[patch] Fix PR middle-end/53590

[Eric Botcazou]

This PR is about straight-line code not being as much vectorized in Ada as in C 
or C++.  The problem stems from the very conservative semantics implemented 
under -fnon-call-exceptions for the sake of Java.  We don't need it in Ada.

Tested on x86_64-suse-linux, OK for the mainline?


2012-06-13  Eric Botcazou  <ebotcazou@adacore.com>

	PR middle-end/53590
	* common.opt (-fdelete-dead-exceptions): New switch.
	* doc/invoke.texi (Optimization Options): Document it.
	* cse.c (insn_live_p): Do not return true for an insn that could throw
	if dead exceptions can be deleted.
	* 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): Do not preserve an insn that could throw if dead
	exceptions can be deleted.
	* 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.


-- 
Eric Botcazou
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pr53590.diff
Type: text/x-diff
Size: 5579 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20120613/ae14ee9e/attachment.bin>