re PR tree-optimization/39804 (internal compiler error: in propagate_necessity, at tree-ssa-dce.c:754)

2009-04-18  Richard Guenther  <rguenther@suse.de>

	PR middle-end/39804
	* tree-ssa-ccp.c (fold_stmt_1): New function factored from ...
	(fold_stmt): ... this and ...
	(fold_stmt_inplace): ... this.
	(fold_stmt_1): Fold references in calls and asms.
	* tree-cfg.c (remove_useless_stmts_cond): Use fold_stmt.

	* gcc.target/i386/pr39804.c: New testcase.

From-SVN: r146314