceInfo SI) {`
	`229`	`+ return emitJc(getOffset(Label), SI);`
	`230`	`+}`
	`231`	`+`
`228`	`232`	`bool ByteCodeEmitter::jumpFalse(const LabelTy &Label, SourceInfo SI) {`
`229`	`233`	`return emitJf(getOffset(Label), SI);`
`230`	`234`	`}`