* tree-data-ref.c (analyze_offset): Add a return value (bool) to

	indicate success/failure of the analysis. Add negation to subtrahend
	in case of subtraction. Fail if both operands contain constants.
	(create_data_ref): Fail if analyze_offset fails.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@122817 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 30 insertions, 7 deletions

diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index 7eadde75bd5..d59278c89f5 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -1835,7 +1835,7 @@ object_analysis (tree memref, tree stmt, bool is_read,
    Extract INVARIANT and CONSTANT parts from OFFSET. 
 
 */
-static void 
+static bool 
 analyze_offset (tree offset, tree *invariant, tree *constant)
 {
   tree op0, op1, constant_0, constant_1, invariant_0, invariant_1;
@@ -1851,23 +1851,36 @@ analyze_offset (tree offset, tree *invariant, tree *constant)
 	*constant = offset;
       else
 	*invariant = offset;
-      return;
+      return true;
     }
 
   op0 = TREE_OPERAND (offset, 0);
   op1 = TREE_OPERAND (offset, 1);
 
   /* Recursive call with the operands.  */
-  analyze_offset (op0, &invariant_0, &constant_0);
-  analyze_offset (op1, &invariant_1, &constant_1);
+  if (!analyze_offset (op0, &invariant_0, &constant_0)
+      || !analyze_offset (op1, &invariant_1, &constant_1))
+    return false;
 
-  /* Combine the results.  */
+  /* Combine the results. Add negation to the subtrahend in case of 
+     subtraction.  */
+  if (constant_0 && constant_1)
+    return false;
   *constant = constant_0 ? constant_0 : constant_1;
+  if (code == MINUS_EXPR && constant_1)
+    *constant = fold_build1 (NEGATE_EXPR, TREE_TYPE (*constant), *constant);
+
   if (invariant_0 && invariant_1)
     *invariant = 
       fold_build2 (code, TREE_TYPE (invariant_0), invariant_0, invariant_1);
   else
-    *invariant = invariant_0 ? invariant_0 : invariant_1;
+    {
+      *invariant = invariant_0 ? invariant_0 : invariant_1;
+      if (code == MINUS_EXPR && invariant_1)
+        *invariant = 
+           fold_build1 (NEGATE_EXPR, TREE_TYPE (*invariant), *invariant);
+    }
+  return true;
 }
 
 /* Free the memory used by the data reference DR.  */
@@ -1941,7 +1954,17 @@ create_data_ref (tree memref, tree stmt, bool is_read)
   STRIP_NOPS (offset);
   if (offset != orig_offset)
     type = TREE_TYPE (orig_offset);
-  analyze_offset (offset, &invariant, &constant);
+  if (!analyze_offset (offset, &invariant, &constant))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+        {
+          fprintf (dump_file, "\ncreate_data_ref: failed to analyze dr's");
+          fprintf (dump_file, " offset for ");
+          print_generic_expr (dump_file, memref, TDF_SLIM);
+          fprintf (dump_file, "\n");
+        }
+      return NULL;
+    }
   if (type && invariant)
     invariant = fold_convert (type, invariant);