rlm@1: /*
rlm@1: ** $Id: lcode.c,v 2.25.1.3 2007/12/28 15:32:23 roberto Exp $
rlm@1: ** Code generator for Lua
rlm@1: ** See Copyright Notice in lua.h
rlm@1: */
rlm@1: 
rlm@1: 
rlm@1: #include <stdlib.h>
rlm@1: 
rlm@1: #define lcode_c
rlm@1: #define LUA_CORE
rlm@1: 
rlm@1: #include "lua.h"
rlm@1: 
rlm@1: #include "lcode.h"
rlm@1: #include "ldebug.h"
rlm@1: #include "ldo.h"
rlm@1: #include "lgc.h"
rlm@1: #include "llex.h"
rlm@1: #include "lmem.h"
rlm@1: #include "lobject.h"
rlm@1: #include "lopcodes.h"
rlm@1: #include "lparser.h"
rlm@1: #include "ltable.h"
rlm@1: 
rlm@1: 
rlm@1: #define hasjumps(e)	((e)->t != (e)->f)
rlm@1: 
rlm@1: 
rlm@1: static int isnumeral(expdesc *e) {
rlm@1:   return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_nil (FuncState *fs, int from, int n) {
rlm@1:   Instruction *previous;
rlm@1:   if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */
rlm@1:     if (fs->pc == 0) {  /* function start? */
rlm@1:       if (from >= fs->nactvar)
rlm@1:         return;  /* positions are already clean */
rlm@1:     }
rlm@1:     else {
rlm@1:       previous = &fs->f->code[fs->pc-1];
rlm@1:       if (GET_OPCODE(*previous) == OP_LOADNIL) {
rlm@1:         int pfrom = GETARG_A(*previous);
rlm@1:         int pto = GETARG_B(*previous);
rlm@1:         if (pfrom <= from && from <= pto+1) {  /* can connect both? */
rlm@1:           if (from+n-1 > pto)
rlm@1:             SETARG_B(*previous, from+n-1);
rlm@1:           return;
rlm@1:         }
rlm@1:       }
rlm@1:     }
rlm@1:   }
rlm@1:   luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0);  /* else no optimization */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_jump (FuncState *fs) {
rlm@1:   int jpc = fs->jpc;  /* save list of jumps to here */
rlm@1:   int j;
rlm@1:   fs->jpc = NO_JUMP;
rlm@1:   j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
rlm@1:   luaK_concat(fs, &j, jpc);  /* keep them on hold */
rlm@1:   return j;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_ret (FuncState *fs, int first, int nret) {
rlm@1:   luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
rlm@1:   luaK_codeABC(fs, op, A, B, C);
rlm@1:   return luaK_jump(fs);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void fixjump (FuncState *fs, int pc, int dest) {
rlm@1:   Instruction *jmp = &fs->f->code[pc];
rlm@1:   int offset = dest-(pc+1);
rlm@1:   lua_assert(dest != NO_JUMP);
rlm@1:   if (abs(offset) > MAXARG_sBx)
rlm@1:     luaX_syntaxerror(fs->ls, "control structure too long");
rlm@1:   SETARG_sBx(*jmp, offset);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** returns current `pc' and marks it as a jump target (to avoid wrong
rlm@1: ** optimizations with consecutive instructions not in the same basic block).
