| /* |
| ** $Id: lcode.c $ |
| ** Code generator for Lua |
| ** See Copyright Notice in lua.h |
| */ |
| |
| #define lcode_c |
| #define LUA_CORE |
| |
| #include "lprefix.h" |
| |
| |
| #include <float.h> |
| #include <limits.h> |
| #include <math.h> |
| #include <stdlib.h> |
| |
| #include "lua.h" |
| |
| #include "lcode.h" |
| #include "ldebug.h" |
| #include "ldo.h" |
| #include "lgc.h" |
| #include "llex.h" |
| #include "lmem.h" |
| #include "lobject.h" |
| #include "lopcodes.h" |
| #include "lparser.h" |
| #include "lstring.h" |
| #include "ltable.h" |
| #include "lvm.h" |
| |
| |
| /* (note that expressions VJMP also have jumps.) */ |
| #define hasjumps(e) ((e)->t != (e)->f) |
| |
| |
| static int codesJ (FuncState *fs, OpCode o, int sj, int k); |
| |
| |
| |
| /* semantic error */ |
| l_noret luaK_semerror (LexState *ls, const char *msg) { |
| ls->t.token = 0; /* remove "near <token>" from final message */ |
| luaX_syntaxerror(ls, msg); |
| } |
| |
| |
| /* |
| ** If expression is a numeric constant, fills 'v' with its value |
| ** and returns 1. Otherwise, returns 0. |
| */ |
| static int tonumeral (const expdesc *e, TValue *v) { |
| if (hasjumps(e)) |
| return 0; /* not a numeral */ |
| switch (e->k) { |
| case VKINT: |
| if (v) setivalue(v, e->u.ival); |
| return 1; |
| case VKFLT: |
| if (v) setfltvalue(v, e->u.nval); |
| return 1; |
| default: return 0; |
| } |
| } |
| |
| |
| /* |
| ** Get the constant value from a constant expression |
| */ |
| static TValue *const2val (FuncState *fs, const expdesc *e) { |
| lua_assert(e->k == VCONST); |
| return &fs->ls->dyd->actvar.arr[e->u.info].k; |
| } |
| |
| |
| /* |
| ** If expression is a constant, fills 'v' with its value |
| ** and returns 1. Otherwise, returns 0. |
| */ |
| int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v) { |
| if (hasjumps(e)) |
| return 0; /* not a constant */ |
| switch (e->k) { |
| case VFALSE: |
| setbfvalue(v); |
| return 1; |
| case VTRUE: |
| setbtvalue(v); |
| return 1; |
| case VNIL: |
| setnilvalue(v); |
| return 1; |
| case VKSTR: { |
| setsvalue(fs->ls->L, v, e->u.strval); |
| return 1; |
| } |
| case VCONST: { |
| setobj(fs->ls->L, v, const2val(fs, e)); |
| return 1; |
| } |
| default: return tonumeral(e, v); |
| } |
| } |
| |
| |
| /* |
| ** Return the previous instruction of the current code. If there |
| ** may be a jump target between the current instruction and the |
| ** previous one, return an invalid instruction (to avoid wrong |
| ** optimizations). |
| */ |
| static Instruction *previousinstruction (FuncState *fs) { |
| static const Instruction invalidinstruction = ~(Instruction)0; |
| if (fs->pc > fs->lasttarget) |
| return &fs->f->code[fs->pc - 1]; /* previous instruction */ |
| else |
| return cast(Instruction*, &invalidinstruction); |
| } |
| |
| |
| /* |
| ** Create a OP_LOADNIL instruction, but try to optimize: if the previous |
| ** instruction is also OP_LOADNIL and ranges are compatible, adjust |
| ** range of previous instruction instead of emitting a new one. (For |
| ** instance, 'local a; local b' will generate a single opcode.) |
| */ |
| void luaK_nil (FuncState *fs, int from, int n) { |
| int l = from + n - 1; /* last register to set nil */ |
| Instruction *previous = previousinstruction(fs); |
| if (GET_OPCODE(*previous) == OP_LOADNIL) { /* previous is LOADNIL? */ |
| int pfrom = GETARG_A(*previous); /* get previous range */ |
| int pl = pfrom + GETARG_B(*previous); |
| if ((pfrom <= from && from <= pl + 1) || |
| (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */ |
| if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */ |
| if (pl > l) l = pl; /* l = max(l, pl) */ |
| SETARG_A(*previous, from); |
| SETARG_B(*previous, l - from); |
| return; |
| } /* else go through */ |
| } |
| luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */ |
| } |
| |
| |
| /* |
| ** Gets the destination address of a jump instruction. Used to traverse |
| ** a list of jumps. |
| */ |
| static int getjump (FuncState *fs, int pc) { |
| int offset = GETARG_sJ(fs->f->code[pc]); |
| if (offset == NO_JUMP) /* point to itself represents end of list */ |
| return NO_JUMP; /* end of list */ |
| else |
| return (pc+1)+offset; /* turn offset into absolute position */ |
| } |
| |
| |
| /* |
| ** Fix jump instruction at position 'pc' to jump to 'dest'. |
| ** (Jump addresses are relative in Lua) |
| */ |
| static void fixjump (FuncState *fs, int pc, int dest) { |
| Instruction *jmp = &fs->f->code[pc]; |
| int offset = dest - (pc + 1); |
| lua_assert(dest != NO_JUMP); |
| if (!(-OFFSET_sJ <= offset && offset <= MAXARG_sJ - OFFSET_sJ)) |
| luaX_syntaxerror(fs->ls, "control structure too long"); |
| lua_assert(GET_OPCODE(*jmp) == OP_JMP); |
| SETARG_sJ(*jmp, offset); |
| } |
| |
| |
| /* |
| ** Concatenate jump-list 'l2' into jump-list 'l1' |
| */ |
| void luaK_concat (FuncState *fs, int *l1, int l2) { |
| if (l2 == NO_JUMP) return; /* nothing to concatenate? */ |
| else if (*l1 == NO_JUMP) /* no original list? */ |
| *l1 = l2; /* 'l1' points to 'l2' */ |
| else { |
| int list = *l1; |
| int next; |
| while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */ |
| list = next; |
| fixjump(fs, list, l2); /* last element links to 'l2' */ |
| } |
| } |
| |
| |
| /* |
| ** Create a jump instruction and return its position, so its destination |
| ** can be fixed later (with 'fixjump'). |
| */ |
| int luaK_jump (FuncState *fs) { |
| return codesJ(fs, OP_JMP, NO_JUMP, 0); |
| } |
| |
| |
| /* |
| ** Code a 'return' instruction |
| */ |
| void luaK_ret (FuncState *fs, int first, int nret) { |
| OpCode op; |
| switch (nret) { |
| case 0: op = OP_RETURN0; break; |
| case 1: op = OP_RETURN1; break; |
| default: op = OP_RETURN; break; |
| } |
| luaY_checklimit(fs, nret + 1, MAXARG_B, "returns"); |
| luaK_codeABC(fs, op, first, nret + 1, 0); |
| } |
| |
| |
| /* |
| ** Code a "conditional jump", that is, a test or comparison opcode |
| ** followed by a jump. Return jump position. |
| */ |
| static int condjump (FuncState *fs, OpCode op, int A, int B, int C, int k) { |
| luaK_codeABCk(fs, op, A, B, C, k); |
| return luaK_jump(fs); |
| } |
| |
| |
| /* |
| ** returns current 'pc' and marks it as a jump target (to avoid wrong |
| ** optimizations with consecutive instructions not in the same basic block). |
| */ |
| int luaK_getlabel (FuncState *fs) { |
| fs->lasttarget = fs->pc; |
| return fs->pc; |
| } |
| |
| |
| /* |
| ** Returns the position of the instruction "controlling" a given |
| ** jump (that is, its condition), or the jump itself if it is |
| ** unconditional. |
| */ |
| static Instruction *getjumpcontrol (FuncState *fs, int pc) { |
| Instruction *pi = &fs->f->code[pc]; |
| if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1)))) |
| return pi-1; |
| else |
| return pi; |
| } |
| |
| |
| /* |
| ** Patch destination register for a TESTSET instruction. |
| ** If instruction in position 'node' is not a TESTSET, return 0 ("fails"). |
| ** Otherwise, if 'reg' is not 'NO_REG', set it as the destination |
