The Tor Browser: media/libvpx/vp9/encoder/x86/vp9_error

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

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 ;

    11 %include "third_party/x86inc/x86inc.asm"

    13 SECTION .text

    15 ; int64_t vp9_block_error(int16_t *coeff, int16_t *dqcoeff, intptr_t block_size,

    16 ;                         int64_t *ssz)

    18 INIT_XMM sse2

    19 cglobal block_error, 3, 3, 8, uqc, dqc, size, ssz

    20   pxor      m4, m4                 ; sse accumulator

    21   pxor      m6, m6                 ; ssz accumulator

    22   pxor      m5, m5                 ; dedicated zero register

    23   lea     uqcq, [uqcq+sizeq*2]

    24   lea     dqcq, [dqcq+sizeq*2]

    25   neg    sizeq

    26 .loop:

    27   mova      m2, [uqcq+sizeq*2]

    28   mova      m0, [dqcq+sizeq*2]

    29   mova      m3, [uqcq+sizeq*2+mmsize]

    30   mova      m1, [dqcq+sizeq*2+mmsize]

    31   psubw     m0, m2

    32   psubw     m1, m3

    33   ; individual errors are max. 15bit+sign, so squares are 30bit, and

    34   ; thus the sum of 2 should fit in a 31bit integer (+ unused sign bit)

    35   pmaddwd   m0, m0

    36   pmaddwd   m1, m1

    37   pmaddwd   m2, m2

    38   pmaddwd   m3, m3

    39   ; accumulate in 64bit

    40   punpckldq m7, m0, m5

    41   punpckhdq m0, m5

    42   paddq     m4, m7

    43   punpckldq m7, m1, m5

    44   paddq     m4, m0

    45   punpckhdq m1, m5

    46   paddq     m4, m7

    47   punpckldq m7, m2, m5

    48   paddq     m4, m1

    49   punpckhdq m2, m5

    50   paddq     m6, m7

    51   punpckldq m7, m3, m5

    52   paddq     m6, m2

    53   punpckhdq m3, m5

    54   paddq     m6, m7

    55   paddq     m6, m3

    56   add    sizeq, mmsize

    57   jl .loop

    59   ; accumulate horizontally and store in return value

    60   movhlps   m5, m4

    61   movhlps   m7, m6

    62   paddq     m4, m5

    63   paddq     m6, m7

    64 %if ARCH_X86_64

    65   movq    rax, m4

    66   movq [sszq], m6

    67 %else

    68   mov     eax, sszm

    69   pshufd   m5, m4, 0x1

    70   movq  [eax], m6

    71   movd    eax, m4

    72   movd    edx, m5

    73 %endif

    74   RET

The Tor Browser / file revision

media/libvpx/vp9/encoder/x86/vp9_error_sse2.asm@ac0c01689b40

media/libvpx/vp9/encoder/x86/vp9_error_sse2.asm