about summary refs log tree commit diff
path: root/src/math/e_remainderf.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/math/e_remainderf.c')
-rw-r--r--src/math/e_remainderf.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/src/math/e_remainderf.c b/src/math/e_remainderf.c
new file mode 100644
index 00000000..c292367d
--- /dev/null
+++ b/src/math/e_remainderf.c
@@ -0,0 +1,61 @@
+/* e_remainderf.c -- float version of e_remainder.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 <math.h>
+#include "math_private.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) return (x*p)/(x*p);           /* p = 0 */
+        if((hx>=0x7f800000)||                   /* x not finite */
+          ((hp>0x7f800000)))                    /* p is NaN */
+            return (x*p)/(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);
+        SET_FLOAT_WORD(x,hx^sx);
+        return x;
+}