diff --git a/Documentation/components/libs/libc/index.rst b/Documentation/components/libs/libc/index.rst index 82d2d45294401..902f27c2cfe60 100644 --- a/Documentation/components/libs/libc/index.rst +++ b/Documentation/components/libs/libc/index.rst @@ -51,6 +51,7 @@ functions. So we have:: sched - sched.h search - search.h semaphore - semaphore.h + stdbit - stdbit.h (optional C23) stdio - stdio.h stdlib - stdlib.h string - string.h (and legacy strings.h and non-standard nuttx/b2c.h) @@ -155,5 +156,6 @@ Implementation Details :caption: Contents: search.rst + stdbit.rst stream.rst zoneinfo.rst diff --git a/Documentation/components/libs/libc/stdbit.rst b/Documentation/components/libs/libc/stdbit.rst new file mode 100644 index 0000000000000..8460cacfa3fd9 --- /dev/null +++ b/Documentation/components/libs/libc/stdbit.rst @@ -0,0 +1,30 @@ +======== +stdbit.h +======== + +The optional C23 ``stdbit.h`` header provides bit manipulation macros +(endianness, leading/trailing zeros and ones, count, single-bit test, +bit width, bit floor, bit ceil). NuttX provides this header only when +explicitly enabled via Kconfig. + +Configuration +============= + +- **CONFIG_ARCH_HAVE_STDBIT_H** (bool, selected by arch) + Architecture indicates it provides ``arch//include/stdbit.h``. + +- **CONFIG_ARCH_STDBIT_H** (bool "stdbit.h", depends on ARCH_HAVE_STDBIT_H) + Use the redirecting header. The build copies + ``include/nuttx/lib/stdbit.h`` to ``include/stdbit.h``; that header + then includes ```` when this option is set. + +- **CONFIG_LIBC_STDBIT_GENERIC** (bool "stdbit.h (generic C23)") + Use the generic C23 implementation. The same redirecting file + ``include/nuttx/lib/stdbit.h`` is copied to ``include/stdbit.h``, + and the generic implementation is used (no arch header). Requires + compiler builtins (e.g. ``__builtin_clz``, ``__builtin_ctz``, + ``__builtin_popcount``); see ``CONFIG_HAVE_BUILTIN_*`` in + ``nuttx/compiler.h``. + +Either **CONFIG_ARCH_STDBIT_H** or **CONFIG_LIBC_STDBIT_GENERIC** may be +enabled so that ``#include `` is available. diff --git a/Kconfig b/Kconfig index f87d144c90a04..b5774f42ba0db 100644 --- a/Kconfig +++ b/Kconfig @@ -625,6 +625,31 @@ config ARCH_STDARG_H ARCH_STDARG_H=y and providing. If ARCH_STDARG_H, is not defined, then the stdarg.h header file will stay out-of-the-way in include/nuttx/. +config ARCH_HAVE_STDBIT_H + bool + default n + ---help--- + Selected by architecture specific logic if the architecture + provides a stdbit.h header file. + +config ARCH_STDBIT_H + bool "stdbit.h" + depends on ARCH_HAVE_STDBIT_H + default n + ---help--- + Redirecting stdbit.h lives at include/nuttx/lib/stdbit.h. When + this is set, the build copies it to include/stdbit.h and it + includes arch/stdbit.h if the architecture provides one. + +config LIBC_STDBIT_GENERIC + bool "stdbit.h (generic C23)" + default n + ---help--- + Use generic C23 stdbit implementation. When set, copy + include/nuttx/lib/stdbit.h to include/stdbit.h. No arch + header is used; builtins (e.g. __builtin_clz) must be + available (see CONFIG_HAVE_BUILTIN_* in compiler.h). + config ARCH_HAVE_SETJMP bool default n diff --git a/cmake/nuttx_generate_headers.cmake b/cmake/nuttx_generate_headers.cmake index 1e12a42b7d895..2bc3c82c63b4c 100644 --- a/cmake/nuttx_generate_headers.cmake +++ b/cmake/nuttx_generate_headers.cmake @@ -137,6 +137,17 @@ else() file(REMOVE ${CMAKE_BINARY_DIR}/include/setjmp.h) endif() +# Target used to copy include/nuttx/lib/stdbit.h. If CONFIG_ARCH_STDBIT_H or +# CONFIG_LIBC_STDBIT_GENERIC is set, copy stdbit.h to include/ for C23 bit +# utilities. + +if(CONFIG_ARCH_STDBIT_H OR CONFIG_LIBC_STDBIT_GENERIC) + nuttx_create_symlink(${NUTTX_DIR}/include/nuttx/lib/stdbit.h + ${CMAKE_BINARY_DIR}/include/stdbit.h) +else() + file(REMOVE ${CMAKE_BINARY_DIR}/include/stdbit.h) +endif() + # Add final context target that ties together all of the above The context # target is invoked on each target build to assure that NuttX is properly # configured. The basic configuration steps include creation of the the @@ -151,7 +162,10 @@ add_custom_target( $<$:${CMAKE_BINARY_DIR}/include/stdarg.h> $<$:${CMAKE_BINARY_DIR}/include/math.h> $<$:${CMAKE_BINARY_DIR}/include/float.h> - $<$:${CMAKE_BINARY_DIR}/include/setjmp.h>) + $<$:${CMAKE_BINARY_DIR}/include/setjmp.h> + $<$:${CMAKE_BINARY_DIR}/include/stdbit.h> + $<$:${CMAKE_BINARY_DIR}/include/stdbit.h> +) # apps_context is a PHONY target used as an intermediate process to control the # time order of context preparation actions of app building diff --git a/include/nuttx/lib/stdbit.h b/include/nuttx/lib/stdbit.h new file mode 100644 index 0000000000000..b305b96196520 --- /dev/null +++ b/include/nuttx/lib/stdbit.h @@ -0,0 +1,245 @@ +/**************************************************************************** + * include/nuttx/lib/stdbit.h + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to you under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + ****************************************************************************/ + +#ifndef __INCLUDE_NUTTX_LIB_STDBIT_H +#define __INCLUDE_NUTTX_LIB_STDBIT_H + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include +#include +#include + +#ifdef CONFIG_ARCH_STDBIT_H +# include +#else + +/**************************************************************************** + * Generic C23 stdbit implementation (CONFIG_LIBC_STDBIT_GENERIC). + * Requires __builtin_clz, __builtin_ctz, __builtin_popcount (and ll + * variants). If the toolchain does not provide them, enable the + * corresponding CONFIG_HAVE_BUILTIN_* in nuttx/compiler.h or do not + * use LIBC_STDBIT_GENERIC. + ****************************************************************************/ + +# if !defined(CONFIG_HAVE_BUILTIN_CLZ) || \ + !defined(CONFIG_HAVE_BUILTIN_CTZ) || \ + !defined(CONFIG_HAVE_BUILTIN_POPCOUNT) +# error "Generic stdbit requires CONFIG_HAVE_BUILTIN_CLZ, CTZ, POPCOUNT" +# endif + +# if defined(CONFIG_HAVE_LONG_LONG) && \ + !defined(CONFIG_HAVE_BUILTIN_POPCOUNTLL) +# error "Generic stdbit 64-bit requires CONFIG_HAVE_BUILTIN_POPCOUNTLL" +# endif + +/**************************************************************************** + * C23 endianness macros + ****************************************************************************/ + +# ifdef CONFIG_ENDIAN_BIG +# define __STDC_ENDIAN_LITTLE__ 1234 +# define __STDC_ENDIAN_BIG__ 4321 +# define __STDC_ENDIAN_NATIVE__ __STDC_ENDIAN_BIG__ +# else +# define __STDC_ENDIAN_LITTLE__ 1234 +# define __STDC_ENDIAN_BIG__ 4321 +# define __STDC_ENDIAN_NATIVE__ __STDC_ENDIAN_LITTLE__ +# endif + +/**************************************************************************** + * Leading / trailing zeros (C23: zero input returns bit width) + ****************************************************************************/ + +# define stdc_leading_zeros_uc(x) \ + ((unsigned char)(x) == 0 ? 