libvpx: Add VP9 decoder.

source/libvpx/vp9/encoder/ppc/vp9_variance_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_get8x8var_ppc
+    .globl vp8_get16x16var_ppc
+    .globl vp8_mse16x16_ppc
+    .globl vp9_variance16x16_ppc
+    .globl vp9_variance16x8_ppc
+    .globl vp9_variance8x16_ppc
+    .globl vp9_variance8x8_ppc
+    .globl vp9_variance4x4_ppc
+
+.macro load_aligned_16 V R O
+    lvsl    v3,  0, \R          ;# permutate value for alignment
+
+    lvx     v1,  0, \R
+    lvx     v2, \O, \R
+
+    vperm   \V, v1, v2, v3
+.endm
+
+.macro prologue
+    mfspr   r11, 256            ;# get old VRSAVE
+    oris    r12, r11, 0xffc0
+    mtspr   256, r12            ;# set VRSAVE
+
+    stwu    r1, -32(r1)         ;# create space on the stack
+
+    li      r10, 16             ;# load offset and loop counter
+
+    vspltisw v7, 0              ;# zero for merging
+    vspltisw v8, 0              ;# zero out total to start
+    vspltisw v9, 0              ;# zero out total for dif^2
+.endm
+
+.macro epilogue
+    addi    r1, r1, 32          ;# recover stack
+
+    mtspr   256, r11            ;# reset old VRSAVE
+.endm
+
+.macro compute_sum_sse
+    ;# Compute sum first.  Unpack to so signed subract
+    ;#  can be used.  Only have a half word signed
+    ;#  subract.  Do high, then low.
+    vmrghb  v2, v7, v4
+    vmrghb  v3, v7, v5
+    vsubshs v2, v2, v3
+    vsum4shs v8, v2, v8
+
+    vmrglb  v2, v7, v4
+    vmrglb  v3, v7, v5
+    vsubshs v2, v2, v3
+    vsum4shs v8, v2, v8
+
+    ;# Now compute sse.
+    vsububs v2, v4, v5
+    vsububs v3, v5, v4
+    vor     v2, v2, v3
+
+    vmsumubm v9, v2, v2, v9
+.endm
+
+.macro variance_16 DS loop_label store_sum
+\loop_label:
+    ;# only one of the inputs should need to be aligned.
+    load_aligned_16 v4, r3, r10
+    load_aligned_16 v5, r5, r10
+
+    ;# move onto the next line
+    add     r3, r3, r4
+    add     r5, r5, r6
+
+    compute_sum_sse
+
+    bdnz    \loop_label
+
+    vsumsws v8, v8, v7
+    vsumsws v9, v9, v7
+
+    stvx    v8, 0, r1
+    lwz     r3, 12(r1)
+
+    stvx    v9, 0, r1
+    lwz     r4, 12(r1)
+
+.if \store_sum
+    stw     r3, 0(r8)           ;# sum
+.endif
+    stw     r4, 0(r7)           ;# sse
+
+    mullw   r3, r3, r3          ;# sum*sum
+    srawi   r3, r3, \DS         ;# (sum*sum) >> DS
+    subf    r3, r3, r4          ;# sse - ((sum*sum) >> DS)
+.endm
+
+.macro variance_8 DS loop_label store_sum
+\loop_label:
+    ;# only one of the inputs should need to be aligned.
+    load_aligned_16 v4, r3, r10
+    load_aligned_16 v5, r5, r10
+
+    ;# move onto the next line
+    add     r3, r3, r4
+    add     r5, r5, r6
+
+    ;# only one of the inputs should need to be aligned.
