/*
** Trace recorder (bytecode -> SSA IR).
** Copyright (C) 2005-2020 Mike Pall. See Copyright Notice in luajit.h
*/
#define lj_record_c
#define LUA_CORE
#include "lj_obj.h"
#if LJ_HASJIT
#include "lj_err.h"
#include "lj_str.h"
#include "lj_tab.h"
#include "lj_meta.h"
#include "lj_frame.h"
#if LJ_HASFFI
#include "lj_ctype.h"
#endif
#include "lj_bc.h"
#include "lj_ff.h"
#include "lj_ir.h"
#include "lj_jit.h"
#include "lj_ircall.h"
#include "lj_iropt.h"
#include "lj_trace.h"
#include "lj_record.h"
#include "lj_ffrecord.h"
#include "lj_snap.h"
#include "lj_dispatch.h"
#include "lj_vm.h"
/* Some local macros to save typing. Undef'd at the end. */
#define IR(ref) (&J->cur.ir[(ref)])
/* Pass IR on to next optimization in chain (FOLD). */
#define emitir(ot, a, b) (lj_ir_set(J, (ot), (a), (b)), lj_opt_fold(J))
/* Emit raw IR without passing through optimizations. */
#define emitir_raw(ot, a, b) (lj_ir_set(J, (ot), (a), (b)), lj_ir_emit(J))
/* -- Sanity checks ------------------------------------------------------- */
#ifdef LUA_USE_ASSERT
/* Sanity check the whole IR -- sloooow. */
static void rec_check_ir(jit_State *J)
{
IRRef i, nins = J->cur.nins, nk = J->cur.nk;
lua_assert(nk <= REF_BIAS && nins >= REF_BIAS && nins < 65536);
for (i = nins-1; i >= nk; i--) {
IRIns *ir = IR(i);
uint32_t mode = lj_ir_mode[ir->o];
IRRef op1 = ir->op1;
IRRef op2 = ir->op2;
switch (irm_op1(mode)) {
case IRMnone: lua_assert(op1 == 0); break;
case IRMref: lua_assert(op1 >= nk);
lua_assert(i >= REF_BIAS ? op1 < i : op1 > i); break;
case IRMlit: break;
case IRMcst: lua_assert(i < REF_BIAS); continue;
}
switch (irm_op2(mode)) {
case IRMnone: lua_assert(op2 == 0); break;
case IRMref: lua_assert(op2 >= nk);
lua_assert(i >= REF_BIAS ? op2 < i : op2 > i); break;
case IRMlit: break;
case IRMcst: lua_assert(0); break;
}
if (ir->prev) {
lua_assert(ir->prev >= nk);
lua_assert(i >= REF_BIAS ? ir->prev < i : ir->prev > i);
lua_assert(ir->o == IR_NOP || IR(ir->prev)->o == ir->o);
}
}
}
/* Compare stack slots and frames of the recorder and the VM. */
static void rec_check_slots(jit_State *J)
{
BCReg s, nslots = J->baseslot + J->maxslot;
int32_t depth = 0;
cTValue *base = J->L->base - J->baseslot;
lua_assert(J->baseslot >= 1);
lua_assert(J->baseslot == 1 || (J->slot[J->baseslot-1] & TREF_FRAME));
lua_assert(nslots <= LJ_MAX_JSLOTS);
for (s = 0; s < nslots; s++) {
TRef tr = J->slot[s];
if (tr) {
cTValue *tv = &base[s];
IRRef ref = tref_ref(tr);
IRIns *ir;
lua_assert(ref >= J->cur.nk && ref < J->cur.nins);
ir = IR(ref);
lua_assert(irt_t(ir->t) == tref_t(tr));
if (s == 0) {
lua_assert(tref_isfunc(tr));
} else if ((tr & TREF_FRAME)) {
GCfunc *fn = gco2func(frame_gc(tv));
BCReg delta = (BCReg)(tv - frame_prev(tv));
lua_assert(tref_isfunc(tr));
if (tref_isk(tr)) lua_assert(fn == ir_kfunc(ir));
lua_assert(s > delta ? (J->slot[s-delta] & TREF_FRAME) : (s == delta));
depth++;
} else if ((tr & TREF_CONT)) {
lua_assert(ir_kptr(ir) == gcrefp(tv->gcr, void));
lua_assert((J->slot[s+1] & TREF_FRAME));
depth++;
} else {
if (tvisnumber(tv))
lua_assert(tref_isnumber(tr)); /* Could be IRT_INT etc., too. */
else
lua_assert(itype2irt(tv) == tref_type(tr));
if (tref_isk(tr)) { /* Compare constants. */
TValue tvk;
lj_ir_kvalue(J->L, &tvk, ir);
if (!(tvisnum(&tvk) && tvisnan(&tvk)))
lua_assert(lj_obj_equal(tv, &tvk));
else
lua_assert(tvisnum(tv) && tvisnan(tv));
}
}
}
}
lua_assert(J->framedepth == depth);
}
#endif
/* -- Type handling and specialization ------------------------------------ */
/* Note: these functions return tagged references (TRef). */
/* Specialize a slot to a specific type. Note: slot can be negative! */
static TRef sloadt(jit_State *J, int32_t slot, IRType t, int mode)
{
/* Caller may set IRT_GUARD in t. */
TRef ref = emitir_raw(IRT(IR_SLOAD, t), (int32_t)J->baseslot+slot, mode);
J->base[slot] = ref;
return ref;
}
/* Specialize a slot to the runtime type. Note: slot can be negative! */
static TRef sload(jit_State *J, int32_t slot)
{
IRType t = itype2irt(&J->L->base[slot]);
TRef ref = emitir_raw(IRTG(IR_SLOAD, t), (int32_t)J->baseslot+slot,
IRSLOAD_TYPECHECK);
if (irtype_ispri(t)) ref = TREF_PRI(t); /* Canonicalize primitive refs. */
J->base[slot] = ref;
return ref;
}
/* Get TRef from slot. Load slot and specialize if not done already. */
#define getslot(J, s) (J->base[(s)] ? J->base[(s)] : sload(J, (int32_t)(s)))
/* Get TRef for current function. */
static TRef getcurrf(jit_State *J)
{
if (J->base[-1])
return J->base[-1];
lua_assert(J->baseslot == 1);
return sloadt(J, -1, IRT_FUNC, IRSLOAD_READONLY);
}
/* Compare for raw object equality.
