[clang] fdd9555 - [clang][bytecode] Fix discarded Mulc/DivC opcodes (#180537)

[via cfe-commits]

Author: Timm Baeder
Date: 2026-02-10T05:46:16+01:00
New Revision: fdd9555fc015b0be790226c68391537d12581a82

URL: https://github.com/llvm/llvm-project/commit/fdd9555fc015b0be790226c68391537d12581a82
DIFF: https://github.com/llvm/llvm-project/commit/fdd9555fc015b0be790226c68391537d12581a82.diff

LOG: [clang][bytecode] Fix discarded Mulc/DivC opcodes (#180537)

We need to pop the pointer in that case.

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Compiler.cpp
    clang/test/AST/ByteCode/complex.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index b981cd3c7090d..07237263e2971 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -1217,7 +1217,11 @@ bool Compiler<Emitter>::VisitComplexBinOp(const BinaryOperator *E) {
       return false;
     if (!this->visit(RHS))
       return false;
-    return this->emitMulc(ElemT, E);
+    if (!this->emitMulc(ElemT, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopPtr(E);
+    return true;
   }
 
   if (Op == BO_Div && RHSIsComplex) {
@@ -1254,7 +1258,11 @@ bool Compiler<Emitter>::VisitComplexBinOp(const BinaryOperator *E) {
 
     if (!this->visit(RHS))
       return false;
-    return this->emitDivc(ElemT, E);
+    if (!this->emitDivc(ElemT, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopPtr(E);
+    return true;
   }
 
   // Evaluate LHS and save value to LHSOffset.

diff  --git a/clang/test/AST/ByteCode/complex.cpp b/clang/test/AST/ByteCode/complex.cpp
index 4440f201bb059..716b798277589 100644
--- a/clang/test/AST/ByteCode/complex.cpp
+++ b/clang/test/AST/ByteCode/complex.cpp
@@ -459,4 +459,11 @@ namespace Discard {
     return k;
   }
   static_assert(test_side_effect() == 1);
+
+  constexpr int discardedMulDiv() {
+    (void)(3 * 2i);
+    (void)(3 / 2i);
+    return 0;
+  }
+  static_assert(discardedMulDiv() == 0, "");
 }