/* Test fscale instruction. */ #include #include union u { struct { uint64_t sig; uint16_t sign_exp; } s; long double ld; }; volatile long double ld_third = 1.0L / 3.0L; volatile long double ld_four_thirds = 4.0L / 3.0L; volatile union u ld_invalid_1 = { .s = { 1, 1234 } }; volatile union u ld_invalid_2 = { .s = { 0, 1234 } }; volatile union u ld_invalid_3 = { .s = { 0, 0x7fff } }; volatile union u ld_invalid_4 = { .s = { (UINT64_C(1) << 63) - 1, 0x7fff } }; volatile long double ld_res; int isnan_ld(long double x) { union u tmp = { .ld = x }; return ((tmp.s.sign_exp & 0x7fff) == 0x7fff && (tmp.s.sig >> 63) != 0 && (tmp.s.sig << 1) != 0); } int issignaling_ld(long double x) { union u tmp = { .ld = x }; return isnan_ld(x) && (tmp.s.sig & UINT64_C(0x4000000000000000)) == 0; } int main(void) { short cw; int ret = 0; __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (2.5L), "u" (__builtin_nansl(""))); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale snan\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (2.5L), "u" (ld_invalid_1.ld)); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale invalid 1\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (2.5L), "u" (ld_invalid_2.ld)); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale invalid 2\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (2.5L), "u" (ld_invalid_3.ld)); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale invalid 3\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (2.5L), "u" (ld_invalid_4.ld)); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale invalid 4\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (0.0L), "u" (__builtin_infl())); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale 0 up inf\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (__builtin_infl()), "u" (-__builtin_infl())); if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { printf("FAIL: fscale inf down inf\n"); ret = 1; } /* Set round-downward. */ __asm__ volatile ("fnstcw %0" : "=m" (cw)); cw = (cw & ~0xc00) | 0x400; __asm__ volatile ("fldcw %0" : : "m" (cw)); __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (1.0L), "u" (__builtin_infl())); if (ld_res != __builtin_infl()) { printf("FAIL: fscale finite up inf\n"); ret = 1; } __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (-1.0L), "u" (-__builtin_infl())); if (ld_res != -0.0L || __builtin_copysignl(1.0L, ld_res) != -1.0L) { printf("FAIL: fscale finite down inf\n"); ret = 1; } /* Set round-to-nearest with single-precision rounding. */ cw = cw & ~0xf00; __asm__ volatile ("fldcw %0" : : "m" (cw)); __asm__ volatile ("fscale" : "=t" (ld_res) : "0" (ld_third), "u" (2.0L)); cw = cw | 0x300; __asm__ volatile ("fldcw %0" : : "m" (cw)); if (ld_res != ld_four_thirds) { printf("FAIL: fscale single-precision\n"); ret = 1; } return ret; }