1*e4e9d57bSmiod /* $OpenBSD: fpsetround.c,v 1.5 2023/01/27 11:25:16 miod Exp $ */ 2c9d6e9aeSmiod 3c9d6e9aeSmiod /* 44451fc0fSmiod * Written by Miodrag Vallat. Public domain 5c9d6e9aeSmiod */ 6c9d6e9aeSmiod 7c9d6e9aeSmiod #include <sys/types.h> 8c9d6e9aeSmiod #include <ieeefp.h> 9c9d6e9aeSmiod 10c9d6e9aeSmiod fp_rnd fpsetround(rnd_dir)11c9d6e9aeSmiodfpsetround(rnd_dir) 12c9d6e9aeSmiod fp_rnd rnd_dir; 13c9d6e9aeSmiod { 148524f5e4Smickey u_int64_t fpsr; 15c9d6e9aeSmiod fp_rnd old; 16c9d6e9aeSmiod 17b5aa3b33Sguenther __asm__ volatile("fstd %%fr0,0(%1)" : "=m" (fpsr) : "r" (&fpsr)); 188524f5e4Smickey old = (fpsr >> 41) & 0x03; 198524f5e4Smickey fpsr = (fpsr & 0xfffff9ff00000000LL) | 208524f5e4Smickey ((u_int64_t)(rnd_dir & 0x03) << 41); 21*e4e9d57bSmiod __asm__ volatile("fldd 0(%0),%%fr0" : : "r"(&fpsr), "m"(fpsr)); 22c9d6e9aeSmiod return (old); 23c9d6e9aeSmiod } 24