https://github.com/bjope created https://github.com/llvm/llvm-project/pull/175152
In ScalarExprEmitter::EmitScalarPrePostIncDec we create ConstantInt values that are either 1 or -1. There is a special case when the type is i1 (e.g. for unsigned _BitInt(1)) when we need to be able to create a "i1 true" value for both inc and dec. To avoid triggering the assertions added by the pull request #171456 we now treat the ConstantInt as unsigned for increments and as signed for decrements. From 648ae5c5c1d64ac1e0f3b2d7895e5b83cd12c603 Mon Sep 17 00:00:00 2001 From: Bjorn Pettersson <[email protected]> Date: Fri, 9 Jan 2026 11:50:37 +0100 Subject: [PATCH] [clang][CodeGen] Deal with ConstantInt::get for i1 in EmitScalarPrePostIncDec In ScalarExprEmitter::EmitScalarPrePostIncDec we create ConstantInt values that are either 1 or -1. There is a special case when the type is i1 (e.g. for unsigned _BitInt(1)) when we need to be able to create a "i1 true" value for both inc and dec. To avoid triggering the assertions added by the pull request #171456 we now treat the ConstantInt as unsigned for increments and as signed for decrements. --- clang/lib/CodeGen/CGExprScalar.cpp | 5 +++- clang/test/CodeGen/ext-int.c | 42 ++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp index 84421fef9f524..6fd94752f5126 100644 --- a/clang/lib/CodeGen/CGExprScalar.cpp +++ b/clang/lib/CodeGen/CGExprScalar.cpp @@ -3333,7 +3333,10 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, value = EmitOverflowCheckedBinOp(createBinOpInfoFromIncDec( E, value, isInc, E->getFPFeaturesInEffect(CGF.getLangOpts()))); } else { - llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true); + // Treat positive amount as unsigned to support inc of i1 (needed for + // unsigned _BitInt(1)). + llvm::Value *amt = + llvm::ConstantInt::get(value->getType(), amount, !isInc); value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); } diff --git a/clang/test/CodeGen/ext-int.c b/clang/test/CodeGen/ext-int.c index aebacd6f22ffc..a12b11adbf00d 100644 --- a/clang/test/CodeGen/ext-int.c +++ b/clang/test/CodeGen/ext-int.c @@ -79,6 +79,48 @@ void Size1ExtIntParam(unsigned _BitInt(1) A) { B[2] = A; } +unsigned _BitInt(1) Size1PreIncUnsigned(unsigned _BitInt(1) A) { + // CHECK: %[[PARAM_ADDR:.+]] = alloca i8 + // CHECK: %[[PARAM_LOAD:.+]] = load i8, ptr %[[PARAM_ADDR]] + // CHECK: %[[LOADEDV:.+]] = trunc i8 %0 to i1 + // CHECK: %[[INCDEC:.+]] = add i1 %[[LOADEDV]], true + // CHECK: %[[STOREDV1:.+]] = zext i1 %[[INCDEC]] to i8 + // CHECK: store i8 %[[STOREDV1]], ptr %[[PARAM_ADDR]] + return ++A; +} + +unsigned _BitInt(1) Size1PreDecUnsigned(unsigned _BitInt(1) A) { + // CHECK: %[[PARAM_ADDR:.+]] = alloca i8 + // CHECK: %[[PARAM_LOAD:.+]] = load i8, ptr %[[PARAM_ADDR]] + // CHECK: %[[LOADEDV:.+]] = trunc i8 %0 to i1 + // CHECK: %[[INCDEC:.+]] = add i1 %[[LOADEDV]], true + // CHECK: %[[STOREDV1:.+]] = zext i1 %[[INCDEC]] to i8 + // CHECK: store i8 %[[STOREDV1]], ptr %[[PARAM_ADDR]] + return --A; +} + +unsigned _BitInt(1) Size1PostIncUnsigned(unsigned _BitInt(1) A) { + // CHECK: %[[PARAM_ADDR:.+]] = alloca i8 + // CHECK: %[[PARAM_LOAD:.+]] = load i8, ptr %[[PARAM_ADDR]] + // CHECK: %[[LOADEDV:.+]] = trunc i8 %0 to i1 + // CHECK: %[[INCDEC:.+]] = add i1 %[[LOADEDV]], true + // CHECK: %[[STOREDV1:.+]] = zext i1 %[[INCDEC]] to i8 + // CHECK: store i8 %[[STOREDV1]], ptr %[[PARAM_ADDR]] + A++; + return A; +} + +unsigned _BitInt(1) Size1PostDecUnsigned(unsigned _BitInt(1) A) { + // CHECK: %[[PARAM_ADDR:.+]] = alloca i8 + // CHECK: %[[PARAM_LOAD:.+]] = load i8, ptr %[[PARAM_ADDR]] + // CHECK: %[[LOADEDV:.+]] = trunc i8 %0 to i1 + // CHECK: %[[INCDEC:.+]] = add i1 %[[LOADEDV]], true + // CHECK: %[[STOREDV1:.+]] = zext i1 %[[INCDEC]] to i8 + // CHECK: store i8 %[[STOREDV1]], ptr %[[PARAM_ADDR]] + A--; + return A; +} + #if __BITINT_MAXWIDTH__ > 128 struct S1 { _BitInt(17) A; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
