Author: Aaron Ballman Date: 2022-03-22T10:00:05-04:00 New Revision: 9cf8f81ca45de198013f29442a7de6600b226d70
URL: https://github.com/llvm/llvm-project/commit/9cf8f81ca45de198013f29442a7de6600b226d70 DIFF: https://github.com/llvm/llvm-project/commit/9cf8f81ca45de198013f29442a7de6600b226d70.diff LOG: Fix _BitInt suffix width calculation @mgehre-amd pointed out the following post-commit review feedback on the changes in 8cba72177dcd8de5d37177dbaf2347e5c1f0f1e8: As an example, the paper says 3wb /* Yields an _BitInt(3); two value bits, one sign bit */. So I would expect that 0xFwb gives _BitInt(5); four value bits, one sign bit, but with this implementation I get _BitInt(2). This is because ResultVal as 4 bits, and getMinSignedBits() inteprets it as negative and thus says that 1 bit is enough to represent -1. This corrects the behavior for calculating the bit-width and adds some test coverage. Added: Modified: clang/lib/Sema/SemaExpr.cpp clang/test/Lexer/bitint-constants.c Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index be90c58e066d8..7fdeb7a8e30be 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -3979,8 +3979,8 @@ ExprResult Sema::ActOnNumericConstant(const Token &Tok, Scope *UDLScope) { if (Literal.isBitInt) { // The signed version has one more bit for the sign value. There are no // zero-width bit-precise integers, even if the literal value is 0. - Width = Literal.isUnsigned ? std::max(ResultVal.getActiveBits(), 1u) - : std::max(ResultVal.getMinSignedBits(), 2u); + Width = std::max(ResultVal.getActiveBits(), 1u) + + (Literal.isUnsigned ? 0u : 1u); // Diagnose if the width of the constant is larger than BITINT_MAXWIDTH, // and reset the type to the largest supported width. diff --git a/clang/test/Lexer/bitint-constants.c b/clang/test/Lexer/bitint-constants.c index 243f8c0377c27..2ff35e8207786 100644 --- a/clang/test/Lexer/bitint-constants.c +++ b/clang/test/Lexer/bitint-constants.c @@ -142,3 +142,18 @@ void ValidSuffixInvalidValue(void) { 0xFFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'1wb; // expected-error {{integer literal is too large to be represented in any signed integer type}} 0xFFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'1uwb; // expected-error {{integer literal is too large to be represented in any integer type}} } + +void TestTypes(void) { + // 2 value bits, one sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(3wb), _BitInt(3))); + // 2 value bits, one sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(-3wb), _BitInt(3))); + // 2 value bits, no sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(3uwb), unsigned _BitInt(2))); + // 4 value bits, one sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(0xFwb), _BitInt(5))); + // 4 value bits, one sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(-0xFwb), _BitInt(5))); + // 4 value bits, no sign bit + _Static_assert(__builtin_types_compatible_p(__typeof__(0xFuwb), unsigned _BitInt(4))); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits