1/*
2 * Written by J.T. Conklin <jtc@netbsd.org>.
3 * Public domain.
4 *
5 * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
6 *
7 * Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>.
8 */
9
10#include <machine/asm.h>
11
12RCSID("$NetBSD: $")
13
14#ifdef __ELF__
15	.section .rodata
16#else
17	.text
18#endif
19	.align ALIGNARG(4)
20	ASM_TYPE_DIRECTIVE(one,@object)
21one:	.double 1.0
22	ASM_SIZE_DIRECTIVE(one)
23	/* It is not important that this constant is precise.  It is only
24	   a value which is known to be on the safe side for using the
25	   fyl2xp1 instruction.  */
26	ASM_TYPE_DIRECTIVE(limit,@object)
27limit:	.double 0.29
28	ASM_SIZE_DIRECTIVE(limit)
29
30
31#ifdef PIC
32#define MO(op) op##@GOTOFF(%edx)
33#else
34#define MO(op) op
35#endif
36
37	.text
38ENTRY(__ieee754_log10l)
39	fldlg2			// log10(2)
40	fldt	4(%esp)		// x : log10(2)
41#ifdef PIC
42	call	1f
431:	popl	%edx
44	addl	$_GLOBAL_OFFSET_TABLE_+[.-1b], %edx
45#endif
46	fxam
47	fnstsw
48	fld	%st		// x : x : log10(2)
49	sahf
50	jc	3f		// in case x is NaN or �Inf
514:	fsubl	MO(one)		// x-1 : x : log10(2)
52	fld	%st		// x-1 : x-1 : x : log10(2)
53	fabs			// |x-1| : x-1 : x : log10(2)
54	fcompl	MO(limit)	// x-1 : x : log10(2)
55	fnstsw			// x-1 : x : log10(2)
56	andb	$0x45, %ah
57	jz	2f
58	fstp	%st(1)		// x-1 : log10(2)
59	fyl2xp1			// log10(x)
60	ret
61
622:	fstp	%st(0)		// x : log10(2)
63	fyl2x			// log10(x)
64	ret
65
663:	jp	4b		// in case x is �Inf
67	fstp	%st(1)
68	fstp	%st(1)
69	ret
70END(__ieee754_log10l)
71