Re: [Qemu-devel] tcg problem running SPARC program on x86

["Blue Swirl" <blauwirbel@gmail.com>]

On 8/18/08, Vince Weaver <vince@csl.cornell.edu> wrote:
> Hello
>
>  I'm continuing on my quest to get the SPEC2000 benchmarks running under
> sparc32-linux-user (so far 8 out of 48 work).
>
>  Many of the benchmarks die early on with the following error:
>
>     /fusion/research4/vince/qemu/svn/tcg/tcg.c:1455: tcg
> fatal error
>
>  This error is caused when tcg_reg_alloc_mov() is called but ts->val_type
>  is equal to 0 (which is TEMP_VAL_DEAD). So maybe the optimizer is
> optimizing away something that it shouldn't?
>
>  This happens in a block with multiple calls to the SPARC "mulscc"
>  instruction which is a complicated instruction, so maybe this is finding an
> obscure corner case.
>
>  I've attached a very small sample program that exhibits the bug when run
> with ./sparc32-linux-user/qemu-sparc32plus

Okay, I can finally reproduce this. Strangely it does not occur if -d
flag is used and "op" is one of the log items. I have to check if
older reports where I could not reproduce the bug were suffering from
the same problem.

But I haven't found any fix yet.