Fix PR tree-optimization/98272

This fixes the precision mismatch introduced by the previous change.

gcc/ChangeLog:
	PR tree-optimization/98272
	* tree-switch-conversion.c (bit_test_cluster::emit): When finding
	out whether the entry test can be merged in the bit test, do the
	computation using the type of the index expression.

gcc/testsuite/ChangeLog:
	* gcc.dg/pr98272.c: New test.

diff --git a/gcc/testsuite/gcc.dg/pr98272.c b/gcc/testsuite/gcc.dg/pr98272.c
new file mode 100644 (file)
index 0000000..126a616
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr98272.c
@@ -0,0 +1,22 @@
+/* PR tree-optimization/98272 */
+/* Reported by Zdenek Sojka <zsojka@seznam.cz> */
+
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-forwprop" } */
+
+void bar (void);
+
+void
+foo (unsigned char uc)
+{
+  if (uc >= 5)
+    return;
+
+  switch (uc)
+    {
+    case 0:
+    case 2:
+    case 4:
+      bar ();
+    }
+}

diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
index 989bd7710d1f84a0c5e2c45a8b1ba12e1b3528ef..08dfd6f3580e120f30aaf877b54bb4544f789128 100644 (file)
--- a/gcc/tree-switch-conversion.c
+++ b/gcc/tree-switch-conversion.c
@@ -1557,21 +1557,22 @@ bit_test_cluster::emit (tree index_expr, tree index_type,
       && get_range_info (index_expr, &min, &max) == VR_RANGE
       && wi::leu_p (max - min, prec - 1))
     {
+      tree index_type = TREE_TYPE (index_expr);
+      minval = fold_convert (index_type, minval);
       wide_int iminval = wi::to_wide (minval);
-      tree minval_type = TREE_TYPE (minval);
-      if (wi::lt_p (min, iminval, TYPE_SIGN (minval_type)))
+      if (wi::lt_p (min, iminval, TYPE_SIGN (index_type)))
        {
-         minval = wide_int_to_tree (minval_type, min);
+         minval = wide_int_to_tree (index_type, min);
          for (i = 0; i < count; i++)
            test[i].mask = wi::lshift (test[i].mask, iminval - min);
        }
-      else if (wi::gt_p (min, iminval, TYPE_SIGN (minval_type)))
+      else if (wi::gt_p (min, iminval, TYPE_SIGN (index_type)))
        {
-         minval = wide_int_to_tree (minval_type, min);
+         minval = wide_int_to_tree (index_type, min);
          for (i = 0; i < count; i++)
            test[i].mask = wi::lrshift (test[i].mask, min - iminval);
        }
-      maxval = wide_int_to_tree (minval_type, max);
+      maxval = wide_int_to_tree (index_type, max);
       entry_test_needed = false;
     }
   else