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Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/remquo.c')
-rw-r--r--lib/mlibc/options/ansi/musl-generic-math/remquo.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/remquo.c b/lib/mlibc/options/ansi/musl-generic-math/remquo.c
new file mode 100644
index 0000000..59d5ad5
--- /dev/null
+++ b/lib/mlibc/options/ansi/musl-generic-math/remquo.c
@@ -0,0 +1,82 @@
+#include <math.h>
+#include <stdint.h>
+
+double remquo(double x, double y, int *quo)
+{
+ union {double f; uint64_t i;} ux = {x}, uy = {y};
+ int ex = ux.i>>52 & 0x7ff;
+ int ey = uy.i>>52 & 0x7ff;
+ int sx = ux.i>>63;
+ int sy = uy.i>>63;
+ uint32_t q;
+ uint64_t i;
+ uint64_t uxi = ux.i;
+
+ *quo = 0;
+ if (uy.i<<1 == 0 || isnan(y) || ex == 0x7ff)
+ return (x*y)/(x*y);
+ if (ux.i<<1 == 0)
+ return x;
+
+ /* normalize x and y */
+ if (!ex) {
+ for (i = uxi<<12; i>>63 == 0; ex--, i <<= 1);
+ uxi <<= -ex + 1;
+ } else {
+ uxi &= -1ULL >> 12;
+ uxi |= 1ULL << 52;
+ }
+ if (!ey) {
+ for (i = uy.i<<12; i>>63 == 0; ey--, i <<= 1);
+ uy.i <<= -ey + 1;
+ } else {
+ uy.i &= -1ULL >> 12;
+ uy.i |= 1ULL << 52;
+ }
+
+ q = 0;
+ if (ex < ey) {
+ if (ex+1 == ey)
+ goto end;
+ return x;
+ }
+
+ /* x mod y */
+ for (; ex > ey; ex--) {
+ i = uxi - uy.i;
+ if (i >> 63 == 0) {
+ uxi = i;
+ q++;
+ }
+ uxi <<= 1;
+ q <<= 1;
+ }
+ i = uxi - uy.i;
+ if (i >> 63 == 0) {
+ uxi = i;
+ q++;
+ }
+ if (uxi == 0)
+ ex = -60;
+ else
+ for (; uxi>>52 == 0; uxi <<= 1, ex--);
+end:
+ /* scale result and decide between |x| and |x|-|y| */
+ if (ex > 0) {
+ uxi -= 1ULL << 52;
+ uxi |= (uint64_t)ex << 52;
+ } else {
+ uxi >>= -ex + 1;
+ }
+ ux.i = uxi;
+ 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;
+}