| ** register. Otherwise, change instruction to a simple 'TEST' (produces |
| ** no register value) |
| */ |
| static int patchtestreg (FuncState *fs, int node, int reg) { |
| Instruction *i = getjumpcontrol(fs, node); |
| if (GET_OPCODE(*i) != OP_TESTSET) |
| return 0; /* cannot patch other instructions */ |
| if (reg != NO_REG && reg != GETARG_B(*i)) |
| SETARG_A(*i, reg); |
| else { |
| /* no register to put value or register already has the value; |
| change instruction to simple test */ |
| *i = CREATE_ABCk(OP_TEST, GETARG_B(*i), 0, 0, GETARG_k(*i)); |
| } |
| return 1; |
| } |
| |
| |
| /* |
| ** Traverse a list of tests ensuring no one produces a value |
| */ |
| static void removevalues (FuncState *fs, int list) { |
| for (; list != NO_JUMP; list = getjump(fs, list)) |
| patchtestreg(fs, list, NO_REG); |
| } |
| |
| |
| /* |
| ** Traverse a list of tests, patching their destination address and |
| ** registers: tests producing values jump to 'vtarget' (and put their |
| ** values in 'reg'), other tests jump to 'dtarget'. |
| */ |
| static void patchlistaux (FuncState *fs, int list, int vtarget, int reg, |
| int dtarget) { |
| while (list != NO_JUMP) { |
| int next = getjump(fs, list); |
| if (patchtestreg(fs, list, reg)) |
| fixjump(fs, list, vtarget); |
| else |
| fixjump(fs, list, dtarget); /* jump to default target */ |
| list = next; |
| } |
| } |
| |
| |
| /* |
| ** Path all jumps in 'list' to jump to 'target'. |
| ** (The assert means that we cannot fix a jump to a forward address |
| ** because we only know addresses once code is generated.) |
| */ |
| void luaK_patchlist (FuncState *fs, int list, int target) { |
| lua_assert(target <= fs->pc); |
| patchlistaux(fs, list, target, NO_REG, target); |
| } |
| |
| |
| void luaK_patchtohere (FuncState *fs, int list) { |
| int hr = luaK_getlabel(fs); /* mark "here" as a jump target */ |
| luaK_patchlist(fs, list, hr); |
| } |
| |
| |
| /* limit for difference between lines in relative line info. */ |
| #define LIMLINEDIFF 0x80 |
| |
| |
| /* |
| ** Save line info for a new instruction. If difference from last line |
| ** does not fit in a byte, of after that many instructions, save a new |
| ** absolute line info; (in that case, the special value 'ABSLINEINFO' |
| ** in 'lineinfo' signals the existence of this absolute information.) |
| ** Otherwise, store the difference from last line in 'lineinfo'. |
| */ |
| static void savelineinfo (FuncState *fs, Proto *f, int line) { |
| int linedif = line - fs->previousline; |
| int pc = fs->pc - 1; /* last instruction coded */ |
| if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ >= MAXIWTHABS) { |
| luaM_growvector(fs->ls->L, f->abslineinfo, fs->nabslineinfo, |
| f->sizeabslineinfo, AbsLineInfo, INT_MAX, "lines"); |
| f->abslineinfo[fs->nabslineinfo].pc = pc; |
| f->abslineinfo[fs->nabslineinfo++].line = line; |
| linedif = ABSLINEINFO; /* signal that there is absolute information */ |
| fs->iwthabs = 1; /* restart counter */ |
| } |
| luaM_growvector(fs->ls->L, f->lineinfo, pc, f->sizelineinfo, ls_byte, |
| INT_MAX, "opcodes"); |
| f->lineinfo[pc] = cast(ls_byte, linedif); |
| fs->previousline = line; /* last line saved */ |
| } |
| |
| |
| /* |
| ** Remove line information from the last instruction. |
| ** If line information for that instruction is absolute, set 'iwthabs' |
| ** above its max to force the new (replacing) instruction to have |
| ** absolute line info, too. |
| */ |
| static void removelastlineinfo (FuncState *fs) { |
| Proto *f = fs->f; |
| int pc = fs->pc - 1; /* last instruction coded */ |
| if (f->lineinfo[pc] != ABSLINEINFO) { /* relative line info? */ |
| fs->previousline -= f->lineinfo[pc]; /* correct last line saved */ |
| fs->iwthabs--; /* undo previous increment */ |
| } |
| else { /* absolute line information */ |
| lua_assert(f->abslineinfo[fs->nabslineinfo - 1].pc == pc); |
| fs->nabslineinfo--; /* remove it */ |
| fs->iwthabs = MAXIWTHABS + 1; /* force next line info to be absolute */ |
| } |
| } |
| |
| |
| /* |
| ** Remove the last instruction created, correcting line information |
| ** accordingly. |
| */ |
| static void removelastinstruction (FuncState *fs) { |
| removelastlineinfo(fs); |
| fs->pc--; |
| } |
| |
| |
| /* |
| ** Emit instruction 'i', checking for array sizes and saving also its |
| ** line information. Return 'i' position. |
| */ |
| int luaK_code (FuncState *fs, Instruction i) { |
| Proto *f = fs->f; |
| /* put new instruction in code array */ |
| luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction, |
| INT_MAX, "opcodes"); |
| f->code[fs->pc++] = i; |
| savelineinfo(fs, f, fs->ls->lastline); |
| return fs->pc - 1; /* index of new instruction */ |
| } |
| |
| |
| /* |
| ** Format and emit an 'iABC' instruction. (Assertions check consistency |
| ** of parameters versus opcode.) |
| */ |
| int luaK_codeABCk (FuncState *fs, OpCode o, int A, int B, int C, int k) { |
| lua_assert(getOpMode(o) == iABC); |
| lua_assert(A <= MAXARG_A && B <= MAXARG_B && |
| C <= MAXARG_C && (k & ~1) == 0); |
| return luaK_code(fs, CREATE_ABCk(o, A, B, C, k)); |
| } |
| |
| |
| int luaK_codevABCk (FuncState *fs, OpCode o, int A, int B, int C, int k) { |
| lua_assert(getOpMode(o) == ivABC); |
| lua_assert(A <= MAXARG_A && B <= MAXARG_vB && |
| C <= MAXARG_vC && (k & ~1) == 0); |
| return luaK_code(fs, CREATE_vABCk(o, A, B, C, k)); |
| } |
| |
| |
| /* |
| ** Format and emit an 'iABx' instruction. |
| */ |
| int luaK_codeABx (FuncState *fs, OpCode o, int A, int Bc) { |
| lua_assert(getOpMode(o) == iABx); |
| lua_assert(A <= MAXARG_A && Bc <= MAXARG_Bx); |
| return luaK_code(fs, CREATE_ABx(o, A, Bc)); |
| } |
| |
| |
| /* |
| ** Format and emit an 'iAsBx' instruction. |
| */ |
| static int codeAsBx (FuncState *fs, OpCode o, int A, int Bc) { |
| int b = Bc + OFFSET_sBx; |
| lua_assert(getOpMode(o) == iAsBx); |
| lua_assert(A <= MAXARG_A && b <= MAXARG_Bx); |
| return luaK_code(fs, CREATE_ABx(o, A, b)); |
| } |
| |
| |
| /* |
| ** Format and emit an 'isJ' instruction. |
| */ |
| static int codesJ (FuncState *fs, OpCode o, int sj, int k) { |
| int j = sj + OFFSET_sJ; |
| lua_assert(getOpMode(o) == isJ); |
| lua_assert(j <= MAXARG_sJ && (k & ~1) == 0); |
| return luaK_code(fs, CREATE_sJ(o, j, k)); |
| } |
| |
| |
| /* |
| ** Emit an "extra argument" instruction (format 'iAx') |
| */ |
| static int codeextraarg (FuncState *fs, int A) { |
| lua_assert(A <= MAXARG_Ax); |
| return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, A)); |
| } |
| |
| |
| /* |
| ** Emit a "load constant" instruction, using either 'OP_LOADK' |
| ** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX' |
| ** instruction with "extra argument". |
| */ |
| static int luaK_codek (FuncState *fs, int reg, int k) { |
| if (k <= MAXARG_Bx) |
| return luaK_codeABx(fs, OP_LOADK, reg, k); |
| else { |
| int p = luaK_codeABx(fs, OP_LOADKX, reg, 0); |
| codeextraarg(fs, k); |
| return p; |
| } |
| } |
| |
| |
| /* |
| ** Check register-stack level, keeping track of its maximum size |
| ** in field 'maxstacksize' |
| */ |
