glibc/sysdeps/i386/fpu/e_log.S
Ulrich Drepper 6b2665f534 [BZ #3919]
* math/libm-test.inc (log_test): Test -Inf and NaN.
	(log10_test, log1p_test, log2_test): Test -Inf.
	* sysdeps/i386/fpu/e_log.S (__ieee754_log): Don't raise
	FE_INVALID when argument is qNaN.
	* sysdeps/i386/fpu/e_logl.S (__ieee754_logl): Likewise.
	* sysdeps/i386/fpu/e_logf.S (__ieee754_logf): Likewise.
	* sysdeps/x86_64/fpu/e_logl.S (__ieee754_logl): Likewise.
	* sysdeps/x86_64/fpu/e_log10l.S (__ieee754_log10l): Replace
	andb $1, %ah with testb $1, %ah, don't test for parity, instead
	testb $4, %ah and jump if non-zero.
	* sysdeps/x86_64/fpu/e_log2l.S (__ieee754_log2l): Likewise.
	* sysdeps/x86_64/fpu/s_log1pl.S (__log1pl): Likewise.

2007-03-15  Jakub Jelinek  <jakub@redhat.com>
2007-03-15 20:10:51 +00:00

67 lines
1.3 KiB
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>.
*/
#include <machine/asm.h>
RCSID("$NetBSD: e_log.S,v 1.4 1995/05/08 23:48:39 jtc Exp $")
#ifdef __ELF__
.section .rodata
#else
.text
#endif
.align ALIGNARG(4)
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##@GOTOFF(%edx)
#else
#define MO(op) op
#endif
.text
ENTRY(__ieee754_log)
fldln2 // log(2)
fldl 4(%esp) // x : log(2)
fxam
fnstsw
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
fld %st // x : x : log(2)
sahf
jc 3f // in case x is NaN or +-Inf
4: fsubl MO(one) // x-1 : x : log(2)
fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl MO(limit) // x-1 : x : log(2)
fnstsw // x-1 : x : log(2)
andb $0x45, %ah
jz 2f
fstp %st(1) // x-1 : log(2)
fyl2xp1 // log(x)
ret
2: fstp %st(0) // x : log(2)
fyl2x // log(x)
ret
3: jp 4b // in case x is +-Inf
fstp %st(1)
fstp %st(1)
ret
END (__ieee754_log)