First version of mark-compact GC, runtime.c is severely outdated at the moment

runtime/runtime_common.h

@@ -0,0 +1,67 @@
+#ifndef __LAMA_RUNTIME_COMMON__
+#define __LAMA_RUNTIME_COMMON__
+
+#define DEBUG_VERSION
+
+# define STRING_TAG  0x00000001
+//# define STRING_TAG  0x00000000
+# define ARRAY_TAG   0x00000003
+//# define ARRAY_TAG   0x00000002
+# define SEXP_TAG    0x00000005
+//# define SEXP_TAG    0x00000004
+# define CLOSURE_TAG 0x00000007
+//# define CLOSURE_TAG 0x00000006
+# define UNBOXED_TAG 0x00000009 // Not actually a data_header; used to return from LkindOf
+
+# define LEN(x) ((x & 0xFFFFFFF8) >> 3)
+# define TAG(x)  (x & 0x00000007)
+//# define TAG(x)  (x & 0x00000006)
+
+
+# define SEXP_ONLY_HEADER_SZ (2 * sizeof(int))
+# ifndef DEBUG_VERSION
+# define DATA_HEADER_SZ (sizeof(size_t) + sizeof(int))
+# else
+# define DATA_HEADER_SZ (sizeof(size_t) + sizeof(size_t) + sizeof(int))
+#endif
+# define MEMBER_SIZE sizeof(int)
+
+# define TO_DATA(x) ((data*)((char*)(x)-DATA_HEADER_SZ))
+# define TO_SEXP(x) ((sexp*)((char*)(x)-DATA_HEADER_SZ-SEXP_ONLY_HEADER_SZ))
+
+# define UNBOXED(x)  (((int) (x)) &  0x0001)
+# define UNBOX(x)    (((int) (x)) >> 1)
+# define BOX(x)      ((((int) (x)) << 1) | 0x0001)
+
+# define BYTES_TO_WORDS(bytes) (((bytes) - 1) / sizeof(size_t) + 1)
+# define WORDS_TO_BYTES(words) ((words) * sizeof(size_t))
+
+// CAREFUL WITH DOUBLE EVALUATION!
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+
+typedef struct {
+    // store tag in the last three bits to understand what structure this is, other bits are filled with
+    // other utility info (i.e., size for array, number of fields for s-expression)
+    int data_header;
+
+#ifdef DEBUG_VERSION
+    size_t id;
+#endif
+
+    // last bit is used as MARK-BIT, the rest are used to store address where object should move
+    // last bit can be used because due to alignment we can assume that last two bits are always 0's
+    size_t forward_address;
+    char contents[0];
+} data;
+
+typedef struct {
+    // duplicates contents.data_header in order to be able to understand if it is s-exp during iteration over heap
+    int sexp_header;
+    // stores hashed s-expression constructor name
+    int tag;
+    data contents;
+} sexp;
+
+#endif