| void luaK_checkstack (FuncState *fs, int n) { |
| int newstack = fs->freereg + n; |
| if (newstack > fs->f->maxstacksize) { |
| luaY_checklimit(fs, newstack, MAX_FSTACK, "registers"); |
| fs->f->maxstacksize = cast_byte(newstack); |
| } |
| } |
| |
| |
| /* |
| ** Reserve 'n' registers in register stack |
| */ |
| void luaK_reserveregs (FuncState *fs, int n) { |
| luaK_checkstack(fs, n); |
| fs->freereg = cast_byte(fs->freereg + n); |
| } |
| |
| |
| /* |
| ** Free register 'reg', if it is neither a constant index nor |
| ** a local variable. |
| ) |
| */ |
| static void freereg (FuncState *fs, int reg) { |
| if (reg >= luaY_nvarstack(fs)) { |
| fs->freereg--; |
| lua_assert(reg == fs->freereg); |
| } |
| } |
| |
| |
| /* |
| ** Free two registers in proper order |
| */ |
| static void freeregs (FuncState *fs, int r1, int r2) { |
| if (r1 > r2) { |
| freereg(fs, r1); |
| freereg(fs, r2); |
| } |
| else { |
| freereg(fs, r2); |
| freereg(fs, r1); |
| } |
| } |
| |
| |
| /* |
| ** Free register used by expression 'e' (if any) |
| */ |
| static void freeexp (FuncState *fs, expdesc *e) { |
| if (e->k == VNONRELOC) |
| freereg(fs, e->u.info); |
| } |
| |
| |
| /* |
| ** Free registers used by expressions 'e1' and 'e2' (if any) in proper |
| ** order. |
| */ |
| static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) { |
| int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1; |
| int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1; |
| freeregs(fs, r1, r2); |
| } |
| |
| |
| /* |
| ** Add constant 'v' to prototype's list of constants (field 'k'). |
| ** Use scanner's table to cache position of constants in constant list |
| ** and try to reuse constants. Because some values should not be used |
| ** as keys (nil cannot be a key, integer keys can collapse with float |
| ** keys), the caller must provide a useful 'key' for indexing the cache. |
| ** Note that all functions share the same table, so entering or exiting |
| ** a function can make some indices wrong. |
| */ |
| static int addk (FuncState *fs, TValue *key, TValue *v) { |
| TValue val; |
| lua_State *L = fs->ls->L; |
| Proto *f = fs->f; |
| int tag = luaH_get(fs->ls->h, key, &val); /* query scanner table */ |
| int k, oldsize; |
| if (tag == LUA_VNUMINT) { /* is there an index there? */ |
| k = cast_int(ivalue(&val)); |
| /* correct value? (warning: must distinguish floats from integers!) */ |
| if (k < fs->nk && ttypetag(&f->k[k]) == ttypetag(v) && |
| luaV_rawequalobj(&f->k[k], v)) |
| return k; /* reuse index */ |
| } |
| /* constant not found; create a new entry */ |
| oldsize = f->sizek; |
| k = fs->nk; |
| /* numerical value does not need GC barrier; |
| table has no metatable, so it does not need to invalidate cache */ |
| setivalue(&val, k); |
| luaH_set(L, fs->ls->h, key, &val); |
| luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants"); |
| while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]); |
| setobj(L, &f->k[k], v); |
| fs->nk++; |
| luaC_barrier(L, f, v); |
| return k; |
| } |
| |
| |
| /* |
| ** Add a string to list of constants and return its index. |
| */ |
| static int stringK (FuncState *fs, TString *s) { |
| TValue o; |
| setsvalue(fs->ls->L, &o, s); |
| return addk(fs, &o, &o); /* use string itself as key */ |
| } |
| |
| |
| /* |
| ** Add an integer to list of constants and return its index. |
| */ |
| static int luaK_intK (FuncState *fs, lua_Integer n) { |
| TValue o; |
| setivalue(&o, n); |
| return addk(fs, &o, &o); /* use integer itself as key */ |
| } |
| |
| /* |
| ** Add a float to list of constants and return its index. Floats |
| ** with integral values need a different key, to avoid collision |
| ** with actual integers. To that, we add to the number its smaller |
| ** power-of-two fraction that is still significant in its scale. |
| ** For doubles, that would be 1/2^52. |
| ** (This method is not bulletproof: there may be another float |
| ** with that value, and for floats larger than 2^53 the result is |
| ** still an integer. At worst, this only wastes an entry with |
| ** a duplicate.) |
| */ |
| static int luaK_numberK (FuncState *fs, lua_Number r) { |
| TValue o; |
| lua_Integer ik; |
| setfltvalue(&o, r); |
| if (!luaV_flttointeger(r, &ik, F2Ieq)) /* not an integral value? */ |
| return addk(fs, &o, &o); /* use number itself as key */ |
| else { /* must build an alternative key */ |
| const int nbm = l_floatatt(MANT_DIG); |
| const lua_Number q = l_mathop(ldexp)(l_mathop(1.0), -nbm + 1); |
| const lua_Number k = (ik == 0) ? q : r + r*q; /* new key */ |
| TValue kv; |
| setfltvalue(&kv, k); |
| /* result is not an integral value, unless value is too large */ |
| lua_assert(!luaV_flttointeger(k, &ik, F2Ieq) || |
| l_mathop(fabs)(r) >= l_mathop(1e6)); |
| return addk(fs, &kv, &o); |
| } |
| } |
| |
| |
| /* |
| ** Add a false to list of constants and return its index. |
| */ |
| static int boolF (FuncState *fs) { |
| TValue o; |
| setbfvalue(&o); |
| return addk(fs, &o, &o); /* use boolean itself as key */ |
| } |
| |
| |
| /* |
| ** Add a true to list of constants and return its index. |
| */ |
| static int boolT (FuncState *fs) { |
| TValue o; |
| setbtvalue(&o); |
| return addk(fs, &o, &o); /* use boolean itself as key */ |
| } |
| |
| |
| /* |
| ** Add nil to list of constants and return its index. |
| */ |
| static int nilK (FuncState *fs) { |
| TValue k, v; |
| setnilvalue(&v); |
| /* cannot use nil as key; instead use table itself to represent nil */ |
| sethvalue(fs->ls->L, &k, fs->ls->h); |
| return addk(fs, &k, &v); |
| } |
| |
| |
| /* |
| ** Check whether 'i' can be stored in an 'sC' operand. Equivalent to |
| ** (0 <= int2sC(i) && int2sC(i) <= MAXARG_C) but without risk of |
| ** overflows in the hidden addition inside 'int2sC'. |
| */ |
| static int fitsC (lua_Integer i) { |
| return (l_castS2U(i) + OFFSET_sC <= cast_uint(MAXARG_C)); |
| } |
| |
| |
| /* |
| ** Check whether 'i' can be stored in an 'sBx' operand. |
| */ |
| static int fitsBx (lua_Integer i) { |
| return (-OFFSET_sBx <= i && i <= MAXARG_Bx - OFFSET_sBx); |
| } |
| |
| |
| void luaK_int (FuncState *fs, int reg, lua_Integer i) { |
| if (fitsBx(i)) |
| codeAsBx(fs, OP_LOADI, reg, cast_int(i)); |
| else |
| luaK_codek(fs, reg, luaK_intK(fs, i)); |
| } |
| |
| |
| static void luaK_float (FuncState *fs, int reg, lua_Number f) { |
| lua_Integer fi; |
| if (luaV_flttointeger(f, &fi, F2Ieq) && fitsBx(fi)) |
| codeAsBx(fs, OP_LOADF, reg, cast_int(fi)); |
| else |
| luaK_codek(fs, reg, luaK_numberK(fs, f)); |
| } |
| |
| |
| /* |
| ** Convert a constant in 'v' into an expression description 'e' |
| */ |
| static void const2exp (TValue *v, expdesc *e) { |
| switch (ttypetag(v)) { |
| case LUA_VNUMINT: |
| e->k = VKINT; e->u.ival = ivalue(v); |
| break; |
| case LUA_VNUMFLT: |
| e->k = VKFLT; e->u.nval = fltvalue(v); |
| break; |
| case LUA_VFALSE: |
| e->k = VFALSE; |
| break; |
| case LUA_VTRUE: |
| e->k = VTRUE; |
| break; |
| case LUA_VNIL: |
| e->k = VNIL; |
| break; |
| case LUA_VSHRSTR: case LUA_VLNGSTR: |
