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Oi vey, sar is sign-extending, which is not what we want

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Nero 2019-09-10 13:44:44 +00:00
parent cd258ccbe4
commit e4dec4b14c
1 changed files with 3 additions and 3 deletions
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6
lib/popcnt.asm
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@ -5,21 +5,21 @@ popcnt:
mov bx, ax mov bx, ax
and ax, 0x5555 ; 8x 01 and ax, 0x5555 ; 8x 01
and bx, 0xaaaa ; 8x 10 and bx, 0xaaaa ; 8x 10
sar bx, 1 shr bx, 1
add ax, bx add ax, bx
mov bx, ax mov bx, ax
and ax, 0x3333 ; 4x 0011 and ax, 0x3333 ; 4x 0011
and bx, 0xcccc ; 4x 1100 and bx, 0xcccc ; 4x 1100
mov cl, 2 mov cl, 2
sar bx, cl shr bx, cl
add ax, bx add ax, bx
mov bx, ax mov bx, ax
and ax, 0x0f0f ; 2x 00001111 and ax, 0x0f0f ; 2x 00001111
and bx, 0xf0f0 ; 2x 11110000 and bx, 0xf0f0 ; 2x 11110000
mov cl, 4 mov cl, 4
sar bx, cl shr bx, cl
add ax, bx add ax, bx
add al, ah add al, ah