[Bug tree-optimization/19624] PRE pessimizes ivopts

["cvs-commit at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-30 19:09 -------
Subject: Bug 19624

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dberlin@gcc.gnu.org	2005-01-30 19:08:37

Modified files:
	gcc            : Makefile.in tree-ssa-pre.c 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: ssa-pre-4.c ssa-pre-5.c 
	                               ssa-pre-6.c 

Log message:
	2005-01-30  Daniel Berlin  <dberlin@dberlin.org>
	
	Fix PR tree-optimization/19624
	
	* Makefile.in (tree-ssa-pre.o): Add CFGLOOP_H.
	* tree-ssa-pre.c: Add cfgloop.h.
	Update comment.
	(pre_stats): New member, constified.
	(inserted_exprs): New static variable.
	(NECESSARY): New macro.
	(create_expression_by_pieces): Fold the expression, and
	mark it as defaulting to not necessary. Also put in
	inserted_exprs.
	(fully_constant_expression): New function.
	(insert_into_preds_of_block): Modify to not insert phis when we
	are playing with induction variables.
	Push phis onto the inserted_exprs vector, and mark them as not
	necessary by default.
	(insert_aux): Call fully_constant_expression on eprime.
	If all edges produce the same value, mark it constant.
	(mark_operand_necessary): New function.
	(remove_dead_inserted_code): New function.
	(init_pre): Init loop optimizer to get loop info.
	(fini_pre): Free loop_optimizer, and inserted_exprs vec.
	(execute_pre): Commit edge inserts, then remove dead code.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/Makefile.in.diff?cvsroot=gcc&r1=1.1444&r2=1.1445
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-pre.c.diff?cvsroot=gcc&r1=2.62&r2=2.63
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-4.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-5.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-6.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624