openwrt/package/lua/patches/300-opcode_performance.patch

--- a/src/lvm.c
+++ b/src/lvm.c
@@ -31,6 +31,9 @@
 /* limit for table tag-method chains (to avoid loops) */
 #define MAXTAGLOOP	100
 
+#ifdef __GNUC__
+#define COMPUTED_GOTO 1
+#endif
 
 /*
  * If 'obj' is a string, it is tried to be interpreted as a number.
@@ -562,12 +565,63 @@ static inline int arith_mode( const TVal
     ARITH_OP1_END
 #endif
 
+#ifdef COMPUTED_GOTO
+#define OPCODE_TARGET(op) DO_OP_##op:
+#define CALL_OPCODE(op) goto *opcodes[op];
+#define OPCODE_PTR(op) [OP_##op] = &&DO_OP_##op
+#else
+#define OPCODE_TARGET(op) case OP_##op:
+#define CALL_OPCODE(op) switch (op)
+#endif
+
 
 void luaV_execute (lua_State *L, int nexeccalls) {
   LClosure *cl;
   StkId base;
   TValue *k;
   const Instruction *pc;
+#ifdef COMPUTED_GOTO
+  static const void *opcodes[] = {
+   OPCODE_PTR(MOVE),
+   OPCODE_PTR(LOADK),
+   OPCODE_PTR(LOADBOOL),
+   OPCODE_PTR(LOADNIL),
+   OPCODE_PTR(GETUPVAL),
+   OPCODE_PTR(GETGLOBAL),
+   OPCODE_PTR(GETTABLE),
+   OPCODE_PTR(SETGLOBAL),
+   OPCODE_PTR(SETUPVAL),
+   OPCODE_PTR(SETTABLE),
+   OPCODE_PTR(NEWTABLE),
+   OPCODE_PTR(SELF),
+   OPCODE_PTR(ADD),
+   OPCODE_PTR(SUB),
+   OPCODE_PTR(MUL),
+   OPCODE_PTR(DIV),
+   OPCODE_PTR(MOD),
+   OPCODE_PTR(POW),
+   OPCODE_PTR(UNM),
+   OPCODE_PTR(NOT),
+   OPCODE_PTR(LEN),
+   OPCODE_PTR(CONCAT),
+   OPCODE_PTR(JMP),
+   OPCODE_PTR(EQ),
+   OPCODE_PTR(LT),
+   OPCODE_PTR(LE),
+   OPCODE_PTR(TEST),
+   OPCODE_PTR(TESTSET),
+   OPCODE_PTR(CALL),
+   OPCODE_PTR(TAILCALL),
+   OPCODE_PTR(RETURN),
+   OPCODE_PTR(FORLOOP),
+   OPCODE_PTR(FORPREP),
+   OPCODE_PTR(TFORLOOP),
+   OPCODE_PTR(SETLIST),
+   OPCODE_PTR(CLOSE),
+   OPCODE_PTR(CLOSURE),
+   OPCODE_PTR(VARARG)
+  };
+#endif
  reentry:  /* entry point */
   lua_assert(isLua(L->ci));
   pc = L->savedpc;
@@ -592,33 +646,33 @@ void luaV_execute (lua_State *L, int nex
     lua_assert(base == L->base && L->base == L->ci->base);
     lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
     lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
-    switch (GET_OPCODE(i)) {
-      case OP_MOVE: {
+    CALL_OPCODE(GET_OPCODE(i)) {
+      OPCODE_TARGET(MOVE) {
         setobjs2s(L, ra, RB(i));
         continue;
       }
-      case OP_LOADK: {
+      OPCODE_TARGET(LOADK) {
         setobj2s(L, ra, KBx(i));
         continue;
       }
-      case OP_LOADBOOL: {
+      OPCODE_TARGET(LOADBOOL) {
         setbvalue(ra, GETARG_B(i));
         if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
         continue;
       }
-      case OP_LOADNIL: {
+      OPCODE_TARGET(LOADNIL) {
         TValue *rb = RB(i);
         do {
           setnilvalue(rb--);
         } while (rb >= ra);
         continue;
       }
-      case OP_GETUPVAL: {
+      OPCODE_TARGET(GETUPVAL) {
         int b = GETARG_B(i);
         setobj2s(L, ra, cl->upvals[b]->v);
         continue;
       }
-      case OP_GETGLOBAL: {
+      OPCODE_TARGET(GETGLOBAL) {
         TValue g;
         TValue *rb = KBx(i);
         sethvalue(L, &g, cl->env);
@@ -626,88 +680,88 @@ void luaV_execute (lua_State *L, int nex
         Protect(luaV_gettable(L, &g, rb, ra));
         continue;
       }
-      case OP_GETTABLE: {
+      OPCODE_TARGET(GETTABLE) {
         Protect(luaV_gettable(L, RB(i), RKC(i), ra));
         continue;
       }
-      case OP_SETGLOBAL: {
+      OPCODE_TARGET(SETGLOBAL) {
         TValue g;
         sethvalue(L, &g, cl->env);
         lua_assert(ttisstring(KBx(i)));