rlm@1: */
rlm@1: int luaK_getlabel (FuncState *fs) {
rlm@1:   fs->lasttarget = fs->pc;
rlm@1:   return fs->pc;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int getjump (FuncState *fs, int pc) {
rlm@1:   int offset = GETARG_sBx(fs->f->code[pc]);
rlm@1:   if (offset == NO_JUMP)  /* point to itself represents end of list */
rlm@1:     return NO_JUMP;  /* end of list */
rlm@1:   else
rlm@1:     return (pc+1)+offset;  /* turn offset into absolute position */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static Instruction *getjumpcontrol (FuncState *fs, int pc) {
rlm@1:   Instruction *pi = &fs->f->code[pc];
rlm@1:   if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
rlm@1:     return pi-1;
rlm@1:   else
rlm@1:     return pi;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** check whether list has any jump that do not produce a value
rlm@1: ** (or produce an inverted value)
rlm@1: */
rlm@1: static int need_value (FuncState *fs, int list) {
rlm@1:   for (; list != NO_JUMP; list = getjump(fs, list)) {
rlm@1:     Instruction i = *getjumpcontrol(fs, list);
rlm@1:     if (GET_OPCODE(i) != OP_TESTSET) return 1;
rlm@1:   }
rlm@1:   return 0;  /* not found */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int patchtestreg (FuncState *fs, int node, int reg) {
rlm@1:   Instruction *i = getjumpcontrol(fs, node);
rlm@1:   if (GET_OPCODE(*i) != OP_TESTSET)
rlm@1:     return 0;  /* cannot patch other instructions */
rlm@1:   if (reg != NO_REG && reg != GETARG_B(*i))
rlm@1:     SETARG_A(*i, reg);
rlm@1:   else  /* no register to put value or register already has the value */
rlm@1:     *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
rlm@1: 
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void removevalues (FuncState *fs, int list) {
rlm@1:   for (; list != NO_JUMP; list = getjump(fs, list))
rlm@1:       patchtestreg(fs, list, NO_REG);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
rlm@1:                           int dtarget) {
rlm@1:   while (list != NO_JUMP) {
rlm@1:     int next = getjump(fs, list);
rlm@1:     if (patchtestreg(fs, list, reg))
rlm@1:       fixjump(fs, list, vtarget);
rlm@1:     else
rlm@1:       fixjump(fs, list, dtarget);  /* jump to default target */
rlm@1:     list = next;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void dischargejpc (FuncState *fs) {
rlm@1:   patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
rlm@1:   fs->jpc = NO_JUMP;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_patchlist (FuncState *fs, int list, int target) {
rlm@1:   if (target == fs->pc)
rlm@1:     luaK_patchtohere(fs, list);
rlm@1:   else {
rlm@1:     lua_assert(target < fs->pc);
rlm@1:     patchlistaux(fs, list, target, NO_REG, target);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_patchtohere (FuncState *fs, int list) {
rlm@1:   luaK_getlabel(fs);
rlm@1:   luaK_concat(fs, &fs->jpc, list);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_concat (FuncState *fs, int *l1, int l2) {
rlm@1:   if (l2 == NO_JUMP) return;
rlm@1:   else if (*l1 == NO_JUMP)
rlm@1:     *l1 = l2;
rlm@1:   else {
rlm@1:     int list = *l1;
rlm@1:     int next;
rlm@1:     while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */
rlm@1:       list = next;
rlm@1:     fixjump(fs, list, l2);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_checkstack (FuncState *fs, int n) {
rlm@1:   int newstack = fs->freereg + n;
