aboutsummaryrefslogtreecommitdiff
path: root/REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S
diff options
context:
space:
mode:
Diffstat (limited to 'REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S')
-rw-r--r--REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S74
1 files changed, 74 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S b/REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S
new file mode 100644
index 0000000000..947e5e4552
--- /dev/null
+++ b/REORG.TODO/sysdeps/x86_64/fpu/s_log1pl.S
@@ -0,0 +1,74 @@
+/*
+ * 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 $")
+
+ .section .rodata
+
+ .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
+ testb $1, %ah
+ jnz 3f // in case x is NaN or ħInf
+4:
+ fabs
+ fldt MO(limit)
+ fcompp
+ fnstsw
+ andb $1,%ah
+ jz 2f
+
+ movzwl 8+8(%rsp), %eax
+ xorb $0x80, %ah
+ cmpl $0xc040, %eax
+ jae 5f
+
+ faddl MO(one)
+5: fyl2x
+ ret
+
+2: fyl2xp1
+ ret
+
+3: testb $4, %ah
+ jnz 4b // in case x is ħInf
+ fstp %st(1)
+ fstp %st(1)
+ fadd %st(0)
+ ret
+
+END (__log1pl)