         Protect(luaV_settable(L, &g, KBx(i), ra));
         continue;
       }
-      case OP_SETUPVAL: {
+      OPCODE_TARGET(SETUPVAL) {
         UpVal *uv = cl->upvals[GETARG_B(i)];
         setobj(L, uv->v, ra);
         luaC_barrier(L, uv, ra);
         continue;
       }
-      case OP_SETTABLE: {
+      OPCODE_TARGET(SETTABLE) {
         Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
         continue;
       }
-      case OP_NEWTABLE: {
+      OPCODE_TARGET(NEWTABLE) {
         int b = GETARG_B(i);
         int c = GETARG_C(i);
         sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
         Protect(luaC_checkGC(L));
         continue;
       }
-      case OP_SELF: {
+      OPCODE_TARGET(SELF) {
         StkId rb = RB(i);
         setobjs2s(L, ra+1, rb);
         Protect(luaV_gettable(L, rb, RKC(i), ra));
         continue;
       }
-      case OP_ADD: {
+      OPCODE_TARGET(ADD) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue( luai_numadd, try_addint, luai_vectadd );
         Protect(Arith(L, ra, rb, rc, TM_ADD)); \
         continue;
       }
-      case OP_SUB: {
+      OPCODE_TARGET(SUB) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue( luai_numsub, try_subint, luai_vectsub );
         Protect(Arith(L, ra, rb, rc, TM_SUB));
         continue;
       }
-      case OP_MUL: {
+      OPCODE_TARGET(MUL) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue(luai_nummul, try_mulint, luai_vectmul);
         Protect(Arith(L, ra, rb, rc, TM_MUL));
         continue;
       }
-      case OP_DIV: {
+      OPCODE_TARGET(DIV) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue(luai_numdiv, try_divint, luai_vectdiv);
         Protect(Arith(L, ra, rb, rc, TM_DIV));
         continue;
       }
-      case OP_MOD: {
+      OPCODE_TARGET(MOD) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue_scalar(luai_nummod, try_modint);  /* scalars only */
         Protect(Arith(L, ra, rb, rc, TM_MOD));
         continue;
       }
-      case OP_POW: {
+      OPCODE_TARGET(POW) {
         TValue *rb = RKB(i), *rc= RKC(i);
         arith_op_continue(luai_numpow, try_powint, luai_vectpow);
         Protect(Arith(L, ra, rb, rc, TM_POW));
         continue;
       }
-      case OP_UNM: {
+      OPCODE_TARGET(UNM) {
         TValue *rb = RB(i);
         arith_op1_continue(luai_numunm, try_unmint, luai_vectunm);
         Protect(Arith(L, ra, rb, rb, TM_UNM));
         continue;
       }
-      case OP_NOT: {
+      OPCODE_TARGET(NOT) {
         int res = l_isfalse(RB(i));  /* next assignment may change this value */
         setbvalue(ra, res);
         continue;
       }
-      case OP_LEN: {
+      OPCODE_TARGET(LEN) {
         const TValue *rb = RB(i);
         switch (ttype(rb)) {
           case LUA_TTABLE: {
@@ -727,18 +781,18 @@ void luaV_execute (lua_State *L, int nex
         }
         continue;
       }
-      case OP_CONCAT: {
+      OPCODE_TARGET(CONCAT) {
         int b = GETARG_B(i);
         int c = GETARG_C(i);
         Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
         setobjs2s(L, RA(i), base+b);
         continue;
       }
-      case OP_JMP: {
+      OPCODE_TARGET(JMP) {
         dojump(L, pc, GETARG_sBx(i));
         continue;
       }
-      case OP_EQ: {
+      OPCODE_TARGET(EQ) {
         TValue *rb = RKB(i);
         TValue *rc = RKC(i);
         Protect(
@@ -748,7 +802,7 @@ void luaV_execute (lua_State *L, int nex
         pc++;
