RAM saving in the Lua interpreter

radio/src/lua/src/linit.c

@@ -29,7 +29,7 @@ static const luaL_Reg loadedlibs[] = {
   {"_G", luaopen_base},
   // {LUA_LOADLIBNAME, luaopen_package},
   // {LUA_COLIBNAME, luaopen_coroutine},
-  {LUA_TABLIBNAME, luaopen_table},
+  // {LUA_TABLIBNAME, luaopen_table},
   // {LUA_IOLIBNAME, luaopen_io},
   // {LUA_OSLIBNAME, luaopen_os},
   // {LUA_STRLIBNAME, luaopen_string},

radio/src/lua/src/lmem.c

@@ -40,7 +40,7 @@
 
 
 
-#define MINSIZEARRAY	4
+#define MINSIZEARRAY	2
 
 void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
                      int limit, const char *what) {
@@ -80,6 +80,7 @@ void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
   if (nsize > realosize && g->gcrunning)
     luaC_fullgc(L, 1);  /* force a GC whenever possible */
 #endif
+  // TRACE("ALLOC %d %d", (int)osize, (int)nsize);
   newblock = (*g->frealloc)(g->ud, block, osize, nsize);
   if (newblock == NULL && nsize > 0) {
     api_check(L, nsize > realosize,

radio/src/lua/src/lobject.h

@@ -8,6 +8,9 @@
 #ifndef lobject_h
 #define lobject_h
 
+#ifndef PACK
+#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#endif
 
 #include <stdarg.h>
 
@@ -101,9 +104,9 @@ typedef union Value Value;
 ** an actual value plus a tag with its type.
 */
 
-#define TValuefields	Value value_; int tt_
+#define TValuefields	Value value_; int8_t tt_
 
-typedef struct lua_TValue TValue;
+#define TValue lua_TValue
 
 
 /* macro defining a nil value */
@@ -394,9 +397,9 @@ union Value {
 };
 
 
-struct lua_TValue {
+PACK(typedef struct {
   TValuefields;
-};
+}) lua_TValue;
 
 
 typedef TValue *StkId;  /* index to stack elements */
@@ -543,10 +546,10 @@ typedef union Closure {
 */
 
 typedef union TKey {
-  struct {
+  PACK(struct {
     TValuefields;
     struct Node *next;  /* for chaining */
-  } nk;
+  }) nk;
   TValue tvk;
 } TKey;
 
@@ -560,7 +563,7 @@ typedef struct Node {
 typedef struct Table {
   CommonHeader;
   lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
-  lu_byte lsizenode;  /* log2 of size of `node' array */
+  lu_byte lsizenode;  /* size of `node' array */
   struct Table *metatable;
   TValue *array;  /* array part */
   Node *node;
@@ -579,7 +582,7 @@ typedef struct Table {
 
 
 #define twoto(x)	(1<<(x))
-#define sizenode(t)	(twoto((t)->lsizenode))
+#define sizenode(t)	((t)->lsizenode)
 
 
 /*

radio/src/lua/src/ltable.c

@@ -282,14 +282,16 @@ static void setnodevector (lua_State *L, Table *t, int size) {
   int lsize;
   if (size == 0) {  /* no elements to hash part? */
     t->node = cast(Node *, dummynode);  /* use common `dummynode' */
-    lsize = 0;
+    lsize = 1;
   }
   else {
     int i;
-    lsize = luaO_ceillog2(size);
-    if (lsize > MAXBITS)
-      luaG_runerror(L, "table overflow");
-    size = twoto(lsize);
+    // lsize = luaO_ceillog2(size);
+    // if (lsize > MAXBITS)
+    //  luaG_runerror(L, "table overflow");
+    // size = twoto(lsize);
+    // size += size/2;
+    lsize = size;
     t->node = luaM_newvector(L, size, Node);
     for (i=0; i<size; i++) {
       Node *n = gnode(t, i);
@@ -322,7 +324,7 @@ void luaH_resize (lua_State *L, Table *t, int nasize, int nhsize) {
     luaM_reallocvector(L, t->array, oldasize, nasize, TValue);
   }
   /* re-insert elements from hash part */
-  for (i = twoto(oldhsize) - 1; i >= 0; i--) {
+  for (i = oldhsize - 1; i >= 0; i--) {
     Node *old = nold+i;
     if (!ttisnil(gval(old))) {
       /* doesn't need barrier/invalidate cache, as entry was
@@ -331,7 +333,7 @@ void luaH_resize (lua_State *L, Table *t, int nasize, int nhsize) {
     }
   }
   if (!isdummy(nold))
-    luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old array */
+    luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old array */
 }