1 files changed, 51 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.target/avr/pr46779-1.c b/gcc/testsuite/gcc.target/avr/pr46779-1.c
new file mode 100644
index 00000000000..24522f175be
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/pr46779-1.c
@@ -0,0 +1,51 @@
+/* { dg-do run } */
+/* { dg-options "-Os -fsplit-wide-types" } */
+
+/* This testcase should uncover bugs like
+   PR46779
+   PR45291
+   PR41894
+
+   The inline asm just serves to direct y into the Y register.
+   Otherwise, it is hard to write a "stable" test case that
+   also fails with slight variations in source code, middle- resp.
+   backend.
+
+   The problem is that Y is also the frame-pointer, and
+   avr.c:avr_hard_regno_mode_ok disallows QI to get in Y-reg.
+   However, the y.a = 0 generates a
+       (set (subreg:QI (reg:HI pseudo)) ...)
+   where pseudo gets allocated to Y.
+
+   Reload fails to generate the right spill.
+*/
+
+#include <stdlib.h>
+
+struct S
+{
+    unsigned char a, b;
+} ab = {12, 34};
+
+void yoo (struct S y)
+{
+    __asm volatile ("ldi %B0, 56" : "+y" (y));
+    y.a = 0;
+    __asm volatile ("; y = %0" : "+y" (y));
+    ab = y;
+}
+
+int main ()
+{
+    yoo (ab);
+
+    if (ab.a != 0)
+        abort();
+
+    if (ab.b != 56)
+        abort();
+
+    exit (0);
+    
+    return 0;
+}