[PATCH] Fix PR52459

[Richard Guenther]

This fixes PR52459, we re-use VN reference to encode calls but
we are not interested in restricting call insertions in
PREs inhibit_phi_insertion (we at most have pure calls).

Boostrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2012-03-21  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/52459
	* tree-ssa-pre.c (inhibit_phi_insertion): Do not inhibit
	PHI insertion for calls.

Index: gcc/tree-ssa-pre.c
===================================================================
*** gcc/tree-ssa-pre.c	(revision 185597)
--- gcc/tree-ssa-pre.c	(working copy)
*************** inhibit_phi_insertion (basic_block bb, p
*** 3242,3247 ****
--- 3242,3251 ----
      {
        switch (op->opcode)
  	{
+ 	case CALL_EXPR:
+ 	  /* Calls are not a problem.  */
+ 	  return false;
+ 
  	case ARRAY_REF:
  	case ARRAY_RANGE_REF:
  	  if (TREE_CODE (op->op0) != SSA_NAME)