re PR middle-end/38492 ([graphite] segfaulting code when compiled with -fgraphite -fgraphite-identity)

2009-01-07  Jan Sjodin  <jan.sjodin@amd.com>

	PR tree-optimization/38492
	PR tree-optimization/38498
	* tree-check.c (operator_is_linear, scev_is_linear_expression): New.
	* tree-chrec.h (scev_is_linear_expression): Declared.
	* graphite.c (graphite_cannot_represent_loop_niter): New.
	(scopdet_basic_block_info): Call graphite_cannot_represent_loop_niter.
	(graphite_loop_normal_form): Use gcc_assert.
	(scan_tree_for_params): Use CASE_CONVERT.
	(phi_node_is_iv, bb_contains_non_iv_scalar_phi_nodes): New.
	(build_scop_conditions_1): Call bb_contains_non_iv_scalar_phi_nodes.
	Use gcc_assert.  Discard scops that contain unhandled cases.
	(build_scop_conditions): Return a boolean status for unhandled cases.
	(strip_mine_profitable_p): Print the loop number, not its depth.
	(is_interchange_valid): Pass the depth of the loop nest, don't
	recompute it wrongly.
	(graphite_trans_bb_block): Same.
	(graphite_trans_bb_block): Print tentative of loop blocking.
	(graphite_trans_scop_block): Do not print that the loop has been
	blocked.
	(graphite_transform_loops): Do not handle scops that contain condition
	scalar phi nodes.

	* testsuite/gcc.dg/graphite/pr38500.c: Fixed warning as committed
	in trunk.
	* testsuite/gcc.dg/graphite/block-0.c: Update test.
	* testsuite/gcc.dg/graphite/block-1.c: Same.
	* testsuite/gcc.dg/graphite/block-2.c: Remove xfail and test for blocking.
	* testsuite/gcc.dg/graphite/block-4.c: Remove test for strip mine.
	* testsuite/gcc.dg/graphite/block-3.c: New.
	* testsuite/gcc.dg/graphite/pr38498.c: New.

From-SVN: r143159

1 files changed, 61 insertions, 0 deletions

diff --git a/gcc/tree-chrec.c b/gcc/tree-chrec.c
index 26ae9b4..7a065b6 100644
--- a/gcc/tree-chrec.c
+++ b/gcc/tree-chrec.c
@@ -1430,3 +1430,64 @@ for_each_scev_op (tree *scev, bool (*cbck) (tree *, void *), void *data)
     }
 }
 
+/* Returns true when the operation can be part of a linear
+   expression.  */
+
+static inline bool
+operator_is_linear (tree scev)
+{
+  switch (TREE_CODE (scev))
+    {
+    case INTEGER_CST:
+    case POLYNOMIAL_CHREC:
+    case PLUS_EXPR:
+    case POINTER_PLUS_EXPR:
+    case MULT_EXPR:
+    case MINUS_EXPR:
+    case NEGATE_EXPR:
+    case SSA_NAME:
+    case NON_LVALUE_EXPR:
+    CASE_CONVERT:
+      return true;
+
+    default:
+      return false;
+    }
+}
+
+/* Return true when SCEV is a linear expression.  Linear expressions
+   can contain additions, substractions and multiplications.
+   Multiplications are restricted to constant scaling: "cst * x".  */
+
+bool
+scev_is_linear_expression (tree scev)
+{
+  if (scev == NULL
+      || !operator_is_linear (scev))
+    return false;
+
+  if (TREE_CODE (scev) == MULT_EXPR)
+    return !(tree_contains_chrecs (TREE_OPERAND (scev, 0), NULL)
+	     && tree_contains_chrecs (TREE_OPERAND (scev, 1), NULL));
+
+  switch (TREE_CODE_LENGTH (TREE_CODE (scev)))
+    {
+    case 3:
+      return scev_is_linear_expression (TREE_OPERAND (scev, 0))
+	&& scev_is_linear_expression (TREE_OPERAND (scev, 1))
+	&& scev_is_linear_expression (TREE_OPERAND (scev, 2));
+
+    case 2:
+      return scev_is_linear_expression (TREE_OPERAND (scev, 0))
+	&& scev_is_linear_expression (TREE_OPERAND (scev, 1));
+      
+    case 1:
+      return scev_is_linear_expression (TREE_OPERAND (scev, 0));
+
+    case 0:
+      return true;
+
+    default:
+      return false;
+    }
+}