[PATCH] Fix PR44393^W44684

[Richard Guenther]

On Sun, 27 Jun 2010, Richard Guenther wrote:

> 
> My last fix caused some ICEs.  So here we go making the thing
> safe again and avoid some bogus calls into ref_may_alias_p_1.

Err, that was the wrong patch and PR number.

> Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2010-06-26  Richard Guenther  <rguenther@suse.de>

	PR middle-end/44684
	* tree-ssa-alias.c (refs_may_alias_p_1): Allow SSA name refs.
	(stmt_may_clobber_ref_p_1): Do not bother to call the oracle
	for register LHS.  Or non-store assignments.

Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c	(revision 161435)
--- gcc/tree-ssa-alias.c	(working copy)
*************** refs_may_alias_p_1 (ao_ref *ref1, ao_ref
*** 801,811 ****
--- 801,813 ----
    alias_set_type set;
  
    gcc_checking_assert ((!ref1->ref
+ 			|| TREE_CODE (ref1->ref) == SSA_NAME
  			|| DECL_P (ref1->ref)
  			|| handled_component_p (ref1->ref)
  			|| INDIRECT_REF_P (ref1->ref)
  			|| TREE_CODE (ref1->ref) == TARGET_MEM_REF)
  		       && (!ref2->ref
+ 			   || TREE_CODE (ref2->ref) == SSA_NAME
  			   || DECL_P (ref2->ref)
  			   || handled_component_p (ref2->ref)
  			   || INDIRECT_REF_P (ref2->ref)
*************** stmt_may_clobber_ref_p_1 (gimple stmt, a
*** 1409,1419 ****
  
        return call_may_clobber_ref_p_1 (stmt, ref);
      }
!   else if (is_gimple_assign (stmt))
      {
!       ao_ref r;
!       ao_ref_init (&r, gimple_assign_lhs (stmt));
!       return refs_may_alias_p_1 (ref, &r, true);
      }
    else if (gimple_code (stmt) == GIMPLE_ASM)
      return true;
--- 1411,1425 ----
  
        return call_may_clobber_ref_p_1 (stmt, ref);
      }
!   else if (gimple_assign_single_p (stmt))
      {
!       tree lhs = gimple_assign_lhs (stmt);
!       if (!is_gimple_reg (lhs))
! 	{
! 	  ao_ref r;
! 	  ao_ref_init (&r, gimple_assign_lhs (stmt));
! 	  return refs_may_alias_p_1 (ref, &r, true);
! 	}
      }
    else if (gimple_code (stmt) == GIMPLE_ASM)
      return true;