[libc-commits] [libc] [libc][stdfix] Generate stdfix.h header with fixed point precision macros according to N1169 standard, and add fixed point type support detection. (PR #81255)

[via libc-commits]

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+//===-- Definitions from stdfix.h -----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_STDFIX_MACROS_H
+#define __LLVM_LIBC_MACROS_STDFIX_MACROS_H
+
+#ifdef __clang__
+#if (!defined(__cplusplus) || (__clang_major__ >= 18))
+// _Fract and _Accum types are avaiable
+#define LIBC_COMPILER_HAS_FIXED_POINT
+#endif // __cplusplus
+#endif // __clang__
+
+#ifdef LIBC_COMPILER_HAS_FIXED_POINT
+
+#define fract _Fract
+#define accum _Accum
+
+// Default values: from N1169 standard - Annex A.3 - Typical desktop processor.
+
+#ifdef __SFRACT_FBIT__
+#define SFRACT_FBIT __SFRACT_FBIT__
+#else
+#define SFRACT_FBIT 7
+#endif // SFRACT_FBIT
+
+#ifdef __SFRACT_MIN__
+#define SFRACT_MIN __SFRACT_MIN__
+#else
+#define SFRACT_MIN (-0.5HR - 0.5HR)
+#endif // SFRACT_MIN
+
+#ifdef __SFRACT_MAX__
+#define SFRACT_MAX __SFRACT_MAX__
+#else
+#define SFRACT_MAX 0x1.FCp-1HR
+#endif // SFRACT_MAX
+
+#ifdef __SFRACT_EPSILON__
+#define SFRACT_EPSILON __SFRACT_EPSILON__
+#else
+#define SFRACT_EPSILON 0x1.0p-7HR
+#endif // SFRACT_EPSILON
+
+#ifdef __USFRACT_FBIT__
+#define USFRACT_FBIT __USFRACT_FBIT__
+#else
+#define USFRACT_FBIT 8
+#endif // USFRACT_FBIT
+
+#ifdef __USFRACT_MIN__
+#define USFRACT_MIN __USFRACT_MIN__
+#else
+#define USFRACT_MIN 0.0UHR
+#endif // USFRACT_MIN
+
+#ifdef __USFRACT_MAX__
+#define USFRACT_MAX __USFRACT_MAX__
+#else
+#define USFRACT_MAX 0x1.FEp-1UHR
+#endif // USFRACT_MAX
+
+#ifdef __USFRACT_EPSILON__
+#define USFRACT_EPSILON __USFRACT_EPSILON__
+#else
+#define USFRACT_EPSILON 0x1.0p-8UHR
+#endif // USFRACT_EPSILON
+
+#ifdef __FRACT_FBIT__
+#define FRACT_FBIT __FRACT_FBIT__
+#else
+#define FRACT_FBIT 15
+#endif // FRACT_FBIT
+
+#ifdef __FRACT_MIN__
+#define FRACT_MIN __FRACT_MIN__
+#else
+#define FRACT_MIN (-0.5R - 0.5R)
+#endif // FRACT_MIN
+
+#ifdef __FRACT_MAX__
+#define FRACT_MAX __FRACT_MAX__
+#else
+#define FRACT_MAX 0x1.FFFCp-1R
+#endif // FRACT_MAX
+
+#ifdef __FRACT_EPSILON__
+#define FRACT_EPSILON __FRACT_EPSILON__
+#else
+#define FRACT_EPSILON 0x1.0p-15R
+#endif // FRACT_EPSILON
+
+#ifdef __UFRACT_FBIT__
+#define UFRACT_FBIT __UFRACT_FBIT__
+#else
+#define UFRACT_FBIT 16
+#endif // UFRACT_FBIT
+
+#ifdef __UFRACT_MIN__
+#define UFRACT_MIN __UFRACT_MIN__
+#else
+#define UFRACT_MIN 0.0UR
+#endif // UFRACT_MIN
+
+#ifdef __UFRACT_MAX__
+#define UFRACT_MAX __UFRACT_MAX__
+#else
+#define UFRACT_MAX 0x1.FFFEp-1UR
+#endif // UFRACT_MAX
+
+#ifdef __UFRACT_EPSILON__
+#define UFRACT_EPSILON __UFRACT_EPSILON__
+#else
+#define UFRACT_EPSILON 0x1.0p-16UR
+#endif // UFRACT_EPSILON
+
+#ifdef __LFRACT_FBIT__
+#define LFRACT_FBIT __LFRACT_FBIT__
+#else
+#define LFRACT_FBIT 31
+#endif // LFRACT_FBIT
+
+#ifdef __LFRACT_MIN__
+#define LFRACT_MIN __LFRACT_MIN__
+#else
+#define LFRACT_MIN (-0.5LR - 0.5LR)
+#endif // LFRACT_MIN
+
+#ifdef __LFRACT_MAX__
+#define LFRACT_MAX __LFRACT_MAX__
+#else
+#define LFRACT_MAX 0x1.FFFFFFFCp-1LR
+#endif // LFRACT_MAX
