1 /* $OpenBSD: fpsetround.c,v 1.1 2018/02/28 11:16:54 kettenis Exp $ */ 2 /* 3 * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <ieeefp.h> 19 #ifdef SOFTFLOAT_FOR_GCC 20 #include "softfloat-for-gcc.h" 21 #endif 22 #include "milieu.h" 23 #include <softfloat.h> 24 #include <stdint.h> 25 26 __weak_alias(_fpsetround,fpsetround); 27 28 fp_rnd 29 fpsetround(fp_rnd rnd_dir) 30 { 31 uint32_t old, new; 32 33 __asm volatile("vmrs %0, fpscr" : "=r" (old)); 34 new = old & ~(3 << 22); 35 new |= (rnd_dir & 3) << 22; 36 __asm volatile("vmsr fpscr, %0" :: "r" (new)); 37 38 float_rounding_mode = rnd_dir; 39 40 return ((old >> 22) & 3); 41 } 42