Improve early simplify and match for phiopt

Previously the idea was gimple_simplify_phiopt would call
resimplify with a NULL sequence but that sometimes fails
even if there was only one statement produced. The cases
where it fails is when there are two simplifications happen.
In the case of the min/max production, the first simplifcation
produces:
(convert (min @1 @2))
And then the convert is removed by a second one. The Min statement
will be in the sequence while the op will be a SSA name. This was
rejected before as could not produce something in the sequence.
So this patch changes the way resimplify is called to always passing
a pointer to the sequence and then decide based on if op is a
SSA_NAME or not.

OK? Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-ssa-phiopt.c (phiopt_early_allow): Change arguments
	to take sequence and gimple_match_op.  Accept the case where
	op is a SSA_NAME and one statement in the sequence.
	Also allow constants.
	(gimple_simplify_phiopt): Always pass a sequence to resimplify.
	Update call to phiopt_early_allow.  Discard the sequence if not
	used.

0 files changed, 0 insertions, 0 deletions