** Returns 0 if the objects are the same.
** Returns 1 if they are different, but the same type.
** Returns 2 for two different types.
** Comparisons between primitives always return 1 -- no caller cares about it.
*/
int lj_record_objcmp(jit_State *J, TRef a, TRef b, cTValue *av, cTValue *bv)
{
int diff = !lj_obj_equal(av, bv);
if (!tref_isk2(a, b)) { /* Shortcut, also handles primitives. */
IRType ta = tref_isinteger(a) ? IRT_INT : tref_type(a);
IRType tb = tref_isinteger(b) ? IRT_INT : tref_type(b);
if (ta != tb) {
/* Widen mixed number/int comparisons to number/number comparison. */
if (ta == IRT_INT && tb == IRT_NUM) {
a = emitir(IRTN(IR_CONV), a, IRCONV_NUM_INT);
ta = IRT_NUM;
} else if (ta == IRT_NUM && tb == IRT_INT) {
b = emitir(IRTN(IR_CONV), b, IRCONV_NUM_INT);
} else {
return 2; /* Two different types are never equal. */
}
}
emitir(IRTG(diff ? IR_NE : IR_EQ, ta), a, b);
}
return diff;
}
/* Constify a value. Returns 0 for non-representable object types. */
TRef lj_record_constify(jit_State *J, cTValue *o)
{
if (tvisgcv(o))
return lj_ir_kgc(J, gcV(o), itype2irt(o));
else if (tvisint(o))
return lj_ir_kint(J, intV(o));
else if (tvisnum(o))
return lj_ir_knumint(J, numV(o));
else if (tvisbool(o))
return TREF_PRI(itype2irt(o));
else
return 0; /* Can't represent lightuserdata (pointless). */
}
/* -- Record loop ops ----------------------------------------------------- */
/* Loop event. */
typedef enum {
LOOPEV_LEAVE, /* Loop is left or not entered. */
LOOPEV_ENTERLO, /* Loop is entered with a low iteration count left. */
LOOPEV_ENTER /* Loop is entered. */
} LoopEvent;
/* Canonicalize slots: convert integers to numbers. */
static void canonicalize_slots(jit_State *J)
{
BCReg s;
if (LJ_DUALNUM) return;
for (s = J->baseslot+J->maxslot-1; s >= 1; s--) {
TRef tr = J->slot[s];
if (tref_isinteger(tr)) {
IRIns *ir = IR(tref_ref(tr));
if (!(ir->o == IR_SLOAD && (ir->op2 & IRSLOAD_READONLY)))
J->slot[s] = emitir(IRTN(IR_CONV), tr, IRCONV_NUM_INT);
}
}
}
/* Stop recording. */
static void rec_stop(jit_State *J, TraceLink linktype, TraceNo lnk)
{
lj_trace_end(J);
J->cur.linktype = (uint8_t)linktype;
J->cur.link = (uint16_t)lnk;
/* Looping back at the same stack level? */
if (lnk == J->cur.traceno && J->framedepth + J->retdepth == 0) {
if ((J->flags & JIT_F_OPT_LOOP)) /* Shall we try to create a loop? */
goto nocanon; /* Do not canonicalize or we lose the narrowing. */
if (J->cur.root) /* Otherwise ensure we always link to the root trace. */
J->cur.link = J->cur.root;
}
canonicalize_slots(J);
nocanon:
/* Note: all loop ops must set J->pc to the following instruction! */
lj_snap_add(J); /* Add loop snapshot. */
J->needsnap = 0;
J->mergesnap = 1; /* In case recording continues. */
}
/* Search bytecode backwards for a int/num constant slot initializer. */
static TRef find_kinit(jit_State *J, const BCIns *endpc, BCReg slot, IRType t)
{
/* This algorithm is rather simplistic and assumes quite a bit about
** how the bytecode is generated. It works fine for FORI initializers,
** but it won't necessarily work in other cases (e.g. iterator arguments).
** It doesn't do anything fancy, either (like backpropagating MOVs).
*/
const BCIns *pc, *startpc = proto_bc(J->pt);
for (pc = endpc-1; pc > startpc; pc--) {
BCIns ins = *pc;
BCOp op = bc_op(ins);
/* First try to find the last instruction that stores to this slot. */
if (bcmode_a(op) == BCMbase && bc_a(ins) <= slot) {
return 0; /* Multiple results, e.g. from a CALL or KNIL. */
} else if (bcmode_a(op) == BCMdst && bc_a(ins) == slot) {
if (op == BC_KSHORT || op == BC_KNUM) { /* Found const. initializer. */
/* Now try to verify there's no forward jump across it. */
const BCIns *kpc = pc;
for (; pc > startpc; pc--)
if (bc_op(*pc) == BC_JMP) {
const BCIns *target = pc+bc_j(*pc)+1;
if (target > kpc && target <= endpc)
return 0; /* Conditional assignment. */
}
if (op == BC_KSHORT) {
int32_t k = (int32_t)(int16_t)bc_d(ins);
return t == IRT_INT ? lj_ir_kint(J, k) : lj_ir_knum(J, (lua_Number)k);
} else {
cTValue *tv = proto_knumtv(J->pt, bc_d(ins));
if (t == IRT_INT) {
int32_t k = numberVint(tv);
if (tvisint(tv) || numV(tv) == (lua_Number)k) /* -0 is ok here. */
return lj_ir_kint(J, k);
return 0; /* Type mismatch. */
} else {
return lj_ir_knum(J, numberVnum(tv));
}
}
}
return 0; /* Non-constant initializer. */
}
}
return 0; /* No assignment to this slot found? */
}
/* Load and optionally convert a FORI argument from a slot. */
static TRef fori_load(jit_State *J, BCReg slot, IRType t, int mode)
{
int conv = (tvisint(&J->L->base[slot]) != (t==IRT_INT)) ? IRSLOAD_CONVERT : 0;
return sloadt(J, (int32_t)slot,
t + (((mode & IRSLOAD_TYPECHECK) ||
(conv && t == IRT_INT && !(mode >> 16))) ?
IRT_GUARD : 0),
mode + conv);
}
/* Peek before FORI to find a const initializer. Otherwise load from slot. */
static TRef fori_arg(jit_State *J, const BCIns *fori, BCReg slot,
IRType t, int mode)
{
TRef tr = J->base[slot];
if (!tr) {
tr = find_kinit(J, fori, slot, t);
if (!tr)
tr = fori_load(J, slot, t, mode);
}
return tr;
}
/* Return the direction of the FOR loop iterator.
** It's important to exactly reproduce the semantics of the interpreter.
*/
static int rec_for_direction(cTValue *o)
{
return (tvisint(o) ? intV(o) : (int32_t)o->u32.hi) >= 0;
}
/* Simulate the runtime behavior of the FOR loop iterator. */
static LoopEvent rec_for_iter(IROp *op, cTValue *o, int isforl)
{
lua_Number stopv = numberVnum(&o[FORL_STOP]);
lua_Number idxv = numberVnum(&o[FORL_IDX]);
lua_Number stepv = numberVnum(&o[FORL_STEP]);
if (isforl)
idxv += stepv;
if (rec_for_direction(&o[FORL_STEP])) {
if (idxv <= stopv) {
*op = IR_LE;
return idxv + 2*stepv > stopv ? LOOPEV_ENTERLO : LOOPEV_ENTER;
}
*op = IR_GT; return LOOPEV_LEAVE;
} else {
if (stopv <= idxv) {
*op = IR_GE;
return idxv + 2*stepv < stopv ? LOOPEV_ENTERLO : LOOPEV_ENTER;
}
*op = IR_LT; return LOOPEV_LEAVE;
}
}
/* Record checks for FOR loop overflow and step direction. */
static void rec_for_check(jit_State *J, IRType t, int dir,
TRef stop, TRef step, int init)
{
if (!tref_isk(step)) {
/* Non-constant step: need a guard for the direction. */
TRef zero = (t == IRT_INT) ? lj_ir_kint(J, 0) : lj_ir_knum_zero(J);
emitir(IRTG(dir ? IR_GE : IR_LT, t), step, zero);
/* Add hoistable overflow checks for a narrowed FORL index. */
if (init && t == IRT_INT) {
if (tref_isk(stop)) {
/* Constant stop: optimize check away or to a range check for step. */
int32_t k = IR(tref_ref(stop))->i;
if (dir) {
if (k > 0)
emitir(IRTGI(IR_LE), step, lj_ir_kint(J, (int32_t)0x7fffffff-k));
} else {
if (k < 0)
emitir(IRTGI(IR_GE), step, lj_ir_kint(J, (int32_t)0x80000000-k));
}
} else {
/* Stop+step variable: need full overflow check. */
TRef tr = emitir(IRTGI(IR_ADDOV), step, stop);
emitir(IRTI(IR_USE), tr, 0); /* ADDOV is weak. Avoid dead result. */
}
}
} else if (init && t == IRT_INT && !tref_isk(stop)) {
/* Constant step: optimize overflow check to a range check for stop. */
int32_t k = IR(tref_ref(step))->i;
k = (int32_t)(dir ? 0x7fffffff : 0x80000000) - k;
emitir(IRTGI(dir ? IR_LE : IR_GE), stop, lj_ir_kint(J, k));
}
}
/* Record a FORL instruction. */
static void rec_for_loop(jit_State *J, const BCIns *fori, ScEvEntry *scev,
int init)
{
BCReg ra = bc_a(*fori);
cTValue *tv = &J->L->base[ra];
TRef idx = J->base[ra+FORL_IDX];
IRType t = idx ? tref_type(idx) :
(init || LJ_DUALNUM) ? lj_opt_narrow_forl(J, tv) : IRT_NUM;
int mode = IRSLOAD_INHERIT +
((!LJ_DUALNUM || tvisint(tv) == (t == IRT_INT)) ? IRSLOAD_READONLY : 0);
TRef stop = fori_arg(J, fori, ra+FORL_STOP, t, mode);
TRef step = fori_arg(J, fori, ra+FORL_STEP, t, mode);
int tc, dir = rec_for_direction(&tv[FORL_STEP]);
lua_assert(bc_op(*fori) == BC_FORI || bc_op(*fori) == BC_JFORI);
scev->t.irt = t;
scev->dir = dir;
scev->stop = tref_ref(stop);
scev->step = tref_ref(step);
rec_for_check(J, t, dir, stop, step, init);
scev->start = tref_ref(find_kinit(J, fori, ra+FORL_IDX, IRT_INT));
tc = (LJ_DUALNUM &&
!(scev->start && irref_isk(scev->stop) && irref_isk(scev->step) &&
tvisint(&tv[FORL_IDX]) == (t == IRT_INT))) ?
