re PR tree-optimization/64410 (gcc 25% slower than clang 3.5 for adding complex numbers)

2015-01-09  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/64410
	* tree-ssa.c (non_rewritable_lvalue_p): Allow REALPART/IMAGPART_EXPR
	on the LHS.
	(execute_update_addresses_taken): Deal with that.
	* tree-ssa-forwprop.c (pass_forwprop::execute): Use component-wise
	loads/stores for complex variables.

	* g++.dg/vect/pr64410.cc: New testcase.

From-SVN: r219380

1 files changed, 91 insertions, 0 deletions

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 04b1509..a8fbccc 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -2210,6 +2210,97 @@ pass_forwprop::execute (function *fun)
 	      else
 		gsi_next (&gsi);
 	    }
+	  else if (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE
+		   && gimple_assign_load_p (stmt)
+		   && !gimple_has_volatile_ops (stmt)
+		   && !stmt_can_throw_internal (stmt))
+	    {
+	      /* Rewrite loads used only in real/imagpart extractions to
+	         component-wise loads.  */
+	      use_operand_p use_p;
+	      imm_use_iterator iter;
+	      bool rewrite = true;
+	      FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
+		{
+		  gimple use_stmt = USE_STMT (use_p);
+		  if (is_gimple_debug (use_stmt))
+		    continue;
+		  if (!is_gimple_assign (use_stmt)
+		      || (gimple_assign_rhs_code (use_stmt) != REALPART_EXPR
+			  && gimple_assign_rhs_code (use_stmt) != IMAGPART_EXPR))
+		    {
+		      rewrite = false;
+		      break;
+		    }
+		}
+	      if (rewrite)
+		{
+		  gimple use_stmt;
+		  FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
+		    {
+		      if (is_gimple_debug (use_stmt))
+			{
+			  if (gimple_debug_bind_p (use_stmt))
+			    {
+			      gimple_debug_bind_reset_value (use_stmt);
+			      update_stmt (use_stmt);
+			    }
+			  continue;
+			}
+
+		      tree new_rhs = build1 (gimple_assign_rhs_code (use_stmt),
+					     TREE_TYPE (TREE_TYPE (rhs)),
+					     unshare_expr (rhs));
+		      gimple new_stmt
+			= gimple_build_assign (gimple_assign_lhs (use_stmt),
+					       new_rhs);
+
+		      gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt);
+		      unlink_stmt_vdef (use_stmt);
+		      gsi_remove (&gsi2, true);
+
+		      gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
+		    }
+		  gsi_remove (&gsi, true);
+		}
+	      else
+		gsi_next (&gsi);
+	    }
+	  else if (code == COMPLEX_EXPR)
+	    {
+	      /* Rewrite stores of a single-use complex build expression
+	         to component-wise stores.  */
+	      use_operand_p use_p;
+	      gimple use_stmt;
+	      if (single_imm_use (lhs, &use_p, &use_stmt)
+		  && gimple_store_p (use_stmt)
+		  && !gimple_has_volatile_ops (use_stmt)
+		  && is_gimple_assign (use_stmt))
+		{
+		  tree use_lhs = gimple_assign_lhs (use_stmt);
+		  tree new_lhs = build1 (REALPART_EXPR,
+					 TREE_TYPE (TREE_TYPE (use_lhs)),
+					 unshare_expr (use_lhs));
+		  gimple new_stmt = gimple_build_assign (new_lhs, rhs);
+		  gimple_set_vuse (new_stmt, gimple_vuse (use_stmt));
+		  gimple_set_vdef (new_stmt, make_ssa_name (gimple_vop (cfun)));
+		  SSA_NAME_DEF_STMT (gimple_vdef (new_stmt)) = new_stmt;
+		  gimple_set_vuse (use_stmt, gimple_vdef (new_stmt));
+		  gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt);
+		  gsi_insert_before (&gsi2, new_stmt, GSI_SAME_STMT);
+
+		  new_lhs = build1 (IMAGPART_EXPR,
+				    TREE_TYPE (TREE_TYPE (use_lhs)),
+				    unshare_expr (use_lhs));
+		  gimple_assign_set_lhs (use_stmt, new_lhs);
+		  gimple_assign_set_rhs1 (use_stmt, gimple_assign_rhs2 (stmt));
+		  update_stmt (use_stmt);
+
+		  gsi_remove (&gsi, true);
+		}
+	      else
+		gsi_next (&gsi);
+	    }
 	  else
 	    gsi_next (&gsi);
 	}