1/*
2 * Public domain.
3 */
4
5#include <machine/asm.h>
6#include <libm-alias-finite.h>
7
8	.section .rodata.cst8,"aM",@progbits,8
9
10	.p2align 3
11	.type one,@object
12one:	.double 1.0
13	ASM_SIZE_DIRECTIVE(one)
14	/* It is not important that this constant is precise.  It is only
15	   a value which is known to be on the safe side for using the
16	   fyl2xp1 instruction.  */
17	.type limit,@object
18limit:	.double 0.29
19	ASM_SIZE_DIRECTIVE(limit)
20
21
22#ifdef PIC
23# define MO(op) op##@GOTOFF(%edx)
24#else
25# define MO(op) op
26#endif
27
28	.text
29ENTRY(__ieee754_log10)
30	fldlg2			// log10(2)
31	fldl	4(%esp)		// x : log10(2)
32#ifdef PIC
33	LOAD_PIC_REG (dx)
34#endif
35	fxam
36	fnstsw
37	fld	%st		// x : x : log10(2)
38	sahf
39	jc	3f		// in case x is NaN or �Inf
404:	fsubl	MO(one)		// x-1 : x : log10(2)
41	fld	%st		// x-1 : x-1 : x : log10(2)
42	fabs			// |x-1| : x-1 : x : log10(2)
43	fcompl	MO(limit)	// x-1 : x : log10(2)
44	fnstsw			// x-1 : x : log10(2)
45	andb	$0x45, %ah
46	jz	2f
47	fxam
48	fnstsw
49	andb	$0x45, %ah
50	cmpb	$0x40, %ah
51	jne	5f
52	fabs			// log10(1) is +0 in all rounding modes.
535:	fstp	%st(1)		// x-1 : log10(2)
54	fyl2xp1			// log10(x)
55	ret
56
572:	fstp	%st(0)		// x : log10(2)
58	fyl2x			// log10(x)
59	ret
60
613:	jp	4b		// in case x is �Inf
62	fstp	%st(1)
63	fstp	%st(1)
64	ret
65END (__ieee754_log10)
66libm_alias_finite (__ieee754_log10, __log10)
67