rlm@1:   if (newstack > fs->f->maxstacksize) {
rlm@1:     if (newstack >= MAXSTACK)
rlm@1:       luaX_syntaxerror(fs->ls, "function or expression too complex");
rlm@1:     fs->f->maxstacksize = cast_byte(newstack);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_reserveregs (FuncState *fs, int n) {
rlm@1:   luaK_checkstack(fs, n);
rlm@1:   fs->freereg += n;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void freereg (FuncState *fs, int reg) {
rlm@1:   if (!ISK(reg) && reg >= fs->nactvar) {
rlm@1:     fs->freereg--;
rlm@1:     lua_assert(reg == fs->freereg);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void freeexp (FuncState *fs, expdesc *e) {
rlm@1:   if (e->k == VNONRELOC)
rlm@1:     freereg(fs, e->u.s.info);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int addk (FuncState *fs, TValue *k, TValue *v) {
rlm@1:   lua_State *L = fs->L;
rlm@1:   TValue *idx = luaH_set(L, fs->h, k);
rlm@1:   Proto *f = fs->f;
rlm@1:   int oldsize = f->sizek;
rlm@1:   if (ttisnumber(idx)) {
rlm@1:     lua_assert(luaO_rawequalObj(&fs->f->k[cast_int(nvalue(idx))], v));
rlm@1:     return cast_int(nvalue(idx));
rlm@1:   }
rlm@1:   else {  /* constant not found; create a new entry */
rlm@1:     setnvalue(idx, cast_num(fs->nk));
rlm@1:     luaM_growvector(L, f->k, fs->nk, f->sizek, TValue,
rlm@1:                     MAXARG_Bx, "constant table overflow");
rlm@1:     while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
rlm@1:     setobj(L, &f->k[fs->nk], v);
rlm@1:     luaC_barrier(L, f, v);
rlm@1:     return fs->nk++;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_stringK (FuncState *fs, TString *s) {
rlm@1:   TValue o;
rlm@1:   setsvalue(fs->L, &o, s);
rlm@1:   return addk(fs, &o, &o);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_numberK (FuncState *fs, lua_Number r) {
rlm@1:   TValue o;
rlm@1:   setnvalue(&o, r);
rlm@1:   return addk(fs, &o, &o);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int boolK (FuncState *fs, int b) {
rlm@1:   TValue o;
rlm@1:   setbvalue(&o, b);
rlm@1:   return addk(fs, &o, &o);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int nilK (FuncState *fs) {
rlm@1:   TValue k, v;
rlm@1:   setnilvalue(&v);
rlm@1:   /* cannot use nil as key; instead use table itself to represent nil */
rlm@1:   sethvalue(fs->L, &k, fs->h);
rlm@1:   return addk(fs, &k, &v);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
rlm@1:   if (e->k == VCALL) {  /* expression is an open function call? */
rlm@1:     SETARG_C(getcode(fs, e), nresults+1);
rlm@1:   }
rlm@1:   else if (e->k == VVARARG) {
rlm@1:     SETARG_B(getcode(fs, e), nresults+1);
rlm@1:     SETARG_A(getcode(fs, e), fs->freereg);
rlm@1:     luaK_reserveregs(fs, 1);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_setoneret (FuncState *fs, expdesc *e) {
rlm@1:   if (e->k == VCALL) {  /* expression is an open function call? */
rlm@1:     e->k = VNONRELOC;
rlm@1:     e->u.s.info = GETARG_A(getcode(fs, e));
rlm@1:   }
rlm@1:   else if (e->k == VVARARG) {
rlm@1:     SETARG_B(getcode(fs, e), 2);
rlm@1:     e->k = VRELOCABLE;  /* can relocate its simple result */
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_dischargevars (FuncState *fs, expdesc *e) {
rlm@1:   switch (e->k) {
rlm@1:     case VLOCAL: {
rlm@1:       e->k = VNONRELOC;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VUPVAL: {