| e->k = VKSTR; e->u.strval = tsvalue(v); |
| break; |
| default: lua_assert(0); |
| } |
| } |
| |
| |
| /* |
| ** Fix an expression to return the number of results 'nresults'. |
| ** 'e' must be a multi-ret expression (function call or vararg). |
| */ |
| void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) { |
| Instruction *pc = &getinstruction(fs, e); |
| luaY_checklimit(fs, nresults + 1, MAXARG_C, "multiple results"); |
| if (e->k == VCALL) /* expression is an open function call? */ |
| SETARG_C(*pc, nresults + 1); |
| else { |
| lua_assert(e->k == VVARARG); |
| SETARG_C(*pc, nresults + 1); |
| SETARG_A(*pc, fs->freereg); |
| luaK_reserveregs(fs, 1); |
| } |
| } |
| |
| |
| /* |
| ** Convert a VKSTR to a VK |
| */ |
| static void str2K (FuncState *fs, expdesc *e) { |
| lua_assert(e->k == VKSTR); |
| e->u.info = stringK(fs, e->u.strval); |
| e->k = VK; |
| } |
| |
| |
| /* |
| ** Fix an expression to return one result. |
| ** If expression is not a multi-ret expression (function call or |
| ** vararg), it already returns one result, so nothing needs to be done. |
| ** Function calls become VNONRELOC expressions (as its result comes |
| ** fixed in the base register of the call), while vararg expressions |
| ** become VRELOC (as OP_VARARG puts its results where it wants). |
| ** (Calls are created returning one result, so that does not need |
| ** to be fixed.) |
| */ |
| void luaK_setoneret (FuncState *fs, expdesc *e) { |
| if (e->k == VCALL) { /* expression is an open function call? */ |
| /* already returns 1 value */ |
| lua_assert(GETARG_C(getinstruction(fs, e)) == 2); |
| e->k = VNONRELOC; /* result has fixed position */ |
| e->u.info = GETARG_A(getinstruction(fs, e)); |
| } |
| else if (e->k == VVARARG) { |
| SETARG_C(getinstruction(fs, e), 2); |
| e->k = VRELOC; /* can relocate its simple result */ |
| } |
| } |
| |
| |
| /* |
| ** Ensure that expression 'e' is not a variable (nor a <const>). |
| ** (Expression still may have jump lists.) |
| */ |
| void luaK_dischargevars (FuncState *fs, expdesc *e) { |
| switch (e->k) { |
| case VCONST: { |
| const2exp(const2val(fs, e), e); |
| break; |
| } |
| case VLOCAL: { /* already in a register */ |
| int temp = e->u.var.ridx; |
| e->u.info = temp; /* (can't do a direct assignment; values overlap) */ |
| e->k = VNONRELOC; /* becomes a non-relocatable value */ |
| break; |
| } |
| case VUPVAL: { /* move value to some (pending) register */ |
| e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0); |
| e->k = VRELOC; |
| break; |
| } |
| case VINDEXUP: { |
| e->u.info = luaK_codeABC(fs, OP_GETTABUP, 0, e->u.ind.t, e->u.ind.idx); |
| e->k = VRELOC; |
| break; |
| } |
| case VINDEXI: { |
| freereg(fs, e->u.ind.t); |
| e->u.info = luaK_codeABC(fs, OP_GETI, 0, e->u.ind.t, e->u.ind.idx); |
| e->k = VRELOC; |
| break; |
| } |
| case VINDEXSTR: { |
| freereg(fs, e->u.ind.t); |
| e->u.info = luaK_codeABC(fs, OP_GETFIELD, 0, e->u.ind.t, e->u.ind.idx); |
| e->k = VRELOC; |
| break; |
| } |
| case VINDEXED: { |
| freeregs(fs, e->u.ind.t, e->u.ind.idx); |
| e->u.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.ind.t, e->u.ind.idx); |
| e->k = VRELOC; |
| break; |
| } |
| case VVARARG: case VCALL: { |
| luaK_setoneret(fs, e); |
| break; |
| } |
| default: break; /* there is one value available (somewhere) */ |
| } |
| } |
| |
| |
| /* |
| ** Ensure expression value is in register 'reg', making 'e' a |
| ** non-relocatable expression. |
| ** (Expression still may have jump lists.) |
| */ |
| static void discharge2reg (FuncState *fs, expdesc *e, int reg) { |
| luaK_dischargevars(fs, e); |
| switch (e->k) { |
| case VNIL: { |
| luaK_nil(fs, reg, 1); |
| break; |
| } |
| case VFALSE: { |
| luaK_codeABC(fs, OP_LOADFALSE, reg, 0, 0); |
| break; |
| } |
| case VTRUE: { |
| luaK_codeABC(fs, OP_LOADTRUE, reg, 0, 0); |
| break; |
| } |
| case VKSTR: { |
| str2K(fs, e); |
| } /* FALLTHROUGH */ |
| case VK: { |
| luaK_codek(fs, reg, e->u.info); |
| break; |
| } |
| case VKFLT: { |
| luaK_float(fs, reg, e->u.nval); |
| break; |
| } |
| case VKINT: { |
| luaK_int(fs, reg, e->u.ival); |
| break; |
| } |
| case VRELOC: { |
| Instruction *pc = &getinstruction(fs, e); |
| SETARG_A(*pc, reg); /* instruction will put result in 'reg' */ |
| break; |
| } |
| case VNONRELOC: { |
| if (reg != e->u.info) |
| luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0); |
| break; |
| } |
| default: { |
| lua_assert(e->k == VJMP); |
| return; /* nothing to do... */ |
| } |
| } |
| e->u.info = reg; |
| e->k = VNONRELOC; |
| } |
| |
| |
| /* |
| ** Ensure expression value is in a register, making 'e' a |
| ** non-relocatable expression. |
| ** (Expression still may have jump lists.) |
| */ |
| static void discharge2anyreg (FuncState *fs, expdesc *e) { |
| if (e->k != VNONRELOC) { /* no fixed register yet? */ |
| luaK_reserveregs(fs, 1); /* get a register */ |
| discharge2reg(fs, e, fs->freereg-1); /* put value there */ |
| } |
| } |
| |
| |
| static int code_loadbool (FuncState *fs, int A, OpCode op) { |
| luaK_getlabel(fs); /* those instructions may be jump targets */ |
| return luaK_codeABC(fs, op, A, 0, 0); |
| } |
| |
| |
| /* |
| ** check whether list has any jump that do not produce a value |
| ** or produce an inverted value |
| */ |
| static int need_value (FuncState *fs, int list) { |
| for (; list != NO_JUMP; list = getjump(fs, list)) { |
| Instruction i = *getjumpcontrol(fs, list); |
| if (GET_OPCODE(i) != OP_TESTSET) return 1; |
| } |
| return 0; /* not found */ |
| } |
| |
| |
| /* |
| ** Ensures final expression result (which includes results from its |
| ** jump lists) is in register 'reg'. |
| ** If expression has jumps, need to patch these jumps either to |
| ** its final position or to "load" instructions (for those tests |
| ** that do not produce values). |
| */ |
| static void exp2reg (FuncState *fs, expdesc *e, int reg) { |
| discharge2reg(fs, e, reg); |
| if (e->k == VJMP) /* expression itself is a test? */ |
| luaK_concat(fs, &e->t, e->u.info); /* put this jump in 't' list */ |
| if (hasjumps(e)) { |
| int final; /* position after whole expression */ |
| int p_f = NO_JUMP; /* position of an eventual LOAD false */ |
| int p_t = NO_JUMP; /* position of an eventual LOAD true */ |
| if (need_value(fs, e->t) || need_value(fs, e->f)) { |
| int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs); |
| p_f = code_loadbool(fs, reg, OP_LFALSESKIP); /* skip next inst. */ |
| p_t = code_loadbool(fs, reg, OP_LOADTRUE); |
| /* jump around these booleans if 'e' is not a test */ |
| luaK_patchtohere(fs, fj); |
| } |
| final = luaK_getlabel(fs); |
| patchlistaux(fs, e->f, final, reg, p_f); |
| patchlistaux(fs, e->t, final, reg, p_t); |
| } |
| e->f = e->t = NO_JUMP; |
| e->u.info = reg; |
| e->k = VNONRELOC; |
| } |
| |
| |
| /* |
| ** Ensures final expression result is in next available register. |
| */ |
| void luaK_exp2nextreg (FuncState *fs, expdesc *e) { |
| luaK_dischargevars(fs, e); |
| freeexp(fs, e); |
| luaK_reserveregs(fs, 1); |
| exp2reg(fs, e, fs->freereg - 1); |
| } |
| |
| |
| /* |
