[4.4 regression] Fix PR tree-optimization/36792

Daniel Berlin dberlin@dberlin.org
Wed Dec 10 19:44:00 GMT 2008

Fixed by not inserting defs into the maximal set (insert defs will
never help) instead letting expressions get inserted in there.
This lets us properly hoist the loads out of the no-scevccp-outer7.c
and no-scevccp-outer13.c
It also caused a spurious failure in ssa-fre-10.c because we now move
one of the loads out of the loop (none of the stores, of course).
After talking with Richard Guenther, neither of us can figure out why
we were testing that :)

(It's also a PRE test masquerading as an FRE test, but c'est la vie).

Bootstrapped and regtested on x86-64-linux and i686-darwin
Committed to mainline.

2008-12-10  Daniel Berlin  <dberlin@dberlin.org>

	PR tree-optimization/36792
	* tree-ssa-pre.c (compute_avail): Don't insert defs into maximal

testsuite changelog:

2008-12-10  Daniel Berlin  <dberlin@dberlin.org>

        PR tree-optimization/36792
        * gcc.dg/tree-ssa/ssa-fre-10.c: Update expected results.
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