This removes restrictions in DOM cprop_operand that inhibit
some optimizations. The volatile pointer thing is really realy
old and no longer necessary while the loop-depth consideration
is only valid for loop-closed PHI nodes (but we're not in
loop-closed SSA in DOM) - the coalescing is handled in out-of-SSA
phase by inserting copies appropriately.
Bootstrapped on x86_64-unknown-linux-gnu, ok?
Thanks,
Richard.
2014-06-25 Richard Biener <rguent...@suse.de>
PR tree-optimization/61607
* tree-ssa-dom.c (cprop_operand): Remove restriction on
propagating volatile pointers and on loop depth.
Index: gcc/tree-ssa-dom.c
===================================================================
--- gcc/tree-ssa-dom.c (revision 211969)
+++ gcc/tree-ssa-dom.c (working copy)
@@ -2247,22 +2247,6 @@ cprop_operand (gimple stmt, use_operand_
if (!may_propagate_copy (op, val))
return;
- /* Do not propagate addresses that point to volatiles into memory
- stmts without volatile operands. */
- if (POINTER_TYPE_P (TREE_TYPE (val))
- && TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (val)))
- && gimple_has_mem_ops (stmt)
- && !gimple_has_volatile_ops (stmt))
- return;
-
- /* Do not propagate copies if the propagated value is at a deeper loop
- depth than the propagatee. Otherwise, this may move loop variant
- variables outside of their loops and prevent coalescing
- opportunities. If the value was loop invariant, it will be hoisted
- by LICM and exposed for copy propagation. */
- if (loop_depth_of_name (val) > loop_depth_of_name (op))
- return;
-
/* Do not propagate copies into simple IV increment statements.
See PR23821 for how this can disturb IV analysis. */
if (TREE_CODE (val) != INTEGER_CST