8 : \ + (unsigned char)__builtin_clz((unsigned)(x) << 24)) +# define stdc_leading_zeros_us(x) \ + ((unsigned short)(x) == 0 ? 16 : \ + (unsigned short)__builtin_clz((unsigned)(x) << 16)) +# define stdc_leading_zeros_ui(x) \ + ((x) == 0 ? 32 : (unsigned)__builtin_clz(x)) +# define stdc_leading_zeros_ul(x) \ + ((x) == 0 ? (unsigned long)(8*sizeof(unsigned long)) : \ + (unsigned long)__builtin_clzl(x)) +# define stdc_leading_zeros_ull(x) \ + ((x) == 0 ? (unsigned long long)(8*sizeof(unsigned long long)) : \ + (unsigned long long)__builtin_clzll(x)) + +# define stdc_trailing_zeros_uc(x) \ + ((unsigned char)(x) == 0 ? 8 : (unsigned char)__builtin_ctz((unsigned)(x))) +# define stdc_trailing_zeros_us(x) \ + ((unsigned short)(x) == 0 ? 16 : \ + (unsigned short)__builtin_ctz((unsigned)(x))) +# define stdc_trailing_zeros_ui(x) \ + ((x) == 0 ? 32 : (unsigned)__builtin_ctz(x)) +# define stdc_trailing_zeros_ul(x) \ + ((x) == 0 ? (unsigned long)(8*sizeof(unsigned long)) : \ + (unsigned long)__builtin_ctzl(x)) +# define stdc_trailing_zeros_ull(x) \ + ((x) == 0 ? (unsigned long long)(8*sizeof(unsigned long long)) : \ + (unsigned long long)__builtin_ctzll(x)) + +/**************************************************************************** + * Leading / trailing ones (C23: zero input returns 0) + ****************************************************************************/ + +# define stdc_leading_ones_uc(x) stdc_leading_zeros_uc((unsigned char)~(x)) +# define stdc_leading_ones_us(x) stdc_leading_zeros_us((unsigned short)~(x)) +# define stdc_leading_ones_ui(x) stdc_leading_zeros_ui(~(x)) +# define stdc_leading_ones_ul(x) stdc_leading_zeros_ul(~(x)) +# define stdc_leading_ones_ull(x) stdc_leading_zeros_ull(~(x)) + +# define stdc_trailing_ones_uc(x) stdc_trailing_zeros_uc((unsigned char)~(x)) +# define stdc_trailing_ones_us(x) stdc_trailing_zeros_us((unsigned short)~(x)) +# define stdc_trailing_ones_ui(x) stdc_trailing_zeros_ui(~(x)) +# define stdc_trailing_ones_ul(x) stdc_trailing_zeros_ul(~(x)) +# define stdc_trailing_ones_ull(x) stdc_trailing_zeros_ull(~(x)) + +/**************************************************************************** + * First leading zero/one (bit index from MSB; C23: 0 returns bit width) + ****************************************************************************/ + +# define stdc_first_leading_zero_uc(x) \ + ((unsigned char)(x) == 0xFF ? 0 : stdc_leading_ones_uc(x) + 1) +# define stdc_first_leading_zero_us(x) \ + ((unsigned short)(x) == 0xFFFF ? 0 : stdc_leading_ones_us(x) + 1) +# define stdc_first_leading_zero_ui(x) \ + ((x) == ~0u ? 0 : stdc_leading_ones_ui(x) + 1) +# define stdc_first_leading_zero_ul(x) \ + ((x) == ~0ul ? 0 : stdc_leading_ones_ul(x) + 1) +# define stdc_first_leading_zero_ull(x) \ + ((x) == ~0ull ? 0 : stdc_leading_ones_ull(x) + 1) + +# define stdc_first_leading_one_uc(x) \ + ((unsigned char)(x) == 0 ? 0 : stdc_leading_zeros_uc(x) + 1) +# define stdc_first_leading_one_us(x) \ + ((unsigned short)(x) == 0 ? 0 : stdc_leading_zeros_us(x) + 1) +# define stdc_first_leading_one_ui(x) \ + ((x) == 0 ? 0 : stdc_leading_zeros_ui(x) + 1) +# define stdc_first_leading_one_ul(x) \ + ((x) == 0 ? 0 : stdc_leading_zeros_ul(x) + 1) +# define stdc_first_leading_one_ull(x) \ + ((x) == 0 ? 