[PATCH] middle-end: Fixup constant integers when expanding __builtin_crc [PR118288]

[Uros Bizjak]

Constant integers with MSB set have to be represented as corresponding
signed integers.  Use gen_int_mode to emit them in the correct way.

    PR middle-end/118288

gcc/ChangeLog:

    * builtins.cc (expand_builtin_crc_table_based):
    Use gen_int_mode to emit constant integers with MSB set.

gcc/testsuite/ChangeLog:

    * gcc.dg/pr118288.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

OK for mainline?

Uros.

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index 468bd65bc42..c8841032f03 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -7803,6 +7803,9 @@ expand_builtin_crc_table_based (internal_fn fn, 
scalar_mode crc_mode,
   gcc_assert (TREE_CODE (rhs3) == INTEGER_CST);
   rtx op3 = gen_int_mode (TREE_INT_CST_LOW (rhs3), crc_mode);
 
+  if (CONST_INT_P (op2))
+    op2 = gen_int_mode (INTVAL (op2), crc_mode);
+
   if (fn == IFN_CRC)
     expand_crc_table_based (target, op1, op2, op3, data_mode);
   else
diff --git a/gcc/testsuite/gcc.dg/pr118288.c b/gcc/testsuite/gcc.dg/pr118288.c
new file mode 100644
index 00000000000..8cc981d065d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr118288.c
@@ -0,0 +1,8 @@
+/* PR middle-end 118288 */
+/* { dg-do compile }  */
+/* { dg-options "-O2" } */
+
+signed char crc8_data8 ()
+{
+  return __builtin_crc8_data8 ('a', 0xff, 0x12);
+}