re PR tree-optimization/93199 (Compile time hog in sink_clobbers)

re PR tree-optimization/93199 (Compile time hog in sink_clobbers)

2019-01-08  Richard Biener  <rguenther@suse.de>

	PR middle-end/93199
	c/
	* gimple-parser.c (c_parser_parse_gimple_body): Remove __PHI IFN
	permanently.

	* gimple-fold.c (rewrite_to_defined_overflow): Mark stmt modified.
	* tree-ssa-loop-im.c (move_computations_worker): Properly adjust
	virtual operand, also updating SSA use.
	* gimple-loop-interchange.cc (loop_cand::undo_simple_reduction):
	Update stmt after resetting virtual operand.
	(tree_loop_interchange::move_code_to_inner_loop): Likewise.

	* gimple-iterator.c (gsi_remove): When not removing the stmt
	permanently do not delink immediate uses or mark the stmt modified.

From-SVN: r280000