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-rw-r--r--src/math/s_truncf.c50
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diff --git a/src/math/s_truncf.c b/src/math/s_truncf.c
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+/* @(#)s_floor.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/*
+ * truncf(x)
+ * Return x rounded toward 0 to integral value
+ * Method:
+ *      Bit twiddling.
+ * Exception:
+ *      Inexact flag raised if x not equal to truncf(x).
+ */
+
+#include <math.h>
+#include "math_private.h"
+
+static const float huge = 1.0e30F;
+
+float
+truncf(float x)
+{
+        int32_t i0,j0;
+        uint32_t i;
+        GET_FLOAT_WORD(i0,x);
+        j0 = ((i0>>23)&0xff)-0x7f;
+        if(j0<23) {
+            if(j0<0) {  /* raise inexact if x != 0 */
+                if(huge+x>0.0F)         /* |x|<1, so return 0*sign(x) */
+                    i0 &= 0x80000000;
+            } else {
+                i = (0x007fffff)>>j0;
+                if((i0&i)==0) return x; /* x is integral */
+                if(huge+x>0.0F)         /* raise inexact flag */
+                    i0 &= (~i);
+            }
+        } else {
+            if(j0==0x80) return x+x;    /* inf or NaN */
+            else return x;              /* x is integral */
+        }
+        SET_FLOAT_WORD(x,i0);
+        return x;
+}