rlm@1:       e->u.s.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.s.info, 0);
rlm@1:       e->k = VRELOCABLE;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VGLOBAL: {
rlm@1:       e->u.s.info = luaK_codeABx(fs, OP_GETGLOBAL, 0, e->u.s.info);
rlm@1:       e->k = VRELOCABLE;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VINDEXED: {
rlm@1:       freereg(fs, e->u.s.aux);
rlm@1:       freereg(fs, e->u.s.info);
rlm@1:       e->u.s.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.s.info, e->u.s.aux);
rlm@1:       e->k = VRELOCABLE;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VVARARG:
rlm@1:     case VCALL: {
rlm@1:       luaK_setoneret(fs, e);
rlm@1:       break;
rlm@1:     }
rlm@1:     default: break;  /* there is one value available (somewhere) */
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int code_label (FuncState *fs, int A, int b, int jump) {
rlm@1:   luaK_getlabel(fs);  /* those instructions may be jump targets */
rlm@1:   return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   switch (e->k) {
rlm@1:     case VNIL: {
rlm@1:       luaK_nil(fs, reg, 1);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VFALSE:  case VTRUE: {
rlm@1:       luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VK: {
rlm@1:       luaK_codeABx(fs, OP_LOADK, reg, e->u.s.info);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VKNUM: {
rlm@1:       luaK_codeABx(fs, OP_LOADK, reg, luaK_numberK(fs, e->u.nval));
rlm@1:       break;
rlm@1:     }
rlm@1:     case VRELOCABLE: {
rlm@1:       Instruction *pc = &getcode(fs, e);
rlm@1:       SETARG_A(*pc, reg);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VNONRELOC: {
rlm@1:       if (reg != e->u.s.info)
rlm@1:         luaK_codeABC(fs, OP_MOVE, reg, e->u.s.info, 0);
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       lua_assert(e->k == VVOID || e->k == VJMP);
rlm@1:       return;  /* nothing to do... */
rlm@1:     }
rlm@1:   }
rlm@1:   e->u.s.info = reg;
rlm@1:   e->k = VNONRELOC;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void discharge2anyreg (FuncState *fs, expdesc *e) {
rlm@1:   if (e->k != VNONRELOC) {
rlm@1:     luaK_reserveregs(fs, 1);
rlm@1:     discharge2reg(fs, e, fs->freereg-1);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void exp2reg (FuncState *fs, expdesc *e, int reg) {
rlm@1:   discharge2reg(fs, e, reg);
rlm@1:   if (e->k == VJMP)
rlm@1:     luaK_concat(fs, &e->t, e->u.s.info);  /* put this jump in `t' list */
rlm@1:   if (hasjumps(e)) {
rlm@1:     int final;  /* position after whole expression */
rlm@1:     int p_f = NO_JUMP;  /* position of an eventual LOAD false */
rlm@1:     int p_t = NO_JUMP;  /* position of an eventual LOAD true */
rlm@1:     if (need_value(fs, e->t) || need_value(fs, e->f)) {
rlm@1:       int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
rlm@1:       p_f = code_label(fs, reg, 0, 1);
rlm@1:       p_t = code_label(fs, reg, 1, 0);
rlm@1:       luaK_patchtohere(fs, fj);
rlm@1:     }
rlm@1:     final = luaK_getlabel(fs);
rlm@1:     patchlistaux(fs, e->f, final, reg, p_f);
rlm@1:     patchlistaux(fs, e->t, final, reg, p_t);
rlm@1:   }
rlm@1:   e->f = e->t = NO_JUMP;
rlm@1:   e->u.s.info = reg;
rlm@1:   e->k = VNONRELOC;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   freeexp(fs, e);
rlm@1:   luaK_reserveregs(fs, 1);
rlm@1:   exp2reg(fs, e, fs->freereg - 1);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   if (e->k == VNONRELOC) {
