[clang] 24e4414 - [clang][bytecode] Fix DiscardResult handling in fixed-point operations (#195013)

[via cfe-commits]

Author: Timm Baeder
Date: 2026-04-30T09:08:17+02:00
New Revision: 24e441428090d81ba8d9d163b65949d43f90e591

URL: https://github.com/llvm/llvm-project/commit/24e441428090d81ba8d9d163b65949d43f90e591
DIFF: https://github.com/llvm/llvm-project/commit/24e441428090d81ba8d9d163b65949d43f90e591.diff

LOG: [clang][bytecode] Fix DiscardResult handling in fixed-point operations (#195013)

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Compiler.cpp
    clang/test/AST/ByteCode/fixed-point.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 349bbed6830ba..626068ce9eee5 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -773,8 +773,12 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *E) {
 
     auto Sem =
         Ctx.getASTContext().getFixedPointSemantics(E->getType()).toOpaqueInt();
-    return this->emitCastIntegralFixedPoint(classifyPrim(SubExpr->getType()),
-                                            Sem, E);
+    if (!this->emitCastIntegralFixedPoint(classifyPrim(SubExpr->getType()), Sem,
+                                          E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopFixedPoint(E);
+    return true;
   }
   case CK_FloatingToFixedPoint: {
     if (!this->visit(SubExpr))
@@ -782,25 +786,42 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *E) {
 
     auto Sem =
         Ctx.getASTContext().getFixedPointSemantics(E->getType()).toOpaqueInt();
-    return this->emitCastFloatingFixedPoint(Sem, E);
+    if (!this->emitCastFloatingFixedPoint(Sem, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopFixedPoint(E);
+    return true;
   }
   case CK_FixedPointToFloating: {
     if (!this->visit(SubExpr))
       return false;
     const auto *TargetSemantics = &Ctx.getFloatSemantics(E->getType());
-    return this->emitCastFixedPointFloating(TargetSemantics, E);
+    if (!this->emitCastFixedPointFloating(TargetSemantics, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopFloat(E);
+    return true;
   }
   case CK_FixedPointToIntegral: {
     if (!this->visit(SubExpr))
       return false;
-    return this->emitCastFixedPointIntegral(classifyPrim(E->getType()), E);
+    PrimType IntegralT = classifyPrim(E->getType());
+    if (!this->emitCastFixedPointIntegral(IntegralT, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPop(IntegralT, E);
+    return true;
   }
   case CK_FixedPointCast: {
     if (!this->visit(SubExpr))
       return false;
     auto Sem =
         Ctx.getASTContext().getFixedPointSemantics(E->getType()).toOpaqueInt();
-    return this->emitCastFixedPoint(Sem, E);
+    if (!this->emitCastFixedPoint(Sem, E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopFixedPoint(E);
+    return true;
   }
 
   case CK_ToVoid:
@@ -1902,7 +1923,11 @@ bool Compiler<Emitter>::VisitFixedPointUnaryOperator(const UnaryOperator *E) {
   case UO_Minus:
     if (!this->visit(SubExpr))
       return false;
-    return this->emitNegFixedPoint(E);
+    if (!this->emitNegFixedPoint(E))
+      return false;
+    if (DiscardResult)
+      return this->emitPopFixedPoint(E);
+    return true;
   default:
     return false;
   }

diff  --git a/clang/test/AST/ByteCode/fixed-point.cpp b/clang/test/AST/ByteCode/fixed-point.cpp
index 5237d758fa257..c8baa1972536a 100644
--- a/clang/test/AST/ByteCode/fixed-point.cpp
+++ b/clang/test/AST/ByteCode/fixed-point.cpp
@@ -12,6 +12,7 @@ static_assert(1.0k != 1); // both-error {{failed due to requirement '1.0k != 1'}
 static_assert(-12.0k == -(-(-12.0k)));
 
 constexpr _Accum acc = (0.5r, 6.9k);
+constexpr _Accum acc2 = (-1e+00r, 2.3);
 
 /// Zero-init.
 constexpr _Accum A{};