i386: Fix up *jcc_bt*_mask{,_1} [PR111408]

The following testcase is miscompiled in GCC 14 because the
*jcc_bt<mode>_mask and *jcc_bt<SWI48:mode>_mask_1 patterns have just
one argument in (match_operator 0 "bt_comparison_operator" [...])
but as bt_comparison_operator is eq,ne, we need two.
The md readers don't warn about it, after all, some checks can
be done in the predicate rather than specified explicitly, and the
behavior is that anything is accepted as the second argument.

I went through all other i386.md match_operator uses and all others
looked right (extract_operator using 3 operands, all others 2).

I think we'll want to fix this at different spots in older releases
because I think the bug was introduced already in 2008, though most
likely just latent.

2023-11-25  Jakub Jelinek  <jakub@redhat.com>

	PR target/111408
	* config/i386/i386.md (*jcc_bt<mode>_mask,
	*jcc_bt<SWI48:mode>_mask_1): Add (const_int 0) as expected
	second operand of bt_comparison_operator.

	* gcc.c-torture/execute/pr111408.c: New test.

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 41de9537a40539b4af9502bf1c85ad27f6213bcc..cb32de7fab87f75b35209cc430ea918be151e1a7 100644 (file)
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -16879,7 +16879,8 @@
                           (const_int 1)
                           (and:QI
                             (match_operand:QI 2 "register_operand")
-                            (match_operand 3 "const_int_operand")))])
+                            (match_operand 3 "const_int_operand")))
+                        (const_int 0)])
                      (label_ref (match_operand 4))
                      (pc)))
    (clobber (reg:CC FLAGS_REG))]
@@ -16915,7 +16916,8 @@
                           (subreg:QI
                             (and:SWI248
                               (match_operand:SWI248 2 "register_operand")
-                              (match_operand 3 "const_int_operand")) 0))])
+                              (match_operand 3 "const_int_operand")) 0))
+                        (const_int 0)])
                      (label_ref (match_operand 4))
                      (pc)))
    (clobber (reg:CC FLAGS_REG))]

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr111408.c b/gcc/testsuite/gcc.c-torture/execute/pr111408.c
new file mode 100644 (file)
index 0000000..6dfb0a3
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr111408.c
@@ -0,0 +1,26 @@
+/* PR target/111408 */
+
+int a, b, c, d;
+short e;
+
+int
+foo ()
+{
+  c = a % (sizeof (int) * 8);
+  if (b & 1 << c)
+    return -1;
+  return 0;
+}
+
+int
+main ()
+{
+  for (; e != 1; e++)
+    {
+      int g = foo ();
+      if (g + d - 9 + d)
+       continue;
+      for (;;)
+       __builtin_abort ();
+    }
+}