| ** Ensures final expression result is in some (any) register |
| ** and return that register. |
| */ |
| int luaK_exp2anyreg (FuncState *fs, expdesc *e) { |
| luaK_dischargevars(fs, e); |
| if (e->k == VNONRELOC) { /* expression already has a register? */ |
| if (!hasjumps(e)) /* no jumps? */ |
| return e->u.info; /* result is already in a register */ |
| if (e->u.info >= luaY_nvarstack(fs)) { /* reg. is not a local? */ |
| exp2reg(fs, e, e->u.info); /* put final result in it */ |
| return e->u.info; |
| } |
| /* else expression has jumps and cannot change its register |
| to hold the jump values, because it is a local variable. |
| Go through to the default case. */ |
| } |
| luaK_exp2nextreg(fs, e); /* default: use next available register */ |
| return e->u.info; |
| } |
| |
| |
| /* |
| ** Ensures final expression result is either in a register |
| ** or in an upvalue. |
| */ |
| void luaK_exp2anyregup (FuncState *fs, expdesc *e) { |
| if (e->k != VUPVAL || hasjumps(e)) |
| luaK_exp2anyreg(fs, e); |
| } |
| |
| |
| /* |
| ** Ensures final expression result is either in a register |
| ** or it is a constant. |
| */ |
| void luaK_exp2val (FuncState *fs, expdesc *e) { |
| if (e->k == VJMP || hasjumps(e)) |
| luaK_exp2anyreg(fs, e); |
| else |
| luaK_dischargevars(fs, e); |
| } |
| |
| |
| /* |
| ** Try to make 'e' a K expression with an index in the range of R/K |
| ** indices. Return true iff succeeded. |
| */ |
| static int luaK_exp2K (FuncState *fs, expdesc *e) { |
| if (!hasjumps(e)) { |
| int info; |
| switch (e->k) { /* move constants to 'k' */ |
| case VTRUE: info = boolT(fs); break; |
| case VFALSE: info = boolF(fs); break; |
| case VNIL: info = nilK(fs); break; |
| case VKINT: info = luaK_intK(fs, e->u.ival); break; |
| case VKFLT: info = luaK_numberK(fs, e->u.nval); break; |
| case VKSTR: info = stringK(fs, e->u.strval); break; |
| case VK: info = e->u.info; break; |
| default: return 0; /* not a constant */ |
| } |
| if (info <= MAXINDEXRK) { /* does constant fit in 'argC'? */ |
| e->k = VK; /* make expression a 'K' expression */ |
| e->u.info = info; |
| return 1; |
| } |
| } |
| /* else, expression doesn't fit; leave it unchanged */ |
| return 0; |
| } |
| |
| |
| /* |
| ** Ensures final expression result is in a valid R/K index |
| ** (that is, it is either in a register or in 'k' with an index |
| ** in the range of R/K indices). |
| ** Returns 1 iff expression is K. |
| */ |
| static int exp2RK (FuncState *fs, expdesc *e) { |
| if (luaK_exp2K(fs, e)) |
| return 1; |
| else { /* not a constant in the right range: put it in a register */ |
| luaK_exp2anyreg(fs, e); |
| return 0; |
| } |
| } |
| |
| |
| static void codeABRK (FuncState *fs, OpCode o, int A, int B, |
| expdesc *ec) { |
| int k = exp2RK(fs, ec); |
| luaK_codeABCk(fs, o, A, B, ec->u.info, k); |
| } |
| |
| |
| /* |
| ** Generate code to store result of expression 'ex' into variable 'var'. |
| */ |
| void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) { |
| switch (var->k) { |
| case VLOCAL: { |
| freeexp(fs, ex); |
| exp2reg(fs, ex, var->u.var.ridx); /* compute 'ex' into proper place */ |
| return; |
| } |
| case VUPVAL: { |
| int e = luaK_exp2anyreg(fs, ex); |
| luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0); |
| break; |
| } |
| case VINDEXUP: { |
| codeABRK(fs, OP_SETTABUP, var->u.ind.t, var->u.ind.idx, ex); |
| break; |
| } |
| case VINDEXI: { |
| codeABRK(fs, OP_SETI, var->u.ind.t, var->u.ind.idx, ex); |
| break; |
| } |
| case VINDEXSTR: { |
| codeABRK(fs, OP_SETFIELD, var->u.ind.t, var->u.ind.idx, ex); |
| break; |
| } |
| case VINDEXED: { |
| codeABRK(fs, OP_SETTABLE, var->u.ind.t, var->u.ind.idx, ex); |
| break; |
| } |
| default: lua_assert(0); /* invalid var kind to store */ |
| } |
| freeexp(fs, ex); |
| } |
| |
| |
| /* |
| ** Emit SELF instruction (convert expression 'e' into 'e:key(e,'). |
| */ |
| void luaK_self (FuncState *fs, expdesc *e, expdesc *key) { |
| int ereg; |
| luaK_exp2anyreg(fs, e); |
| ereg = e->u.info; /* register where 'e' was placed */ |
| freeexp(fs, e); |
| e->u.info = fs->freereg; /* base register for op_self */ |
| e->k = VNONRELOC; /* self expression has a fixed register */ |
| luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */ |
| codeABRK(fs, OP_SELF, e->u.info, ereg, key); |
| freeexp(fs, key); |
| } |
| |
| |
| /* |
| ** Negate condition 'e' (where 'e' is a comparison). |
| */ |
| static void negatecondition (FuncState *fs, expdesc *e) { |
| Instruction *pc = getjumpcontrol(fs, e->u.info); |
| lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET && |
| GET_OPCODE(*pc) != OP_TEST); |
| SETARG_k(*pc, (GETARG_k(*pc) ^ 1)); |
| } |
| |
| |
| /* |
| ** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond' |
| ** is true, code will jump if 'e' is true.) Return jump position. |
| ** Optimize when 'e' is 'not' something, inverting the condition |
| ** and removing the 'not'. |
| */ |
| static int jumponcond (FuncState *fs, expdesc *e, int cond) { |
| if (e->k == VRELOC) { |
| Instruction ie = getinstruction(fs, e); |
| if (GET_OPCODE(ie) == OP_NOT) { |
| removelastinstruction(fs); /* remove previous OP_NOT */ |
| return condjump(fs, OP_TEST, GETARG_B(ie), 0, 0, !cond); |
| } |
| /* else go through */ |
| } |
| discharge2anyreg(fs, e); |
| freeexp(fs, e); |
| return condjump(fs, OP_TESTSET, NO_REG, e->u.info, 0, cond); |
| } |
| |
| |
| /* |
| ** Emit code to go through if 'e' is true, jump otherwise. |
| */ |
| void luaK_goiftrue (FuncState *fs, expdesc *e) { |
| int pc; /* pc of new jump */ |
| luaK_dischargevars(fs, e); |
| switch (e->k) { |
| case VJMP: { /* condition? */ |
| negatecondition(fs, e); /* jump when it is false */ |
| pc = e->u.info; /* save jump position */ |
| break; |
| } |
| case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { |
| pc = NO_JUMP; /* always true; do nothing */ |
| break; |
| } |
| default: { |
| pc = jumponcond(fs, e, 0); /* jump when false */ |
| break; |
| } |
| } |
| luaK_concat(fs, &e->f, pc); /* insert new jump in false list */ |
| luaK_patchtohere(fs, e->t); /* true list jumps to here (to go through) */ |
| e->t = NO_JUMP; |
| } |
| |
| |
| /* |
| ** Emit code to go through if 'e' is false, jump otherwise. |
| */ |
| void luaK_goiffalse (FuncState *fs, expdesc *e) { |
| int pc; /* pc of new jump */ |
| luaK_dischargevars(fs, e); |
| switch (e->k) { |
| case VJMP: { |
| pc = e->u.info; /* already jump if true */ |
| break; |
| } |
| case VNIL: case VFALSE: { |
| pc = NO_JUMP; /* always false; do nothing */ |
| break; |
| } |
| default: { |
| pc = jumponcond(fs, e, 1); /* jump if true */ |
| break; |
| } |
| } |
| luaK_concat(fs, &e->t, pc); /* insert new jump in 't' list */ |
| luaK_patchtohere(fs, e->f); /* false list jumps to here (to go through) */ |
| e->f = NO_JUMP; |
| } |
| |
| |
| /* |
| ** Code 'not e', doing constant folding. |
| */ |
| static void codenot (FuncState *fs, expdesc *e) { |
| switch (e->k) { |
| case VNIL: case VFALSE: { |
| e->k = VTRUE; /* true == not nil == not false */ |
| break; |
| } |
