mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-05-23 05:42:29 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Make gdtoa less tunable (#104)

Browse source 
The -fno-math-errno flag shouldn't impact libraries since it's mostly
intended for permitting the compiler to generate sqrt() instructions.
This commit is contained in:
Justine Tunney 2021-03-07 16:34:16 -08:00
parent 8a6ac6dd63
commit a8945714e8
8 changed files with 485 additions and 124 deletions
Download patch file Download diff file Expand all files Collapse all files

36
libc/tinymath/powl.c
View file

@ -16,6 +16,7 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/errno.h"
#include "libc/math.h"
/**
@ -27,23 +28,34 @@ long double powl(long double x, long double y) {
if (!isinf(y)) {
if (!isinf(x)) {
if (x) {
asm("fyl2x" : "=t"(u) : "0"(fabsl(x)), "u"(y) : "st(1)");
asm("fprem" : "=t"(t) : "0"(u), "u"(1.L));
asm("f2xm1" : "=t"(t) : "0"(t));
asm("fscale" : "=t"(t) : "0"(t + 1), "u"(u));
if (signbit(x)) {
if (y != truncl(y)) return -NAN;
if (!signbit(y) || ((int64_t)y & 1)) t = -t;
if (y) {
if (x < 0 && y != truncl(y)) {
errno = EDOM;
return NAN;
}
asm("fyl2x" : "=t"(u) : "0"(fabsl(x)), "u"(y) : "st(1)");
asm("fprem" : "=t"(t) : "0"(u), "u"(1.L));
asm("f2xm1" : "=t"(t) : "0"(t));
asm("fscale" : "=t"(t) : "0"(t + 1), "u"(u));
if (signbit(x)) {
if (y != truncl(y)) return -NAN;
if ((int64_t)y & 1) t = -t;
}
return t;
} else {
return 1;
}
return t;
} else if (y > 0) {
return 0;
return y == 1 ? x : 0;
} else if (!y) {
return 1;
} else if (y == truncl(y) && ((int64_t)y & 1)) {
return copysignl(INFINITY, x);
} else {
return INFINITY;
errno = ERANGE;
if (y == truncl(y) && ((int64_t)y & 1)) {
return copysignl(INFINITY, x);
} else {
return INFINITY;
}
}
} else if (signbit(x)) {
if (!y) return 1;