mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-09 04:11:27 +08:00
0ac5ae2335
libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized.
83 lines
1.7 KiB
ArmAsm
83 lines
1.7 KiB
ArmAsm
/*
|
|
* Written by J.T. Conklin <jtc@netbsd.org>.
|
|
* Public domain.
|
|
*
|
|
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
|
|
*
|
|
* Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>.
|
|
* Adapted for x86-64 by Andreas Jaeger <aj@suse.de>.
|
|
*/
|
|
|
|
#include <machine/asm.h>
|
|
|
|
#ifdef __ELF__
|
|
.section .rodata.cst8,"aM",@progbits,8
|
|
#else
|
|
.text
|
|
#endif
|
|
.p2align 3
|
|
ASM_TYPE_DIRECTIVE(one,@object)
|
|
one: .double 1.0
|
|
ASM_SIZE_DIRECTIVE(one)
|
|
/* It is not important that this constant is precise. It is only
|
|
a value which is known to be on the safe side for using the
|
|
fyl2xp1 instruction. */
|
|
ASM_TYPE_DIRECTIVE(limit,@object)
|
|
limit: .double 0.29
|
|
ASM_SIZE_DIRECTIVE(limit)
|
|
|
|
|
|
#ifdef PIC
|
|
# define MO(op) op##(%rip)
|
|
#else
|
|
# define MO(op) op
|
|
#endif
|
|
|
|
.text
|
|
ENTRY(__ieee754_log10l)
|
|
fldlg2 // log10(2)
|
|
fldt 8(%rsp) // x : log10(2)
|
|
fxam
|
|
fnstsw
|
|
fld %st // x : x : log10(2)
|
|
testb $1, %ah
|
|
jnz 3f // in case x is NaN or ±Inf
|
|
4: fsubl MO(one) // x-1 : x : log10(2)
|
|
fld %st // x-1 : x-1 : x : log10(2)
|
|
fabs // |x-1| : x-1 : x : log10(2)
|
|
fcompl MO(limit) // x-1 : x : log10(2)
|
|
fnstsw // x-1 : x : log10(2)
|
|
andb $0x45, %ah
|
|
jz 2f
|
|
fstp %st(1) // x-1 : log10(2)
|
|
fyl2xp1 // log10(x)
|
|
ret
|
|
|
|
2: fstp %st(0) // x : log10(2)
|
|
fyl2x // log10(x)
|
|
ret
|
|
|
|
3: testb $4, %ah
|
|
jnz 4b // in case x is ±Inf
|
|
fstp %st(1)
|
|
fstp %st(1)
|
|
ret
|
|
END(__ieee754_log10l)
|
|
|
|
|
|
ENTRY(__log10l_finite)
|
|
fldlg2 // log10(2)
|
|
fldt 8(%rsp) // x : log10(2)
|
|
fld %st // x : x : log10(2)
|
|
4: fsubl MO(one) // x-1 : x : log10(2)
|
|
fld %st // x-1 : x-1 : x : log10(2)
|
|
fabs // |x-1| : x-1 : x : log10(2)
|
|
fcompl MO(limit) // x-1 : x : log10(2)
|
|
fnstsw // x-1 : x : log10(2)
|
|
andb $0x45, %ah
|
|
jz 2b
|
|
fstp %st(1) // x-1 : log10(2)
|
|
fyl2xp1 // log10(x)
|
|
ret
|
|
END(__log10l_finite)
|