(build_binary_op): When checking shift widths, don't assume target integer

fits in a HOST_WIDE_INT.

From-SVN: r2106

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 145a27ba64086ea303fb8669a3a2f41597fdc651..3181f15f5f2214417092d876f2a02e1bd9e62599 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -2347,12 +2347,17 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
        {
          if (TREE_CODE (op1) == INTEGER_CST)
            {
-             if (TREE_INT_CST_LOW (op1) > 0)
-               short_shift = 1;
-             else if (TREE_INT_CST_LOW (op1) < 0)
+             if (tree_int_cst_lt (op1, integer_zero_node))
                warning ("shift count is negative");
-             if (TREE_INT_CST_LOW (op1) >= TYPE_PRECISION (type0))
-               warning ("shift count >= width of type");
+             else
+               {
+                 if (TREE_INT_CST_LOW (op1) | TREE_INT_CST_HIGH (op1))
+                   short_shift = 1;
+                 if (TREE_INT_CST_HIGH (op1) != 0
+                     || ((unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (op1)
+                         >= TYPE_PRECISION (type0)))
+                   warning ("shift count >= width of type");
+               }
            }
          /* Use the type of the value to be shifted.
             This is what most traditional C compilers do.  */
@@ -2372,12 +2377,15 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
     case LSHIFT_EXPR:
       if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
        {
-         if (TREE_CODE (op1) == INTEGER_CST
-             && TREE_INT_CST_LOW (op1) < 0)
-           warning ("shift count is negative");
-         if (TREE_CODE (op1) == INTEGER_CST
-             && TREE_INT_CST_LOW (op1) >= TYPE_PRECISION (type0))
-           warning ("shift count >= width of type");
+         if (TREE_CODE (op1) == INTEGER_CST)
+           {
+             if (tree_int_cst_lt (op1, integer_zero_node))
+               warning ("shift count is negative");
+             else if (TREE_INT_CST_HIGH (op1) != 0
+                      || ((unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (op1)
+                          >= TYPE_PRECISION (type0)))
+               warning ("shift count >= width of type");
+           }
          /* Use the type of the value to be shifted.
             This is what most traditional C compilers do.  */
          result_type = type0;
@@ -2397,12 +2405,15 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
     case LROTATE_EXPR:
       if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
        {
-         if (TREE_CODE (op1) == INTEGER_CST
-             && TREE_INT_CST_LOW (op1) < 0)
-           warning ("shift count is negative");
-         if (TREE_CODE (op1) == INTEGER_CST
-             && TREE_INT_CST_LOW (op1) >= TYPE_PRECISION (type0))
-           warning ("shift count >= width of type");
+         if (TREE_CODE (op1) == INTEGER_CST)
+           {
+             if (tree_int_cst_lt (op1, integer_zero_node))
+               warning ("shift count is negative");
+             else if (TREE_INT_CST_HIGH (op1) != 0
+                      || ((unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (op1)
+                          >= TYPE_PRECISION (type0)))
+               warning ("shift count >= width of type");
+           }
          /* Use the type of the value to be shifted.
             This is what most traditional C compilers do.  */
          result_type = type0;