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qemu/tests/tcg/i386/test-i386-fscale.c

109 lines
3.5 KiB
C

/* Test fscale instruction. */
#include <stdint.h>
#include <stdio.h>
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;
}