re PR tree-optimization/62112 (Optimize out malloc when block is unused or write...

re PR tree-optimization/62112 (Optimize out malloc when block is unused or write-only)

2014-08-21  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/62112
gcc/
	* gimple-iterator.c (gsi_replace): Return whether EH cleanup is needed.
	* gimple-iterator.h (gsi_replace): Return bool.
	* tree-ssa-alias.c (ref_may_alias_global_p_1): New helper, code
	moved from ref_may_alias_global_p.
	(ref_may_alias_global_p, refs_may_alias_p, ref_maybe_used_by_stmt_p):
	New overloads.
	(ref_maybe_used_by_call_p): Take ao_ref* instead of tree.
	(stmt_kills_ref_p_1): Rename...
	(stmt_kills_ref_p): ... to this.
	* tree-ssa-alias.h (ref_may_alias_global_p, ref_maybe_used_by_stmt_p,
	stmt_kills_ref_p): Declare.
	* tree-ssa-dse.c (dse_possible_dead_store_p): New argument, use it.
	Move the self-assignment case...
	(dse_optimize_stmt): ... here. Handle builtin calls. Remove dead code.
gcc/testsuite/
	* gcc.dg/tree-ssa/pr62112-1.c: New file.
	* gcc.dg/tree-ssa/pr62112-2.c: Likewise.
	* gcc.c-torture/execute/pr35472.c: Add noclone attribute.
	* gcc.c-torture/execute/20071219-1.c: Likewise.

From-SVN: r214262