IRSLOAD_TYPECHECK : 0;
if (tc) {
J->base[ra+FORL_STOP] = stop;
J->base[ra+FORL_STEP] = step;
}
if (!idx)
idx = fori_load(J, ra+FORL_IDX, t,
IRSLOAD_INHERIT + tc + (J->scev.start << 16));
if (!init)
J->base[ra+FORL_IDX] = idx = emitir(IRT(IR_ADD, t), idx, step);
J->base[ra+FORL_EXT] = idx;
scev->idx = tref_ref(idx);
setmref(scev->pc, fori);
J->maxslot = ra+FORL_EXT+1;
}
/* Record FORL/JFORL or FORI/JFORI. */
static LoopEvent rec_for(jit_State *J, const BCIns *fori, int isforl)
{
BCReg ra = bc_a(*fori);
TValue *tv = &J->L->base[ra];
TRef *tr = &J->base[ra];
IROp op;
LoopEvent ev;
TRef stop;
IRType t;
if (isforl) { /* Handle FORL/JFORL opcodes. */
TRef idx = tr[FORL_IDX];
if (mref(J->scev.pc, const BCIns) == fori && tref_ref(idx) == J->scev.idx) {
t = J->scev.t.irt;
stop = J->scev.stop;
idx = emitir(IRT(IR_ADD, t), idx, J->scev.step);
tr[FORL_EXT] = tr[FORL_IDX] = idx;
} else {
ScEvEntry scev;
rec_for_loop(J, fori, &scev, 0);
t = scev.t.irt;
stop = scev.stop;
}
} else { /* Handle FORI/JFORI opcodes. */
BCReg i;
lj_meta_for(J->L, tv);
t = (LJ_DUALNUM || tref_isint(tr[FORL_IDX])) ? lj_opt_narrow_forl(J, tv) :
IRT_NUM;
for (i = FORL_IDX; i <= FORL_STEP; i++) {
if (!tr[i]) sload(J, ra+i);
lua_assert(tref_isnumber_str(tr[i]));
if (tref_isstr(tr[i]))
tr[i] = emitir(IRTG(IR_STRTO, IRT_NUM), tr[i], 0);
if (t == IRT_INT) {
if (!tref_isinteger(tr[i]))
tr[i] = emitir(IRTGI(IR_CONV), tr[i], IRCONV_INT_NUM|IRCONV_CHECK);
} else {
if (!tref_isnum(tr[i]))
tr[i] = emitir(IRTN(IR_CONV), tr[i], IRCONV_NUM_INT);
}
}
tr[FORL_EXT] = tr[FORL_IDX];
stop = tr[FORL_STOP];
rec_for_check(J, t, rec_for_direction(&tv[FORL_STEP]),
stop, tr[FORL_STEP], 1);
}
ev = rec_for_iter(&op, tv, isforl);
if (ev == LOOPEV_LEAVE) {
J->maxslot = ra+FORL_EXT+1;
J->pc = fori+1;
} else {
J->maxslot = ra;
J->pc = fori+bc_j(*fori)+1;
}
lj_snap_add(J);
emitir(IRTG(op, t), tr[FORL_IDX], stop);
if (ev == LOOPEV_LEAVE) {
J->maxslot = ra;
J->pc = fori+bc_j(*fori)+1;
} else {
J->maxslot = ra+FORL_EXT+1;
J->pc = fori+1;
}
J->needsnap = 1;
return ev;
}
/* Record ITERL/JITERL. */
static LoopEvent rec_iterl(jit_State *J, const BCIns iterins)
{
BCReg ra = bc_a(iterins);
lua_assert(J->base[ra] != 0);
if (!tref_isnil(J->base[ra])) { /* Looping back? */
J->base[ra-1] = J->base[ra]; /* Copy result of ITERC to control var. */
J->maxslot = ra-1+bc_b(J->pc[-1]);
J->pc += bc_j(iterins)+1;
return LOOPEV_ENTER;
} else {
J->maxslot = ra-3;
J->pc++;
return LOOPEV_LEAVE;
}
}
/* Record LOOP/JLOOP. Now, that was easy. */
static LoopEvent rec_loop(jit_State *J, BCReg ra)
{
if (ra < J->maxslot) J->maxslot = ra;
J->pc++;
return LOOPEV_ENTER;
}
/* Check if a loop repeatedly failed to trace because it didn't loop back. */
static int innerloopleft(jit_State *J, const BCIns *pc)
{
ptrdiff_t i;
for (i = 0; i < PENALTY_SLOTS; i++)
if (mref(J->penalty[i].pc, const BCIns) == pc) {
if ((J->penalty[i].reason == LJ_TRERR_LLEAVE ||
J->penalty[i].reason == LJ_TRERR_LINNER) &&
J->penalty[i].val >= 2*PENALTY_MIN)
return 1;
break;
}
return 0;
}
/* Handle the case when an interpreted loop op is hit. */
static void rec_loop_interp(jit_State *J, const BCIns *pc, LoopEvent ev)
{
if (J->parent == 0) {
if (pc == J->startpc && J->framedepth + J->retdepth == 0) {
/* Same loop? */
if (ev == LOOPEV_LEAVE) /* Must loop back to form a root trace. */
lj_trace_err(J, LJ_TRERR_LLEAVE);
