aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/x86_64/fpu/e_log2l.S
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
committerUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
commit0ac5ae2335292908f39031b1ea9fe8edce433c0f (patch)
treef9d26c8abc0de39d18d4c13e70f6022cdc6b461f /sysdeps/x86_64/fpu/e_log2l.S
parenta843a204a3e8a0dd53584dad3668771abaec84ac (diff)
downloadglibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar
glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz
glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.bz2
glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.zip
Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized.
Diffstat (limited to 'sysdeps/x86_64/fpu/e_log2l.S')
-rw-r--r--sysdeps/x86_64/fpu/e_log2l.S25
1 files changed, 21 insertions, 4 deletions
diff --git a/sysdeps/x86_64/fpu/e_log2l.S b/sysdeps/x86_64/fpu/e_log2l.S
index f04d30a05a..78dc2d5c0e 100644
--- a/sysdeps/x86_64/fpu/e_log2l.S
+++ b/sysdeps/x86_64/fpu/e_log2l.S
@@ -10,11 +10,11 @@
#include <machine/asm.h>
#ifdef __ELF__
- .section .rodata
+ .section .rodata.cst8,"aM",@progbits,8
#else
.text
#endif
- .align ALIGNARG(4)
+ .p2align 3
ASM_TYPE_DIRECTIVE(one,@object)
one: .double 1.0
ASM_SIZE_DIRECTIVE(one)
@@ -27,9 +27,9 @@ limit: .double 0.29
#ifdef PIC
-#define MO(op) op##(%rip)
+# define MO(op) op##(%rip)
#else
-#define MO(op) op
+# define MO(op) op
#endif
.text
@@ -62,3 +62,20 @@ ENTRY(__ieee754_log2l)
fstp %st(1)
ret
END (__ieee754_log2l)
+
+
+ENTRY(__log2l_finite)
+ fldl MO(one)
+ fldt 8(%rsp) // x : 1
+ fld %st // x : x : 1
+ fsub %st(2), %st // x-1 : x : 1
+ fld %st // x-1 : x-1 : x : 1
+ fabs // |x-1| : x-1 : x : 1
+ fcompl MO(limit) // x-1 : x : 1
+ fnstsw // x-1 : x : 1
+ andb $0x45, %ah
+ jz 2b
+ fstp %st(1) // x-1 : 1
+ fyl2xp1 // log(x)
+ ret
+END (__log2l_finite)