| case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { |
| e->k = VFALSE; /* false == not "x" == not 0.5 == not 1 == not true */ |
| break; |
| } |
| case VJMP: { |
| negatecondition(fs, e); |
| break; |
| } |
| case VRELOC: |
| case VNONRELOC: { |
| discharge2anyreg(fs, e); |
| freeexp(fs, e); |
| e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0); |
| e->k = VRELOC; |
| break; |
| } |
| default: lua_assert(0); /* cannot happen */ |
| } |
| /* interchange true and false lists */ |
| { int temp = e->f; e->f = e->t; e->t = temp; } |
| removevalues(fs, e->f); /* values are useless when negated */ |
| removevalues(fs, e->t); |
| } |
| |
| |
| /* |
| ** Check whether expression 'e' is a short literal string |
| */ |
| static int isKstr (FuncState *fs, expdesc *e) { |
| return (e->k == VK && !hasjumps(e) && e->u.info <= MAXARG_B && |
| ttisshrstring(&fs->f->k[e->u.info])); |
| } |
| |
| /* |
| ** Check whether expression 'e' is a literal integer. |
| */ |
| static int isKint (expdesc *e) { |
| return (e->k == VKINT && !hasjumps(e)); |
| } |
| |
| |
| /* |
| ** Check whether expression 'e' is a literal integer in |
| ** proper range to fit in register C |
| */ |
| static int isCint (expdesc *e) { |
| return isKint(e) && (l_castS2U(e->u.ival) <= l_castS2U(MAXARG_C)); |
| } |
| |
| |
| /* |
| ** Check whether expression 'e' is a literal integer in |
| ** proper range to fit in register sC |
| */ |
| static int isSCint (expdesc *e) { |
| return isKint(e) && fitsC(e->u.ival); |
| } |
| |
| |
| /* |
| ** Check whether expression 'e' is a literal integer or float in |
| ** proper range to fit in a register (sB or sC). |
| */ |
| static int isSCnumber (expdesc *e, int *pi, int *isfloat) { |
| lua_Integer i; |
| if (e->k == VKINT) |
| i = e->u.ival; |
| else if (e->k == VKFLT && luaV_flttointeger(e->u.nval, &i, F2Ieq)) |
| *isfloat = 1; |
| else |
| return 0; /* not a number */ |
| if (!hasjumps(e) && fitsC(i)) { |
| *pi = int2sC(cast_int(i)); |
| return 1; |
| } |
| else |
| return 0; |
| } |
| |
| |
| /* |
| ** Create expression 't[k]'. 't' must have its final result already in a |
| ** register or upvalue. Upvalues can only be indexed by literal strings. |
| ** Keys can be literal strings in the constant table or arbitrary |
| ** values in registers. |
| */ |
| void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) { |
| if (k->k == VKSTR) |
| str2K(fs, k); |
| lua_assert(!hasjumps(t) && |
| (t->k == VLOCAL || t->k == VNONRELOC || t->k == VUPVAL)); |
| if (t->k == VUPVAL && !isKstr(fs, k)) /* upvalue indexed by non 'Kstr'? */ |
| luaK_exp2anyreg(fs, t); /* put it in a register */ |
| if (t->k == VUPVAL) { |
| lu_byte temp = cast_byte(t->u.info); /* upvalue index */ |
| lua_assert(isKstr(fs, k)); |
| t->u.ind.t = temp; /* (can't do a direct assignment; values overlap) */ |
| t->u.ind.idx = cast(short, k->u.info); /* literal short string */ |
| t->k = VINDEXUP; |
| } |
| else { |
| /* register index of the table */ |
| t->u.ind.t = cast_byte((t->k == VLOCAL) ? t->u.var.ridx: t->u.info); |
| if (isKstr(fs, k)) { |
| t->u.ind.idx = cast(short, k->u.info); /* literal short string */ |
| t->k = VINDEXSTR; |
| } |
| else if (isCint(k)) { /* int. constant in proper range? */ |
| t->u.ind.idx = cast(short, k->u.ival); |
| t->k = VINDEXI; |
| } |
| else { |
| t->u.ind.idx = cast(short, luaK_exp2anyreg(fs, k)); /* register */ |
| t->k = VINDEXED; |
| } |
| } |
| } |
| |
| |
| /* |
| ** Return false if folding can raise an error. |
| ** Bitwise operations need operands convertible to integers; division |
| ** operations cannot have 0 as divisor. |
| */ |
| static int validop (int op, TValue *v1, TValue *v2) { |
| switch (op) { |
| case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: |
| case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: { /* conversion errors */ |
| lua_Integer i; |
| return (luaV_tointegerns(v1, &i, LUA_FLOORN2I) && |
| luaV_tointegerns(v2, &i, LUA_FLOORN2I)); |
| } |
| case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD: /* division by 0 */ |
| return (nvalue(v2) != 0); |
| default: return 1; /* everything else is valid */ |
| } |
| } |
| |
| |
| /* |
| ** Try to "constant-fold" an operation; return 1 iff successful. |
| ** (In this case, 'e1' has the final result.) |
| */ |
| static int constfolding (FuncState *fs, int op, expdesc *e1, |
| const expdesc *e2) { |
| TValue v1, v2, res; |
| if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2)) |
| return 0; /* non-numeric operands or not safe to fold */ |
| luaO_rawarith(fs->ls->L, op, &v1, &v2, &res); /* does operation */ |
| if (ttisinteger(&res)) { |
| e1->k = VKINT; |
| e1->u.ival = ivalue(&res); |
| } |
| else { /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */ |
| lua_Number n = fltvalue(&res); |
| if (luai_numisnan(n) || n == 0) |
| return 0; |
| e1->k = VKFLT; |
| e1->u.nval = n; |
| } |
| return 1; |
| } |
| |
| |
| /* |
| ** Convert a BinOpr to an OpCode (ORDER OPR - ORDER OP) |
| */ |
| l_sinline OpCode binopr2op (BinOpr opr, BinOpr baser, OpCode base) { |
| lua_assert(baser <= opr && |
| ((baser == OPR_ADD && opr <= OPR_SHR) || |
| (baser == OPR_LT && opr <= OPR_LE))); |
| return cast(OpCode, (cast_int(opr) - cast_int(baser)) + cast_int(base)); |
| } |
| |
| |
| /* |
| ** Convert a UnOpr to an OpCode (ORDER OPR - ORDER OP) |
| */ |
| l_sinline OpCode unopr2op (UnOpr opr) { |
| return cast(OpCode, (cast_int(opr) - cast_int(OPR_MINUS)) + |
| cast_int(OP_UNM)); |
| } |
| |
| |
| /* |
| ** Convert a BinOpr to a tag method (ORDER OPR - ORDER TM) |
| */ |
| l_sinline TMS binopr2TM (BinOpr opr) { |
| lua_assert(OPR_ADD <= opr && opr <= OPR_SHR); |
| return cast(TMS, (cast_int(opr) - cast_int(OPR_ADD)) + cast_int(TM_ADD)); |
| } |
| |
| |
| /* |
| ** Emit code for unary expressions that "produce values" |
| ** (everything but 'not'). |
| ** Expression to produce final result will be encoded in 'e'. |
| */ |
| static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) { |
| int r = luaK_exp2anyreg(fs, e); /* opcodes operate only on registers */ |
| freeexp(fs, e); |
| e->u.info = luaK_codeABC(fs, op, 0, r, 0); /* generate opcode */ |
| e->k = VRELOC; /* all those operations are relocatable */ |
| luaK_fixline(fs, line); |
| } |
| |
| |
| /* |
| ** Emit code for binary expressions that "produce values" |
| ** (everything but logical operators 'and'/'or' and comparison |
| ** operators). |
| ** Expression to produce final result will be encoded in 'e1'. |
| */ |
| static void finishbinexpval (FuncState *fs, expdesc *e1, expdesc *e2, |
| OpCode op, int v2, int flip, int line, |
| OpCode mmop, TMS event) { |
| int v1 = luaK_exp2anyreg(fs, e1); |
| int pc = luaK_codeABCk(fs, op, 0, v1, v2, 0); |
| freeexps(fs, e1, e2); |
| e1->u.info = pc; |
| e1->k = VRELOC; /* all those operations are relocatable */ |
| luaK_fixline(fs, line); |
| luaK_codeABCk(fs, mmop, v1, v2, event, flip); /* to call metamethod */ |
| luaK_fixline(fs, line); |
| } |
| |
| |
| /* |
| ** Emit code for binary expressions that "produce values" over |
| ** two registers. |