rec_stop(J, LJ_TRLINK_LOOP, J->cur.traceno); /* Looping root trace. */
} else if (ev != LOOPEV_LEAVE) { /* Entering inner loop? */
/* It's usually better to abort here and wait until the inner loop
** is traced. But if the inner loop repeatedly didn't loop back,
** this indicates a low trip count. In this case try unrolling
** an inner loop even in a root trace. But it's better to be a bit
** more conservative here and only do it for very short loops.
*/
if (bc_j(*pc) != -1 && !innerloopleft(J, pc))
lj_trace_err(J, LJ_TRERR_LINNER); /* Root trace hit an inner loop. */
if ((ev != LOOPEV_ENTERLO &&
J->loopref && J->cur.nins - J->loopref > 24) || --J->loopunroll < 0)
lj_trace_err(J, LJ_TRERR_LUNROLL); /* Limit loop unrolling. */
J->loopref = J->cur.nins;
}
} else if (ev != LOOPEV_LEAVE) { /* Side trace enters an inner loop. */
J->loopref = J->cur.nins;
if (--J->loopunroll < 0)
lj_trace_err(J, LJ_TRERR_LUNROLL); /* Limit loop unrolling. */
} /* Side trace continues across a loop that's left or not entered. */
}
/* Handle the case when an already compiled loop op is hit. */
static void rec_loop_jit(jit_State *J, TraceNo lnk, LoopEvent ev)
{
if (J->parent == 0) { /* Root trace hit an inner loop. */
/* Better let the inner loop spawn a side trace back here. */
lj_trace_err(J, LJ_TRERR_LINNER);
} else if (ev != LOOPEV_LEAVE) { /* Side trace enters a compiled loop. */
J->instunroll = 0; /* Cannot continue across a compiled loop op. */
if (J->pc == J->startpc && J->framedepth + J->retdepth == 0)
rec_stop(J, LJ_TRLINK_LOOP, J->cur.traceno); /* Form an extra loop. */
else
rec_stop(J, LJ_TRLINK_ROOT, lnk); /* Link to the loop. */
} /* Side trace continues across a loop that's left or not entered. */
}
/* -- Record calls and returns -------------------------------------------- */
/* Specialize to the runtime value of the called function or its prototype. */
static TRef rec_call_specialize(jit_State *J, GCfunc *fn, TRef tr)
{
TRef kfunc;
if (isluafunc(fn)) {
GCproto *pt = funcproto(fn);
/* Too many closures created? Probably not a monomorphic function. */
if (pt->flags >= PROTO_CLC_POLY) { /* Specialize to prototype instead. */
TRef trpt = emitir(IRT(IR_FLOAD, IRT_P32), tr, IRFL_FUNC_PC);
emitir(IRTG(IR_EQ, IRT_P32), trpt, lj_ir_kptr(J, proto_bc(pt)));
(void)lj_ir_kgc(J, obj2gco(pt), IRT_PROTO); /* Prevent GC of proto. */
return tr;
}
}
/* Otherwise specialize to the function (closure) value itself. */
kfunc = lj_ir_kfunc(J, fn);
emitir(IRTG(IR_EQ, IRT_FUNC), tr, kfunc);
return kfunc;
}
/* Record call setup. */
static void rec_call_setup(jit_State *J, BCReg func, ptrdiff_t nargs)
{
RecordIndex ix;
TValue *functv = &J->L->base[func];
TRef *fbase = &J->base[func];
ptrdiff_t i;
for (i = 0; i <= nargs; i++)
(void)getslot(J, func+i); /* Ensure func and all args have a reference. */
if (!tref_isfunc(fbase[0])) { /* Resolve __call metamethod. */
ix.tab = fbase[0];
copyTV(J->L, &ix.tabv, functv);
if (!lj_record_mm_lookup(J, &ix, MM_call) || !tref_isfunc(ix.mobj))
lj_trace_err(J, LJ_TRERR_NOMM);
for (i = ++nargs; i > 0; i--) /* Shift arguments up. */
fbase[i] = fbase[i-1];
fbase[0] = ix.mobj; /* Replace function. */
functv = &ix.mobjv;
}
fbase[0] = TREF_FRAME | rec_call_specialize(J, funcV(functv), fbase[0]);
J->maxslot = (BCReg)nargs;
}
/* Record call. */
void lj_record_call(jit_State *J, BCReg func, ptrdiff_t nargs)
{
rec_call_setup(J, func, nargs);
/* Bump frame. */
J->framedepth++;
J->base += func+1;
J->baseslot += func+1;
if (J->baseslot + J->maxslot >= LJ_MAX_JSLOTS)
lj_trace_err(J, LJ_TRERR_STACKOV);
}
/* Record tail call. */
void lj_record_tailcall(jit_State *J, BCReg func, ptrdiff_t nargs)
{
rec_call_setup(J, func, nargs);
if (frame_isvarg(J->L->base - 1)) {
BCReg cbase = (BCReg)frame_delta(J->L->base - 1);
if (--J->framedepth < 0)
lj_trace_err(J, LJ_TRERR_NYIRETL);
J->baseslot -= (BCReg)cbase;
J->base -= cbase;
func += cbase;
}
/* Move func + args down. */
memmove(&J->base[-1], &J->base[func], sizeof(TRef)*(J->maxslot+1));
/* Note: the new TREF_FRAME is now at J->base[-1] (even for slot #0). */
/* Tailcalls can form a loop, so count towards the loop unroll limit. */
if (++J->tailcalled > J->loopunroll)
lj_trace_err(J, LJ_TRERR_LUNROLL);
}
/* Check unroll limits for down-recursion. */
static int check_downrec_unroll(jit_State *J, GCproto *pt)
{
IRRef ptref;
for (ptref = J->chain[IR_KGC]; ptref; ptref = IR(ptref)->prev)
if (ir_kgc(IR(ptref)) == obj2gco(pt)) {
int count = 0;
IRRef ref;
for (ref = J->chain[IR_RETF]; ref; ref = IR(ref)->prev)
if (IR(ref)->op1 == ptref)
count++;
if (count) {
if (J->pc == J->startpc) {
if (count + J->tailcalled > J->param[JIT_P_recunroll])
return 1;
} else {
lj_trace_err(J, LJ_TRERR_DOWNREC);
}
}
}
return 0;
}
/* Record return. */
void lj_record_ret(jit_State *J, BCReg rbase, ptrdiff_t gotresults)
{
TValue *frame = J->L->base - 1;
ptrdiff_t i;
for (i = 0; i < gotresults; i++)
(void)getslot(J, rbase+i); /* Ensure all results have a reference. */
while (frame_ispcall(frame)) { /* Immediately resolve pcall() returns. */
BCReg cbase = (BCReg)frame_delta(frame);
if (--J->framedepth <= 0)
lj_trace_err(J, LJ_TRERR_NYIRETL);
lua_assert(J->baseslot > 1);
gotresults++;
rbase += cbase;
J->baseslot -= (BCReg)cbase;
J->base -= cbase;
J->base[--rbase] = TREF_TRUE; /* Prepend true to results. */
frame = frame_prevd(frame);
}
/* Return to lower frame via interpreter for unhandled cases. */
if (J->framedepth == 0 && J->pt && bc_isret(bc_op(*J->pc)) &&
(!frame_islua(frame) ||
(J->parent == 0 && !bc_isret(bc_op(J->cur.startins))))) {
/* NYI: specialize to frame type and return directly, not via RET*. */
for (i = 0; i < (ptrdiff_t)rbase; i++)
J->base[i] = 0; /* Purge dead slots. */
J->maxslot = rbase + (BCReg)gotresults;
rec_stop(J, LJ_TRLINK_RETURN, 0); /* Return to interpreter. */
return;
}
if (frame_isvarg(frame)) {
BCReg cbase = (BCReg)frame_delta(frame);
if (--J->framedepth < 0) /* NYI: return of vararg func to lower frame. */
lj_trace_err(J, LJ_TRERR_NYIRETL);
lua_assert(J->baseslot > 1);
rbase += cbase;
J->baseslot -= (BCReg)cbase;
J->base -= cbase;
frame = frame_prevd(frame);
}
if (frame_islua(frame)) { /* Return to Lua frame. */
BCIns callins = *(frame_pc(frame)-1);
ptrdiff_t nresults = bc_b(callins) ? (ptrdiff_t)bc_b(callins)-1 :gotresults;
BCReg cbase = bc_a(callins);
GCproto *pt = funcproto(frame_func(frame - (cbase+1)));
if ((pt->flags & PROTO_NOJIT))
lj_trace_err(J, LJ_TRERR_CJITOFF);
if (J->framedepth == 0 && J->pt && frame == J->L->base - 1) {
if (check_downrec_unroll(J, pt)) {
J->maxslot = (BCReg)(rbase + gotresults);
lj_snap_purge(J);
rec_stop(J, LJ_TRLINK_DOWNREC, J->cur.traceno); /* Down-recursion. */
return;
}
lj_snap_add(J);
}
for (i = 0; i < nresults; i++) /* Adjust results. */
J->base[i-1] = i < gotresults ? J->base[rbase+i] : TREF_NIL;
J->maxslot = cbase+(BCReg)nresults;
if (J->framedepth > 0) { /* Return to a frame that is part of the trace. */
J->framedepth--;
lua_assert(J->baseslot > cbase+1);
J->baseslot -= cbase+1;
J->base -= cbase+1;
} else if (J->parent == 0 && !bc_isret(bc_op(J->cur.startins))) {
/* Return to lower frame would leave the loop in a root trace. */
lj_trace_err(J, LJ_TRERR_LLEAVE);
} else if (J->needsnap) { /* Tailcalled to ff with side-effects. */
lj_trace_err(J, LJ_TRERR_NYIRETL); /* No way to insert snapshot here. */
} else { /* Return to lower frame. Guard for the target we return to. */
TRef trpt = lj_ir_kgc(J, obj2gco(pt), IRT_PROTO);
TRef trpc = lj_ir_kptr(J, (void *)frame_pc(frame));
emitir(IRTG(IR_RETF, IRT_P32), trpt, trpc);
J->retdepth++;
J->needsnap = 1;
lua_assert(J->baseslot == 1);
/* Shift result slots up and clear the slots of the new frame below. */
memmove(J->base + cbase, J->base-1, sizeof(TRef)*nresults);
memset(J->base-1, 0, sizeof(TRef)*(cbase+1));
}
} else if (frame_iscont(frame)) { /* Return to continuation frame. */
ASMFunction cont = frame_contf(frame);
BCReg cbase = (BCReg)frame_delta(frame);
if ((J->framedepth -= 2) < 0)
lj_trace_err(J, LJ_TRERR_NYIRETL);
J->baseslot -= (BCReg)cbase;
J->base -= cbase;
J->maxslot = cbase-2;
if (cont == lj_cont_ra) {
/* Copy result to destination slot. */
BCReg dst = bc_a(*(frame_contpc(frame)-1));
J->base[dst] = gotresults ? J->base[cbase+rbase] : TREF_NIL;
if (dst >= J->maxslot) J->maxslot = dst+1;
} else if (cont == lj_cont_nop) {
/* Nothing to do here. */
} else if (cont == lj_cont_cat) {
lua_assert(0);
} else {
/* Result type already specialized. */
lua_assert(cont == lj_cont_condf || cont == lj_cont_condt);
}
} else {
lj_trace_err(J, LJ_TRERR_NYIRETL); /* NYI: handle return to C frame. */
}
lua_assert(J->baseslot >= 1);
}
/* -- Metamethod handling ------------------------------------------------- */
/* Prepare to record call to metamethod. */
static BCReg rec_mm_prep(jit_State *J, ASMFunction cont)
{
BCReg s, top = curr_proto(J->L)->framesize;
TRef trcont;
setcont(&J->L->base[top], cont);
#if LJ_64
trcont = lj_ir_kptr(J, (void *)((int64_t)cont - (int64_t)lj_vm_asm_begin));
#else
trcont = lj_ir_kptr(J, (void *)cont);
#endif
J->base[top] = trcont | TREF_CONT;
J->framedepth++;
for (s = J->maxslot; s < top; s++)
J->base[s] = 0; /* Clear frame gap to avoid resurrecting previous refs. */
return top+1;
}
/* Record metamethod lookup. */
int lj_record_mm_lookup(jit_State *J, RecordIndex *ix, MMS mm)
{
RecordIndex mix;
GCtab *mt;
if (tref_istab(ix->tab)) {
mt = tabref(tabV(&ix->tabv)->metatable);
mix.tab = emitir(IRT(IR_FLOAD, IRT_TAB), ix->tab, IRFL_TAB_META);
} else if (tref_isudata(ix->tab)) {
int udtype = udataV(&ix->tabv)->udtype;
mt = tabref(udataV(&ix->tabv)->metatable);
/* The metatables of special userdata objects are treated as immutable. */
if (udtype != UDTYPE_USERDATA) {
cTValue *mo;
if (LJ_HASFFI && udtype == UDTYPE_FFI_CLIB) {
/* Specialize to the C library namespace object. */
emitir(IRTG(IR_EQ, IRT_P32), ix->tab, lj_ir_kptr(J, udataV(&ix->tabv)));
} else {
/* Specialize to the type of userdata. */
TRef tr = emitir(IRT(IR_FLOAD, IRT_U8), ix->tab, IRFL_UDATA_UDTYPE);
emitir(IRTGI(IR_EQ), tr, lj_ir_kint(J, udtype));
}
immutable_mt:
mo = lj_tab_getstr(mt, mmname_str(J2G(J), mm));
if (!mo || tvisnil(mo))
return 0; /* No metamethod. */
/* Treat metamethod or index table as immutable, too. */
if (!(tvisfunc(mo) || tvistab(mo)))
lj_trace_err(J, LJ_TRERR_BADTYPE);
copyTV(J->L, &ix->mobjv, mo);
ix->mobj = lj_ir_kgc(J, gcV(mo), tvisfunc(mo) ? IRT_FUNC : IRT_TAB);
ix->mtv = mt;
ix->mt = TREF_NIL; /* Dummy value for comparison semantics. */
return 1; /* Got metamethod or index table. */
}
mix.tab = emitir(IRT(IR_FLOAD, IRT_TAB), ix->tab, IRFL_UDATA_META);
} else {
/* Specialize to base metatable. Must flush mcode in lua_setmetatable(). */
mt = tabref(basemt_obj(J2G(J), &ix->tabv));
if (mt == NULL) {
ix->mt = TREF_NIL;
return 0; /* No metamethod. */
}
/* The cdata metatable is treated as immutable. */
if (LJ_HASFFI && tref_iscdata(ix->tab)) goto immutable_mt;
ix->mt = mix.tab = lj_ir_ktab(J, mt);
goto nocheck;
}
ix->mt = mt ? mix.tab : TREF_NIL;
emitir(IRTG(mt ? IR_NE : IR_EQ, IRT_TAB), mix.tab, lj_ir_knull(J, IRT_TAB));
nocheck:
if (mt) {
GCstr *mmstr = mmname_str(J2G(J), mm);
cTValue *mo = lj_tab_getstr(mt, mmstr);
if (mo && !tvisnil(mo))
copyTV(J->L, &ix->mobjv, mo);
ix->mtv = mt;
settabV(J->L, &mix.tabv, mt);
setstrV(J->L, &mix.keyv, mmstr);
mix.key = lj_ir_kstr(J, mmstr);
mix.val = 0;
mix.idxchain = 0;
ix->mobj = lj_record_idx(J, &mix);
return !tref_isnil(ix->mobj); /* 1 if metamethod found, 0 if not. */
}
return 0; /* No metamethod. */
}
/* Record call to arithmetic metamethod. */
static TRef rec_mm_arith(jit_State *J, RecordIndex *ix, MMS mm)
{
/* Set up metamethod call first to save ix->tab and ix->tabv. */
BCReg func = rec_mm_prep(J, lj_cont_ra);
TRef *base = J->base + func;
TValue *basev = J->L->base + func;
base[1] = ix->tab; base[2] = ix->key;
copyTV(J->L, basev+1, &ix->tabv);
copyTV(J->L, basev+2, &ix->keyv);
if (!lj_record_mm_lookup(J, ix, mm)) { /* Lookup mm on 1st operand. */
if (mm != MM_unm) {
ix->tab = ix->key;
copyTV(J->L, &ix->tabv, &ix->keyv);
if (lj_record_mm_lookup(J, ix, mm)) /* Lookup mm on 2nd operand. */
goto ok;
}
lj_trace_err(J, LJ_TRERR_NOMM);
}
ok:
base[0] = ix->mobj;
copyTV(J->L, basev+0, &ix->mobjv);
lj_record_call(J, func, 2);
return 0; /* No result yet. */
}
/* Record call to __len metamethod. */
static TRef rec_mm_len(jit_State *J, TRef tr, TValue *tv)
{
RecordIndex ix;
ix.tab = tr;
copyTV(J->L, &ix.tabv, tv);
if (lj_record_mm_lookup(J, &ix, MM_len)) {
BCReg func = rec_mm_prep(J, lj_cont_ra);
TRef *base = J->base + func;
TValue *basev = J->L->base + func;
base[0] = ix.mobj; copyTV(J->L, basev+0, &ix.mobjv);
base[1] = tr; copyTV(J->L, basev+1, tv);
#if LJ_52
base[2] = tr; copyTV(J->L, basev+2, tv);
#else
base[2] = TREF_NIL; setnilV(basev+2);
#endif
lj_record_call(J, func, 2);
} else {
if (LJ_52 && tref_istab(tr))
return lj_ir_call(J, IRCALL_lj_tab_len, tr);
lj_trace_err(J, LJ_TRERR_NOMM);
}
return 0; /* No result yet. */
}
/* Call a comparison metamethod. */
static void rec_mm_callcomp(jit_State *J, RecordIndex *ix, int op)
{
BCReg func = rec_mm_prep(J, (op&1) ? lj_cont_condf : lj_cont_condt);
TRef *base = J->base + func;
TValue *tv = J->L->base + func;
base[0] = ix->mobj; base[1] = ix->val; base[2] = ix->key;
copyTV(J->L, tv+0, &ix->mobjv);
copyTV(J->L, tv+1, &ix->valv);
copyTV(J->L, tv+2, &ix->keyv);
lj_record_call(J, func, 2);
}
/* Record call to equality comparison metamethod (for tab and udata only). */
static void rec_mm_equal(jit_State *J, RecordIndex *ix, int op)
{
ix->tab = ix->val;
copyTV(J->L, &ix->tabv, &ix->valv);
if (lj_record_mm_lookup(J, ix, MM_eq)) { /* Lookup mm on 1st operand. */
cTValue *bv;
TRef mo1 = ix->mobj;
TValue mo1v;
copyTV(J->L, &mo1v, &ix->mobjv);
/* Avoid the 2nd lookup and the objcmp if the metatables are equal. */
bv = &ix->keyv;
if (tvistab(bv) && tabref(tabV(bv)->metatable) == ix->mtv) {
TRef mt2 = emitir(IRT(IR_FLOAD, IRT_TAB), ix->key, IRFL_TAB_META);
emitir(IRTG(IR_EQ, IRT_TAB), mt2, ix->mt);
} else if (tvisudata(bv) && tabref(udataV(bv)->metatable) == ix->mtv) {
TRef mt2 = emitir(IRT(IR_FLOAD, IRT_TAB), ix->key, IRFL_UDATA_META);
emitir(IRTG(IR_EQ, IRT_TAB), mt2, ix->mt);
} else { /* Lookup metamethod on 2nd operand and compare both. */
ix->tab = ix->key;
copyTV(J->L, &ix->tabv, bv);
if (!lj_record_mm_lookup(J, ix, MM_eq) ||
lj_record_objcmp(J, mo1, ix->mobj, &mo1v, &ix->mobjv))
return;
}
rec_mm_callcomp(J, ix, op);
}
}
/* Record call to ordered comparison metamethods (for arbitrary objects). */
static void rec_mm_comp(jit_State *J, RecordIndex *ix, int op)
{
ix->tab = ix->val;
copyTV(J->L, &ix->tabv, &ix->valv);
while (1) {
MMS mm = (op & 2) ? MM_le : MM_lt; /* Try __le + __lt or only __lt. */
#if LJ_52
if (!lj_record_mm_lookup(J, ix, mm)) { /* Lookup mm on 1st operand. */
ix->tab = ix->key;
copyTV(J->L, &ix->tabv, &ix->keyv);
if (!lj_record_mm_lookup(J, ix, mm)) /* Lookup mm on 2nd operand. */
goto nomatch;
}
rec_mm_callcomp(J, ix, op);
return;
#else
if (lj_record_mm_lookup(J, ix, mm)) { /* Lookup mm on 1st operand. */
cTValue *bv;
TRef mo1 = ix->mobj;
TValue mo1v;
copyTV(J->L, &mo1v, &ix->mobjv);
/* Avoid the 2nd lookup and the objcmp if the metatables are equal. */
bv = &ix->keyv;
if (tvistab(bv) && tabref(tabV(bv)->metatable) == ix->mtv) {
TRef mt2 = emitir(IRT(IR_FLOAD, IRT_TAB), ix->key, IRFL_TAB_META);
emitir(IRTG(IR_EQ, IRT_TAB), mt2, ix->mt);
} else if (tvisudata(bv) && tabref(udataV(bv)->metatable) == ix->mtv) {
TRef mt2 = emitir(IRT(IR_FLOAD, IRT_TAB), ix->key, IRFL_UDATA_META);
emitir(IRTG(IR_EQ, IRT_TAB), mt2, ix->mt);
} else { /* Lookup metamethod on 2nd operand and compare both. */
ix->tab = ix->key;
copyTV(J->L, &ix->tabv, bv);
if (!lj_record_mm_lookup(J, ix, mm) ||
lj_record_objcmp(J, mo1, ix->mobj, &mo1v, &ix->mobjv))
goto nomatch;
}
rec_mm_callcomp(J, ix, op);
return;
}
#endif
nomatch:
/* Lookup failed. Retry with __lt and swapped operands. */
if (!(op & 2)) break; /* Already at __lt. Interpreter will throw. */
ix->tab = ix->key; ix->key = ix->val; ix->val = ix->tab;
copyTV(J->L, &ix->tabv, &ix->keyv);
copyTV(J->L, &ix->keyv, &ix->valv);
copyTV(J->L, &ix->valv, &ix->tabv);
op ^= 3;
}
}
#if LJ_HASFFI
/* Setup call to cdata comparison metamethod. */
static void rec_mm_comp_cdata(jit_State *J, RecordIndex *ix, int op, MMS mm)
{
lj_snap_add(J);
if (tref_iscdata(ix->val)) {
ix->tab = ix->val;
copyTV(J->L, &ix->tabv, &ix->valv);
} else {
lua_assert(tref_iscdata(ix->key));
ix->tab = ix->key;
copyTV(J->L, &ix->tabv, &ix->keyv);
}
lj_record_mm_lookup(J, ix, mm);
rec_mm_callcomp(J, ix, op);
}
#endif
/* -- Indexed access ------------------------------------------------------ */
/* Record bounds-check. */
static void rec_idx_abc(jit_State *J, TRef asizeref, TRef ikey, uint32_t asize)
{
/* Try to emit invariant bounds checks. */
if ((J->flags & (JIT_F_OPT_LOOP|JIT_F_OPT_ABC)) ==
(JIT_F_OPT_LOOP|JIT_F_OPT_ABC)) {
IRRef ref = tref_ref(ikey);
IRIns *ir = IR(ref);
int32_t ofs = 0;
IRRef ofsref = 0;
/* Handle constant offsets. */
