better way to cope with opcode variants

1 files changed, 60 insertions, 120 deletions

diff --git a/lua.stx b/lua.stx
index 51159737..c7d90e20 100644
--- a/lua.stx
+++ b/lua.stx
@@ -1,6 +1,6 @@
 %{
 /*
-** $Id: lua.stx,v 1.2 1997/09/19 18:40:32 roberto Exp roberto $
+** $Id: lua.stx,v 1.3 1997/09/19 21:17:52 roberto Exp roberto $
 ** Syntax analizer and code generator
 ** See Copyright Notice in lua.h
 */
@@ -94,6 +94,22 @@ static void code_byte (Byte c)
 }
 
 
+static void code_word_at (int pc, int n)
+{
+  Word w = n;
+  if (w != n)
+    luaY_error("block too big");
+  currState->f->code[pc] = n&0xFF;
+  currState->f->code[pc+1] = n>>8;
+}
+
+static void code_word (int n)
+{
+  code_byte(n&0xFF);
+  code_byte(n>>8);
+}
+
+
 static void deltastack (int delta)
 {
   currState->stacksize += delta;
@@ -112,9 +128,25 @@ static void code_opcode (OpCode op, int delta)
 }
 
 
-static void code_push (OpCode op)
+static void code_opborw(OpCode opbyte, int arg, int delta)
 {
-  code_opcode(op, 1);
+  if (arg <= 255) {
+    code_opcode(opbyte, delta);
+    code_byte(arg);
+  }
+  else {
+    code_opcode(opbyte+1, delta);
+    code_word(arg);
+  }
+}
+
+
+static void code_oparg (OpCode firstop, OpCode opbyte, int arg, int delta)
+{
+  if (firstop+arg < opbyte)
+     code_opcode(firstop+arg, delta);
+  else
+    code_opborw(opbyte, arg, delta);
 }
 
 
@@ -133,31 +165,9 @@ static void code_pop (OpCode op)
 #define code_unop(op)   code_neutralop(op)
 
 
-static void code_word_at (int pc, int n)
-{
-  Word w = n;
-  if (w != n)
-    luaY_error("block too big");
-  currState->f->code[pc] = n&0xFF;
-  currState->f->code[pc+1] = n>>8;
-}
-
-static void code_word (int n)
-{
-  code_byte(n&0xFF);
-  code_byte(n>>8);
-}
-
 static void code_constant (int c)
 {
-  if (c <= 255) {
-    code_push(PUSHCONSTANTB);
-    code_byte(c);
-  }
-  else {
-    code_push(PUSHCONSTANT);
-    code_word(c);
-  }
+  code_opborw(PUSHCONSTANTB, c, 1);
 }
 
 
@@ -216,18 +226,8 @@ static int real_constant (real r)
 static void code_number (real f)
 {
   Word i;
-  if (f >= 0 && f <= (real)MAX_WORD && (real)(i=(Word)f) == f) {
-    /* f has an (short) integer value */
-    if (i <= 2) code_push(PUSH0 + i);
-    else if (i <= 255) {
-      code_push(PUSHBYTE);
-      code_byte(i);
-    }
-    else {
-      code_push(PUSHWORD);
-      code_word(i);
-    }
-  }
+  if (f >= 0 && f <= (real)MAX_WORD && (real)(i=(Word)f) == f)
+    code_oparg(PUSH0, PUSHBYTE, i, 1);  /* f has an (short) integer value */
   else
     code_constant(real_constant(f));
 }
@@ -344,12 +344,7 @@ static void pushupvalue (TaggedString *n)
   if (aux_localname(n, currState) >= 0)
     luaY_syntaxerror("cannot access an upvalue in current scope", n->str);
   i = indexupvalue(n);
-  if (i == 0)
-    code_push(PUSHUPVALUE0);
-  else {
-    code_push(PUSHUPVALUE);
-    code_byte(i);
-  }
+  code_oparg(PUSHUPVALUE0, PUSHUPVALUE, i, 1);
 }
 
 
@@ -366,18 +361,10 @@ void luaY_codedebugline (int line)
 
 static void adjuststack (int n)
 {
-  if (n > 0) {
-    code_opcode(POPS, -n);
-    code_byte(n);
-  }
-  else if (n < 0) {
-    if (n == -1)
-      code_push(PUSHNIL);
-    else {
-      code_opcode(PUSHNILS, -n);
-      code_byte(-n);
-    }
-  }
+  if (n > 0)
+    code_oparg(POP1-1, POPS, n, -n);  /* POP1-1 = POP0 */
+  else if (n < 0)
+    code_oparg(PUSHNIL-1, PUSHNILS, -n, -n);  /* PUSHNIL1-1 = PUSHNIL0 */
 }
 
