1 files changed, 33 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/crc-6.c b/gcc/testsuite/gcc.dg/crc-6.c
new file mode 100644
index 0000000..7fa60b2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/crc-6.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-crc" } */
+
+#include <stdint.h>
+
+typedef uint8_t crc;
+#define WIDTH (8 * sizeof(crc))
+#define TOPBIT (1 << (WIDTH - 1))
+
+crc
+crcSlow(uint8_t const message[], int nBytes) {
+    crc remainder = 0;
+/*
+* Perform modulo-2 division, a byte at a time.
+*/
+    for (int byte = 0; byte < nBytes; ++byte) {
+        remainder ^= (message[byte] << (WIDTH - 8));
+        for (uint8_t bit = 8; bit > 0; --bit) {
+            if (remainder & TOPBIT) {
+                remainder = (remainder << 1) ^ 1234;
+            } else {
+                remainder = (remainder << 1);
+            }
+        }
+    }
+    return (remainder);
+}
+
+/* { dg-final { scan-tree-dump "Attention! crcSlow function calculates CRC." "crc"} } */
+/* { dg-final { scan-tree-dump "Return size is 8" "crc"} } */
+/* { dg-final { scan-tree-dump "Loop iteration number is 7" "crc"} } */
+/* { dg-final { scan-tree-dump "Bit forward" "crc"} } */
+