rlm@1:     if (!hasjumps(e)) return e->u.s.info;  /* exp is already in a register */
rlm@1:     if (e->u.s.info >= fs->nactvar) {  /* reg. is not a local? */
rlm@1:       exp2reg(fs, e, e->u.s.info);  /* put value on it */
rlm@1:       return e->u.s.info;
rlm@1:     }
rlm@1:   }
rlm@1:   luaK_exp2nextreg(fs, e);  /* default */
rlm@1:   return e->u.s.info;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_exp2val (FuncState *fs, expdesc *e) {
rlm@1:   if (hasjumps(e))
rlm@1:     luaK_exp2anyreg(fs, e);
rlm@1:   else
rlm@1:     luaK_dischargevars(fs, e);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_exp2RK (FuncState *fs, expdesc *e) {
rlm@1:   luaK_exp2val(fs, e);
rlm@1:   switch (e->k) {
rlm@1:     case VKNUM:
rlm@1:     case VTRUE:
rlm@1:     case VFALSE:
rlm@1:     case VNIL: {
rlm@1:       if (fs->nk <= MAXINDEXRK) {  /* constant fit in RK operand? */
rlm@1:         e->u.s.info = (e->k == VNIL)  ? nilK(fs) :
rlm@1:                       (e->k == VKNUM) ? luaK_numberK(fs, e->u.nval) :
rlm@1:                                         boolK(fs, (e->k == VTRUE));
rlm@1:         e->k = VK;
rlm@1:         return RKASK(e->u.s.info);
rlm@1:       }
rlm@1:       else break;
rlm@1:     }
rlm@1:     case VK: {
rlm@1:       if (e->u.s.info <= MAXINDEXRK)  /* constant fit in argC? */
rlm@1:         return RKASK(e->u.s.info);
rlm@1:       else break;
rlm@1:     }
rlm@1:     default: break;
rlm@1:   }
rlm@1:   /* not a constant in the right range: put it in a register */
rlm@1:   return luaK_exp2anyreg(fs, e);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
rlm@1:   switch (var->k) {
rlm@1:     case VLOCAL: {
rlm@1:       freeexp(fs, ex);
rlm@1:       exp2reg(fs, ex, var->u.s.info);
rlm@1:       return;
rlm@1:     }
rlm@1:     case VUPVAL: {
rlm@1:       int e = luaK_exp2anyreg(fs, ex);
rlm@1:       luaK_codeABC(fs, OP_SETUPVAL, e, var->u.s.info, 0);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VGLOBAL: {
rlm@1:       int e = luaK_exp2anyreg(fs, ex);
rlm@1:       luaK_codeABx(fs, OP_SETGLOBAL, e, var->u.s.info);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VINDEXED: {
rlm@1:       int e = luaK_exp2RK(fs, ex);
rlm@1:       luaK_codeABC(fs, OP_SETTABLE, var->u.s.info, var->u.s.aux, e);
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       lua_assert(0);  /* invalid var kind to store */
rlm@1:       break;
rlm@1:     }
rlm@1:   }
rlm@1:   freeexp(fs, ex);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
rlm@1:   int func;
rlm@1:   luaK_exp2anyreg(fs, e);
rlm@1:   freeexp(fs, e);
rlm@1:   func = fs->freereg;
rlm@1:   luaK_reserveregs(fs, 2);
rlm@1:   luaK_codeABC(fs, OP_SELF, func, e->u.s.info, luaK_exp2RK(fs, key));
rlm@1:   freeexp(fs, key);
rlm@1:   e->u.s.info = func;
rlm@1:   e->k = VNONRELOC;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void invertjump (FuncState *fs, expdesc *e) {
rlm@1:   Instruction *pc = getjumpcontrol(fs, e->u.s.info);
rlm@1:   lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
rlm@1:                                            GET_OPCODE(*pc) != OP_TEST);
rlm@1:   SETARG_A(*pc, !(GETARG_A(*pc)));
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int jumponcond (FuncState *fs, expdesc *e, int cond) {
rlm@1:   if (e->k == VRELOCABLE) {
rlm@1:     Instruction ie = getcode(fs, e);
rlm@1:     if (GET_OPCODE(ie) == OP_NOT) {
rlm@1:       fs->pc--;  /* remove previous OP_NOT */
