How implement signum for float value ?

flat assembler
Message board for the users of flat assembler.

Index > Main > How implement signum for float value ?

Goto page Previous 1, 2

Author

Thread

macgub

Joined: 11 Jan 2006
Posts: 376
Location: Poland

macgub 16 Aug 2026, 06:19

What about:

Code:

movd   xmm1, eax
pshufd xmm1, xmm1, 0
pslld  xmm1, 31       ; 0 or 0x80000000 per lane
xorps  xmm0, xmm1
subps  xmm7, xmm0 ; subps instead addps

16 Aug 2026, 06:19

macgub

Joined: 11 Jan 2006
Posts: 376
Location: Poland

macgub 17 Aug 2026, 16:56

Stop beeing lazy - I checked in x64dbg:

Code:

pcmpeqd xmm7,xmm7
pslld xmm7,31    ; 0x80000000 at lane
subps xmm7,xmm6

Negate signs in xmm6 as:

Code:

pxor xmm7,xmm7 ; 0  at each lane
subps xmm7,xmm6

17 Aug 2026, 16:56

Goto page Previous 1, 2

< Last Thread | Next Thread >

Forum Rules:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum