[Bug optimization/11059] [3.3/3.4 regression] empty union optimization ice

[cvs-commit at gcc dot gnu dot org]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11059



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-07-07 18:54 -------
Subject: Bug 11059

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	sayle@gcc.gnu.org	2003-07-07 18:54:28

Modified files:
	gcc            : ChangeLog expr.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/opt: emptyunion.C 

Log message:
	PR optimization/11059
	* expr.c (can_store_by_pieces): Return true if length is zero.
	(store_by_pieces): If length is zero and endp is two, abort,
	othwerise, if length is zero and endp is not two, return "to".
	(clear_by_pieces): Do nothing if length is zero.
	(clear_storage): Do nothing if length is zero.
	(store_constructor): Simplify code when size is zero, or the
	target has already been cleared.  This avoids emitting a
	blockage instruction when initializing empty structures.
	
	* g++.dg/opt/emptyunion.C: New testcase.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.380&r2=2.381
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/expr.c.diff?cvsroot=gcc&r1=1.565&r2=1.566
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2846&r2=1.2847
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/opt/emptyunion.C.diff?cvsroot=gcc&r1=NONE&r2=1.1