+
+#ifdef __LFRACT_EPSILON__
+#define LFRACT_EPSILON __LFRACT_EPSILON__
+#else
+#define LFRACT_EPSILON 0x1.0p-31LR
+#endif // LFRACT_EPSILON
+
+#ifdef __ULFRACT_FBIT__
+#define ULFRACT_FBIT __ULFRACT_FBIT__
+#else
+#define ULFRACT_FBIT 32
+#endif // ULFRACT_FBIT
+
+#ifdef __ULFRACT_MIN__
+#define ULFRACT_MIN __ULFRACT_MIN__
+#else
+#define ULFRACT_MIN 0.0ULR
+#endif // ULFRACT_MIN
+
+#ifdef __ULFRACT_MAX__
+#define ULFRACT_MAX __ULFRACT_MAX__
+#else
+#define ULFRACT_MAX 0x1.FFFFFFFEp-1ULR
+#endif // ULFRACT_MAX
+
+#ifdef __ULFRACT_EPSILON__
+#define ULFRACT_EPSILON __ULFRACT_EPSILON__
+#else
+#define ULFRACT_EPSILON 0x1.0p-32ULR
+#endif // ULFRACT_EPSILON
+
+#ifdef __SACCUM_FBIT__
+#define SACCUM_FBIT __SACCUM_FBIT__
+#else
+#define SACCUM_FBIT 7
+#endif // SACCUM_FBIT
+
+#ifdef __SACCUM_IBIT__
+#define SACCUM_IBIT __SACCUM_IBIT__
+#else
+#define SACCUM_IBIT 8
+#endif // SACCUM_IBIT
+
+#ifdef __SACCUM_MIN__
+#define SACCUM_MIN __SACCUM_MIN__
+#else
+#define SACCUM_MIN (-0x1.0p+7HK - 0x1.0p+7HK)
+#endif // SACCUM_MIN
+
+#ifdef __SACCUM_MAX__
+#define SACCUM_MAX __SACCUM_MAX__
+#else
+#define SACCUM_MAX 0x1.FFFCp+7HK
+#endif // SACCUM_MAX
+
+#ifdef __SACCUM_EPSILON__
+#define SACCUM_EPSILON __SACCUM_EPSILON__
+#else
+#define SACCUM_EPSILON 0x1.0p-7HK
+#endif // SACCUM_EPSILON
+
+#ifdef __USACCUM_FBIT__
+#define USACCUM_FBIT __USACCUM_FBIT__
+#else
+#define USACCUM_FBIT 8
+#endif // USACCUM_FBIT
+
+#ifdef __USACCUM_IBIT__
+#define USACCUM_IBIT __USACCUM_IBIT__
+#else
+#define USACCUM_IBIT 8
+#endif // USACCUM_IBIT
+
+#ifdef __USACCUM_MIN__
+#define USACCUM_MIN __USACCUM_MIN__
+#else
+#define USACCUM_MIN 0.0UHK
+#endif // USACCUM_MIN
+
+#ifdef __USACCUM_MAX__
+#define USACCUM_MAX __USACCUM_MAX__
+#else
+#define USACCUM_MAX 0x1.FFFEp+7UHK
+#endif // USACCUM_MAX
+
+#ifdef __USACCUM_EPSILON__
+#define USACCUM_EPSILON __USACCUM_EPSILON__
+#else
+#define USACCUM_EPSILON 0x1.0p-8UHK
+#endif // USACCUM_EPSILON
+
+#ifdef __ACCUM_FBIT__
+#define ACCUM_FBIT __ACCUM_FBIT__
+#else
+#define ACCUM_FBIT 15
+#endif // ACCUM_FBIT
+
+#ifdef __ACCUM_IBIT__
+#define ACCUM_IBIT __ACCUM_IBIT__
+#else
+#define ACCUM_IBIT 16
+#endif // ACCUM_IBIT
+
+#ifdef __ACCUM_MIN__
+#define ACCUM_MIN __ACCUM_MIN__
+#else
+#define ACCUM_MIN (-0x1.0p+15K - 0x1.0p+15K)
+#endif // ACCUM_MIN
+
+#ifdef __ACCUM_MAX__
+#define ACCUM_MAX __ACCUM_MAX__
+#else
+#define ACCUM_MAX 0x1.FFFFFFFCp+15K
+#endif // ACCUM_MAX
+
+#ifdef __ACCUM_EPSILON__
+#define ACCUM_EPSILON __ACCUM_EPSILON__
+#else
+#define ACCUM_EPSILON 0x1.0p-15K
+#endif // ACCUM_EPSILON
+
+#ifdef __UACCUM_FBIT__
+#define UACCUM_FBIT __UACCUM_FBIT__
+#else
+#define UACCUM_FBIT 16
+#endif // UACCUM_FBIT
+
+#ifdef __UACCUM_IBIT__
+#define UACCUM_IBIT __UACCUM_IBIT__
+#else
+#define UACCUM_IBIT 16
+#endif // UACCUM_IBIT
+
+#ifdef __UACCUM_MIN__
+#define UACCUM_MIN __UACCUM_MIN__
----------------
PiJoules wrote:

Technically the unsigned types don't have a `*_MIN__` equivalent macro since they're all just zero, but we could probably add them and say they're an extension just like gcc, or we could just unconditionally define them as 0.

https://github.com/llvm/llvm-project/pull/81255