xref: /OK3568_Linux_fs/kernel/arch/sparc/lib/fls64.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* fls64.S: SPARC default __fls definition.
2*4882a593Smuzhiyun *
3*4882a593Smuzhiyun * SPARC default __fls definition, which follows the same algorithm as
4*4882a593Smuzhiyun * in generic __fls(). This function will be boot time patched on T4
5*4882a593Smuzhiyun * and onward.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun#include <linux/linkage.h>
9*4882a593Smuzhiyun#include <asm/export.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun	.text
12*4882a593Smuzhiyun	.register	%g2, #scratch
13*4882a593Smuzhiyun	.register	%g3, #scratch
14*4882a593SmuzhiyunENTRY(__fls)
15*4882a593Smuzhiyun	mov	-1, %g2
16*4882a593Smuzhiyun	sllx	%g2, 32, %g2
17*4882a593Smuzhiyun	and	%o0, %g2, %g2
18*4882a593Smuzhiyun	brnz,pt	%g2, 1f
19*4882a593Smuzhiyun	 mov	63, %g1
20*4882a593Smuzhiyun	sllx	%o0, 32, %o0
21*4882a593Smuzhiyun	mov	31, %g1
22*4882a593Smuzhiyun1:
23*4882a593Smuzhiyun	mov	-1, %g2
24*4882a593Smuzhiyun	sllx	%g2, 48, %g2
25*4882a593Smuzhiyun	and	%o0, %g2, %g2
26*4882a593Smuzhiyun	brnz,pt	%g2, 2f
27*4882a593Smuzhiyun	 mov	-1, %g2
28*4882a593Smuzhiyun	sllx	%o0, 16, %o0
29*4882a593Smuzhiyun	add	%g1, -16, %g1
30*4882a593Smuzhiyun2:
31*4882a593Smuzhiyun	mov	-1, %g2
32*4882a593Smuzhiyun	sllx	%g2, 56, %g2
33*4882a593Smuzhiyun	and	%o0, %g2, %g2
34*4882a593Smuzhiyun	brnz,pt	%g2, 3f
35*4882a593Smuzhiyun	 mov	-1, %g2
36*4882a593Smuzhiyun	sllx	%o0, 8, %o0
37*4882a593Smuzhiyun	add	%g1, -8, %g1
38*4882a593Smuzhiyun3:
39*4882a593Smuzhiyun	sllx	%g2, 60, %g2
40*4882a593Smuzhiyun	and	%o0, %g2, %g2
41*4882a593Smuzhiyun	brnz,pt	%g2, 4f
42*4882a593Smuzhiyun	 mov	-1, %g2
43*4882a593Smuzhiyun	sllx	%o0, 4, %o0
44*4882a593Smuzhiyun	add	%g1, -4, %g1
45*4882a593Smuzhiyun4:
46*4882a593Smuzhiyun	sllx	%g2, 62, %g2
47*4882a593Smuzhiyun	and	%o0, %g2, %g2
48*4882a593Smuzhiyun	brnz,pt	%g2, 5f
49*4882a593Smuzhiyun	 mov	-1, %g3
50*4882a593Smuzhiyun	sllx	%o0, 2, %o0
51*4882a593Smuzhiyun	add	%g1, -2, %g1
52*4882a593Smuzhiyun5:
53*4882a593Smuzhiyun	mov	0, %g2
54*4882a593Smuzhiyun	sllx	%g3, 63, %g3
55*4882a593Smuzhiyun	and	%o0, %g3, %o0
56*4882a593Smuzhiyun	movre	%o0, 1, %g2
57*4882a593Smuzhiyun	sub	%g1, %g2, %g1
58*4882a593Smuzhiyun	jmp	%o7+8
59*4882a593Smuzhiyun	 sra	%g1, 0, %o0
60*4882a593SmuzhiyunENDPROC(__fls)
61*4882a593SmuzhiyunEXPORT_SYMBOL(__fls)
62