[webkit-dev] want to port JIT to MIPS - cti_op_mod(STUB_ARGS) seg fault

[x yz]

this part of code has been ever tested or not? any body can tell me?
#else  //non X86
void JIT::compileFastArith_op_mod(unsigned result, unsigned op1, unsigned op2)
{
    emitPutJITStubArgFromVirtualRegister(op1, 1, regT2);
    emitPutJITStubArgFromVirtualRegister(op2, 2, regT2);
    emitCTICall(JITStubs::cti_op_mod);
    emitPutVirtualRegister(result);
}

thanks alot,
joe

--- On Wed, 4/22/09, x yz <lastguy at yahoo.com> wrote:

> From: x yz <lastguy at yahoo.com>
> Subject: Re: [webkit-dev] want to port JIT to MIPS - cti_op_mod(STUB_ARGS) seg fault
> To: "WebKit Development" <webkit-dev at lists.webkit.org>, "Gavin Barraclough" <barraclough at apple.com>
> Date: Wednesday, April 22, 2009, 8:31 AM
> I use MIPS32EL, VA_LIST call, MIPS pushes function argument
> from left to right. I wrote a simple VA_LIST test it works
> on my box.
> 
> BEGIN_STUB_FUNCTION() cause seg fault due to MIPS uses gp
> reg to read sth.
> I treied to rewrite the code like that:
> JSObject* JITStubs::cti_op_new_func_exp(STUB_ARGS)
> {
>     va_list vl_args; 
>     va_start(vl_args, args);
>     StackHack stackHack(&STUB_RETURN_ADDRESS_SLOT);
>     JSValuePtr dividendValue = va_arg(vl_args, JSC::JSCell*
> );
>     JSValuePtr divisorValue = va_arg(vl_args, JSC::JSCell*
> );
> ...
> }
> 
> Still fail in stackHack(), if I comment out stackHack()
> then fails at va_arg.
> 
> gp is a global register for common/public variables, the
> same usage before I call cti_op_mod() works fine.
> 
> I also tried not use VA_LIST but REGISTER calling
> convention, still fail:
> (gdb) x/2i $at
> 0x6ab500
> <_ZN3JSC8JITStubs10cti_op_modEPPv>:	lui	gp,0xf96
> 0x6ab504
> <_ZN3JSC8JITStubs10cti_op_modEPPv+4>:	addiu	gp,gp,9008
> (gdb) x/20i $at
> 0x6ab500
> <_ZN3JSC8JITStubs10cti_op_modEPPv>:	lui	gp,0xf96
> 0x6ab504
> <_ZN3JSC8JITStubs10cti_op_modEPPv+4>:	addiu	gp,gp,9008
> 0x6ab508
> <_ZN3JSC8JITStubs10cti_op_modEPPv+8>:	addu	gp,gp,t9
> 0x6ab50c
> <_ZN3JSC8JITStubs10cti_op_modEPPv+12>:	addiu	sp,sp,-80
> 0x6ab510
> <_ZN3JSC8JITStubs10cti_op_modEPPv+16>:	sw	ra,72(sp)
> 0x6ab514
> <_ZN3JSC8JITStubs10cti_op_modEPPv+20>:	sw	s8,68(sp)
> 0x6ab518
> <_ZN3JSC8JITStubs10cti_op_modEPPv+24>:	sw	s0,64(sp)
> 0x6ab51c
> <_ZN3JSC8JITStubs10cti_op_modEPPv+28>:	move	s8,sp
> 0x6ab520
> <_ZN3JSC8JITStubs10cti_op_modEPPv+32>:	sw	gp,16(sp)
> 0x6ab524
> <_ZN3JSC8JITStubs10cti_op_modEPPv+36>:	sw	a0,80(s8)
> 0x6ab528
> <_ZN3JSC8JITStubs10cti_op_modEPPv+40>:	lw	v0,80(s8)
> 0x6ab52c
> <_ZN3JSC8JITStubs10cti_op_modEPPv+44>:	addiu	v0,v0,-4
> 0x6ab530
> <_ZN3JSC8JITStubs10cti_op_modEPPv+48>:	addiu	a0,s8,24
> 0x6ab534
> <_ZN3JSC8JITStubs10cti_op_modEPPv+52>:	move	a1,v0
> 0x6ab538
> <_ZN3JSC8JITStubs10cti_op_modEPPv+56>:	lw	t9,-19012(gp)
> 0x6ab53c
> <_ZN3JSC8JITStubs10cti_op_modEPPv+60>:	jalr	t9
> 0x6ab540 <_ZN3JSC8JITStubs10cti_op_modEPPv+64>:	nop
> 0x6ab544
> <_ZN3JSC8JITStubs10cti_op_modEPPv+68>:	lw	gp,16(s8)
> 0x6ab548
> <_ZN3JSC8JITStubs10cti_op_modEPPv+72>:	addiu	v0,s8,32
> 0x6ab54c
> <_ZN3JSC8JITStubs10cti_op_modEPPv+76>:	lw	v1,80(s8)
> (gdb) stepi 14
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x006ab538 in JSC::JITStubs::cti_op_mod (args=0x2aac9500)
> at
> /home/jdai/depot/mp/mediabase/head/libs/webkit-1.1.1/JavaScriptCore/jit/JITStubs.cpp:1685
> 1685	    BEGIN_STUB_FUNCTION();
> 
> another question is that there is no matched va_end() and
> it is a bug.
> thanks a lot for help,
> joe