1*6296500aSRobert Clausecker /* 2*6296500aSRobert Clausecker * Copyright (c) 2025 Robert Clausecker <fuz@FreeBSD.org> 3*6296500aSRobert Clausecker * 4*6296500aSRobert Clausecker * SPDX-License-Identifier: BSD-2-Clause 5*6296500aSRobert Clausecker */ 6*6296500aSRobert Clausecker 7*6296500aSRobert Clausecker #include <limits.h> 8*6296500aSRobert Clausecker #include <stdbit.h> 9*6296500aSRobert Clausecker 10*6296500aSRobert Clausecker unsigned char stdc_bit_floor_uc(unsigned char x)11*6296500aSRobert Clauseckerstdc_bit_floor_uc(unsigned char x) 12*6296500aSRobert Clausecker { 13*6296500aSRobert Clausecker if (x == 0) 14*6296500aSRobert Clausecker return (0); 15*6296500aSRobert Clausecker 16*6296500aSRobert Clausecker return (1U << (UINT_WIDTH - __builtin_clz(x) - 1)); 17*6296500aSRobert Clausecker } 18*6296500aSRobert Clausecker 19*6296500aSRobert Clausecker unsigned short stdc_bit_floor_us(unsigned short x)20*6296500aSRobert Clauseckerstdc_bit_floor_us(unsigned short x) 21*6296500aSRobert Clausecker { 22*6296500aSRobert Clausecker if (x == 0) 23*6296500aSRobert Clausecker return (0); 24*6296500aSRobert Clausecker 25*6296500aSRobert Clausecker return (1U << (UINT_WIDTH - __builtin_clz(x) - 1)); 26*6296500aSRobert Clausecker } 27*6296500aSRobert Clausecker 28*6296500aSRobert Clausecker unsigned int stdc_bit_floor_ui(unsigned int x)29*6296500aSRobert Clauseckerstdc_bit_floor_ui(unsigned int x) 30*6296500aSRobert Clausecker { 31*6296500aSRobert Clausecker if (x == 0) 32*6296500aSRobert Clausecker return (0); 33*6296500aSRobert Clausecker 34*6296500aSRobert Clausecker return (1U << (UINT_WIDTH - __builtin_clz(x) - 1)); 35*6296500aSRobert Clausecker } 36*6296500aSRobert Clausecker 37*6296500aSRobert Clausecker unsigned long stdc_bit_floor_ul(unsigned long x)38*6296500aSRobert Clauseckerstdc_bit_floor_ul(unsigned long x) 39*6296500aSRobert Clausecker { 40*6296500aSRobert Clausecker if (x == 0) 41*6296500aSRobert Clausecker return (0); 42*6296500aSRobert Clausecker 43*6296500aSRobert Clausecker return (1UL << (ULONG_WIDTH - __builtin_clzl(x) - 1)); 44*6296500aSRobert Clausecker } 45*6296500aSRobert Clausecker 46*6296500aSRobert Clausecker unsigned long long stdc_bit_floor_ull(unsigned long long x)47*6296500aSRobert Clauseckerstdc_bit_floor_ull(unsigned long long x) 48*6296500aSRobert Clausecker { 49*6296500aSRobert Clausecker if (x == 0) 50*6296500aSRobert Clausecker return (0); 51*6296500aSRobert Clausecker 52*6296500aSRobert Clausecker return (1ULL << (ULLONG_WIDTH - __builtin_clzll(x) - 1)); 53*6296500aSRobert Clausecker } 54