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-rw-r--r--src/math/s_modff.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/src/math/s_modff.c b/src/math/s_modff.c
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+++ b/src/math/s_modff.c
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+/* s_modff.c -- float version of s_modf.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 one = 1.0;
+
+float
+modff(float x, float *iptr)
+{
+        int32_t i0,j0;
+        uint32_t i;
+        GET_FLOAT_WORD(i0,x);
+        j0 = ((i0>>23)&0xff)-0x7f;      /* exponent of x */
+        if(j0<23) {                     /* integer part in x */
+            if(j0<0) {                  /* |x|<1 */
+                SET_FLOAT_WORD(*iptr,i0&0x80000000);    /* *iptr = +-0 */
+                return x;
+            } else {
+                i = (0x007fffff)>>j0;
+                if((i0&i)==0) {                 /* x is integral */
+                    uint32_t ix;
+                    *iptr = x;
+                    GET_FLOAT_WORD(ix,x);
+                    SET_FLOAT_WORD(x,ix&0x80000000);    /* return +-0 */
+                    return x;
+                } else {
+                    SET_FLOAT_WORD(*iptr,i0&(~i));
+                    return x - *iptr;
+                }
+            }
+        } else {                        /* no fraction part */
+            uint32_t ix;
+            *iptr = x*one;
+            GET_FLOAT_WORD(ix,x);
+            SET_FLOAT_WORD(x,ix&0x80000000);    /* return +-0 */
+            return x;
+        }
+}