summaryrefslogtreecommitdiff
path: root/lib/mlibc/options/ansi/musl-generic-math/remquol.c
diff options
context:
space:
mode:
authorIan Moffett <ian@osmora.org>2024-03-07 17:28:00 -0500
committerIan Moffett <ian@osmora.org>2024-03-07 17:28:32 -0500
commitbd5969fc876a10b18613302db7087ef3c40f18e1 (patch)
tree7c2b8619afe902abf99570df2873fbdf40a4d1a1 /lib/mlibc/options/ansi/musl-generic-math/remquol.c
parenta95b38b1b92b172e6cc4e8e56a88a30cc65907b0 (diff)
lib: Add mlibc
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/remquol.c')
-rw-r--r--lib/mlibc/options/ansi/musl-generic-math/remquol.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/remquol.c b/lib/mlibc/options/ansi/musl-generic-math/remquol.c
new file mode 100644
index 0000000..9b065c0
--- /dev/null
+++ b/lib/mlibc/options/ansi/musl-generic-math/remquol.c
@@ -0,0 +1,124 @@
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double remquol(long double x, long double y, int *quo)
+{
+ return remquo(x, y, quo);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+long double remquol(long double x, long double y, int *quo)
+{
+ union ldshape ux = {x}, uy = {y};
+ int ex = ux.i.se & 0x7fff;
+ int ey = uy.i.se & 0x7fff;
+ int sx = ux.i.se >> 15;
+ int sy = uy.i.se >> 15;
+ uint32_t q;
+
+ *quo = 0;
+ if (y == 0 || isnan(y) || ex == 0x7fff)
+ return (x*y)/(x*y);
+ if (x == 0)
+ return x;
+
+ /* normalize x and y */
+ if (!ex) {
+ ux.i.se = ex;
+ ux.f *= 0x1p120f;
+ ex = ux.i.se - 120;
+ }
+ if (!ey) {
+ uy.i.se = ey;
+ uy.f *= 0x1p120f;
+ ey = uy.i.se - 120;
+ }
+
+ q = 0;
+ if (ex >= ey) {
+ /* x mod y */
+#if LDBL_MANT_DIG == 64
+ uint64_t i, mx, my;
+ mx = ux.i.m;
+ my = uy.i.m;
+ for (; ex > ey; ex--) {
+ i = mx - my;
+ if (mx >= my) {
+ mx = 2*i;
+ q++;
+ q <<= 1;
+ } else if (2*mx < mx) {
+ mx = 2*mx - my;
+ q <<= 1;
+ q++;
+ } else {
+ mx = 2*mx;
+ q <<= 1;
+ }
+ }
+ i = mx - my;
+ if (mx >= my) {
+ mx = i;
+ q++;
+ }
+ if (mx == 0)
+ ex = -120;
+ else
+ for (; mx >> 63 == 0; mx *= 2, ex--);
+ ux.i.m = mx;
+#elif LDBL_MANT_DIG == 113
+ uint64_t hi, lo, xhi, xlo, yhi, ylo;
+ xhi = (ux.i2.hi & -1ULL>>16) | 1ULL<<48;
+ yhi = (uy.i2.hi & -1ULL>>16) | 1ULL<<48;
+ xlo = ux.i2.lo;
+ ylo = ux.i2.lo;
+ for (; ex > ey; ex--) {
+ hi = xhi - yhi;
+ lo = xlo - ylo;
+ if (xlo < ylo)
+ hi -= 1;
+ if (hi >> 63 == 0) {
+ xhi = 2*hi + (lo>>63);
+ xlo = 2*lo;
+ q++;
+ } else {
+ xhi = 2*xhi + (xlo>>63);
+ xlo = 2*xlo;
+ }
+ q <<= 1;
+ }
+ hi = xhi - yhi;
+ lo = xlo - ylo;
+ if (xlo < ylo)
+ hi -= 1;
+ if (hi >> 63 == 0) {
+ xhi = hi;
+ xlo = lo;
+ q++;
+ }
+ if ((xhi|xlo) == 0)
+ ex = -120;
+ else
+ for (; xhi >> 48 == 0; xhi = 2*xhi + (xlo>>63), xlo = 2*xlo, ex--);
+ ux.i2.hi = xhi;
+ ux.i2.lo = xlo;
+#endif
+ }
+
+ /* scale result and decide between |x| and |x|-|y| */
+ if (ex <= 0) {
+ ux.i.se = ex + 120;
+ ux.f *= 0x1p-120f;
+ } else
+ ux.i.se = ex;
+ x = ux.f;
+ if (sy)
+ y = -y;
+ if (ex == ey || (ex+1 == ey && (2*x > y || (2*x == y && q%2)))) {
+ x -= y;
+ q++;
+ }
+ q &= 0x7fffffff;
+ *quo = sx^sy ? -(int)q : (int)q;
+ return sx ? -x : x;
+}
+#endif