diff mbox

[gccgo] Do array index computations in sizetype

Message ID mcrzkxbn2hg.fsf@google.com
State New
Headers show

Commit Message

Ian Lance Taylor July 28, 2010, 1:46 p.m. UTC 
Array indexes are stored as int, but when we compute an array offset we
should use sizetype (aka size_t).  That way, although the number of
elements in the array is restricted to 32 bits, the total size of the
array is not.  Committed to gccgo branch.

Ian
diff mbox

Patch

diff -r 9bddc2bbd1b7 go/expressions.cc
--- a/go/expressions.cc	Wed Jul 28 06:37:17 2010 -0700
+++ b/go/expressions.cc	Wed Jul 28 06:42:37 2010 -0700
@@ -8670,6 +8670,7 @@ 
 			  build3(COND_EXPR, void_type_node,
 				 bad_index, crash, NULL_TREE),
 			  start_tree);
+      start_tree = fold_convert_loc(loc, sizetype, start_tree);
 
       if (array_type->length() != NULL)
 	{
@@ -8683,14 +8684,10 @@ 
 	  tree values = array_type->value_pointer_tree(gogo, array_tree);
 	  tree element_type_tree = array_type->element_type()->get_tree(gogo);
 	  tree element_size = TYPE_SIZE_UNIT(element_type_tree);
-	  tree offset = fold_build2_loc(loc, MULT_EXPR, TREE_TYPE(length_tree),
-					start_tree,
-					fold_convert_loc(loc,
-							 TREE_TYPE(length_tree),
-							 element_size));
+	  tree offset = fold_build2_loc(loc, MULT_EXPR, sizetype,
+					start_tree, element_size);
 	  tree ptr = fold_build2_loc(loc, POINTER_PLUS_EXPR,
-				     TREE_TYPE(values), values,
-				     fold_convert_loc(loc, sizetype, offset));
+				     TREE_TYPE(values), values, offset);
 	  return build_fold_indirect_ref(ptr);
 	}
     }
@@ -8727,17 +8724,16 @@ 
 
   tree element_type_tree = array_type->element_type()->get_tree(gogo);
   tree element_size = TYPE_SIZE_UNIT(element_type_tree);
-  element_size = fold_convert_loc(loc, TREE_TYPE(length_tree), element_size);
-
-  tree offset = fold_build2_loc(loc, MULT_EXPR, TREE_TYPE(length_tree),
-				start_tree, element_size);
+
+  tree offset = fold_build2_loc(loc, MULT_EXPR, sizetype,
+				fold_convert_loc(loc, sizetype, start_tree),
+				element_size);
 
   tree value_pointer = array_type->value_pointer_tree(gogo, array_tree);
 
   value_pointer = fold_build2_loc(loc, POINTER_PLUS_EXPR,
 				  TREE_TYPE(value_pointer),
-				  value_pointer,
-				  fold_convert_loc(loc, sizetype, offset));
+				  value_pointer, offset);
 
   tree result_length_tree = fold_build2_loc(loc, MINUS_EXPR,
 					    TREE_TYPE(length_tree),