rlm@1:       return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
rlm@1:     }
rlm@1:     /* else go through */
rlm@1:   }
rlm@1:   discharge2anyreg(fs, e);
rlm@1:   freeexp(fs, e);
rlm@1:   return condjump(fs, OP_TESTSET, NO_REG, e->u.s.info, cond);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_goiftrue (FuncState *fs, expdesc *e) {
rlm@1:   int pc;  /* pc of last jump */
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   switch (e->k) {
rlm@1:     case VK: case VKNUM: case VTRUE: {
rlm@1:       pc = NO_JUMP;  /* always true; do nothing */
rlm@1:       break;
rlm@1:     }
rlm@1:     case VFALSE: {
rlm@1:       pc = luaK_jump(fs);  /* always jump */
rlm@1:       break;
rlm@1:     }
rlm@1:     case VJMP: {
rlm@1:       invertjump(fs, e);
rlm@1:       pc = e->u.s.info;
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       pc = jumponcond(fs, e, 0);
rlm@1:       break;
rlm@1:     }
rlm@1:   }
rlm@1:   luaK_concat(fs, &e->f, pc);  /* insert last jump in `f' list */
rlm@1:   luaK_patchtohere(fs, e->t);
rlm@1:   e->t = NO_JUMP;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void luaK_goiffalse (FuncState *fs, expdesc *e) {
rlm@1:   int pc;  /* pc of last jump */
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   switch (e->k) {
rlm@1:     case VNIL: case VFALSE: {
rlm@1:       pc = NO_JUMP;  /* always false; do nothing */
rlm@1:       break;
rlm@1:     }
rlm@1:     case VTRUE: {
rlm@1:       pc = luaK_jump(fs);  /* always jump */
rlm@1:       break;
rlm@1:     }
rlm@1:     case VJMP: {
rlm@1:       pc = e->u.s.info;
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       pc = jumponcond(fs, e, 1);
rlm@1:       break;
rlm@1:     }
rlm@1:   }
rlm@1:   luaK_concat(fs, &e->t, pc);  /* insert last jump in `t' list */
rlm@1:   luaK_patchtohere(fs, e->f);
rlm@1:   e->f = NO_JUMP;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void codenot (FuncState *fs, expdesc *e) {
rlm@1:   luaK_dischargevars(fs, e);
rlm@1:   switch (e->k) {
rlm@1:     case VNIL: case VFALSE: {
rlm@1:       e->k = VTRUE;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VK: case VKNUM: case VTRUE: {
rlm@1:       e->k = VFALSE;
rlm@1:       break;
rlm@1:     }
rlm@1:     case VJMP: {
rlm@1:       invertjump(fs, e);
rlm@1:       break;
rlm@1:     }
rlm@1:     case VRELOCABLE:
rlm@1:     case VNONRELOC: {
rlm@1:       discharge2anyreg(fs, e);
rlm@1:       freeexp(fs, e);
rlm@1:       e->u.s.info = luaK_codeABC(fs, OP_NOT, 0, e->u.s.info, 0);
rlm@1:       e->k = VRELOCABLE;
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       lua_assert(0);  /* cannot happen */
rlm@1:       break;
rlm@1:     }
rlm@1:   }
rlm@1:   /* interchange true and false lists */
rlm@1:   { int temp = e->f; e->f = e->t; e->t = temp; }
rlm@1:   removevalues(fs, e->f);
rlm@1:   removevalues(fs, e->t);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
rlm@1:   t->u.s.aux = luaK_exp2RK(fs, k);
rlm@1:   t->k = VINDEXED;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {
rlm@1:   lua_Number v1, v2, r;
rlm@1:   if (!isnumeral(e1) || !isnumeral(e2)) return 0;
rlm@1:   v1 = e1->u.nval;
rlm@1:   v2 = e2->u.nval;
rlm@1:   switch (op) {
rlm@1:     case OP_ADD: r = luai_numadd(v1, v2); break;
rlm@1:     case OP_SUB: r = luai_numsub(v1, v2); break;
rlm@1:     case OP_MUL: r = luai_nummul(v1, v2); break;
rlm@1:     case OP_DIV:
