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-rw-r--r--src/math/s_rintf.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/src/math/s_rintf.c b/src/math/s_rintf.c
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+/* s_rintf.c -- float version of s_rint.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
+TWO23[2]={
+ 8.3886080000e+06, /* 0x4b000000 */
+ -8.3886080000e+06, /* 0xcb000000 */
+};
+
+float
+rintf(float x)
+{
+ int32_t i0,j0,sx;
+ volatile float w,t; /* volatile works around gcc bug */
+ GET_FLOAT_WORD(i0,x);
+ sx = (i0>>31)&1;
+ j0 = ((i0>>23)&0xff)-0x7f;
+ if(j0<23) {
+ if(j0<0) {
+ if((i0&0x7fffffff)==0) return x;
+ w = TWO23[sx]+x;
+ t = w-TWO23[sx];
+ return t;
+ }
+ w = TWO23[sx]+x;
+ return w-TWO23[sx];
+ }
+ if(j0==0x80) return x+x; /* inf or NaN */
+ else return x; /* x is integral */
+}