fold-const: Fix up ((1 << x) & y) != 0 folding for vectors [PR99225]

This optimization was written purely with scalar integers in mind,
can work fine even with vectors, but we can't use build_int_cst but
need to use build_one_cst instead.

2021-02-24  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/99225
	* fold-const.c (fold_binary_loc) <case NE_EXPR>: In (x & (1 << y)) != 0
	to ((x >> y) & 1) != 0 simplifications use build_one_cst instead of
	build_int_cst (..., 1).  Formatting fixes.

	* gcc.c-torture/compile/pr99225.c: New test.

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index afc3b7f..e0bdb4b 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -12044,23 +12044,23 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
              && integer_onep (TREE_OPERAND (arg00, 0)))
            {
              tree tem = fold_build2_loc (loc, RSHIFT_EXPR, TREE_TYPE (arg00),
-                                     arg01, TREE_OPERAND (arg00, 1));
+                                         arg01, TREE_OPERAND (arg00, 1));
              tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg0), tem,
-                                build_int_cst (TREE_TYPE (arg0), 1));
+                                    build_one_cst (TREE_TYPE (arg0)));
              return fold_build2_loc (loc, code, type,
-                                 fold_convert_loc (loc, TREE_TYPE (arg1), tem),
-                                 arg1);
+                                     fold_convert_loc (loc, TREE_TYPE (arg1),
+                                                       tem), arg1);
            }
          else if (TREE_CODE (arg01) == LSHIFT_EXPR
                   && integer_onep (TREE_OPERAND (arg01, 0)))
            {
              tree tem = fold_build2_loc (loc, RSHIFT_EXPR, TREE_TYPE (arg01),
-                                     arg00, TREE_OPERAND (arg01, 1));
+                                         arg00, TREE_OPERAND (arg01, 1));
              tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg0), tem,
-                                build_int_cst (TREE_TYPE (arg0), 1));
+                                    build_one_cst (TREE_TYPE (arg0)));
              return fold_build2_loc (loc, code, type,
-                                 fold_convert_loc (loc, TREE_TYPE (arg1), tem),
-                                 arg1);
+                                     fold_convert_loc (loc, TREE_TYPE (arg1),
+                                                       tem), arg1);
            }
        }
 

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr99225.c b/gcc/testsuite/gcc.c-torture/compile/pr99225.c
new file mode 100644 (file)
index 0000000..0ef7602
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr99225.c
@@ -0,0 +1,31 @@
+/* PR tree-optimization/99225 */
+
+typedef int V __attribute__((vector_size (4 * sizeof (int))));
+
+void
+foo (V *x)
+{
+  x[2] = (x[0] & (1 << x[1])) != 0;
+}
+
+void
+bar (V *x)
+{
+  x[2] = ((1 << x[1]) & x[0]) != 0;
+}
+
+void
+baz (V *x)
+{
+  V a = 1 << x[1];
+  V b = a & x[0];
+  x[2] = b != 0;
+}
+
+void
+qux (V *x)
+{
+  V a = 1 << x[1];
+  V b = x[0] & a;
+  x[2] = b != 0;
+}