ref: 5cba6516aa020e420106d276bf2dbebc6b517e3f
dir: /vp8/encoder/ppc/rdopt_altivec.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.
;
.globl vp8_block_error_ppc
.align 2
;# r3 short *Coeff
;# r4 short *dqcoeff
vp8_block_error_ppc:
mfspr r11, 256 ;# get old VRSAVE
oris r12, r11, 0xf800
mtspr 256, r12 ;# set VRSAVE
stwu r1,-32(r1) ;# create space on the stack
stw r5, 12(r1) ;# tranfer dc to vector register
lvx v0, 0, r3 ;# Coeff
lvx v1, 0, r4 ;# dqcoeff
li r10, 16
vspltisw v3, 0
vsubshs v0, v0, v1
vmsumshm v2, v0, v0, v3 ;# multiply differences
lvx v0, r10, r3 ;# Coeff
lvx v1, r10, r4 ;# dqcoeff
vsubshs v0, v0, v1
vmsumshm v1, v0, v0, v2 ;# multiply differences
vsumsws v1, v1, v3 ;# sum up
stvx v1, 0, r1
lwz r3, 12(r1) ;# return value
addi r1, r1, 32 ;# recover stack
mtspr 256, r11 ;# reset old VRSAVE
blr