qemu/tests/tcg/i386/test-i386-fldcst.c
Joseph Myers 80b4008c80 target/i386: fix floating-point load-constant rounding
The implementations of the fldl2t, fldl2e, fldpi, fldlg2 and fldln2
instructions load fixed constants independent of the rounding mode.
Fix them to load a value correctly rounded for the current rounding
mode (but always rounded to 64-bit precision independent of the
precision control, and without setting "inexact") as specified.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <alpine.DEB.2.21.2005132348310.11687@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:24 -04:00

200 lines
6.2 KiB
C

/* Test instructions loading floating-point constants. */
#include <stdint.h>
#include <stdio.h>
volatile long double ld_res;
int main(void)
{
short cw;
int ret = 0;
/* Round to nearest. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x000;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2t" : "=t" (ld_res));
if (ld_res != 0x3.5269e12f346e2bf8p+0L) {
printf("FAIL: fldl2t N\n");
ret = 1;
}
/* Round downward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x400;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2t" : "=t" (ld_res));
if (ld_res != 0x3.5269e12f346e2bf8p+0L) {
printf("FAIL: fldl2t D\n");
ret = 1;
}
/* Round toward zero. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0xc00;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2t" : "=t" (ld_res));
if (ld_res != 0x3.5269e12f346e2bf8p+0L) {
printf("FAIL: fldl2t Z\n");
ret = 1;
}
/* Round upward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x800;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2t" : "=t" (ld_res));
if (ld_res != 0x3.5269e12f346e2bfcp+0L) {
printf("FAIL: fldl2t U\n");
ret = 1;
}
/* Round to nearest. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x000;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2e" : "=t" (ld_res));
if (ld_res != 0x1.71547652b82fe178p+0L) {
printf("FAIL: fldl2e N\n");
ret = 1;
}
/* Round downward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x400;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2e" : "=t" (ld_res));
if (ld_res != 0x1.71547652b82fe176p+0L) {
printf("FAIL: fldl2e D\n");
ret = 1;
}
/* Round toward zero. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0xc00;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2e" : "=t" (ld_res));
if (ld_res != 0x1.71547652b82fe176p+0L) {
printf("FAIL: fldl2e Z\n");
ret = 1;
}
/* Round upward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x800;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldl2e" : "=t" (ld_res));
if (ld_res != 0x1.71547652b82fe178p+0L) {
printf("FAIL: fldl2e U\n");
ret = 1;
}
/* Round to nearest. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x000;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldpi" : "=t" (ld_res));
if (ld_res != 0x3.243f6a8885a308d4p+0L) {
printf("FAIL: fldpi N\n");
ret = 1;
}
/* Round downward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x400;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldpi" : "=t" (ld_res));
if (ld_res != 0x3.243f6a8885a308dp+0L) {
printf("FAIL: fldpi D\n");
ret = 1;
}
/* Round toward zero. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0xc00;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldpi" : "=t" (ld_res));
if (ld_res != 0x3.243f6a8885a308dp+0L) {
printf("FAIL: fldpi Z\n");
ret = 1;
}
/* Round upward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x800;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldpi" : "=t" (ld_res));
if (ld_res != 0x3.243f6a8885a308d4p+0L) {
printf("FAIL: fldpi U\n");
ret = 1;
}
/* Round to nearest. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x000;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldlg2" : "=t" (ld_res));
if (ld_res != 0x4.d104d427de7fbcc8p-4L) {
printf("FAIL: fldlg2 N\n");
ret = 1;
}
/* Round downward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x400;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldlg2" : "=t" (ld_res));
if (ld_res != 0x4.d104d427de7fbccp-4L) {
printf("FAIL: fldlg2 D\n");
ret = 1;
}
/* Round toward zero. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0xc00;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldlg2" : "=t" (ld_res));
if (ld_res != 0x4.d104d427de7fbccp-4L) {
printf("FAIL: fldlg2 Z\n");
ret = 1;
}
/* Round upward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x800;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldlg2" : "=t" (ld_res));
if (ld_res != 0x4.d104d427de7fbcc8p-4L) {
printf("FAIL: fldlg2 U\n");
ret = 1;
}
/* Round to nearest. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x000;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldln2" : "=t" (ld_res));
if (ld_res != 0xb.17217f7d1cf79acp-4L) {
printf("FAIL: fldln2 N\n");
ret = 1;
}
/* Round downward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x400;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldln2" : "=t" (ld_res));
if (ld_res != 0xb.17217f7d1cf79abp-4L) {
printf("FAIL: fldln2 D\n");
ret = 1;
}
/* Round toward zero. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0xc00;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldln2" : "=t" (ld_res));
if (ld_res != 0xb.17217f7d1cf79abp-4L) {
printf("FAIL: fldln2 Z\n");
ret = 1;
}
/* Round upward. */
__asm__ volatile ("fnstcw %0" : "=m" (cw));
cw = (cw & ~0xc00) | 0x800;
__asm__ volatile ("fldcw %0" : : "m" (cw));
__asm__ volatile ("fldln2" : "=t" (ld_res));
if (ld_res != 0xb.17217f7d1cf79acp-4L) {
printf("FAIL: fldln2 U\n");
ret = 1;
}
return ret;
}