Re: GCC 4.3.4 is casting my QImode vars to SImode for libcall

[Paolo Bonzini]

On 06/15/2010 11:02 AM, Paulo J. Matos wrote:
Just noticed the following also in optabs.c:
   /* We can't do it with an insn, so use a library call.  But first ensure
      that the mode of TO is at least as wide as SImode, since those are the
      only library calls we know about.  */

   if (GET_MODE_SIZE (GET_MODE (to))<  GET_MODE_SIZE (SImode))
     {
       target = gen_reg_rtx (SImode);
       expand_fix (target, from, unsignedp);
     }

This comment provides some insight on to why gcc keeps converting to
SImode.

I think the comment dates back to before the introduction of conversion 
optabs.

Maybe the right thing to compare with is the size of an int in bytes?

Paolo