0 : stdc_leading_zeros_ull(x) + 1) + +/**************************************************************************** + * First trailing zero/one (bit index from LSB; C23: 0 returns bit width) + ****************************************************************************/ + +# define stdc_first_trailing_zero_uc(x) \ + ((unsigned char)(x) == 0xFF ? 0 : stdc_trailing_ones_uc(x) + 1) +# define stdc_first_trailing_zero_us(x) \ + ((unsigned short)(x) == 0xFFFF ? 0 : stdc_trailing_ones_us(x) + 1) +# define stdc_first_trailing_zero_ui(x) \ + ((x) == ~0u ? 0 : stdc_trailing_ones_ui(x) + 1) +# define stdc_first_trailing_zero_ul(x) \ + ((x) == ~0ul ? 0 : stdc_trailing_ones_ul(x) + 1) +# define stdc_first_trailing_zero_ull(x) \ + ((x) == ~0ull ? 0 : stdc_trailing_ones_ull(x) + 1) + +# define stdc_first_trailing_one_uc(x) \ + ((unsigned char)(x) == 0 ? 0 : stdc_trailing_zeros_uc(x) + 1) +# define stdc_first_trailing_one_us(x) \ + ((unsigned short)(x) == 0 ? 0 : stdc_trailing_zeros_us(x) + 1) +# define stdc_first_trailing_one_ui(x) \ + ((x) == 0 ? 0 : stdc_trailing_zeros_ui(x) + 1) +# define stdc_first_trailing_one_ul(x) \ + ((x) == 0 ? 0 : stdc_trailing_zeros_ul(x) + 1) +# define stdc_first_trailing_one_ull(x) \ + ((x) == 0 ? 0 : stdc_trailing_zeros_ull(x) + 1) + +/**************************************************************************** + * Count zeros / ones + ****************************************************************************/ + +# define stdc_count_ones_uc(x) \ + ((unsigned char)__builtin_popcount((unsigned)(x))) +# define stdc_count_ones_us(x) \ + ((unsigned short)__builtin_popcount((unsigned)(x))) +# define stdc_count_ones_ui(x) ((unsigned)__builtin_popcount(x)) +# define stdc_count_ones_ul(x) ((unsigned long)__builtin_popcountl(x)) +# define stdc_count_ones_ull(x) ((unsigned long long)__builtin_popcountll(x)) + +# define stdc_count_zeros_uc(x) ((unsigned char)8 - stdc_count_ones_uc(x)) +# define stdc_count_zeros_us(x) ((unsigned short)16 - stdc_count_ones_us(x)) +# define stdc_count_zeros_ui(x) (32 - stdc_count_ones_ui(x)) +# define stdc_count_zeros_ul(x) \ + ((unsigned long)(8*sizeof(unsigned long)) - stdc_count_ones_ul(x)) +# define stdc_count_zeros_ull(x) \ + ((unsigned long long)(8*sizeof(unsigned long long)) - \ + stdc_count_ones_ull(x)) + +/**************************************************************************** + * Single-bit test, bit width, bit floor, bit ceil + ****************************************************************************/ + +# define stdc_has_single_bit_uc(x) (stdc_count_ones_uc(x) == 1) +# define stdc_has_single_bit_us(x) (stdc_count_ones_us(x) == 1) +# define stdc_has_single_bit_ui(x) (stdc_count_ones_ui(x) == 1) +# define stdc_has_single_bit_ul(x) (stdc_count_ones_ul(x) == 1) +# define stdc_has_single_bit_ull(x) (stdc_count_ones_ull(x) == 1) + +# define stdc_bit_width_uc(x) \ + ((unsigned char)(x) == 0 ? 0 : 8 - stdc_leading_zeros_uc(x)) +# define stdc_bit_width_us(x) \ + ((unsigned short)(x) == 0 ? 0 : 16 - stdc_leading_zeros_us(x)) +# define stdc_bit_width_ui(x) ((x) == 0 ? 0 : 32 - stdc_leading_zeros_ui(x)) +# define stdc_bit_width_ul(x) \ + ((x) == 0 ? 0 : (int)(8*sizeof(unsigned long) - \ + stdc_leading_zeros_ul(x))) +# define stdc_bit_width_ull(x) \ + ((x) == 0 ? 0 : (int)(8*sizeof(unsigned long long) - \ + stdc_leading_zeros_ull(x))) + +# define stdc_bit_floor_uc(x) \ + ((unsigned char)((x) != 0 ? 