From mboxrd@z Thu Jan  1 00:00:00 1970
From: Scott Sibley <sisibley@gmail.com>
Subject: Troubles with JIT compiler
Date: Thu, 21 Jan 2010 22:12:41 -0600
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I'm debugging a script engine. The engine compiles expressions into
asm instructions, assigns that data to a function pointer, and
executes the function, passing one argument.

I'm new to assembly, and pretty much stuck on the first issue I ran int=
o.

Here are the function's instructions for a basic assignment operation:

0x8067990:=A0=A0=A0 push=A0=A0 %ebp
0x8067991:=A0=A0=A0 mov=A0=A0=A0 %esp,%ebp
0x8067993:=A0=A0=A0 sub=A0=A0=A0 $0x8,%esp
0x8067999:=A0=A0=A0 fnstcw (%esp)
0x806799c:=A0=A0=A0 mov=A0=A0=A0 (%esp),%eax
0x806799f:=A0=A0=A0 or=A0=A0=A0=A0 $0xc00,%eax
0x80679a4:=A0=A0=A0 mov=A0=A0=A0 %eax,0x4(%esp)
0x80679a8:=A0=A0=A0 fldcw=A0 0x4(%esp)
0x80679ac:=A0=A0=A0 flds=A0=A0 0x806793c
0x80679b2:=A0=A0=A0 fsts=A0=A0 0x805f014
0x80679b8:=A0=A0=A0 fstps=A0 0x8067954
0x80679be:=A0=A0=A0 fldcw=A0 (%esp)
0x80679c1:=A0=A0=A0 add=A0=A0=A0 $0x8,%esp
0x80679c7:=A0=A0=A0 emms
0x80679c9:=A0=A0=A0 leave
0x80679ca:=A0=A0=A0 ret

Well, it appears to be crashing at the first instruction. Here are the
values of ebp and esp.

(gdb) x/x $ebp
0xbffff168:=A0=A0=A0 0xbffff188
(gdb) x/x $esp
0xbffff14c:=A0=A0=A0 0x0804e481

Any clue why this would cause problems? Let me know if I need to
provide more info.
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