cuserid: don't return truncated results

[musl] / src / math / rintf.c

diff --git a/src/math/rintf.c b/src/math/rintf.c
index e8d4496..9047688 100644 (file)
--- a/src/math/rintf.c
+++ b/src/math/rintf.c
@@ -1,48 +1,30 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/s_rintf.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 <float.h>
+#include <math.h>
+#include <stdint.h>
 
-#include "libm.h"
-
-static const float
-TWO23[2] = {
-  8.3886080000e+06, /* 0x4b000000 */
- -8.3886080000e+06, /* 0xcb000000 */
-};
+#if FLT_EVAL_METHOD==0
+#define EPS FLT_EPSILON
+#elif FLT_EVAL_METHOD==1
+#define EPS DBL_EPSILON
+#elif FLT_EVAL_METHOD==2
+#define EPS LDBL_EPSILON
+#endif
+static const float_t toint = 1/EPS;
 
 float rintf(float x)
 {
-       int32_t i0,j0,sx;
-       float w,t;
+       union {float f; uint32_t i;} u = {x};
+       int e = u.i>>23 & 0xff;
+       int s = u.i>>31;
+       float_t y;
 
-       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;
-                       STRICT_ASSIGN(float, w, TWO23[sx] + x);
-                       t = w - TWO23[sx];
-                       GET_FLOAT_WORD(i0, t);
-                       SET_FLOAT_WORD(t, (i0&0x7fffffff)|(sx<<31));
-                       return t;
-               }
-               STRICT_ASSIGN(float, w, TWO23[sx] + x);
-               return w - TWO23[sx];
-       }
-       if (j0 == 0x80)
-               return x+x;  /* inf or NaN */
-       return x;            /* x is integral */
+       if (e >= 0x7f+23)
+               return x;
+       if (s)
+               y = x - toint + toint;
+       else
+               y = x + toint - toint;
+       if (y == 0)
+               return s ? -0.0f : 0.0f;
+       return y;
 }