Newsgroups: comp.os.msdos.djgpp
From: Peter Berdeklis <peter AT atmosp DOT physics DOT utoronto DOT ca>
Subject: Re: 32 bit registers 
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Date: Thu, 26 Dec 1996 17:07:35 GMT
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On Thu, 26 Dec 1996, Ove Kaaven wrote:
> To load the 16-bit value in bx into the high-order word of eax and
> preserving everything else, you could try:
> 
> roll $16,%eax
> movw %bx,%ax
> roll $16,%eax
       ^^^ should be $17

roll moves the last bit into the carry flag, so you have to roll one more 
bit (the last time only) to get the bit out of the carry flag and into 
the MSB of the register.

---------------
Peter Berdeklis
Dept. of Physics, Univ. of Toronto