avcodec/x86/v210: add some comments to the improved avx2 function

This commit is contained in:
James Darnley 2022-12-15 11:19:30 +01:00
parent f1f41d6ff5
commit f30b4c2f47
1 changed files with 6 additions and 6 deletions

View File

@ -65,18 +65,18 @@ cglobal v210_planar_unpack_%1, 5, 5, 6 + 2 * cpuflag(avx2), src, y, u, v, w
mova m0, [srcq]
%endif
pmullw m1, m0, m3
pslld m0, 12
psrlw m1, 6 ; yB yA u5 v4 y8 y7 v3 u3 y5 y4 u2 v1 y2 y1 v0 u0
psrld m0, 22 ; 00 v5 00 y9 00 u4 00 y6 00 v2 00 y3 00 u1 00 y0
pmullw m1, m0, m3 ; shifts the 1st and 3rd sample of each dword into the high 10 bits of each word
pslld m0, 12 ; shifts the 2nd sample of each dword into the high 10 bits of each dword
psrlw m1, 6 ; shifts the 1st and 3rd samples back into the low 10 bits
psrld m0, 22 ; shifts the 2nd sample back into the low 10 bits of each dword
%if cpuflag(avx2)
vpblendd m2, m1, m0, 0x55 ; yB yA 00 y9 y8 y7 00 y6 y5 y4 00 y3 y2 y1 00 y0
vpblendd m2, m1, m0, 0x55 ; merge the odd dwords from m0 and even from m1 ; yB yA 00 y9 y8 y7 00 y6 y5 y4 00 y3 y2 y1 00 y0
pshufb m2, m4 ; 00 00 yB yA y9 y8 y7 y6 00 00 y5 y4 y3 y2 y1 y0
vpermd m2, m6, m2 ; 00 00 00 00 yB yA y9 y8 y7 y6 y5 y4 y3 y2 y1 y0
movu [yq+2*wq], m2
vpblendd m1, m1, m0, 0xaa ; 00 v5 u5 v4 00 u4 v3 u3 00 v2 u2 v1 00 u1 v0 u0
vpblendd m1, m1, m0, 0xaa ; merge the even dwords from m0 and odd from m1 ; 00 v5 u5 v4 00 u4 v3 u3 00 v2 u2 v1 00 u1 v0 u0
pshufb m1, m5 ; 00 v5 v4 v3 00 u5 u4 u3 00 v2 v1 v0 00 u2 u1 u0
vpermq m1, m1, 0xd8 ; 00 v5 v4 v3 00 v2 v1 v0 00 u5 u4 u3 00 u2 u1 u0
pshufb m1, m7 ; 00 00 v5 v4 v3 v2 v1 v0 00 00 u5 u4 u3 u2 u1 u0