Hi Levente,<div><br></div><div> essentially correct. The bug was caused by an incorrect asm. Changing</div><div><br></div><div><div># define BYTE_SWAP(w) __asm__("bswap %%eax" : "=r" (w) : "r" (w))</div>
<div># define WORD_SWAP(w) __asm__("roll $16, %%eax" : "=r" (w) : "r" (w))</div><div><br></div><div>to</div><div><br></div><div># define BYTE_SWAP(w) __asm__("bswap %0" : "=r" (w) : "r" (w))</div>
<div># define WORD_SWAP(w) __asm__("roll $16, %0" : "=r" (w) : "r" (w))</div><div><br></div><div>in platforms/win32/vm/sqWin32Window.c's byte & word image reversal code fixes it. This worked back on 2.95.x because it always chose $eax as the register for the value variable in</div>
<div><br></div><div>unsigned int value = *srcPixPtr++;</div><div><br></div><div>but gcc 3.x is more devious.</div><div><br></div><div>I've updated svn and will upload a new engine soon.</div><div><br></div><div>thanks,</div>
<div>Eliot</div><div><br></div><br><div class="gmail_quote">On Sun, Aug 22, 2010 at 1:56 PM, Levente Uzonyi <span dir="ltr"><<a href="mailto:leves@elte.hu">leves@elte.hu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<br>
Hi,<br>
<br>
<br>
evaluating [Display newDepth: x] where the value of x is 1, 4, 8 or 16 crashes the VM. No crash dump is written. If x is 2, -1, -2 or -4, then the image informs me that the depth is not available on the system. If x is -8 or -16 then the code works. For the x=16 case gdb shows the following:<br>
<br>
Program received signal SIGSEGV, Segmentation fault.<br>
reverse_image_words (dst=0x1450eca4, src=0x1450eca4, depth=0, width=1272,<br>
rect=0x561e60) at ../platforms/win32/vm/sqWin32Window.c:1875<br>
1875 unsigned int value = *srcPixPtr++;<br>
(gdb) where<br>
#0 reverse_image_words (dst=0x1450eca4, src=0x1450eca4, depth=0, width=1272,<br>
rect=0x561e60) at ../platforms/win32/vm/sqWin32Window.c:1875<br>
#1 0x0043f61a in ioShowDisplay (dispBits=340847780, width=1272, height=745,<br>
depth=16, affectedL=0, affectedR=1000, affectedT=0, affectedB=0)<br>
at ../platforms/win32/vm/sqWin32Window.c:2324<br>
#2 0x00403270 in displayBitsOfLeftTopRightBottom (aForm=-719257650, l=0,<br>
t=0, r=1272, b=745) at ../src/vm/gcc3x-cointerp.c:13701<br>
#3 0x00405ff9 in fullDisplayUpdate () at ../src/vm/gcc3x-cointerp.c:16777<br>
#4 0x0044093a in MainWndProcW (hwnd=0xf05f6, message=15, wParam=0, lParam=0)<br>
at ../platforms/win32/vm/sqWin32Window.c:447<br>
#5 0x75fef8d2 in USER32!GetMessageW ()<br>
from /cygdrive/c/Windows/system32/user32.dll<br>
#6 0x75fef794 in USER32!GetWindowLongW ()<br>
from /cygdrive/c/Windows/system32/user32.dll<br>
#7 0x004403dc in sqLaunchDrop ()<br>
at ../platforms/win32/vm/sqWin32Window.c:2773<br>
#8 0x75ff0817 in USER32!ReleaseDC ()<br>
from /cygdrive/c/Windows/system32/user32.dll<br>
#9 0x75ff0a65 in USER32!GetWindowThreadProcessId ()<br>
from /cygdrive/c/Windows/system32/user32.dll<br>
#10 0x776a99ce in ntdll!LdrEnumResources ()<br>
from /cygdrive/c/Windows/system32/ntdll.dll<br>
#11 0x00ace008 in ?? ()<br>
#12 0x00000018 in ?? ()<br>
---Type <return> to continue, or q <return> to quit---<br>
#13 0x00ace058 in ?? ()<br>
#14 0x776a9980 in ntdll!LdrDisableThreadCalloutsForDll ()<br>
from /cygdrive/c/Windows/system32/ntdll.dll<br>
#15 0x0204c1d8 in ?? ()<br>
#16 0x0000000f in ?? ()<br>
#17 0x00000000 in ?? ()<br>
(gdb) info registers<br>
eax 0xd520ffce -719257650<br>
ecx 0x3 3<br>
edx 0x0 0<br>
ebx 0x1f4 500<br>
esp 0xacd5b4 0xacd5b4<br>
ebp 0x0 0x0<br>
esi 0x1511a000 353476608<br>
edi 0x1511a000 353476608<br>
eip 0x43ed0c 0x43ed0c <reverse_image_words+353><br>
eflags 0x10216 [ PF AF IF RF ]<br>
cs 0x1b 27<br>
ss 0x23 35<br>
ds 0x23 35<br>
es 0x23 35<br>
fs 0x3b 59<br>
gs 0x0 0<br>
<br>
It may be a compiler bug, because the 4.0.2 SqueakVM doesn't have this issue. It's a bit suspicious that depth is 0 here:<br>
#0 reverse_image_words (dst=0x1450eca4, src=0x1450eca4, depth=0, width=1272,<br>
rect=0x561e60) at ../platforms/win32/vm/sqWin32Window.c:1875<br>
but the value of depth is known at compilation time (16), so it may be some compiler "magic".<br>
Here are the values of the variables in the method:<br>
(gdb) p dst<br>
$2 = (unsigned int *) 0x1450eca4<br>
(gdb) p src<br>
$3 = (unsigned int *) 0x1450eca4<br>
(gdb) p depth<br>
$4 = 0<br>
(gdb) p width<br>
$5 = 1272<br>
(gdb) p rect<br>
$6 = (RECT *) 0x561e60<br>
(gdb) p rect->left<br>
$7 = 0<br>
(gdb) p rect->right<br>
$8 = 1000<br>
(gdb) p rect->top<br>
$9 = 0<br>
(gdb) p rect->bottom<br>
$10 = 745<br>
(gdb) p pitch<br>
$11 = 353476608<br>
(gdb) p first<br>
$12 = 3<br>
(gdb) p last<br>
No symbol "last" in current context.<br>
(gdb) p nWords<br>
$13 = 500<br>
(gdb) p delta<br>
$14 = 0<br>
(gdb) p yy<br>
$15 = 0<br>
(gdb) p srcPixPtr<br>
$16 = (DWORD *) 0x1511a000<br>
(gdb) p dstPixPtr<br>
$17 = (DWORD *) 0x1511a000<br>
(gdb) p i<br>
$18 = -719257650<br>
(gdb) p value<br>
$19 = 0<br>
<br>
<br>
Cheers,<br><font color="#888888">
Levente<br>
</font></blockquote></div><br></div>