rlm@1:       if (v2 == 0) return 0;  /* do not attempt to divide by 0 */
rlm@1:       r = luai_numdiv(v1, v2); break;
rlm@1:     case OP_MOD:
rlm@1:       if (v2 == 0) return 0;  /* do not attempt to divide by 0 */
rlm@1:       r = luai_nummod(v1, v2); break;
rlm@1:     case OP_POW: r = luai_numpow(v1, v2); break;
rlm@1:     case OP_UNM: r = luai_numunm(v1); break;
rlm@1:     case OP_LEN: return 0;  /* no constant folding for 'len' */
rlm@1:     default: lua_assert(0); r = 0; break;
rlm@1:   }
rlm@1:   if (luai_numisnan(r)) return 0;  /* do not attempt to produce NaN */
rlm@1:   e1->u.nval = r;
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void codearith (FuncState *fs, OpCode op, expdesc *e1, expdesc *e2) {
rlm@1:   if (constfolding(op, e1, e2))
rlm@1:     return;
rlm@1:   else {
rlm@1:     int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;
rlm@1:     int o1 = luaK_exp2RK(fs, e1);
rlm@1:     if (o1 > o2) {
rlm@1:       freeexp(fs, e1);
rlm@1:       freeexp(fs, e2);
rlm@1:     }
rlm@1:     else {
rlm@1:       freeexp(fs, e2);
rlm@1:       freeexp(fs, e1);
rlm@1:     }
rlm@1:     e1->u.s.info = luaK_codeABC(fs, op, 0, o1, o2);
rlm@1:     e1->k = VRELOCABLE;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,
rlm@1:                                                           expdesc *e2) {
rlm@1:   int o1 = luaK_exp2RK(fs, e1);
rlm@1:   int o2 = luaK_exp2RK(fs, e2);
rlm@1:   freeexp(fs, e2);
rlm@1:   freeexp(fs, e1);
rlm@1:   if (cond == 0 && op != OP_EQ) {
rlm@1:     int temp;  /* exchange args to replace by `<' or `<=' */
rlm@1:     temp = o1; o1 = o2; o2 = temp;  /* o1 <==> o2 */
rlm@1:     cond = 1;
rlm@1:   }
rlm@1:   e1->u.s.info = condjump(fs, op, cond, o1, o2);
rlm@1:   e1->k = VJMP;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e) {
rlm@1:   expdesc e2;
rlm@1:   e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
rlm@1:   switch (op) {
rlm@1:     case OPR_MINUS: {
rlm@1:       if (!isnumeral(e))
rlm@1:         luaK_exp2anyreg(fs, e);  /* cannot operate on non-numeric constants */
rlm@1:       codearith(fs, OP_UNM, e, &e2);
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_NOT: codenot(fs, e); break;
rlm@1:     case OPR_LEN: {
rlm@1:       luaK_exp2anyreg(fs, e);  /* cannot operate on constants */
rlm@1:       codearith(fs, OP_LEN, e, &e2);
rlm@1:       break;
rlm@1:     }
rlm@1:     default: lua_assert(0);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
rlm@1:   switch (op) {
rlm@1:     case OPR_AND: {
rlm@1:       luaK_goiftrue(fs, v);
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_OR: {
rlm@1:       luaK_goiffalse(fs, v);
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_CONCAT: {
rlm@1:       luaK_exp2nextreg(fs, v);  /* operand must be on the `stack' */
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
rlm@1:     case OPR_MOD: case OPR_POW: {
rlm@1:       if (!isnumeral(v)) luaK_exp2RK(fs, v);
rlm@1:       break;
rlm@1:     }
rlm@1:     default: {
rlm@1:       luaK_exp2RK(fs, v);
rlm@1:       break;
rlm@1:     }
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_posfix (FuncState *fs, BinOpr op, expdesc *e1, expdesc *e2) {
rlm@1:   switch (op) {
rlm@1:     case OPR_AND: {
rlm@1:       lua_assert(e1->t == NO_JUMP);  /* list must be closed */
rlm@1:       luaK_dischargevars(fs, e2);
rlm@1:       luaK_concat(fs, &e2->f, e1->f);
rlm@1:       *e1 = *e2;
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_OR: {