         continue;
       }
-      case OP_LT: {
+      OPCODE_TARGET(LT) {
         Protect(
           if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
             dojump(L, pc, GETARG_sBx(*pc));
@@ -756,7 +810,7 @@ void luaV_execute (lua_State *L, int nex
         pc++;
         continue;
       }
-      case OP_LE: {
+      OPCODE_TARGET(LE) {
         Protect(
           if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
             dojump(L, pc, GETARG_sBx(*pc));
@@ -764,13 +818,13 @@ void luaV_execute (lua_State *L, int nex
         pc++;
         continue;
       }
-      case OP_TEST: {
+      OPCODE_TARGET(TEST) {
         if (l_isfalse(ra) != GETARG_C(i))
           dojump(L, pc, GETARG_sBx(*pc));
         pc++;
         continue;
       }
-      case OP_TESTSET: {
+      OPCODE_TARGET(TESTSET) {
         TValue *rb = RB(i);
         if (l_isfalse(rb) != GETARG_C(i)) {
           setobjs2s(L, ra, rb);
@@ -779,7 +833,7 @@ void luaV_execute (lua_State *L, int nex
         pc++;
         continue;
       }
-      case OP_CALL: {
+      OPCODE_TARGET(CALL) {
         int b = GETARG_B(i);
         int nresults = GETARG_C(i) - 1;
         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
@@ -800,7 +854,7 @@ void luaV_execute (lua_State *L, int nex
           }
         }
       }
-      case OP_TAILCALL: {
+      OPCODE_TARGET(TAILCALL) {
         int b = GETARG_B(i);
         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
         L->savedpc = pc;
@@ -832,7 +886,7 @@ void luaV_execute (lua_State *L, int nex
           }
         }
       }
-      case OP_RETURN: {
+      OPCODE_TARGET(RETURN) {
         int b = GETARG_B(i);
         if (b != 0) L->top = ra+b-1;
         if (L->openupval) luaF_close(L, base);
@@ -847,7 +901,7 @@ void luaV_execute (lua_State *L, int nex
           goto reentry;
         }
       }
-      case OP_FORLOOP: {
+      OPCODE_TARGET(FORLOOP) {
         /* If start,step and limit are all integers, we don't need to check
          * against overflow in the looping.
          */
@@ -875,7 +929,7 @@ void luaV_execute (lua_State *L, int nex
         }
         continue;
       }
-      case OP_FORPREP: {
+      OPCODE_TARGET(FORPREP) {
         const TValue *init = ra;
         const TValue *plimit = ra+1;
         const TValue *pstep = ra+2;
@@ -898,7 +952,7 @@ void luaV_execute (lua_State *L, int nex
         dojump(L, pc, GETARG_sBx(i));
         continue;
       }
-      case OP_TFORLOOP: {
+      OPCODE_TARGET(TFORLOOP) {
         StkId cb = ra + 3;  /* call base */
         setobjs2s(L, cb+2, ra+2);
         setobjs2s(L, cb+1, ra+1);
@@ -914,7 +968,7 @@ void luaV_execute (lua_State *L, int nex
         pc++;
         continue;
       }
-      case OP_SETLIST: {
+      OPCODE_TARGET(SETLIST) {
         int n = GETARG_B(i);
         int c = GETARG_C(i);
         int last;
@@ -936,11 +990,11 @@ void luaV_execute (lua_State *L, int nex
         }
         continue;
       }
-      case OP_CLOSE: {
+      OPCODE_TARGET(CLOSE) {
         luaF_close(L, ra);
         continue;
       }
-      case OP_CLOSURE: {
+      OPCODE_TARGET(CLOSURE) {
         Proto *p;
         Closure *ncl;
         int nup, j;
@@ -960,7 +1014,7 @@ void luaV_execute (lua_State *L, int nex
         Protect(luaC_checkGC(L));
         continue;
       }
-      case OP_VARARG: {
+      OPCODE_TARGET(VARARG) {
         int b = GETARG_B(i) - 1;
         int j;
         CallInfo *ci = L->ci;