Message-ID:	<0b3001c3206f$a20aeeb0$0600000a@broadpark.no>
From:	"Gisle Vanem" <giva AT bgnett DOT no>
To:	"djgpp workers" <djgpp-workers AT delorie DOT com>
Subject:	Add with carry
Date:	Thu, 22 May 2003 16:37:12 +0200
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Reply-To:	djgpp-workers AT delorie DOT com

In libc/crt0/crt0.s (line 250):

/* Maybe lock the initial block, expects BX:CX */
        movl    %ecx,%ebx
        movl    %edx,%ecx
        addw    $4096,%cx                       /* Skip null page */
        adcl    $0,%ebx

-----------

What happens if carry was set prior to the 'addw' ?

I was just hit by this elsewhere in some 16-bit nasm code. 
To increment a 32-bit variable I used
  inc word [di]
  adc word [di+2], 0

Seems resonable, but got wrong result cause the carry
was already set. Adding a 'clc' before the 'inc' fixed it.

--gv

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