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Re: [patch] gcc.dg/tree-ssa/*.c: Use -O2 in some testcases.
- From: Diego Novillo <dnovillo at redhat dot com>
- To: Kazu Hirata <kazu at cs dot umass dot edu>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 9 May 2005 19:55:20 -0400
- Subject: Re: [patch] gcc.dg/tree-ssa/*.c: Use -O2 in some testcases.
- References: <20050509.191530.104250286.kazu@cs.umass.edu>
On Mon, May 09, 2005 at 07:15:30PM -0400, Kazu Hirata wrote:
> The patch partially fixes this problem by raising -O1 to -O2. In
> 20040721-1.c, I was able to disable DOM and still get expected
> optimizations. In other testcases, we seem to at least partially
> depend on DOM to get expected optimizations.
>
After I commit the pass reorg patch I'm working on, DOM will run
after the initial scalar cleanups, so this should not be
necessary. But this is fine in the meantime.
> A complete fix would involve checking messages from the propagator so
> that expected optimizations will happen in nothing but store_ccp, but
> that's not as easy as I thought. For example, we can't just turn the
> FRE portion of DOM and disable the rest, at least in the current pass
> ordering.
>
Well, I'm not so interested in *what* does the optimization so
much as in getting it done. The problem with testing
pass-specific optimizations is that reshuffling the optimization
pipeline becomes an annoying process. I would much prefer doing
either link-time tests or .optimized dump scans.
I know it's not perfect, because we may get the program optimized
by blind-luck otherwise, but we could for instance enable just
the pass that is supposed to do the work, and nothing else.
> PR testsuite/21443
> * gcc.dg/tree-ssa/20030731-2.c, gcc.dg/tree-ssa/20030917-1.c,
> gcc.dg/tree-ssa/20030917-3.c, gcc.dg/tree-ssa/ssa-ccp-1.c,
> gcc.dg/tree-ssa/ssa-ccp-2.c, gcc.dg/tree-ssa/ssa-ccp-3.c,
> gcc.dg/tree-ssa/ssa-ccp-7.c, gcc.dg/tree-ssa/ssa-ccp-9.c:
> Change -O1 to -O2.
> * gcc.dg/tree-ssa/20040721-1.c: Change -O1 to -O2. Add
> -fno-dominator-opts.
>
OK.
Diego.