llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Timm Baeder (tbaederr) <details> <summary>Changes</summary> --- Full diff: https://github.com/llvm/llvm-project/pull/104663.diff 2 Files Affected: - (modified) clang/lib/AST/ByteCode/Interp.h (+11) - (modified) clang/test/AST/ByteCode/cxx23.cpp (+14) ``````````diff diff --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h index c3ce21cb13770..9891e3dba0d30 100644 --- a/clang/lib/AST/ByteCode/Interp.h +++ b/clang/lib/AST/ByteCode/Interp.h @@ -2354,6 +2354,17 @@ inline bool DoShift(InterpState &S, CodePtr OpPC, LT &LHS, RT &RHS) { LT::AsUnsigned::from(RHS, Bits), Bits, &R); } + // We did the shift above as unsigned. Restore the sign bit if we need to. + if constexpr (Dir == ShiftDir::Right) { + if (LHS.isSigned() && LHS.isNegative()) { + typename LT::AsUnsigned SignBit; + LT::AsUnsigned::shiftLeft(LT::AsUnsigned::from(1, Bits), + LT::AsUnsigned::from(Bits - 1, Bits), Bits, + &SignBit); + LT::AsUnsigned::bitOr(R, SignBit, Bits, &R); + } + } + S.Stk.push<LT>(LT::from(R)); return true; } diff --git a/clang/test/AST/ByteCode/cxx23.cpp b/clang/test/AST/ByteCode/cxx23.cpp index eb05a9fda0dfb..756eec5b82560 100644 --- a/clang/test/AST/ByteCode/cxx23.cpp +++ b/clang/test/AST/ByteCode/cxx23.cpp @@ -224,3 +224,17 @@ namespace ExplicitLambdaInstancePointer { static_assert(fp(1) == 1, ""); } } + +namespace TwosComplementShifts { + using uint32 = __UINT32_TYPE__; + using int32 = __INT32_TYPE__; + static_assert(uint32(int32(0x1234) << 16) == 0x12340000); + static_assert(uint32(int32(0x1234) << 19) == 0x91a00000); + static_assert(uint32(int32(0x1234) << 20) == 0x23400000); + static_assert(uint32(int32(0x1234) << 24) == 0x34000000); + static_assert(uint32(int32(-1) << 31) == 0x80000000); + + static_assert(-2 >> 1 == -1); + static_assert(-3 >> 1 == -2); + static_assert(-7 >> 1 == -4); +} `````````` </details> https://github.com/llvm/llvm-project/pull/104663 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