rlm@1:       lua_assert(e1->f == NO_JUMP);  /* list must be closed */
rlm@1:       luaK_dischargevars(fs, e2);
rlm@1:       luaK_concat(fs, &e2->t, e1->t);
rlm@1:       *e1 = *e2;
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_CONCAT: {
rlm@1:       luaK_exp2val(fs, e2);
rlm@1:       if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
rlm@1:         lua_assert(e1->u.s.info == GETARG_B(getcode(fs, e2))-1);
rlm@1:         freeexp(fs, e1);
rlm@1:         SETARG_B(getcode(fs, e2), e1->u.s.info);
rlm@1:         e1->k = VRELOCABLE; e1->u.s.info = e2->u.s.info;
rlm@1:       }
rlm@1:       else {
rlm@1:         luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */
rlm@1:         codearith(fs, OP_CONCAT, e1, e2);
rlm@1:       }
rlm@1:       break;
rlm@1:     }
rlm@1:     case OPR_ADD: codearith(fs, OP_ADD, e1, e2); break;
rlm@1:     case OPR_SUB: codearith(fs, OP_SUB, e1, e2); break;
rlm@1:     case OPR_MUL: codearith(fs, OP_MUL, e1, e2); break;
rlm@1:     case OPR_DIV: codearith(fs, OP_DIV, e1, e2); break;
rlm@1:     case OPR_MOD: codearith(fs, OP_MOD, e1, e2); break;
rlm@1:     case OPR_POW: codearith(fs, OP_POW, e1, e2); break;
rlm@1:     case OPR_EQ: codecomp(fs, OP_EQ, 1, e1, e2); break;
rlm@1:     case OPR_NE: codecomp(fs, OP_EQ, 0, e1, e2); break;
rlm@1:     case OPR_LT: codecomp(fs, OP_LT, 1, e1, e2); break;
rlm@1:     case OPR_LE: codecomp(fs, OP_LE, 1, e1, e2); break;
rlm@1:     case OPR_GT: codecomp(fs, OP_LT, 0, e1, e2); break;
rlm@1:     case OPR_GE: codecomp(fs, OP_LE, 0, e1, e2); break;
rlm@1:     default: lua_assert(0);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_fixline (FuncState *fs, int line) {
rlm@1:   fs->f->lineinfo[fs->pc - 1] = line;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaK_code (FuncState *fs, Instruction i, int line) {
rlm@1:   Proto *f = fs->f;
rlm@1:   dischargejpc(fs);  /* `pc' will change */
rlm@1:   /* put new instruction in code array */
rlm@1:   luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
rlm@1:                   MAX_INT, "code size overflow");
rlm@1:   f->code[fs->pc] = i;
rlm@1:   /* save corresponding line information */
rlm@1:   luaM_growvector(fs->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
rlm@1:                   MAX_INT, "code size overflow");
rlm@1:   f->lineinfo[fs->pc] = line;
rlm@1:   return fs->pc++;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
rlm@1:   lua_assert(getOpMode(o) == iABC);
rlm@1:   lua_assert(getBMode(o) != OpArgN || b == 0);
rlm@1:   lua_assert(getCMode(o) != OpArgN || c == 0);
rlm@1:   return luaK_code(fs, CREATE_ABC(o, a, b, c), fs->ls->lastline);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
rlm@1:   lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
rlm@1:   lua_assert(getCMode(o) == OpArgN);
rlm@1:   return luaK_code(fs, CREATE_ABx(o, a, bc), fs->ls->lastline);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
rlm@1:   int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;
rlm@1:   int b = (tostore == LUA_MULTRET) ? 0 : tostore;
rlm@1:   lua_assert(tostore != 0);
rlm@1:   if (c <= MAXARG_C)
rlm@1:     luaK_codeABC(fs, OP_SETLIST, base, b, c);
rlm@1:   else {
rlm@1:     luaK_codeABC(fs, OP_SETLIST, base, b, 0);
rlm@1:     luaK_code(fs, cast(Instruction, c), fs->ls->lastline);
rlm@1:   }
rlm@1:   fs->freereg = base + 1;  /* free registers with list values */
rlm@1: }
rlm@1: