diff options
Diffstat (limited to 'source/luametatex/source/luacore/lua54/src/lcode.c')
| -rw-r--r-- | source/luametatex/source/luacore/lua54/src/lcode.c | 1844 |
1 files changed, 1844 insertions, 0 deletions
diff --git a/source/luametatex/source/luacore/lua54/src/lcode.c b/source/luametatex/source/luacore/lua54/src/lcode.c new file mode 100644 index 000000000..911dbd5f1 --- /dev/null +++ b/source/luametatex/source/luacore/lua54/src/lcode.c @@ -0,0 +1,1844 @@ +/* +** $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" + + +/* Maximum number of registers in a Lua function (must fit in 8 bits) */ +#define MAXREGS 255 + + +#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; + } + 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, MAX_INT, "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, + MAX_INT, "opcodes"); + f->lineinfo[pc] = 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, + MAX_INT, "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)); +} + + +/* +** Format and emit an 'iABx' instruction. +*/ +int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned 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. +*/ +int luaK_codeAsBx (FuncState *fs, OpCode o, int a, int bc) { + unsigned 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) { + unsigned 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) { + if (newstack >= MAXREGS) + luaX_syntaxerror(fs->ls, + "function or expression needs too many 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 += 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; + const TValue *idx = luaH_get(fs->ls->h, key); /* query scanner table */ + int k, oldsize; + if (ttisinteger(idx)) { /* is there an index there? */ + k = cast_int(ivalue(idx)); + /* 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_finishset(L, fs->ls->h, key, idx, &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)) + luaK_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)) + luaK_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); + 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 */ + e->u.info = e->u.var.ridx; + 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 (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. +*/ +int luaK_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 = luaK_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 small 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. +*/ +int luaK_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 luaK_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 luaK_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) { + t->u.ind.t = t->u.info; /* upvalue index */ + t->u.ind.idx = k->u.info; /* literal string */ + t->k = VINDEXUP; + } + else { + /* register index of the table */ + t->u.ind.t = (t->k == VLOCAL) ? t->u.var.ridx: t->u.info; + if (isKstr(fs, k)) { + t->u.ind.idx = k->u.info; /* literal string */ + t->k = VINDEXSTR; + } + else if (isCint(k)) { + t->u.ind.idx = cast_int(k->u.ival); /* int. constant in proper range */ + t->k = VINDEXI; + } + else { + t->u.ind.idx = 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; +} + + +/* +** 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, OpCode op, + expdesc *e1, expdesc *e2, int line) { + 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, + cast(TMS, (op - OP_ADD) + TM_ADD)); +} + + +/* +** 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 = cast(TMS, opr + TM_ADD); + int v2 = e2->u.info; /* K index */ + OpCode op = cast(OpCode, opr + 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 (!luaK_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) { + OpCode op = cast(OpCode, opr + OP_ADD); + if (flip) + swapexps(e1, e2); /* back to original order */ + codebinexpval(fs, op, 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, cast(OpCode, 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, OpCode op, expdesc *e1, expdesc *e2) { + int r1, r2; + int im; + int isfloat = 0; + if (isSCnumber(e2, &im, &isfloat)) { + /* use immediate operand */ + r1 = luaK_exp2anyreg(fs, e1); + r2 = im; + op = cast(OpCode, (op - OP_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 = (op == OP_LT) ? OP_GTI : OP_GEI; + } + else { /* regular case, compare two registers */ + r1 = luaK_exp2anyreg(fs, e1); + r2 = luaK_exp2anyreg(fs, e2); + } + 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 (luaK_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 op, expdesc *e, int line) { + static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP}; + luaK_dischargevars(fs, e); + switch (op) { + case OPR_MINUS: case OPR_BNOT: /* use 'ef' as fake 2nd operand */ + if (constfolding(fs, op + LUA_OPUNM, e, &ef)) + break; + /* else */ /* FALLTHROUGH */ + case OPR_LEN: + codeunexpval(fs, cast(OpCode, op + OP_UNM), 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)) + luaK_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, 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, OP_SHL, 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, OP_SHR, e1, e2, line); + break; + } + case OPR_EQ: case OPR_NE: { + codeeq(fs, opr, e1, e2); + break; + } + case OPR_LT: case OPR_LE: { + OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ); + codeorder(fs, op, e1, e2); + break; + } + case OPR_GT: case OPR_GE: { + /* '(a > b)' <=> '(b < a)'; '(a >= b)' <=> '(b <= a)' */ + OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ); + swapexps(e1, e2); + codeorder(fs, op, 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 rb = (hsize != 0) ? luaO_ceillog2(hsize) + 1 : 0; /* hash size */ + int extra = asize / (MAXARG_C + 1); /* higher bits of array size */ + int rc = asize % (MAXARG_C + 1); /* lower bits of array size */ + int k = (extra > 0); /* true iff needs extra argument */ + *inst = CREATE_ABCk(OP_NEWTABLE, ra, rb, 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 && tostore <= LFIELDS_PER_FLUSH); + if (tostore == LUA_MULTRET) + tostore = 0; + if (nelems <= MAXARG_C) + luaK_codeABC(fs, OP_SETLIST, base, tostore, nelems); + else { + int extra = nelems / (MAXARG_C + 1); + nelems %= (MAXARG_C + 1); + luaK_codeABCk(fs, OP_SETLIST, base, tostore, nelems, 1); + codeextraarg(fs, extra); + } + fs->freereg = 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. +*/ +void luaK_finish (FuncState *fs) { + int i; + Proto *p = fs->f; + for (i = 0; i < fs->pc; i++) { + Instruction *pc = &p->code[i]; + lua_assert(i == 0 || isOT(*(pc - 1)) == isIT(*pc)); + switch (GET_OPCODE(*pc)) { + case OP_RETURN0: case OP_RETURN1: { + if (!(fs->needclose || p->is_vararg)) + 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->is_vararg) + 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; + } + } +} |