> I would first ask why subreg_get_info is being called with ymode ==
> QImode for a hard register which can not hold QImode. That implies
> that there is a QImode value in the register, which you say is
> invalid.
Are there any ports besides m32c that have registers which can hold HI
(or SI I suppose) but not QI values?
What I've done as a workaround is check for the zero and fail nicely:
Index: rtlanal.c
===================================================================
--- rtlanal.c (revision 131405)
+++ rtlanal.c (working copy)
@@ -3135,12 +3135,20 @@ subreg_get_info (unsigned int xregno, en
else
info->offset = 0;
info->nregs = nregs_ymode;
return;
}
+ if (nregs_ymode == 0)
+ {
+ info->representable_p = false;
+ info->nregs = 1;
+ info->offset = offset;
+ return false;
+ }
+
/* If registers store different numbers of bits in the different
modes, we cannot generally form this subreg. */
if (!HARD_REGNO_NREGS_HAS_PADDING (xregno, xmode)
&& !HARD_REGNO_NREGS_HAS_PADDING (xregno, ymode)
&& (GET_MODE_SIZE (xmode) % nregs_xmode) == 0
&& (GET_MODE_SIZE (ymode) % nregs_ymode) == 0)
