re PR tree-optimization/90020 (-O2 -Os x86-64 wrong code generated for GNU Emacs)

re PR tree-optimization/90020 (-O2 -Os x86-64 wrong code generated for GNU Emacs)

2019-04-11  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/90020
	* tree-ssa-sccvn.c (vn_reference_may_trap): New function.
	* tree-ssa-sccvn.h (vn_reference_may_trap): Declare.
	* tree-ssa-pre.c (compute_avail): Use it to not put
	possibly trapping references after a call that might not
	return into EXP_GEN.
	* gcse.c (compute_hash_table_work): Do not elide
	marking a block containing a call if the call might not
	return.

	* gcc.dg/torture/pr90020.c: New testcase.

From-SVN: r270275