PR middle-end/53590

	* common.opt (-fdelete-dead-exceptions): New switch.
	* doc/invoke.texi (Code Gen Options): Document it.
	* cse.c (count_reg_usage) <CALL_INSN>: Use !insn_nothrow_p in lieu of
	insn_could_throw_p predicate.  Do not skip an insn that could throw
	if dead exceptions can be deleted.
	(insn_live_p): Likewise, do not return true in that case.
	* dce.c (can_alter_cfg): New flag.
	(deletable_insn_p): Do not return false for an insn that can throw if
	the CFG can be altered and dead exceptions can be deleted.
	(init_dce): Set can_alter_cfg to false for fast DCE, true otherwise.
	* dse.c (scan_insn): Use !insn_nothrow_p in lieu of insn_could_throw_
	predicate. Do not preserve an insn that could throw if dead exceptions
	can be deleted.
	* function.h (struct function): Add can_delete_dead_exceptions flag.
	* function.c (allocate_struct_function): Set it.
	* lto-streamer-in.c (input_struct_function_base): Stream it.
	* lto-streamer-out.c (input_struct_function_base): Likewise.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Do not mark a
	statement that could throw as necessary if dead exceptions can be
	deleted.
ada/
	* gcc-interface/misc.c (gnat_init_options_struct): Set
	opts->x_flag_delete_dead_exceptions to 1.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@188651 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 1 insertions, 1 deletions

diff --git a/gcc/dse.c b/gcc/dse.c
index da52415083e..0e40c8539cf 100644
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -2628,7 +2628,7 @@ scan_insn (bb_info_t bb_info, rtx insn)
      them.  */
   if ((GET_CODE (PATTERN (insn)) == CLOBBER)
       || volatile_refs_p (PATTERN (insn))
-      || insn_could_throw_p (insn)
+      || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn))
       || (RTX_FRAME_RELATED_P (insn))
       || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX))
     insn_info->cannot_delete = true;