1 files changed, 32 insertions, 0 deletions
diff --git a/c/bit_compose.c b/c/bit_compose.c
new file mode 100644
index 0000000..bd250db
--- /dev/null
+++ b/c/bit_compose.c
@@ -0,0 +1,32 @@
+#include <stdint.h>
+#include <stdio.h>
+
+typedef union __attribute__ ((__packed__))
+{
+    struct __attribute__ ((__packed__))
+    {
+        unsigned int table_id      : 11;
+        unsigned int int_table_id  : 11;
+        unsigned int entry_id      : 12;
+        unsigned int generation    : 30;
+    };
+    uintptr_t i;
+} BITS;
+
+uintptr_t compose(uintptr_t a, uintptr_t b, uintptr_t c, uintptr_t d)
+{
+    BITS i;
+    i.table_id = a;
+    i.int_table_id = b;
+    i.entry_id = c;
+    i.generation = d;
+    return i.i;
+}
+
+int main(int argc, char **argv, char **env)
+{
+    uintptr_t t = compose(666,777,888,999);
+    printf("%d %d %d %d -> 0x%lu\n", 666, 777, 888, 999, t);
+
+    return 0;
+}