Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(738)

Unified Diff: fusl/src/math/fmod.c

Issue 1573973002: Add a "fork" of musl as //fusl. (Closed) Base URL: https://github.com/domokit/mojo.git@master
Patch Set: Created 4 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « fusl/src/math/fminl.c ('k') | fusl/src/math/fmodf.c » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: fusl/src/math/fmod.c
diff --git a/fusl/src/math/fmod.c b/fusl/src/math/fmod.c
new file mode 100644
index 0000000000000000000000000000000000000000..6849722bac50e477b9210f57f0271dcdabd8ae0c
--- /dev/null
+++ b/fusl/src/math/fmod.c
@@ -0,0 +1,68 @@
+#include <math.h>
+#include <stdint.h>
+
+double fmod(double x, double y)
+{
+ 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;
+ uint64_t i;
+
+ /* in the followings uxi should be ux.i, but then gcc wrongly adds */
+ /* float load/store to inner loops ruining performance and code size */
+ uint64_t uxi = ux.i;
+
+ if (uy.i<<1 == 0 || isnan(y) || ex == 0x7ff)
+ 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<<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;
+ }
+
+ /* x mod y */
+ for (; ex > ey; ex--) {
+ i = uxi - uy.i;
+ if (i >> 63 == 0) {
+ if (i == 0)
+ return 0*x;
+ uxi = i;
+ }
+ uxi <<= 1;
+ }
+ i = uxi - uy.i;
+ if (i >> 63 == 0) {
+ if (i == 0)
+ return 0*x;
+ uxi = i;
+ }
+ for (; uxi>>52 == 0; uxi <<= 1, ex--);
+
+ /* scale result */
+ if (ex > 0) {
+ uxi -= 1ULL << 52;
+ uxi |= (uint64_t)ex << 52;
+ } else {
+ uxi >>= -ex + 1;
+ }
+ uxi |= (uint64_t)sx << 63;
+ ux.i = uxi;
+ return ux.f;
+}
« no previous file with comments | « fusl/src/math/fminl.c ('k') | fusl/src/math/fmodf.c » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698