| */ |
| static void codebinexpval (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int line) { |
| OpCode op = binopr2op(opr, OPR_ADD, OP_ADD); |
| int v2 = luaK_exp2anyreg(fs, e2); /* make sure 'e2' is in a register */ |
| /* 'e1' must be already in a register or it is a constant */ |
| lua_assert((VNIL <= e1->k && e1->k <= VKSTR) || |
| e1->k == VNONRELOC || e1->k == VRELOC); |
| lua_assert(OP_ADD <= op && op <= OP_SHR); |
| finishbinexpval(fs, e1, e2, op, v2, 0, line, OP_MMBIN, binopr2TM(opr)); |
| } |
| |
| |
| /* |
| ** Code binary operators with immediate operands. |
| */ |
| static void codebini (FuncState *fs, OpCode op, |
| expdesc *e1, expdesc *e2, int flip, int line, |
| TMS event) { |
| int v2 = int2sC(cast_int(e2->u.ival)); /* immediate operand */ |
| lua_assert(e2->k == VKINT); |
| finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINI, event); |
| } |
| |
| |
| /* |
| ** Code binary operators with K operand. |
| */ |
| static void codebinK (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int flip, int line) { |
| TMS event = binopr2TM(opr); |
| int v2 = e2->u.info; /* K index */ |
| OpCode op = binopr2op(opr, OPR_ADD, OP_ADDK); |
| finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINK, event); |
| } |
| |
| |
| /* Try to code a binary operator negating its second operand. |
| ** For the metamethod, 2nd operand must keep its original value. |
| */ |
| static int finishbinexpneg (FuncState *fs, expdesc *e1, expdesc *e2, |
| OpCode op, int line, TMS event) { |
| if (!isKint(e2)) |
| return 0; /* not an integer constant */ |
| else { |
| lua_Integer i2 = e2->u.ival; |
| if (!(fitsC(i2) && fitsC(-i2))) |
| return 0; /* not in the proper range */ |
| else { /* operating a small integer constant */ |
| int v2 = cast_int(i2); |
| finishbinexpval(fs, e1, e2, op, int2sC(-v2), 0, line, OP_MMBINI, event); |
| /* correct metamethod argument */ |
| SETARG_B(fs->f->code[fs->pc - 1], int2sC(v2)); |
| return 1; /* successfully coded */ |
| } |
| } |
| } |
| |
| |
| static void swapexps (expdesc *e1, expdesc *e2) { |
| expdesc temp = *e1; *e1 = *e2; *e2 = temp; /* swap 'e1' and 'e2' */ |
| } |
| |
| |
| /* |
| ** Code binary operators with no constant operand. |
| */ |
| static void codebinNoK (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int flip, int line) { |
| if (flip) |
| swapexps(e1, e2); /* back to original order */ |
| codebinexpval(fs, opr, e1, e2, line); /* use standard operators */ |
| } |
| |
| |
| /* |
| ** Code arithmetic operators ('+', '-', ...). If second operand is a |
| ** constant in the proper range, use variant opcodes with K operands. |
| */ |
| static void codearith (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int flip, int line) { |
| if (tonumeral(e2, NULL) && luaK_exp2K(fs, e2)) /* K operand? */ |
| codebinK(fs, opr, e1, e2, flip, line); |
| else /* 'e2' is neither an immediate nor a K operand */ |
| codebinNoK(fs, opr, e1, e2, flip, line); |
| } |
| |
| |
| /* |
| ** Code commutative operators ('+', '*'). If first operand is a |
| ** numeric constant, change order of operands to try to use an |
| ** immediate or K operator. |
| */ |
| static void codecommutative (FuncState *fs, BinOpr op, |
| expdesc *e1, expdesc *e2, int line) { |
| int flip = 0; |
| if (tonumeral(e1, NULL)) { /* is first operand a numeric constant? */ |
| swapexps(e1, e2); /* change order */ |
| flip = 1; |
| } |
| if (op == OPR_ADD && isSCint(e2)) /* immediate operand? */ |
| codebini(fs, OP_ADDI, e1, e2, flip, line, TM_ADD); |
| else |
| codearith(fs, op, e1, e2, flip, line); |
| } |
| |
| |
| /* |
| ** Code bitwise operations; they are all commutative, so the function |
| ** tries to put an integer constant as the 2nd operand (a K operand). |
| */ |
| static void codebitwise (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int line) { |
| int flip = 0; |
| if (e1->k == VKINT) { |
| swapexps(e1, e2); /* 'e2' will be the constant operand */ |
| flip = 1; |
| } |
| if (e2->k == VKINT && luaK_exp2K(fs, e2)) /* K operand? */ |
| codebinK(fs, opr, e1, e2, flip, line); |
| else /* no constants */ |
| codebinNoK(fs, opr, e1, e2, flip, line); |
| } |
| |
| |
| /* |
| ** Emit code for order comparisons. When using an immediate operand, |
| ** 'isfloat' tells whether the original value was a float. |
| */ |
| static void codeorder (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { |
| int r1, r2; |
| int im; |
| int isfloat = 0; |
| OpCode op; |
| if (isSCnumber(e2, &im, &isfloat)) { |
| /* use immediate operand */ |
| r1 = luaK_exp2anyreg(fs, e1); |
| r2 = im; |
| op = binopr2op(opr, OPR_LT, OP_LTI); |
| } |
| else if (isSCnumber(e1, &im, &isfloat)) { |
| /* transform (A < B) to (B > A) and (A <= B) to (B >= A) */ |
| r1 = luaK_exp2anyreg(fs, e2); |
| r2 = im; |
| op = binopr2op(opr, OPR_LT, OP_GTI); |
| } |
| else { /* regular case, compare two registers */ |
| r1 = luaK_exp2anyreg(fs, e1); |
| r2 = luaK_exp2anyreg(fs, e2); |
| op = binopr2op(opr, OPR_LT, OP_LT); |
| } |
| freeexps(fs, e1, e2); |
| e1->u.info = condjump(fs, op, r1, r2, isfloat, 1); |
| e1->k = VJMP; |
| } |
| |
| |
| /* |
| ** Emit code for equality comparisons ('==', '~='). |
| ** 'e1' was already put as RK by 'luaK_infix'. |
| */ |
| static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { |
| int r1, r2; |
| int im; |
| int isfloat = 0; /* not needed here, but kept for symmetry */ |
| OpCode op; |
| if (e1->k != VNONRELOC) { |
| lua_assert(e1->k == VK || e1->k == VKINT || e1->k == VKFLT); |
| swapexps(e1, e2); |
| } |
| r1 = luaK_exp2anyreg(fs, e1); /* 1st expression must be in register */ |
| if (isSCnumber(e2, &im, &isfloat)) { |
| op = OP_EQI; |
| r2 = im; /* immediate operand */ |
| } |
| else if (exp2RK(fs, e2)) { /* 2nd expression is constant? */ |
| op = OP_EQK; |
| r2 = e2->u.info; /* constant index */ |
| } |
| else { |
| op = OP_EQ; /* will compare two registers */ |
| r2 = luaK_exp2anyreg(fs, e2); |
| } |
| freeexps(fs, e1, e2); |
| e1->u.info = condjump(fs, op, r1, r2, isfloat, (opr == OPR_EQ)); |
| e1->k = VJMP; |
| } |
| |
| |
| /* |
| ** Apply prefix operation 'op' to expression 'e'. |
| */ |
| void luaK_prefix (FuncState *fs, UnOpr opr, expdesc *e, int line) { |
| static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP}; |
| luaK_dischargevars(fs, e); |
| switch (opr) { |
| case OPR_MINUS: case OPR_BNOT: /* use 'ef' as fake 2nd operand */ |
| if (constfolding(fs, cast_int(opr + LUA_OPUNM), e, &ef)) |
| break; |
| /* else */ /* FALLTHROUGH */ |
| case OPR_LEN: |
| codeunexpval(fs, unopr2op(opr), e, line); |
| break; |
| case OPR_NOT: codenot(fs, e); break; |
| default: lua_assert(0); |
| } |
| } |
| |
| |
| /* |
| ** Process 1st operand 'v' of binary operation 'op' before reading |
| ** 2nd operand. |
| */ |
| void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) { |
| luaK_dischargevars(fs, v); |
| switch (op) { |
| case OPR_AND: { |
| luaK_goiftrue(fs, v); /* go ahead only if 'v' is true */ |
| break; |
| } |
| case OPR_OR: { |
| luaK_goiffalse(fs, v); /* go ahead only if 'v' is false */ |
