PR rtl-optimization/63843

	* simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For
	optimization of ashiftrt of subreg of lshiftrt, check that code
	is ASHIFTRT.

	* gcc.c-torture/execute/pr63843.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217753 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 31 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr63843.c b/gcc/testsuite/gcc.c-torture/execute/pr63843.c
new file mode 100644
index 00000000000..9f6c7b06c39
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr63843.c
@@ -0,0 +1,31 @@
+/* PR rtl-optimization/63843 */
+
+static inline __attribute__ ((always_inline))
+unsigned short foo (unsigned short v)
+{
+  return (v << 8) | (v >> 8);
+}
+
+unsigned short __attribute__ ((noinline, noclone, hot))
+bar (unsigned char *x)
+{
+  unsigned int a;
+  unsigned short b;
+  __builtin_memcpy (&a, &x[0], sizeof (a));
+  a ^= 0x80808080U;
+  __builtin_memcpy (&x[0], &a, sizeof (a));
+  __builtin_memcpy (&b, &x[2], sizeof (b));
+  return foo (b);
+}
+
+int
+main ()
+{
+  unsigned char x[8] = { 0x01, 0x01, 0x01, 0x01 };
+  if (__CHAR_BIT__ == 8
+      && sizeof (short) == 2
+      && sizeof (int) == 4
+      && bar (x) != 0x8181U)
+    __builtin_abort ();
+  return 0;
+}