This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: gcse pass: expression hash table
On Feb 24, 2005 11:13 AM, Tarun Kawatra <tarun@cse.iitb.ac.in> wrote:
> >> Such expressions occur in PARALLEL along with clobbers.
> >
> > You didn't mention the target, or exactly what the mult looks like.
>
> Target is i386 and the mult instruction looks like the following in RTL
>
> (insn 22 21 23 1 (parallel [
> (set (reg/v:SI 62 [ c ])
> (mult:SI (reg:SI 66 [ a ])
> (reg:SI 67 [ b ])))
> (clobber (reg:CC 17 flags))
> ]) 172 {*mulsi3_1} (nil)
> (nil))
Hmm...,
Does GCSE look into stuff in PARALLELs at all? From gcse.c:
1804: Single sets in a PARALLEL could be handled, but it's an extra complication
1805: that isn't dealt with right now. The trick is handling the CLOBBERs that
1806: are also in the PARALLEL. Later.
IIRC it is one of those things that worked on the cfg-branch or
the rtlopt-branch (and probably on the hammer-branch) but that
never got merged to the mainline. Honza knows more about it, I
think...
Gr.
Steven