| break; |
| } |
| case OPR_CONCAT: { |
| luaK_exp2nextreg(fs, v); /* operand must be on the stack */ |
| break; |
| } |
| case OPR_ADD: case OPR_SUB: |
| case OPR_MUL: case OPR_DIV: case OPR_IDIV: |
| case OPR_MOD: case OPR_POW: |
| case OPR_BAND: case OPR_BOR: case OPR_BXOR: |
| case OPR_SHL: case OPR_SHR: { |
| if (!tonumeral(v, NULL)) |
| luaK_exp2anyreg(fs, v); |
| /* else keep numeral, which may be folded or used as an immediate |
| operand */ |
| break; |
| } |
| case OPR_EQ: case OPR_NE: { |
| if (!tonumeral(v, NULL)) |
| exp2RK(fs, v); |
| /* else keep numeral, which may be an immediate operand */ |
| break; |
| } |
| case OPR_LT: case OPR_LE: |
| case OPR_GT: case OPR_GE: { |
| int dummy, dummy2; |
| if (!isSCnumber(v, &dummy, &dummy2)) |
| luaK_exp2anyreg(fs, v); |
| /* else keep numeral, which may be an immediate operand */ |
| break; |
| } |
| default: lua_assert(0); |
| } |
| } |
| |
| /* |
| ** Create code for '(e1 .. e2)'. |
| ** For '(e1 .. e2.1 .. e2.2)' (which is '(e1 .. (e2.1 .. e2.2))', |
| ** because concatenation is right associative), merge both CONCATs. |
| */ |
| static void codeconcat (FuncState *fs, expdesc *e1, expdesc *e2, int line) { |
| Instruction *ie2 = previousinstruction(fs); |
| if (GET_OPCODE(*ie2) == OP_CONCAT) { /* is 'e2' a concatenation? */ |
| int n = GETARG_B(*ie2); /* # of elements concatenated in 'e2' */ |
| lua_assert(e1->u.info + 1 == GETARG_A(*ie2)); |
| freeexp(fs, e2); |
| SETARG_A(*ie2, e1->u.info); /* correct first element ('e1') */ |
| SETARG_B(*ie2, n + 1); /* will concatenate one more element */ |
| } |
| else { /* 'e2' is not a concatenation */ |
| luaK_codeABC(fs, OP_CONCAT, e1->u.info, 2, 0); /* new concat opcode */ |
| freeexp(fs, e2); |
| luaK_fixline(fs, line); |
| } |
| } |
| |
| |
| /* |
| ** Finalize code for binary operation, after reading 2nd operand. |
| */ |
| void luaK_posfix (FuncState *fs, BinOpr opr, |
| expdesc *e1, expdesc *e2, int line) { |
| luaK_dischargevars(fs, e2); |
| if (foldbinop(opr) && constfolding(fs, cast_int(opr + LUA_OPADD), e1, e2)) |
| return; /* done by folding */ |
| switch (opr) { |
| case OPR_AND: { |
| lua_assert(e1->t == NO_JUMP); /* list closed by 'luaK_infix' */ |
| luaK_concat(fs, &e2->f, e1->f); |
| *e1 = *e2; |
| break; |
| } |
| case OPR_OR: { |
| lua_assert(e1->f == NO_JUMP); /* list closed by 'luaK_infix' */ |
| luaK_concat(fs, &e2->t, e1->t); |
| *e1 = *e2; |
| break; |
| } |
| case OPR_CONCAT: { /* e1 .. e2 */ |
| luaK_exp2nextreg(fs, e2); |
| codeconcat(fs, e1, e2, line); |
| break; |
| } |
| case OPR_ADD: case OPR_MUL: { |
| codecommutative(fs, opr, e1, e2, line); |
| break; |
| } |
| case OPR_SUB: { |
| if (finishbinexpneg(fs, e1, e2, OP_ADDI, line, TM_SUB)) |
| break; /* coded as (r1 + -I) */ |
| /* ELSE */ |
| } /* FALLTHROUGH */ |
| case OPR_DIV: case OPR_IDIV: case OPR_MOD: case OPR_POW: { |
| codearith(fs, opr, e1, e2, 0, line); |
| break; |
| } |
| case OPR_BAND: case OPR_BOR: case OPR_BXOR: { |
| codebitwise(fs, opr, e1, e2, line); |
| break; |
| } |
| case OPR_SHL: { |
| if (isSCint(e1)) { |
| swapexps(e1, e2); |
| codebini(fs, OP_SHLI, e1, e2, 1, line, TM_SHL); /* I << r2 */ |
| } |
| else if (finishbinexpneg(fs, e1, e2, OP_SHRI, line, TM_SHL)) { |
| /* coded as (r1 >> -I) */; |
| } |
| else /* regular case (two registers) */ |
| codebinexpval(fs, opr, e1, e2, line); |
| break; |
| } |
| case OPR_SHR: { |
| if (isSCint(e2)) |
| codebini(fs, OP_SHRI, e1, e2, 0, line, TM_SHR); /* r1 >> I */ |
| else /* regular case (two registers) */ |
| codebinexpval(fs, opr, e1, e2, line); |
| break; |
| } |
| case OPR_EQ: case OPR_NE: { |
| codeeq(fs, opr, e1, e2); |
| break; |
| } |
| case OPR_GT: case OPR_GE: { |
| /* '(a > b)' <=> '(b < a)'; '(a >= b)' <=> '(b <= a)' */ |
| swapexps(e1, e2); |
| opr = cast(BinOpr, (opr - OPR_GT) + OPR_LT); |
| } /* FALLTHROUGH */ |
| case OPR_LT: case OPR_LE: { |
| codeorder(fs, opr, e1, e2); |
| break; |
| } |
| default: lua_assert(0); |
| } |
| } |
| |
| |
| /* |
| ** Change line information associated with current position, by removing |
| ** previous info and adding it again with new line. |
| */ |
| void luaK_fixline (FuncState *fs, int line) { |
| removelastlineinfo(fs); |
| savelineinfo(fs, fs->f, line); |
| } |
| |
| |
| void luaK_settablesize (FuncState *fs, int pc, int ra, int asize, int hsize) { |
| Instruction *inst = &fs->f->code[pc]; |
| int extra = asize / (MAXARG_vC + 1); /* higher bits of array size */ |
| int rc = asize % (MAXARG_vC + 1); /* lower bits of array size */ |
| int k = (extra > 0); /* true iff needs extra argument */ |
| hsize = (hsize != 0) ? luaO_ceillog2(cast_uint(hsize)) + 1 : 0; |
| *inst = CREATE_vABCk(OP_NEWTABLE, ra, hsize, rc, k); |
| *(inst + 1) = CREATE_Ax(OP_EXTRAARG, extra); |
| } |
| |
| |
| /* |
| ** Emit a SETLIST instruction. |
| ** 'base' is register that keeps table; |
| ** 'nelems' is #table plus those to be stored now; |
| ** 'tostore' is number of values (in registers 'base + 1',...) to add to |
| ** table (or LUA_MULTRET to add up to stack top). |
| */ |
| void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) { |
| lua_assert(tostore != 0); |
| if (tostore == LUA_MULTRET) |
| tostore = 0; |
| if (nelems <= MAXARG_vC) |
| luaK_codevABCk(fs, OP_SETLIST, base, tostore, nelems, 0); |
| else { |
| int extra = nelems / (MAXARG_vC + 1); |
| nelems %= (MAXARG_vC + 1); |
| luaK_codevABCk(fs, OP_SETLIST, base, tostore, nelems, 1); |
| codeextraarg(fs, extra); |
| } |
| fs->freereg = cast_byte(base + 1); /* free registers with list values */ |
| } |
| |
| |
| /* |
| ** return the final target of a jump (skipping jumps to jumps) |
| */ |
| static int finaltarget (Instruction *code, int i) { |
| int count; |
| for (count = 0; count < 100; count++) { /* avoid infinite loops */ |
| Instruction pc = code[i]; |
| if (GET_OPCODE(pc) != OP_JMP) |
| break; |
| else |
| i += GETARG_sJ(pc) + 1; |
| } |
| return i; |
| } |
| |
| |
| /* |
| ** Do a final pass over the code of a function, doing small peephole |
| ** optimizations and adjustments. |
| */ |
| #include "lopnames.h" |
| void luaK_finish (FuncState *fs) { |
| int i; |
| Proto *p = fs->f; |
| for (i = 0; i < fs->pc; i++) { |
| Instruction *pc = &p->code[i]; |
| /* avoid "not used" warnings when assert is off (for 'onelua.c') */ |
| (void)luaP_isOT; (void)luaP_isIT; |
| lua_assert(i == 0 || luaP_isOT(*(pc - 1)) == luaP_isIT(*pc)); |
| switch (GET_OPCODE(*pc)) { |
| case OP_RETURN0: case OP_RETURN1: { |
| if (!(fs->needclose || (p->flag & PF_ISVARARG))) |
| break; /* no extra work */ |
| /* else use OP_RETURN to do the extra work */ |
| SET_OPCODE(*pc, OP_RETURN); |
| } /* FALLTHROUGH */ |
| case OP_RETURN: case OP_TAILCALL: { |
| if (fs->needclose) |
| SETARG_k(*pc, 1); /* signal that it needs to close */ |
| if (p->flag & PF_ISVARARG) |
| SETARG_C(*pc, p->numparams + 1); /* signal that it is vararg */ |
| break; |
| } |
| case OP_JMP: { |
| int target = finaltarget(p->code, i); |
| fixjump(fs, i, target); |
| break; |
| } |
| default: break; |
| } |
| } |
| } |