aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/vector.S
blob: 12cb90bc209c99feac3310aee41df6ffccd394c6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
#include <linux/config.h>
#include <asm/ppc_asm.h>
#include <asm/processor.h>

/*
 * The routines below are in assembler so we can closely control the
 * usage of floating-point registers.  These routines must be called
 * with preempt disabled.
 */
#ifdef CONFIG_PPC32
	.data
fpzero:
	.long	0
fpone:
	.long	0x3f800000	/* 1.0 in single-precision FP */
fphalf:
	.long	0x3f000000	/* 0.5 in single-precision FP */

#define LDCONST(fr, name)	\
	lis	r11,name@ha;	\
	lfs	fr,name@l(r11)
#else

	.section ".toc","aw"
fpzero:
	.tc	FD_0_0[TC],0
fpone:
	.tc	FD_3ff00000_0[TC],0x3ff0000000000000	/* 1.0 */
fphalf:
	.tc	FD_3fe00000_0[TC],0x3fe0000000000000	/* 0.5 */

#define LDCONST(fr, name)	\
	lfd	fr,name@toc(r2)
#endif

	.text
/*
 * Internal routine to enable floating point and set FPSCR to 0.
 * Don't call it from C; it doesn't use the normal calling convention.
 */
fpenable:
#ifdef CONFIG_PPC32
	stwu	r1,-64(r1)
#else
	stdu	r1,-64(r1)
#endif
	mfmsr	r10
	ori	r11,r10,MSR_FP
	mtmsr	r11
	isync
	stfd	fr0,24(r1)
	stfd	fr1,16(r1)
	stfd	fr31,8(r1)
	LDCONST(fr1, fpzero)
	mffs	fr31
	mtfsf	0xff,fr1
	blr

fpdisable:
	mtlr	r12
	mtfsf	0xff,fr31
	lfd	fr31,8(r1)
	lfd	fr1,16(r1)
	lfd	fr0,24(r1)
	mtmsr	r10
	isync
	addi	r1,r1,64
	blr

/*
 * Vector add, floating point.
 */
_GLOBAL(vaddfp)
	mflr	r12
	bl	fpenable
	li	r0,4
	mtctr	r0
	li	r6,0
1:	lfsx	fr0,r4,r6
	lfsx	fr1,r5,r6
	fadds	fr0,fr0,fr1
	stfsx	fr0,r3,r6
	addi	r6,r6,4
	bdnz	1b
	b	fpdisable

/*
 * Vector subtract, floating point.
 */
_GLOBAL(vsubfp)
	mflr	r12
	bl	fpenable
	li	r0,4
	mtctr	r0
	li	r6,0
1:	lfsx	fr0,r4,r6
	lfsx	fr1,r5,r6
	fsubs	fr0,fr0,fr1
	stfsx	fr0,r3,r6
	addi	r6,r6,4
	bdnz	1b
	b	fpdisable

/*
 * Vector multiply and add, floating point.
 */
_GLOBAL(vmaddfp)
	mflr	r12
	bl	fpenable
	stfd	fr2,32(r1)
	li	r0,4
	mtctr	r0
	li	r7,0
1:	lfsx	fr0,r4,r7
	lfsx	fr1,r5,r7
	lfsx	fr2,r6,r7
	fmadds	fr0,fr0,fr2,fr1
	stfsx	fr0,r3,r7
	addi	r7,r7,4
	bdnz	1b
	lfd	fr2,32(r1)
	b	fpdisable

/*
 * Vector negative multiply and subtract, floating point.
 */
_GLOBAL(vnmsubfp)
	mflr	r12
	bl	fpenable
	stfd	fr2,32(r1)
	li	r0,4
	mtctr	r0
	li	r7,0
1:	lfsx	fr0,r4,r7
	lfsx	fr1,r5,r7
	lfsx	fr2,r6,r7
	fnmsubs	fr0,fr0,fr2,fr1
	stfsx	fr0,r3,r7
	addi	r7,r7,4
	bdnz	1b
	lfd	fr2,32(r1)
	b	fpdisable

/*
 * Vector reciprocal estimate.  We just compute 1.0/x.
 * r3 -> destination, r4 -> source.
 */
_GLOBAL(vrefp)
	mflr	r12
	bl	fpenable
	li	r0,4
	LDCONST(fr1, fpone)
	mtctr	r0
	li	r6,0
1:	lfsx	fr0,r4,r6
	fdivs	fr0,fr1,fr0
	stfsx	fr0,r3,r6
	addi	r6,r6,4
	bdnz	1b
	b	fpdisable

/*
 * Vector reciprocal square-root estimate, floating point.
 * We use the frsqrte instruction for the initial estimate followed
 * by 2 iterations of Newton-Raphson to get sufficient accuracy.
 * r3 -> destination, r4 -> source.
 */
_GLOBAL(vrsqrtefp)
	mflr	r12
	bl	fpenable
	stfd	fr2,32(r1)
	stfd	fr3,40(r1)
	stfd	fr4,48(r1)
	stfd	fr5,56(r1)
	li	r0,4
	LDCONST(fr4, fpone)
	LDCONST(fr5, fphalf)
	mtctr	r0
	li	r6,0
1:	lfsx	fr0,r4,r6
	frsqrte	fr1,fr0		/* r = frsqrte(s) */
	fmuls	fr3,fr1,fr0	/* r * s */
	fmuls	fr2,fr1,fr5	/* r * 0.5 */
	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
	fmuls	fr3,fr1,fr0	/* r * s */
	fmuls	fr2,fr1,fr5	/* r * 0.5 */
	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
	stfsx	fr1,r3,r6
	addi	r6,r6,4
	bdnz	1b
	lfd	fr5,56(r1)
	lfd	fr4,48(r1)
	lfd	fr3,40(r1)
	lfd	fr2,32(r1)
	b	fpdisable