Re: [Qemu-devel] Re: [PATCH 1/5] Fix i386 Host

[Michael Matz]

Hi,

On Fri, 18 Jan 2008, Johannes Schindelin wrote:

> > Well, I can tell you why, but it doesn't help you: the 3.4.2 compiler 
> > has different deficiencies in reload than the 4.x line of compilers.  
> > To make the whole thingy work on all compilers trying and testing is 
> > required to avoid all these different deficiencies.  My patch is 
> > partly real bug fixes (the "q" constraint part for instance) and 
> > partly changes helping to lessen the register pressure which reload 
> > needs to fix (the %ecx thingy for instance).  Both of these might 
> > expose the bugs in 3.4.2, in which case we need to hack around those 
> > as well.  That's what I tried to do with the patch from 
> > http://article.gmane.org/gmane.comp.emulators.qemu/22762 , but it 
> > needs of course testing by someone who actually uses 3.4.2.
> 
> I just downloaded it, and tested it on MinGW with 3.4.2, and I still get 
> the "can't find register in class `Q_REGS´ while reloading `asm´" error.

Bummer.  As a test of theory (I'm not proposing this as patch), can you 
see what happens if you make vtmp volatile, i.e. make it look like so ? :

#if DATA_SIZE == 1 || DATA_SIZE == 2
    volatile RES_TYPE vtmp = v;
#endif

Bah, remote work-arounding of reload sucks :-)


Ciao,
Michael.