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authorAndreas Schwab <schwab@linux-m68k.org>2012-05-21 21:18:45 +0200
committerAndreas Schwab <schwab@linux-m68k.org>2012-05-21 21:22:53 +0200
commit41ddd7da3c04e8426f9b0220324a893dafacb95a (patch)
tree4e9d3e3acb396d08b2e45b919b767e7fee9f81c8
parent2eaac3387763387bbcf1a02601d65d1d8584f4ce (diff)
downloadglibc-41ddd7da3c04e8426f9b0220324a893dafacb95a.tar.xz
glibc-41ddd7da3c04e8426f9b0220324a893dafacb95a.zip
m68k: properly implement logbl for Motorola extended float
-rw-r--r--ChangeLog.m68k2
-rw-r--r--sysdeps/m68k/m680x0/fpu/s_logbl.c49
2 files changed, 51 insertions, 0 deletions
diff --git a/ChangeLog.m68k b/ChangeLog.m68k
index 393f3978df..a6f1871200 100644
--- a/ChangeLog.m68k
+++ b/ChangeLog.m68k
@@ -1,5 +1,7 @@
2012-05-21 Andreas Schwab <schwab@linux-m68k.org>
+ * sysdeps/m68k/m680x0/fpu/s_logbl.c: New file.
+
* sysdeps/unix/sysv/linux/m68k/m680x0/nptl/libc.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/coldfire/nptl/libc.abilist: Update.
diff --git a/sysdeps/m68k/m680x0/fpu/s_logbl.c b/sysdeps/m68k/m680x0/fpu/s_logbl.c
new file mode 100644
index 0000000000..2586622bf7
--- /dev/null
+++ b/sysdeps/m68k/m680x0/fpu/s_logbl.c
@@ -0,0 +1,49 @@
+/* s_logbl.c -- long double version of s_logb.c.
+ * Conversion to long double by Ulrich Drepper,
+ * Cygnus Support, drepper@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.
+ * ====================================================
+ */
+
+/*
+ * long double logbl(x)
+ * IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
+ * Use ilogb instead.
+ */
+
+#include <math.h>
+#include <math_private.h>
+
+long double
+__logbl (long double x)
+{
+ int32_t es, lx, ix;
+
+ GET_LDOUBLE_WORDS (es, ix, lx, x);
+ es &= 0x7fff; /* exponent */
+ if ((es | ix | lx) == 0)
+ return -1.0 / fabsl (x);
+ if (es == 0x7fff)
+ return x * x;
+ if (es == 0) /* IEEE 754 logb */
+ {
+ /* POSIX specifies that denormal number is treated as
+ though it were normalized. */
+ if (ix == 0)
+ es = -(__builtin_clz (lx) + 32);
+ else
+ es = -__builtin_clz (ix);
+ }
+ return (long double) (es - 16383);
+}
+
+weak_alias (__logbl, logbl)