 
@@ -426,29 +413,12 @@ static void code_args (int dots)
 
 static void lua_pushvar (vardesc number)
 {
-  if (number > 0) {  /* global var */
-    number--;
-    if (number <= 255) {
-      code_push(PUSHGLOBALB);
-      code_byte(number);
-    }
-    else {
-      code_push(PUSHGLOBAL);
-      code_word(number);
-    }
-  }
-  else if (number < 0) {  /* local var */
-    number = (-number) - 1;
-    if (number < 10)
-      code_push(PUSHLOCAL0 + number);
-    else {
-      code_push(PUSHLOCAL);
-      code_byte(number);
-    }
-  }
-  else {
+  if (number > 0)  /* global var */
+    code_opborw(GETGLOBALB, number-1, 1);
+  else if (number < 0)  /* local var */
+    code_oparg(PUSHLOCAL0, PUSHLOCAL, (-number)-1, 1);
+  else
     code_pop(GETTABLE);
-  }
 }
 
 
@@ -456,26 +426,10 @@ static void storevar (vardesc number)
 {
   if (number == 0)  /* indexed var */
     code_opcode(SETTABLE0, -3);
-  else if (number > 0) {  /* global var */
-    number--;
-    if (number <= 255) {
-      code_pop(SETGLOBALB);
-      code_byte(number);
-    }
-    else {
-      code_pop(SETGLOBAL);
-      code_word(number);
-    }
-  }
-  else {  /* number < 0 - local var */
-    number = (-number) - 1;
-    if (number < 10)
-      code_pop(SETLOCAL0 + number);
-    else {
-      code_pop(SETLOCAL);
-      code_byte(number);
-    }
-  }
+  else if (number > 0)  /* global var */
+    code_opborw(SETGLOBALB, number-1, -1);
+  else  /* number < 0 - local var */
+    code_oparg(SETLOCAL0, SETLOCAL, (-number)-1, -1);
 }
 
 
@@ -535,8 +489,7 @@ static void func_onstack (TProtoFunc *f)
   currState->f->consts[c].value.tf = (currState+1)->f;
   for (i=0; i<nupvalues; i++)
     lua_pushvar((currState+1)->upvalues[i]);
-  code_constant(c);
-  code_opcode(CLOSURE, -nupvalues);
+  code_opborw(CLOSUREB, c, 1-nupvalues);
 }
 
 
@@ -771,7 +724,7 @@ expr :  '(' expr ')'     { $$ = $2; }
      |  varexp           { $$ = 0;}
      |  NUMBER           { code_number($1); $$ = 0; }
      |  STRING           { code_string($1); $$ = 0; }
-     |  NIL              {code_push(PUSHNIL); $$ = 0; }
+     |  NIL              {code_opcode(PUSHNIL, 1); $$ = 0; }
      |  functioncall     { $$ = $1; }
      |  expr1 AND PrepJumpPop expr1 { code_shortcircuit($3, ONFJMP); $$ = 0; }
      |  expr1 OR PrepJumpPop expr1  { code_shortcircuit($3, ONTJMP); $$ = 0; }
@@ -779,14 +732,9 @@ expr :  '(' expr ')'     { $$ = $2; }
      ;
 
 table :
-     {
-      code_push(CREATEARRAY);
-      $<vInt>$ = currState->pc; code_word(0);
-     }
-      '{' fieldlist '}'
-     {
-      code_word_at($<vInt>1, $3);
-     }
+     { code_opcode(CREATEARRAY, 1); $<vInt>$ = currState->pc; code_word(0); }
+       '{' fieldlist '}'
+     { code_word_at($<vInt>1, $3); }
          ;
 
 functioncall : funcvalue funcParams
@@ -801,8 +749,7 @@ functioncall : funcvalue funcParams
 funcvalue    : varexp { $$ = 0; }
              | varexp ':' NAME
              {
-               code_push(PUSHSELF);
-               code_word(string_constant($3, currState));
+               code_opborw(PUSHSELFB, string_constant($3, currState), 1);
                $$ = 1;
              }
              ;
@@ -909,15 +856,8 @@ varlist1  :	var
           ;
                 
 var       :     singlevar { $$ = $1; }
-          |     varexp '[' expr1 ']'
-          {
-           $$ = 0;              /* indexed variable */
-          }
-          |     varexp '.' NAME
-          {
-            code_string($3);
-            $$ = 0;             /* indexed variable */
-          }
+          |     varexp '[' expr1 ']' { $$ = 0; }  /* indexed variable */
+          |     varexp '.' NAME { code_string($3); $$ = 0; }/* ind. var. */
           ;
                 
 singlevar :     NAME { $$ = singlevar($1, currState); }