OLD | NEW |
| (Empty) |
1 ; | |
2 ; Copyright (c) 2010 The Webm project authors. All Rights Reserved. | |
3 ; | |
4 ; Use of this source code is governed by a BSD-style license | |
5 ; that can be found in the LICENSE file in the root of the source | |
6 ; tree. An additional intellectual property rights grant can be found | |
7 ; in the file PATENTS. All contributing project authors may | |
8 ; be found in the AUTHORS file in the root of the source tree. | |
9 ; | |
10 | |
11 | |
12 EXPORT |idct_dequant_full_2x_neon| | |
13 ARM | |
14 REQUIRE8 | |
15 PRESERVE8 | |
16 | |
17 AREA ||.text||, CODE, READONLY, ALIGN=2 | |
18 ;void idct_dequant_full_2x_neon(short *q, short *dq, | |
19 ; unsigned char *dst, int stride); | |
20 ; r0 *q, | |
21 ; r1 *dq, | |
22 ; r2 *dst | |
23 ; r3 stride | |
24 |idct_dequant_full_2x_neon| PROC | |
25 vpush {d8-d15} | |
26 | |
27 vld1.16 {q0, q1}, [r1] ; dq (same l/r) | |
28 vld1.16 {q2, q3}, [r0] ; l q | |
29 add r0, r0, #32 | |
30 vld1.16 {q4, q5}, [r0] ; r q | |
31 add r12, r2, #4 | |
32 | |
33 ; interleave the predictors | |
34 vld1.32 {d28[0]}, [r2], r3 ; l pre | |
35 vld1.32 {d28[1]}, [r12], r3 ; r pre | |
36 vld1.32 {d29[0]}, [r2], r3 | |
37 vld1.32 {d29[1]}, [r12], r3 | |
38 vld1.32 {d30[0]}, [r2], r3 | |
39 vld1.32 {d30[1]}, [r12], r3 | |
40 vld1.32 {d31[0]}, [r2], r3 | |
41 vld1.32 {d31[1]}, [r12] | |
42 | |
43 adr r1, cospi8sqrt2minus1 ; pointer to the first constant | |
44 | |
45 ; dequant: q[i] = q[i] * dq[i] | |
46 vmul.i16 q2, q2, q0 | |
47 vmul.i16 q3, q3, q1 | |
48 vmul.i16 q4, q4, q0 | |
49 vmul.i16 q5, q5, q1 | |
50 | |
51 vld1.16 {d0}, [r1] | |
52 | |
53 ; q2: l0r0 q3: l8r8 | |
54 ; q4: l4r4 q5: l12r12 | |
55 vswp d5, d8 | |
56 vswp d7, d10 | |
57 | |
58 ; _CONSTANTS_ * 4,12 >> 16 | |
59 ; q6: 4 * sinpi : c1/temp1 | |
60 ; q7: 12 * sinpi : d1/temp2 | |
61 ; q8: 4 * cospi | |
62 ; q9: 12 * cospi | |
63 vqdmulh.s16 q6, q4, d0[2] ; sinpi8sqrt2 | |
64 vqdmulh.s16 q7, q5, d0[2] | |
65 vqdmulh.s16 q8, q4, d0[0] ; cospi8sqrt2minus1 | |
66 vqdmulh.s16 q9, q5, d0[0] | |
67 | |
68 vqadd.s16 q10, q2, q3 ; a1 = 0 + 8 | |
69 vqsub.s16 q11, q2, q3 ; b1 = 0 - 8 | |
70 | |
71 ; vqdmulh only accepts signed values. this was a problem because | |
72 ; our constant had the high bit set, and was treated as a negative value. | |
73 ; vqdmulh also doubles the value before it shifts by 16. we need to | |
74 ; compensate for this. in the case of sinpi8sqrt2, the lowest bit is 0, | |
75 ; so we can shift the constant without losing precision. this avoids | |
76 ; shift again afterward, but also avoids the sign issue. win win! | |
77 ; for cospi8sqrt2minus1 the lowest bit is 1, so we lose precision if we | |
78 ; pre-shift it | |
79 vshr.s16 q8, q8, #1 | |
80 vshr.s16 q9, q9, #1 | |
81 | |
82 ; q4: 4 + 4 * cospi : d1/temp1 | |
83 ; q5: 12 + 12 * cospi : c1/temp2 | |
84 vqadd.s16 q4, q4, q8 | |
85 vqadd.s16 q5, q5, q9 | |
86 | |
87 ; c1 = temp1 - temp2 | |
88 ; d1 = temp1 + temp2 | |
89 vqsub.s16 q2, q6, q5 | |
