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Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/fmodf.c')
-rw-r--r--lib/mlibc/options/ansi/musl-generic-math/fmodf.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/fmodf.c b/lib/mlibc/options/ansi/musl-generic-math/fmodf.c
new file mode 100644
index 0000000..ff58f93
--- /dev/null
+++ b/lib/mlibc/options/ansi/musl-generic-math/fmodf.c
@@ -0,0 +1,65 @@
+#include <math.h>
+#include <stdint.h>
+
+float fmodf(float x, float y)
+{
+ union {float f; uint32_t i;} ux = {x}, uy = {y};
+ int ex = ux.i>>23 & 0xff;
+ int ey = uy.i>>23 & 0xff;
+ uint32_t sx = ux.i & 0x80000000;
+ uint32_t i;
+ uint32_t uxi = ux.i;
+
+ if (uy.i<<1 == 0 || isnan(y) || ex == 0xff)
+ return (x*y)/(x*y);
+ if (uxi<<1 <= uy.i<<1) {
+ if (uxi<<1 == uy.i<<1)
+ return 0*x;
+ return x;
+ }
+
+ /* normalize x and y */
+ if (!ex) {
+ for (i = uxi<<9; i>>31 == 0; ex--, i <<= 1);
+ uxi <<= -ex + 1;
+ } else {
+ uxi &= -1U >> 9;
+ uxi |= 1U << 23;
+ }
+ if (!ey) {
+ for (i = uy.i<<9; i>>31 == 0; ey--, i <<= 1);
+ uy.i <<= -ey + 1;
+ } else {
+ uy.i &= -1U >> 9;
+ uy.i |= 1U << 23;
+ }
+
+ /* x mod y */
+ for (; ex > ey; ex--) {
+ i = uxi - uy.i;
+ if (i >> 31 == 0) {
+ if (i == 0)
+ return 0*x;
+ uxi = i;
+ }
+ uxi <<= 1;
+ }
+ i = uxi - uy.i;
+ if (i >> 31 == 0) {
+ if (i == 0)
+ return 0*x;
+ uxi = i;
+ }
+ for (; uxi>>23 == 0; uxi <<= 1, ex--);
+
+ /* scale result up */
+ if (ex > 0) {
+ uxi -= 1U << 23;
+ uxi |= (uint32_t)ex << 23;
+ } else {
+ uxi >>= -ex + 1;
+ }
+ uxi |= sx;
+ ux.i = uxi;
+ return ux.f;
+}