| mike.h on Thu, 20 Feb 2003 00:52:05 -0500 |
|
Using your functions, my results vary slightly, but are no less
peculiar:
$ grep -A1 sub ex9f
subl $4, %esp
movb $1, -1(%ebp)
--
subl $4, %esp
movb $1, -1(%ebp)
--
subl $24, %esp
movb $1, -22(%ebp)
--
subl $4, %esp
movb $1, -1(%ebp)
--
subl $24, %esp
movb $1, -20(%ebp)
--
subl $24, %esp
movb $1, -19(%ebp)
--
subl $24, %esp
movb $1, -18(%ebp)
--
subl $8, %esp
movb $1, -1(%ebp)
--
subl $24, %esp
movb $1, -16(%ebp)
--
<snip>
On Wed, 2003-02-19 at 22:58, Greg Lopp wrote:
> Additional mystery :
> void f_1(void) { char car[1]; car[0] = 1;}
> void f_2(void) { char car[2]; car[1] = 1;}
> void f_3(void) { char car[3]; car[2] = 1;}
> void f_4(void) { char car[4]; car[3] = 1;}
> void f_5(void) { char car[5]; car[4] = 1;}
> void f_6(void) { char car[6]; car[5] = 1;}
> void f_7(void) { char car[7]; car[6] = 1;}
> void f_8(void) { char car[8]; car[7] = 1;}
> void f_9(void) { char car[9]; car[8] = 1;}
>
> $ gcc -O0 -S bar.c
> $ grep movb bar.s
> movb $1,-1(%ebp)
> movb $1,-1(%ebp)
> movb $1,-2(%ebp)
> movb $1,-1(%ebp)
> movb $1,-4(%ebp)
> movb $1,-3(%ebp)
> movb $1,-2(%ebp)
> movb $1,-1(%ebp)
> movb $1,-4(%ebp)
>
> There are no other differences between these functions....
> f_1:
> pushl %ebp
> movl %esp,%ebp
> subl $24,%esp
> movb $1,-1(%ebp)
> leave
> ret
>
>
>
>
> _________________________________________________________________________
> Philadelphia Linux Users Group -- http://www.phillylinux.org
> Announcements - http://lists.netisland.net/mailman/listinfo/plug-announce
> General Discussion -- http://lists.netisland.net/mailman/listinfo/plug
--
-mike.h
_________________
mike.h@acm.org
mike.h@stemik.com
__________________________________________
Democracy is the worst form of government;
except for all those other forms that have
been tried from time to time.
-Winston Churchill
__________________________________________
GnuPG public key:
//http://www.stemik.com/~mike.h/mike.h.asc
Attachment:
signature.asc
|
|