summaryrefslogtreecommitdiff
path: root/libc/sysdeps/x86_64/fpu/s_log1pl.S
diff options
context:
space:
mode:
authorgcc <gcc@7b3dc134-2b1b-0410-93df-9e9f96275f8d>2006-08-17 01:18:26 +0000
committergcc <gcc@7b3dc134-2b1b-0410-93df-9e9f96275f8d>2006-08-17 01:18:26 +0000
commit15f34685e7a9b5caf761af2ebf6afa20438d440b (patch)
treedc04ce3cdf040f198743c15b64557824de174680 /libc/sysdeps/x86_64/fpu/s_log1pl.S
parent1e848e0e775a36f6359161f5deb890942ef42ff3 (diff)
downloadeglibc2-15f34685e7a9b5caf761af2ebf6afa20438d440b.tar.gz
Import glibc-mainline for 2006-08-16
git-svn-id: svn://svn.eglibc.org/fsf/trunk@4 7b3dc134-2b1b-0410-93df-9e9f96275f8d
Diffstat (limited to 'libc/sysdeps/x86_64/fpu/s_log1pl.S')
-rw-r--r--libc/sysdeps/x86_64/fpu/s_log1pl.S71
1 files changed, 71 insertions, 0 deletions
diff --git a/libc/sysdeps/x86_64/fpu/s_log1pl.S b/libc/sysdeps/x86_64/fpu/s_log1pl.S
new file mode 100644
index 000000000..7fbd0e5aa
--- /dev/null
+++ b/libc/sysdeps/x86_64/fpu/s_log1pl.S
@@ -0,0 +1,71 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ *
+ * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
+ * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>.
+ */
+
+#include <machine/asm.h>
+
+RCSID("$NetBSD: s_log1p.S,v 1.7 1995/05/09 00:10:58 jtc Exp $")
+
+#ifdef __ELF__
+ .section .rodata
+#else
+ .text
+#endif
+ .align ALIGNARG(4)
+ /* The fyl2xp1 can only be used for values in
+ -1 + sqrt(2) / 2 <= x <= 1 - sqrt(2) / 2
+ 0.29 is a safe value.
+ */
+limit: .tfloat 0.29
+ /* Please note: we use a double value here. Since 1.0 has
+ an exact representation this does not effect the accuracy
+ but it helps to optimize the code. */
+one: .double 1.0
+
+/*
+ * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29,
+ * otherwise fyl2x with the needed extra computation.
+ */
+#ifdef PIC
+#define MO(op) op##(%rip)
+#else
+#define MO(op) op
+#endif
+
+ .text
+ENTRY(__log1pl)
+ fldln2
+
+ fldt 8(%rsp)
+
+ fxam
+ fnstsw
+ fld %st
+ andb $1,%ah
+ jnz 3f // in case x is NaN or ħInf
+4:
+ fabs
+ fldt MO(limit)
+ fcompp
+ fnstsw
+ andb $1,%ah
+ jz 2f
+
+ faddl MO(one)
+ fyl2x
+ ret
+
+2: fyl2xp1
+ ret
+
+3: jp 4b // in case x is ħInf
+ fstp %st(1)
+ fstp %st(1)
+ ret
+
+END (__log1pl)
+weak_alias (__log1pl, log1pl)