[Mono-list] Problem with mono_arch_local_regalloc( ) on PPC

[Piyush Garyali]

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<P>=0AHello,<BR>=0A<BR>=0ASorry for the last mail. It got all screwed by as=
 my internet mailer was adding HTML tags.<BR>=0A<BR>=0AComing back to the p=
oint, I was looking at the runtime invoke code generated for Assembly.DoAss=
emblyLoad(). (which comes from mono_domain_fire_assembly_load). Now while t=
he code is being compiled using mono_method_compile--&gt;mono_codegen()--&g=
t;mono_arch_local_regalloc() I found that the follwing instructions were lo=
oked up in the **ppcg4 array.<BR>=0A<BR>=0A372: load_membase<BR>=0A312: com=
pare_imm<BR>=0A59 : beq<BR>=0A..<BR>=0A..<BR>=0A..<BR>=0A56 : br<BR>=0A551:=
 start_handler<BR>=0A&nbsp; &nbsp;  ^^^^^^^^^^^^^<BR>=0A<BR>=0ANow in the &=
quot;cpu-g4.h&quot; the value assigned to &quot;start_handler&quot; is &quo=
t;NULL&quot; which makes the code inside the mono_arch_local_regalloc ..<BR=
>=0A<BR>=0Awhile(ins) {<BR>=0A&nbsp;  spec =3D ins_spec[ins-&gt;opcode];<BR=
>=0A&nbsp;  ..<BR>=0A&nbsp;  if (spec[MONO_INST_SRC1]) {<BR>=0A&nbsp;  ..<B=
R>=0A}<BR>=0A<BR>=0A.. to crash as spec becomes NULL and the if block tried=
 to access a NULL pointer. After hacking the code to work around this excep=
tion, I later found the when the emitted code is run through mono_ldftn() t=
he MonoMethod *method is corrupted and it crashes again.<BR>=0A<BR>=0AIs th=
ere still some problem with the ppc emitter or I am missing something in he=
re.<BR>=0A<BR>=0Aany pointers would be appreciated.<BR>=0A<BR>=0Aregards,<B=
R>=0Agary<BR>=0A =0A</P>=0A<br><br>=0A<A target=3D"_blank" HREF=3D"http://c=
lients.rediff.com/signature/track_sig.asp"><IMG SRC=3D"http://ads.rediff.co=
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Hello,=0A=0ASorry for the last mail. It got all screwed by as my internet m=
ailer was adding HTML tags.=0A=0AComing back to the point, I was looking at=
 the runtime invoke code generated for Assembly.DoAssemblyLoad(). (which co=
mes from mono_domain_fire_assembly_load). Now while the code is being compi=
led using mono_method_compile-->mono_codegen()-->mono_arch_local_regalloc()=
 I found that the follwing instructions were looked up in the **ppcg4 array=
.=0A=0A372: load_membase=0A312: compare_imm=0A59 : beq=0A..=0A..=0A..=0A56 =
: br=0A551: start_handler=0A     ^^^^^^^^^^^^^=0A=0ANow in the "cpu-g4.h" t=
he value assigned to "start_handler" is "NULL" which makes the code inside =
the mono_arch_local_regalloc ..=0A=0Awhile(ins) {=0A   spec =3D ins_spec[in=
s->opcode];=0A   ..=0A   if (spec[MONO_INST_SRC1]) {=0A   ..=0A}=0A=0A.. to=
 crash as spec becomes NULL and the if block tried to access a NULL pointer=
. After hacking the code to work around this exception, I later found the w=
hen the emitted code is run through mono_ldftn() the MonoMethod *method is =
corrupted and it crashes again.=0A=0AIs there still some problem with the p=
pc emitter or I am missing something in here.=0A=0Aany pointers would be ap=
preciated.=0A=0Aregards,=0Agary=0A=20
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