libvpx: Pull from upstream

source/libvpx/vp8/common/arm/armv6/vp8_variance8x8_armv6.asm

 ;
 ;  Copyright (c) 2011 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.
 ;
 
@@ skipping 33 matching lines @@
     usub8   r9, r7, r6          ; calculate difference with reversed operands
     pld     [r2, r3, lsl #1]
     sel     r8, r9, lr          ; select bytes with negative difference
 
     ; calculate partial sums
     usad8   r6, r10, lr         ; calculate sum of positive differences
     usad8   r7, r8, lr          ; calculate sum of negative differences
     orr     r8, r8, r10         ; differences of all 4 pixels
     ; calculate total sum
     add    r4, r4, r6           ; add positive differences to sum
-    sub    r4, r4, r7           ; substract negative differences from sum
+    sub    r4, r4, r7           ; subtract negative differences from sum
 
     ; calculate sse
     uxtb16  r7, r8              ; byte (two pixels) to halfwords
     uxtb16  r10, r8, ror #8     ; another two pixels to halfwords
     smlad   r5, r7, r7, r5      ; dual signed multiply, add and accumulate (1)
 
     ; 2nd 4 pixels
     ldr     r6, [r0, #0x4]      ; load 4 src pixels
     ldr     r7, [r2, #0x4]      ; load 4 ref pixels
     smlad   r5, r10, r10, r5    ; dual signed multiply, add and accumulate (2)
 
     usub8   r8, r6, r7          ; calculate difference
     add     r0, r0, r1          ; set src_ptr to next row
     sel     r10, r8, lr         ; select bytes with positive difference
     usub8   r9, r7, r6          ; calculate difference with reversed operands
     add     r2, r2, r3          ; set dst_ptr to next row
     sel     r8, r9, lr          ; select bytes with negative difference
 
     ; calculate partial sums
     usad8   r6, r10, lr         ; calculate sum of positive differences
     usad8   r7, r8, lr          ; calculate sum of negative differences
     orr     r8, r8, r10         ; differences of all 4 pixels
 
     ; calculate total sum
     add     r4, r4, r6          ; add positive differences to sum
-    sub     r4, r4, r7          ; substract negative differences from sum
+    sub     r4, r4, r7          ; subtract negative differences from sum
 
     ; calculate sse
     uxtb16  r7, r8              ; byte (two pixels) to halfwords
     uxtb16  r10, r8, ror #8     ; another two pixels to halfwords
     smlad   r5, r7, r7, r5      ; dual signed multiply, add and accumulate (1)
     subs    r12, r12, #1        ; next row
     smlad   r5, r10, r10, r5    ; dual signed multiply, add and accumulate (2)
 
     bne     loop
 
     ; return stuff
     ldr     r8, [sp, #32]       ; get address of sse
     mul     r1, r4, r4          ; sum * sum
     str     r5, [r8]            ; store sse
     sub     r0, r5, r1, ASR #6  ; return (sse - ((sum * sum) >> 6))
 
     pop     {r4-r10, pc}
 
     ENDP
 
     END