ref: 7987686397b8dc497d00468b13d030af8a915b8c
dir: /vp8/common/arm/armv6/idct_v6.asm/
;
; Copyright (c) 2010 The WebM project authors. All Rights Reserved.
;
; Use of this source code is governed by a BSD-style license
; that can be found in the LICENSE file in the root of the source
; tree. An additional intellectual property rights grant can be found
; in the file PATENTS. All contributing project authors may
; be found in the AUTHORS file in the root of the source tree.
;
EXPORT |vp8_short_idct4x4llm_v6_dual|
AREA |.text|, CODE, READONLY
; void vp8_short_idct4x4llm_c(short *input, unsigned char *pred, int pitch,
; unsigned char *dst, int stride)
; r0 short* input
; r1 unsigned char* pred
; r2 int pitch
; r3 unsigned char* dst
; sp int stride
|vp8_short_idct4x4llm_v6_dual| PROC
stmdb sp!, {r4-r11, lr}
sub sp, sp, #4
mov r4, #0x00008A00 ; sin
orr r4, r4, #0x0000008C ; sinpi8sqrt2
mov r5, #0x00004E00 ; cos
orr r5, r5, #0x0000007B ; cospi8sqrt2minus1
orr r5, r5, #1<<31 ; loop counter on top bit
loop1_dual
ldr r6, [r0, #(4*2)] ; i5 | i4
ldr r12, [r0, #(12*2)] ; i13|i12
ldr r14, [r0, #(8*2)] ; i9 | i8
smulbt r9, r5, r6 ; (ip[5] * cospi8sqrt2minus1) >> 16
smulbb r7, r5, r6 ; (ip[4] * cospi8sqrt2minus1) >> 16
smulwt r10, r4, r6 ; (ip[5] * sinpi8sqrt2) >> 16
smulwb r8, r4, r6 ; (ip[4] * sinpi8sqrt2) >> 16
smulbt r11, r5, r12 ; (ip[13] * cospi8sqrt2minus1) >> 16
pkhtb r7, r9, r7, asr #16 ; 5c | 4c
pkhbt r8, r8, r10, lsl #16 ; 5s | 4s
uadd16 r6, r6, r7 ; 5c+5 | 4c+4
smulwt r7, r4, r12 ; (ip[13] * sinpi8sqrt2) >> 16
smulbb r9, r5, r12 ; (ip[12] * cospi8sqrt2minus1) >> 16
smulwb r10, r4, r12 ; (ip[12] * sinpi8sqrt2) >> 16
subs r5, r5, #1<<31 ; i--
pkhtb r9, r11, r9, asr #16 ; 13c | 12c
ldr r11, [r0] ; i1 | i0
pkhbt r10, r10, r7, lsl #16 ; 13s | 12s
uadd16 r7, r12, r9 ; 13c+13 | 12c+12
usub16 r7, r8, r7 ; c
uadd16 r6, r6, r10 ; d
uadd16 r10, r11, r14 ; a
usub16 r8, r11, r14 ; b
uadd16 r9, r10, r6 ; a+d
usub16 r10, r10, r6 ; a-d
uadd16 r6, r8, r7 ; b+c
usub16 r7, r8, r7 ; b-c
; use input buffer to store intermediate results
str r6, [r0, #(4*2)] ; o5 | o4
str r7, [r0, #(8*2)] ; o9 | o8
str r10,[r0, #(12*2)] ; o13|o12
str r9, [r0], #4 ; o1 | o0
bcs loop1_dual
sub r0, r0, #8 ; reset input/output
str r0, [sp]
loop2_dual
ldr r6, [r0, #(4*2)] ; i5 | i4
ldr r12,[r0, #(2*2)] ; i3 | i2
ldr r14,[r0, #(6*2)] ; i7 | i6
ldr r0, [r0, #(0*2)] ; i1 | i0
smulbt r9, r5, r6 ; (ip[5] * cospi8sqrt2minus1) >> 16
smulbt r7, r5, r0 ; (ip[1] * cospi8sqrt2minus1) >> 16