+    load_aligned_16 v6, r3, r10
+    load_aligned_16 v0, r5, r10
+
+    ;# move onto the next line
+    add     r3, r3, r4
+    add     r5, r5, r6
+
+    vmrghb  v4, v4, v6
+    vmrghb  v5, v5, v0
+
+    compute_sum_sse
+
+    bdnz    \loop_label
+
+    vsumsws v8, v8, v7
+    vsumsws v9, v9, v7
+
+    stvx    v8, 0, r1
+    lwz     r3, 12(r1)
+
+    stvx    v9, 0, r1
+    lwz     r4, 12(r1)
+
+.if \store_sum
+    stw     r3, 0(r8)           ;# sum
+.endif
+    stw     r4, 0(r7)           ;# sse
+
+    mullw   r3, r3, r3          ;# sum*sum
+    srawi   r3, r3, \DS         ;# (sum*sum) >> 8
+    subf    r3, r3, r4          ;# sse - ((sum*sum) >> 8)
+.endm
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *SSE
+;# r8 int *Sum
+;#
+;# r3 return value
+vp8_get8x8var_ppc:
+
+    prologue
+
+    li      r9, 4
+    mtctr   r9
+
+    variance_8 6, get8x8var_loop, 1
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *SSE
+;# r8 int *Sum
+;#
+;# r3 return value
+vp8_get16x16var_ppc:
+
+    prologue
+
+    mtctr   r10
+
+    variance_16 8, get16x16var_loop, 1
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r 3 return value
+vp8_mse16x16_ppc:
+    prologue
+
+    mtctr   r10
+
+mse16x16_loop:
+    ;# only one of the inputs should need to be aligned.
+    load_aligned_16 v4, r3, r10
+    load_aligned_16 v5, r5, r10
+
+    ;# move onto the next line
+    add     r3, r3, r4
+    add     r5, r5, r6
+
+    ;# Now compute sse.
+    vsububs v2, v4, v5
+    vsububs v3, v5, v4
+    vor     v2, v2, v3
+
+    vmsumubm v9, v2, v2, v9
+
+    bdnz    mse16x16_loop
+
+    vsumsws v9, v9, v7
+
+    stvx    v9, 0, r1
+    lwz     r3, 12(r1)
+
+    stvx    v9, 0, r1
+    lwz     r3, 12(r1)
+
+    stw     r3, 0(r7)           ;# sse
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r3 return value
+vp9_variance16x16_ppc:
+
+    prologue
+
+    mtctr   r10
+
+    variance_16 8, variance16x16_loop, 0
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r3 return value
+vp9_variance16x8_ppc:
+
+    prologue
+
+    li      r9, 8
+    mtctr   r9
+
+    variance_16 7, variance16x8_loop, 0
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r3 return value
+vp9_variance8x16_ppc:
+
+    prologue
+
+    li      r9, 8
+    mtctr   r9
+
+    variance_8 7, variance8x16_loop, 0
+
+    epilogue
+
+    blr
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r3 return value
+vp9_variance8x8_ppc:
+
+    prologue
+
+    li      r9, 4
+    mtctr   r9
+
+    variance_8 6, variance8x8_loop, 0
+
+    epilogue
+
+    blr
+
+.macro transfer_4x4 I P
+    lwz     r0, 0(\I)
+    add     \I, \I, \P
+
+    lwz     r10,0(\I)
+    add     \I, \I, \P
+
+    lwz     r8, 0(\I)
+    add     \I, \I, \P
+
+    lwz     r9, 0(\I)
+
+    stw     r0,  0(r1)
+    stw     r10, 4(r1)
+    stw     r8,  8(r1)
+    stw     r9, 12(r1)
+.endm
+
+    .align 2
+;# r3 unsigned char *src_ptr
+;# r4 int  source_stride
+;# r5 unsigned char *ref_ptr
+;# r6 int  recon_stride
+;# r7 unsigned int *sse
+;#
+;# r3 return value
+vp9_variance4x4_ppc:
+
+    prologue
+
+    transfer_4x4 r3, r4
+    lvx     v4, 0, r1
+
+    transfer_4x4 r5, r6
+    lvx     v5, 0, r1
+
+    compute_sum_sse
+
+    vsumsws v8, v8, v7
+    vsumsws v9, v9, v7
+
+    stvx    v8, 0, r1
+    lwz     r3, 12(r1)
+
+    stvx    v9, 0, r1
+    lwz     r4, 12(r1)
+
+    stw     r4, 0(r7)           ;# sse
+
+    mullw   r3, r3, r3          ;# sum*sum
+    srawi   r3, r3, 4           ;# (sum*sum) >> 4
+    subf    r3, r3, r4          ;# sse - ((sum*sum) >> 4)
+
+    epilogue
+
+    blr