ID: 45215
User updated by: shaunspiller at gmail dot com
Reported By: shaunspiller at gmail dot com
-Status: Feedback
+Status: Open
Bug Type: Reproducible crash
Operating System: Win32
PHP Version: 5.2.6
Assigned To: pajoye
New Comment:
Thanks for the feedback. I can understand it's not reasonable to
degrade the GMP binaries for such old systems. Documenting it would have
saved me a lot of confusion though.
Yes I'm using Windows 98 SE at the moment, although hope to be back on
Windows 2003 soon. Exactly the same problem with PHP versions 5.2.6 and
5.1.6.
Ideally, perhaps the GMP module should check on load to see if 686+
instructions are supported, and if not, fail to load gracefully by
returning an error message to PHP, rather than just crashing the whole
program. Is that possible?
Previous Comments:
------------------------------------------------------------------------
[2008-06-09 14:51:17] [EMAIL PROTECTED]
"I'm using the latest precompiled Win32 binaries of PHP-5.2.6 (and
have
also tried PHP-5.1.6) and get a program crash with an #Undefined
Opcode
exception when loading php_gmp.dll."
Do you mean that you get the same issue with 5.1.6? I think yes as the
gmp library has not been changed since 5.1.6.
About win9x support, which OS do you use? You may know that we plan to
drop win9x support for 5.3+, only 2k+ will be supported.
About i386 support, especially with GMP there is a real improvement by
using 686+, see the gmp website for a detailed list.
And finally good point about the documentation, we should document it
asap.
------------------------------------------------------------------------
[2008-06-09 14:29:25] shaunspiller at gmail dot com
Description:
------------
I'm using the latest precompiled Win32 binaries of PHP-5.2.6 (and have
also tried PHP-5.1.6) and get a program crash with an #Undefined Opcode
exception when loading php_gmp.dll.
I know what the problem is and I'm not sure if one would consider it a
bug or not since it will only happen on very old machines, but I can't
believe I'm the first person to have ever encountered this.
The instruction in php_gmp.dll which causes the crash is CMOVZ EDX,
EAX. The conditional move instructions were only added with the Pentium
Pro. Tough luck for me -- my computer literally blew up last week and
I'm stuck temporarally with a Pentium MMX and a K6 laptop, neither of
which support CMOVcc.
It's understandable that compiling for P6+ instructions might be a good
tradeoff between performance and compatibility, but current versions of
PHP are *stated* to work with even Windows 98 and up, and so are the
precompiled binaries (other extensions seem to work just fine). I don't
know how much CMOVcc is relied on in php_gmp.dll, and changing the build
options to use generic I386+ might be undesirable, but the P6
instruction set requirement should at least be *mentioned* somewhere,
and it isn't (not that I found).
Disappointing for me in either case, because recompiling the DLL is a
little beyond what I can do on this old system right now. I would
normally have just used BCMath instead, but I need the base-conversion
stuff, which that doesn't have.
Reproduce code:
---------------
<?php
dl('php_gmp.dll');
echo 'hi!';
?>
Expected result:
----------------
hi!
Actual result:
--------------
Instant program crash. Windows provides the following info:
PHP executed an invalid instruction in
module PHP_GMP.DLL at 0187:01a760f4.
Registers:
EAX=01a7ced0 CS=0187 EIP=01a760f4 EFLGS=00010202
EBX=01a710e0 SS=018f ESP=00d3f904 EBP=01989c20
ECX=01a710c0 DS=018f ESI=0000001a FS=12c7
EDX=01a710b0 ES=018f EDI=01370ae0 GS=0000
Bytes at CS:EIP:
0f 44 d0 b8 60 cf a7 01 85 c9 0f 44 c8 85 db b8
Stack dump:
1001a380 01a710a4 01a710b0 01a710c0 01a710e0 01a8c2f0 0000000c 01a76120
00000003 0000001a 01370ae0 01a8c2fc 00000013 00000002 00000003 0000001a
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=45215&edit=1