1 << (7 - stdc_leading_zeros_uc(x)) : 0)) +# define stdc_bit_floor_us(x) \ + ((unsigned short)((x) != 0 ? 1 << (15 - stdc_leading_zeros_us(x)) : 0)) +# define stdc_bit_floor_ui(x) \ + ((x) != 0 ? 1u << (31 - stdc_leading_zeros_ui(x)) : 0u) +# define stdc_bit_floor_ul(x) \ + ((x) != 0 ? (unsigned long)1 << (8*sizeof(unsigned long)-1 - \ + stdc_leading_zeros_ul(x)) : 0ul) +# define stdc_bit_floor_ull(x) \ + ((x) != 0 ? (unsigned long long)1 << (8*sizeof(unsigned long long)-1 - \ + stdc_leading_zeros_ull(x)) : 0ull) + +# define stdc_bit_ceil_uc(x) \ + ((unsigned char)((x) <= 1 ? 1 : (unsigned char)1 << (8 - \ + stdc_leading_zeros_uc((unsigned char)(x)-1)))) +# define stdc_bit_ceil_us(x) \ + ((unsigned short)((x) <= 1 ? 1 : (unsigned short)1 << (16 - \ + stdc_leading_zeros_us((unsigned short)(x)-1)))) +# define stdc_bit_ceil_ui(x) \ + ((x) <= 1 ? 1u : 1u << (32 - stdc_leading_zeros_ui((x)-1))) +# define stdc_bit_ceil_ul(x) \ + ((x) <= 1 ? 1ul : 1ul << (8*sizeof(unsigned long) - \ + stdc_leading_zeros_ul((x)-1))) +# define stdc_bit_ceil_ull(x) \ + ((x) <= 1 ? 1ull : 1ull << (8*sizeof(unsigned long long) - \ + stdc_leading_zeros_ull((x)-1))) + +#endif /* CONFIG_ARCH_STDBIT_H */ + +#endif /* __INCLUDE_NUTTX_LIB_STDBIT_H */ diff --git a/tools/Unix.mk b/tools/Unix.mk index a9e0a490cb9aa..a134d9f7c7f54 100644 --- a/tools/Unix.mk +++ b/tools/Unix.mk @@ -212,6 +212,15 @@ include/stdarg.h: include/nuttx/lib/stdarg.h $(Q) cp -f include/nuttx/lib/stdarg.h include/stdarg.h endif +# Target used to copy include/nuttx/lib/stdbit.h. If CONFIG_ARCH_STDBIT_H or +# CONFIG_LIBC_STDBIT_GENERIC is set, copy stdbit.h to include/ for C23 bit +# utilities. + +ifeq ($(firstword $(filter y, $(CONFIG_ARCH_STDBIT_H) $(CONFIG_LIBC_STDBIT_GENERIC))),y) +include/stdbit.h: include/nuttx/lib/stdbit.h + $(Q) cp -f include/nuttx/lib/stdbit.h include/stdbit.h +endif + # Target used to copy include/nuttx/lib/setjmp.h. If CONFIG_ARCH_SETJMP_H is # defined, then there is an architecture specific setjmp.h header file # that will be included indirectly from include/lib/setjmp.h. But first, we @@ -470,6 +479,10 @@ ifeq ($(CONFIG_ARCH_STDARG_H),y) context: include/stdarg.h endif +ifeq ($(firstword $(filter y, $(CONFIG_ARCH_STDBIT_H) $(CONFIG_LIBC_STDBIT_GENERIC))),y) +context: include/stdbit.h +endif + ifeq ($(CONFIG_ARCH_SETJMP_H),y) context: include/setjmp.h endif diff --git a/tools/Win.mk b/tools/Win.mk index 0f3273e2eca36..79e3fe5877058 100644 --- a/tools/Win.mk +++ b/tools/Win.mk @@ -194,6 +194,17 @@ else include\stdarg.h: endif +# Target used to copy include\nuttx\lib\stdbit.h. If CONFIG_ARCH_STDBIT_H or +# CONFIG_LIBC_STDBIT_GENERIC is set, copy stdbit.h to include\ for C23 bit +# utilities. + +ifeq ($(firstword $(filter y, $(CONFIG_ARCH_STDBIT_H) $(CONFIG_LIBC_STDBIT_GENERIC))),y) +include\stdbit.h: include\nuttx\lib\stdbit.h + $(Q) cp -f include\nuttx\lib\stdbit.h include\stdbit.h +else +include\stdbit.h: +endif + # Target used to copy include\nuttx\setjmp.h. If CONFIG_ARCH_SETJMP_H is # defined, then there is an architecture specific setjmp.h header file # that will be included indirectly from include\setjmp.h. But first, we @@ -441,6 +452,10 @@ ifeq ($(CONFIG_ARCH_STDARG_H),y) context: include\stdarg.h endif +ifeq ($(firstword $(filter y, $(CONFIG_ARCH_STDBIT_H) $(CONFIG_LIBC_STDBIT_GENERIC))),y) +context: include\stdbit.h +endif + ifeq ($(CONFIG_ARCH_SETJMP_H),y) context: include\setjmp.h endif