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Diffstat (limited to 'sysdeps/libm-ieee754/s_ilogbf.c')
-rw-r--r--sysdeps/libm-ieee754/s_ilogbf.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_ilogbf.c b/sysdeps/libm-ieee754/s_ilogbf.c
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+++ b/sysdeps/libm-ieee754/s_ilogbf.c
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+/* s_ilogbf.c -- float version of s_ilogb.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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_ilogbf.c,v 1.4 1995/05/10 20:47:31 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+ int __ilogbf(float x)
+#else
+ int __ilogbf(x)
+ float x;
+#endif
+{
+ int32_t hx,ix;
+
+ GET_FLOAT_WORD(hx,x);
+ hx &= 0x7fffffff;
+ if(hx<0x00800000) {
+ if(hx==0)
+ return 0x80000001; /* ilogb(0) = 0x80000001 */
+ else /* subnormal x */
+ for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
+ return ix;
+ }
+ else if (hx<0x7f800000) return (hx>>23)-127;
+ else return 0x7fffffff;
+}
+weak_alias (__ilogbf, ilogbf)