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-rw-r--r--src/math/remainderf.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/src/math/remainderf.c b/src/math/remainderf.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/e_remainderf.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include "libm.h"
+
+static const float zero = 0.0;
+
+float remainderf(float x, float p)
+{
+ int32_t hx,hp;
+ uint32_t sx;
+ float p_half;
+
+ GET_FLOAT_WORD(hx, x);
+ GET_FLOAT_WORD(hp, p);
+ sx = hx & 0x80000000;
+ hp &= 0x7fffffff;
+ hx &= 0x7fffffff;
+
+ /* purge off exception values */
+ if (hp == 0) /* p = 0 */
+ return (x*p)/(x*p);
+ if (hx >= 0x7f800000 || hp > 0x7f800000) /* x not finite, p is NaN */
+ // FIXME: why long double?
+ return ((long double)x*p)/((long double)x*p);
+
+ if (hp <= 0x7effffff)
+ x = fmodf(x, p + p); /* now x < 2p */
+ if (hx - hp == 0)
+ return zero*x;
+ x = fabsf(x);
+ p = fabsf(p);
+ if (hp < 0x01000000) {
+ if (x + x > p) {
+ x -= p;
+ if (x + x >= p)
+ x -= p;
+ }
+ } else {
+ p_half = (float)0.5*p;
+ if (x > p_half) {
+ x -= p;
+ if (x >= p_half)
+ x -= p;
+ }
+ }
+ GET_FLOAT_WORD(hx, x);
+ if ((hx & 0x7fffffff) == 0)
+ hx = 0;
+ SET_FLOAT_WORD(x, hx ^ sx);
+ return x;
+}