if (ir->o == IR_ADD && irref_isk(ir->op2)) {
ofsref = ir->op2;
ofs = IR(ofsref)->i;
ref = ir->op1;
ir = IR(ref);
}
/* Got scalar evolution analysis results for this reference? */
if (ref == J->scev.idx) {
int32_t stop;
lua_assert(irt_isint(J->scev.t) && ir->o == IR_SLOAD);
stop = numberVint(&(J->L->base - J->baseslot)[ir->op1 + FORL_STOP]);
/* Runtime value for stop of loop is within bounds? */
if ((uint64_t)stop + ofs < (uint64_t)asize) {
/* Emit invariant bounds check for stop. */
emitir(IRTG(IR_ABC, IRT_P32), asizeref, ofs == 0 ? J->scev.stop :
emitir(IRTI(IR_ADD), J->scev.stop, ofsref));
/* Emit invariant bounds check for start, if not const or negative. */
if (!(J->scev.dir && J->scev.start &&
(int64_t)IR(J->scev.start)->i + ofs >= 0))
emitir(IRTG(IR_ABC, IRT_P32), asizeref, ikey);
return;
}
}
}
emitir(IRTGI(IR_ABC), asizeref, ikey); /* Emit regular bounds check. */
}
/* Record indexed key lookup. */
static TRef rec_idx_key(jit_State *J, RecordIndex *ix)
{
TRef key;
GCtab *t = tabV(&ix->tabv);
ix->oldv = lj_tab_get(J->L, t, &ix->keyv); /* Lookup previous value. */
/* Integer keys are looked up in the array part first. */
key = ix->key;
if (tref_isnumber(key)) {
int32_t k = numberVint(&ix->keyv);
if (!tvisint(&ix->keyv) && numV(&ix->keyv) != (lua_Number)k)
k = LJ_MAX_ASIZE;
if ((MSize)k < LJ_MAX_ASIZE) { /* Potential array key? */
TRef ikey = lj_opt_narrow_index(J, key);
TRef asizeref = emitir(IRTI(IR_FLOAD), ix->tab, IRFL_TAB_ASIZE);
if ((MSize)k < t->asize) { /* Currently an array key? */
TRef arrayref;
rec_idx_abc(J, asizeref, ikey, t->asize);
arrayref = emitir(IRT(IR_FLOAD, IRT_P32), ix->tab, IRFL_TAB_ARRAY);
return emitir(IRT(IR_AREF, IRT_P32), arrayref, ikey);
} else { /* Currently not in array (may be an array extension)? */
emitir(IRTGI(IR_ULE), asizeref, ikey); /* Inv. bounds check. */
if (k == 0 && tref_isk(key))
key = lj_ir_knum_zero(J); /* Canonicalize 0 or +-0.0 to +0.0. */
/* And continue with the hash lookup. */
}
} else if (!tref_isk(key)) {
/* We can rule out const numbers which failed the integerness test
** above. But all other numbers are potential array keys.
*/
if (t->asize == 0) { /* True sparse tables have an empty array part. */
/* Guard that the array part stays empty. */
TRef tmp = emitir(IRTI(IR_FLOAD), ix->tab, IRFL_TAB_ASIZE);
emitir(IRTGI(IR_EQ), tmp, lj_ir_kint(J, 0));
} else {
lj_trace_err(J, LJ_TRERR_NYITMIX);
}
}
}
/* Otherwise the key is located in the hash part. */
if (t->hmask == 0) { /* Shortcut for empty hash part. */
/* Guard that the hash part stays empty. */
TRef tmp = emitir(IRTI(IR_FLOAD), ix->tab, IRFL_TAB_HMASK);
emitir(IRTGI(IR_EQ), tmp, lj_ir_kint(J, 0));
return lj_ir_kkptr(J, niltvg(J2G(J)));
}
if (tref_isinteger(key)) /* Hash keys are based on numbers, not ints. */
key = emitir(IRTN(IR_CONV), key, IRCONV_NUM_INT);
if (tref_isk(key)) {
/* Optimize lookup of constant hash keys. */
MSize hslot = (MSize)((char *)ix->oldv - (char *)&noderef(t->node)[0].val);
if (t->hmask > 0 && hslot <= t->hmask*(MSize)sizeof(Node) &&
hslot <= 65535*(MSize)sizeof(Node)) {
TRef node, kslot;
TRef hm = emitir(IRTI(IR_FLOAD), ix->tab, IRFL_TAB_HMASK);
emitir(IRTGI(IR_EQ), hm, lj_ir_kint(J, (int32_t)t->hmask));
node = emitir(IRT(IR_FLOAD, IRT_P32), ix->tab, IRFL_TAB_NODE);
kslot = lj_ir_kslot(J, key, hslot / sizeof(Node));
return emitir(IRTG(IR_HREFK, IRT_P32), node, kslot);
}
}
/* Fall back to a regular hash lookup. */
return emitir(IRT(IR_HREF, IRT_P32), ix->tab, key);
}
/* Determine whether a key is NOT one of the fast metamethod names. */
static int nommstr(jit_State *J, TRef key)
{
if (tref_isstr(key)) {
if (tref_isk(key)) {
GCstr *str = ir_kstr(IR(tref_ref(key)));
uint32_t mm;
for (mm = 0; mm <= MM_FAST; mm++)
if (mmname_str(J2G(J), mm) == str)
return 0; /* MUST be one the fast metamethod names. */
} else {
return 0; /* Variable string key MAY be a metamethod name. */
}
}
return 1; /* CANNOT be a metamethod name. */
}
/* Record indexed load/store. */
TRef lj_record_idx(jit_State *J, RecordIndex *ix)
{
TRef xref;
IROp xrefop, loadop;
cTValue *oldv;
while (!tref_istab(ix->tab)) { /* Handle non-table lookup. */
/* Never call raw lj_record_idx() on non-table. */
lua_assert(ix->idxchain != 0);
if (!lj_record_mm_lookup(J, ix, ix->val ? MM_newindex : MM_index))
lj_trace_err(J, LJ_TRERR_NOMM);
handlemm:
if (tref_isfunc(ix->mobj)) { /* Handle metamethod call. */
BCReg func = rec_mm_prep(J, ix->val ? lj_cont_nop : lj_cont_ra);
TRef *base = J->base + func;
TValue *tv = J->L->base + func;
base[0] = ix->mobj; base[1] = ix->tab; base[2] = ix->key;
setfuncV(J->L, tv+0, funcV(&ix->mobjv));
copyTV(J->L, tv+1, &ix->tabv);
copyTV(J->L, tv+2, &ix->keyv);
if (ix->val) {
base[3] = ix->val;
copyTV(J->L, tv+3, &ix->valv);
lj_record_call(J, func, 3); /* mobj(tab, key, val) */
return 0;
} else {
lj_record_call(J, func, 2); /* res = mobj(tab, key) */
return 0; /* No result yet. */
}
}
/* Otherwise retry lookup with metaobject. */
ix->tab = ix->mobj;
copyTV(J->L, &ix->tabv, &ix->mobjv);
if (--ix->idxchain == 0)
lj_trace_err(J, LJ_TRERR_IDXLOOP);
}
/* First catch nil and NaN keys for tables. */
if (tvisnil(&ix->keyv) || (tvisnum(&ix->keyv) && tvisnan(&ix->keyv))) {
if (ix->val) /* Better fail early. */
lj_trace_err(J, LJ_TRERR_STORENN);
if (tref_isk(ix->key)) {
if (ix->idxchain && lj_record_mm_lookup(J, ix, MM_index))
goto handlemm;
return TREF_NIL;
}
}
/* Record the key lookup. */
xref = rec_idx_key(J, ix);
xrefop = IR(tref_ref(xref))->o;
loadop = xrefop == IR_AREF ? IR_ALOAD : IR_HLOAD;
/* The lj_meta_tset() inconsistency is gone, but better play safe. */
oldv = xrefop == IR_KKPTR ? (cTValue *)ir_kptr(IR(tref_ref(xref))) : ix->oldv;
