some simplifications

lcode.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 1.94 2002/04/02 20:34:53 roberto Exp roberto $
+** $Id: lcode.c,v 1.95 2002/04/09 18:49:30 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -293,33 +293,6 @@ static int code_label (FuncState *fs, int A, int b, int jump) {
 }
 
 
-static void dischargejumps (FuncState *fs, expdesc *e, int reg) {
-  if (e->k == VJMP || hasjumps(e)) {
-    int final;  /* position after whole expression */
-    int p_f = NO_JUMP;  /* position of an eventual PUSH false */
-    int p_t = NO_JUMP;  /* position of an eventual PUSH true */
-    if (e->k == VJMP || need_value(fs, e->f, OP_TESTF) ||
-                        need_value(fs, e->t, OP_TESTT)) {
-      /* expression needs values */
-      if (e->k != VJMP) {
-        luaK_getlabel(fs);  /* these instruction may be jump target */
-        luaK_codeAsBc(fs, OP_JMP, 0, 2);  /* to jump over both pushes */
-      }
-      else {  /* last expression is a conditional (test + jump) */
-        fs->pc--;  /* remove its jump */
-        lua_assert(testOpMode(GET_OPCODE(fs->f->code[fs->pc - 1]), OpModeT));
-      }
-      p_t = code_label(fs, reg, 1, 1);
-      p_f = code_label(fs, reg, 0, 0);
-    }
-    final = luaK_getlabel(fs);
-    luaK_patchlistaux(fs, e->f, p_f, NO_REG, final, reg, p_f);
-    luaK_patchlistaux(fs, e->t, final, reg, p_t, NO_REG, p_t);
-  }
-  e->f = e->t = NO_JUMP;
-}
-
-
 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
   luaK_dischargevars(fs, e);
   switch (e->k) {
@@ -340,7 +313,15 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
       SETARG_A(*pc, reg);
       break;
     }
-    default: return;
+    case VNONRELOC: {
+      if (reg != e->info)
+        luaK_codeABC(fs, OP_MOVE, reg, e->info, 0);
+      break;
+    }
+    default: {
+      lua_assert(e->k == VVOID || e->k == VJMP);
+      return;  /* nothing to do... */
+    }
   }
   e->info = reg;
   e->k = VNONRELOC;
@@ -357,36 +338,39 @@ static void discharge2anyreg (FuncState *fs, expdesc *e) {
 
 static void luaK_exp2reg (FuncState *fs, expdesc *e, int reg) {
   discharge2reg(fs, e, reg);
-  switch (e->k) {
-    case VVOID: {
-      return;  /* nothing to do... */
-    }
-    case VNONRELOC: {
-      if (reg != e->info)
-        luaK_codeABC(fs, OP_MOVE, reg, e->info, 0);
-      break;
-    }
-    case VJMP: {
-      break;
-    }
-    default: {
-      lua_assert(0);  /* cannot happen */
-      break;
+  if (e->k == VJMP || hasjumps(e)) {
+    int final;  /* position after whole expression */
+    int p_f = NO_JUMP;  /* position of an eventual PUSH false */
+    int p_t = NO_JUMP;  /* position of an eventual PUSH true */
+    if (e->k == VJMP || need_value(fs, e->f, OP_TESTF) ||
+                        need_value(fs, e->t, OP_TESTT)) {
+      /* expression needs values */
+      if (e->k != VJMP) {
+        luaK_getlabel(fs);  /* these instruction may be jump target */
+        luaK_codeAsBc(fs, OP_JMP, 0, 2);  /* to jump over both pushes */
+      }
+      else {  /* last expression is a conditional (test + jump) */
+        fs->pc--;  /* remove its jump */
+        lua_assert(testOpMode(GET_OPCODE(fs->f->code[fs->pc - 1]), OpModeT));
+      }
+      p_t = code_label(fs, reg, 1, 1);
+      p_f = code_label(fs, reg, 0, 0);
     }
+    final = luaK_getlabel(fs);
+    luaK_patchlistaux(fs, e->f, p_f, NO_REG, final, reg, p_f);
+    luaK_patchlistaux(fs, e->t, final, reg, p_t, NO_REG, p_t);
   }
-  dischargejumps(fs, e, reg);
+  e->f = e->t = NO_JUMP;
   e->info = reg;
   e->k = VNONRELOC;
 }
 
 
 void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
-  int reg;
   luaK_dischargevars(fs, e);
   freeexp(fs, e);
-  reg = fs->freereg;
   luaK_reserveregs(fs, 1);
-  luaK_exp2reg(fs, e, reg);
+  luaK_exp2reg(fs, e, fs->freereg - 1);
 }
 
 
@@ -395,7 +379,7 @@ int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
   if (e->k == VNONRELOC) {
     if (!hasjumps(e)) return e->info;  /* exp is already in a register */ 
     if (e->info >= fs->nactloc) {  /* reg. is not a local? */
-      dischargejumps(fs, e, e->info);  /* put value on it */
+      luaK_exp2reg(fs, e, e->info);  /* put value on it */
       return e->info;
     }
   }
@@ -440,23 +424,20 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *exp) {
     case VLOCAL: {
       freeexp(fs, exp);
       luaK_exp2reg(fs, exp, var->info);
-      break;
+      return;
     }
     case VUPVAL: {
       int e = luaK_exp2anyreg(fs, exp);
-      freereg(fs, e);
       luaK_codeABC(fs, OP_SETUPVAL, e, var->info, 0);
       break;
     }
     case VGLOBAL: {
       int e = luaK_exp2anyreg(fs, exp);
-      freereg(fs, e);
       luaK_codeABc(fs, OP_SETGLOBAL, e, var->info);
       break;
     }
     case VINDEXED: {
       int e = luaK_exp2anyreg(fs, exp);
-      freereg(fs, e);
       luaK_codeABC(fs, OP_SETTABLE, e, var->info, var->aux);
       break;
     }
@@ -465,6 +446,7 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *exp) {
       break;
     }
   }
+  freeexp(fs, exp);
 }