smulwt r10, r4, r6 ; (ip[5] * sinpi8sqrt2) >> 16
smulwt r8, r4, r0 ; (ip[1] * sinpi8sqrt2) >> 16
pkhbt r11, r6, r0, lsl #16 ; i0 | i4
pkhtb r7, r7, r9, asr #16 ; 1c | 5c
pkhtb r0, r0, r6, asr #16 ; i1 | i5
pkhbt r8, r10, r8, lsl #16 ; 1s | 5s = temp1
uadd16 r0, r7, r0 ; 1c+1 | 5c+5 = temp2
pkhbt r9, r14, r12, lsl #16 ; i2 | i6
uadd16 r10, r11, r9 ; a
usub16 r9, r11, r9 ; b
pkhtb r6, r12, r14, asr #16 ; i3 | i7
subs r5, r5, #1<<31 ; i--
smulbt r7, r5, r6 ; (ip[3] * cospi8sqrt2minus1) >> 16
smulwt r11, r4, r6 ; (ip[3] * sinpi8sqrt2) >> 16
smulbb r12, r5, r6 ; (ip[7] * cospi8sqrt2minus1) >> 16
smulwb r14, r4, r6 ; (ip[7] * sinpi8sqrt2) >> 16
pkhtb r7, r7, r12, asr #16 ; 3c | 7c
pkhbt r11, r14, r11, lsl #16 ; 3s | 7s = temp1
uadd16 r6, r7, r6 ; 3c+3 | 7c+7 = temp2
usub16 r12, r8, r6 ; c (o1 | o5)
uadd16 r6, r11, r0 ; d (o3 | o7)
uadd16 r7, r10, r6 ; a+d
mov r8, #4 ; set up 4's
orr r8, r8, #0x40000 ; 4|4
usub16 r6, r10, r6 ; a-d
uadd16 r6, r6, r8 ; a-d+4, 3|7
uadd16 r7, r7, r8 ; a+d+4, 0|4
uadd16 r10, r9, r12 ; b+c
usub16 r0, r9, r12 ; b-c
uadd16 r10, r10, r8 ; b+c+4, 1|5
uadd16 r8, r0, r8 ; b-c+4, 2|6
ldr lr, [sp, #40] ; dst stride
ldrb r0, [r1] ; pred p0
ldrb r11, [r1, #1] ; pred p1
ldrb r12, [r1, #2] ; pred p2
add r0, r0, r7, asr #19 ; p0 + o0
add r11, r11, r10, asr #19 ; p1 + o1
add r12, r12, r8, asr #19 ; p2 + o2
usat r0, #8, r0 ; d0 = clip8(p0 + o0)
usat r11, #8, r11 ; d1 = clip8(p1 + o1)
usat r12, #8, r12 ; d2 = clip8(p2 + o2)
add r0, r0, r11, lsl #8 ; |--|--|d1|d0|
ldrb r11, [r1, #3] ; pred p3
add r0, r0, r12, lsl #16 ; |--|d2|d1|d0|
add r11, r11, r6, asr #19 ; p3 + o3
sxth r7, r7 ;
sxth r10, r10 ;
usat r11, #8, r11 ; d3 = clip8(p3 + o3)
sxth r8, r8 ;
sxth r6, r6 ;
add r0, r0, r11, lsl #24 ; |d3|d2|d1|d0|
ldrb r12, [r1, r2]! ; pred p4
str r0, [r3], lr
ldrb r11, [r1, #1] ; pred p5
add r12, r12, r7, asr #3 ; p4 + o4
add r11, r11, r10, asr #3 ; p5 + o5
usat r12, #8, r12 ; d4 = clip8(p4 + o4)
usat r11, #8, r11 ; d5 = clip8(p5 + o5)
ldrb r7, [r1, #2] ; pred p6
ldrb r10, [r1, #3] ; pred p6
add r12, r12, r11, lsl #8 ; |--|--|d5|d4|
add r7, r7, r8, asr #3 ; p6 + o6
add r10, r10, r6, asr #3 ; p7 + o7
ldr r0, [sp] ; load input pointer
usat r7, #8, r7 ; d6 = clip8(p6 + o6)
usat r10, #8, r10 ; d7 = clip8(p7 + o7)
add r12, r12, r7, lsl #16 ; |--|d6|d5|d4|
add r12, r12, r10, lsl #24 ; |d7|d6|d5|d4|
str r12, [r3], lr
add r0, r0, #16
add r1, r1, r2 ; pred + pitch
bcs loop2_dual
add sp, sp, #4 ; idct_output buffer
ldmia sp!, {r4 - r11, pc}
ENDP
END