90 vqadd.s16 q3, q4, q7 | |
91 | |
92 ; [0]: a1+d1 | |
93 ; [1]: b1+c1 | |
94 ; [2]: b1-c1 | |
95 ; [3]: a1-d1 | |
96 vqadd.s16 q4, q10, q3 | |
97 vqadd.s16 q5, q11, q2 | |
98 vqsub.s16 q6, q11, q2 | |
99 vqsub.s16 q7, q10, q3 | |
100 | |
101 ; rotate | |
102 vtrn.32 q4, q6 | |
103 vtrn.32 q5, q7 | |
104 vtrn.16 q4, q5 | |
105 vtrn.16 q6, q7 | |
106 ; idct loop 2 | |
107 ; q4: l 0, 4, 8,12 r 0, 4, 8,12 | |
108 ; q5: l 1, 5, 9,13 r 1, 5, 9,13 | |
109 ; q6: l 2, 6,10,14 r 2, 6,10,14 | |
110 ; q7: l 3, 7,11,15 r 3, 7,11,15 | |
111 | |
112 ; q8: 1 * sinpi : c1/temp1 | |
113 ; q9: 3 * sinpi : d1/temp2 | |
114 ; q10: 1 * cospi | |
115 ; q11: 3 * cospi | |
116 vqdmulh.s16 q8, q5, d0[2] ; sinpi8sqrt2 | |
117 vqdmulh.s16 q9, q7, d0[2] | |
118 vqdmulh.s16 q10, q5, d0[0] ; cospi8sqrt2minus1 | |
119 vqdmulh.s16 q11, q7, d0[0] | |
120 | |
121 vqadd.s16 q2, q4, q6 ; a1 = 0 + 2 | |
122 vqsub.s16 q3, q4, q6 ; b1 = 0 - 2 | |
123 | |
124 ; see note on shifting above | |
125 vshr.s16 q10, q10, #1 | |
126 vshr.s16 q11, q11, #1 | |
127 | |
128 ; q10: 1 + 1 * cospi : d1/temp1 | |
129 ; q11: 3 + 3 * cospi : c1/temp2 | |
130 vqadd.s16 q10, q5, q10 | |
131 vqadd.s16 q11, q7, q11 | |
132 | |
133 ; q8: c1 = temp1 - temp2 | |
134 ; q9: d1 = temp1 + temp2 | |
135 vqsub.s16 q8, q8, q11 | |
136 vqadd.s16 q9, q10, q9 | |
137 | |
138 ; a1+d1 | |
139 ; b1+c1 | |
140 ; b1-c1 | |
141 ; a1-d1 | |
142 vqadd.s16 q4, q2, q9 | |
143 vqadd.s16 q5, q3, q8 | |
144 vqsub.s16 q6, q3, q8 | |
145 vqsub.s16 q7, q2, q9 | |
146 | |
147 ; +4 >> 3 (rounding) | |
148 vrshr.s16 q4, q4, #3 ; lo | |
149 vrshr.s16 q5, q5, #3 | |
150 vrshr.s16 q6, q6, #3 ; hi | |
151 vrshr.s16 q7, q7, #3 | |
152 | |
153 vtrn.32 q4, q6 | |
154 vtrn.32 q5, q7 | |
155 vtrn.16 q4, q5 | |
156 vtrn.16 q6, q7 | |
157 | |
158 ; adding pre | |
159 ; input is still packed. pre was read interleaved | |
160 vaddw.u8 q4, q4, d28 | |
161 vaddw.u8 q5, q5, d29 | |
162 vaddw.u8 q6, q6, d30 | |
163 vaddw.u8 q7, q7, d31 | |
164 | |
165 vmov.i16 q14, #0 | |
166 vmov q15, q14 | |
167 vst1.16 {q14, q15}, [r0] ; write over high input | |
168 sub r0, r0, #32 | |
169 vst1.16 {q14, q15}, [r0] ; write over low input | |
170 | |
171 sub r2, r2, r3, lsl #2 ; dst - 4*stride | |
172 add r1, r2, #4 ; hi | |
173 | |
174 ;saturate and narrow | |
175 vqmovun.s16 d0, q4 ; lo | |
176 vqmovun.s16 d1, q5 | |
177 vqmovun.s16 d2, q6 ; hi | |
178 vqmovun.s16 d3, q7 | |
179 | |
180 vst1.32 {d0[0]}, [r2], r3 ; lo | |
181 vst1.32 {d0[1]}, [r1], r3 ; hi | |
182 vst1.32 {d1[0]}, [r2], r3 | |
183 vst1.32 {d1[1]}, [r1], r3 | |
184 vst1.32 {d2[0]}, [r2], r3 | |
185 vst1.32 {d2[1]}, [r1], r3 | |
186 vst1.32 {d3[0]}, [r2] | |
187 vst1.32 {d3[1]}, [r1] | |
188 | |
189 vpop {d8-d15} | |
190 bx lr | |
191 | |
192 ENDP ; |idct_dequant_full_2x_neon| | |
193 | |
194 ; Constant Pool | |
195 cospi8sqrt2minus1 DCD 0x4e7b | |
196 ; because the lowest bit in 0x8a8c is 0, we can pre-shift this | |
197 sinpi8sqrt2 DCD 0x4546 | |
198 | |
199 END | |
OLD | NEW |