if (ix->val == 0) { /* Indexed load */
IRType t = itype2irt(oldv);
TRef res;
if (oldv == niltvg(J2G(J))) {
emitir(IRTG(IR_EQ, IRT_P32), xref, lj_ir_kkptr(J, niltvg(J2G(J))));
res = TREF_NIL;
} else {
res = emitir(IRTG(loadop, t), xref, 0);
}
if (t == IRT_NIL && ix->idxchain && lj_record_mm_lookup(J, ix, MM_index))
goto handlemm;
if (irtype_ispri(t)) res = TREF_PRI(t); /* Canonicalize primitives. */
return res;
} else { /* Indexed store. */
GCtab *mt = tabref(tabV(&ix->tabv)->metatable);
int keybarrier = tref_isgcv(ix->key) && !tref_isnil(ix->val);
if (tvisnil(oldv)) { /* Previous value was nil? */
/* Need to duplicate the hasmm check for the early guards. */
int hasmm = 0;
if (ix->idxchain && mt) {
cTValue *mo = lj_tab_getstr(mt, mmname_str(J2G(J), MM_newindex));
hasmm = mo && !tvisnil(mo);
}
if (hasmm)
emitir(IRTG(loadop, IRT_NIL), xref, 0); /* Guard for nil value. */
else if (xrefop == IR_HREF)
emitir(IRTG(oldv == niltvg(J2G(J)) ? IR_EQ : IR_NE, IRT_P32),
xref, lj_ir_kkptr(J, niltvg(J2G(J))));
if (ix->idxchain && lj_record_mm_lookup(J, ix, MM_newindex)) {
lua_assert(hasmm);
goto handlemm;
}
lua_assert(!hasmm);
if (oldv == niltvg(J2G(J))) { /* Need to insert a new key. */
TRef key = ix->key;
if (tref_isinteger(key)) /* NEWREF needs a TValue as a key. */
key = emitir(IRTN(IR_CONV), key, IRCONV_NUM_INT);
xref = emitir(IRT(IR_NEWREF, IRT_P32), ix->tab, key);
keybarrier = 0; /* NEWREF already takes care of the key barrier. */
}
} else if (!lj_opt_fwd_wasnonnil(J, loadop, tref_ref(xref))) {
/* Cannot derive that the previous value was non-nil, must do checks. */
if (xrefop == IR_HREF) /* Guard against store to niltv. */
emitir(IRTG(IR_NE, IRT_P32), xref, lj_ir_kkptr(J, niltvg(J2G(J))));
if (ix->idxchain) { /* Metamethod lookup required? */
/* A check for NULL metatable is cheaper (hoistable) than a load. */
if (!mt) {
TRef mtref = emitir(IRT(IR_FLOAD, IRT_TAB), ix->tab, IRFL_TAB_META);
emitir(IRTG(IR_EQ, IRT_TAB), mtref, lj_ir_knull(J, IRT_TAB));
} else {
IRType t = itype2irt(oldv);
emitir(IRTG(loadop, t), xref, 0); /* Guard for non-nil value. */
}
}
} else {
keybarrier = 0; /* Previous non-nil value kept the key alive. */
}
/* Convert int to number before storing. */
if (!LJ_DUALNUM && tref_isinteger(ix->val))
ix->val = emitir(IRTN(IR_CONV), ix->val, IRCONV_NUM_INT);
emitir(IRT(loadop+IRDELTA_L2S, tref_type(ix->val)), xref, ix->val);
if (keybarrier || tref_isgcv(ix->val))
emitir(IRT(IR_TBAR, IRT_NIL), ix->tab, 0);
/* Invalidate neg. metamethod cache for stores with certain string keys. */
if (!nommstr(J, ix->key)) {
TRef fref = emitir(IRT(IR_FREF, IRT_P32), ix->tab, IRFL_TAB_NOMM);
emitir(IRT(IR_FSTORE, IRT_U8), fref, lj_ir_kint(J, 0));
}
J->needsnap = 1;
return 0;
}
}
/* -- Upvalue access ------------------------------------------------------ */
/* Check whether upvalue is immutable and ok to constify. */
static int rec_upvalue_constify(jit_State *J, GCupval *uvp)
{
if (uvp->immutable) {
cTValue *o = uvval(uvp);
/* Don't constify objects that may retain large amounts of memory. */
#if LJ_HASFFI
if (tviscdata(o)) {
GCcdata *cd = cdataV(o);
if (!cdataisv(cd) && !(cd->marked & LJ_GC_CDATA_FIN)) {
CType *ct = ctype_raw(ctype_ctsG(J2G(J)), cd->ctypeid);
if (!ctype_hassize(ct->info) || ct->size <= 16)
return 1;
}
return 0;
}
#else
UNUSED(J);
#endif
if (!(tvistab(o) || tvisudata(o) || tvisthread(o)))
return 1;
}
return 0;
}
/* Record upvalue load/store. */
static TRef rec_upvalue(jit_State *J, uint32_t uv, TRef val)
{
GCupval *uvp = &gcref(J->fn->l.uvptr[uv])->uv;
TRef fn = getcurrf(J);
IRRef uref;
int needbarrier = 0;
if (rec_upvalue_constify(J, uvp)) { /* Try to constify immutable upvalue. */
TRef tr, kfunc;
lua_assert(val == 0);
if (!tref_isk(fn)) { /* Late specialization of current function. */
if (J->pt->flags >= PROTO_CLC_POLY)
goto noconstify;
kfunc = lj_ir_kfunc(J, J->fn);
emitir(IRTG(IR_EQ, IRT_FUNC), fn, kfunc);
J->base[-1] = TREF_FRAME | kfunc;
fn = kfunc;
}
tr = lj_record_constify(J, uvval(uvp));
if (tr)
return tr;
}
noconstify:
/* Note: this effectively limits LJ_MAX_UPVAL to 127. */
uv = (uv << 8) | (hashrot(uvp->dhash, uvp->dhash + HASH_BIAS) & 0xff);
if (!uvp->closed) {
uref = tref_ref(emitir(IRTG(IR_UREFO, IRT_P32), fn, uv));
/* In current stack? */
if (uvval(uvp) >= tvref(J->L->stack) &&
uvval(uvp) < tvref(J->L->maxstack)) {
int32_t slot = (int32_t)(uvval(uvp) - (J->L->base - J->baseslot));
if (slot >= 0) { /* Aliases an SSA slot? */
emitir(IRTG(IR_EQ, IRT_P32),
REF_BASE,
emitir(IRT(IR_ADD, IRT_P32), uref,
lj_ir_kint(J, (slot - 1) * -8)));
slot -= (int32_t)J->baseslot; /* Note: slot number may be negative! */
if (val == 0) {
return getslot(J, slot);
} else {
J->base[slot] = val;
if (slot >= (int32_t)J->maxslot) J->maxslot = (BCReg)(slot+1);
return 0;
}
}
}
emitir(IRTG(IR_UGT, IRT_P32),
emitir(IRT(IR_SUB, IRT_P32), uref, REF_BASE),
lj_ir_kint(J, (J->baseslot + J->maxslot) * 8));
} else {
needbarrier = 1;
uref = tref_ref(emitir(IRTG(IR_UREFC, IRT_P32), fn, uv));
}
if (val == 0) { /* Upvalue load */
IRType t = itype2irt(uvval(uvp));
TRef res = emitir(IRTG(IR_ULOAD, t), uref, 0);
if (irtype_ispri(t)) res = TREF_PRI(t); /* Canonicalize primitive refs. */
return res;
} else { /* Upvalue store. */
/* Convert int to number before storing. */
if (!LJ_DUALNUM && tref_isinteger(val))
val = emitir(IRTN(IR_CONV), val, IRCONV_NUM_INT);
emitir(IRT(IR_USTORE, tref_type(val)), uref, val);
if (needbarrier && tref_isgcv(val))
emitir(IRT(IR_OBAR, IRT_NIL), uref, val);
J->needsnap = 1;
return 0;
}
}
/* -- Record calls to Lua functions --------------------------------------- */
/* Check unroll limits for calls. */
static void check_call_unroll(jit_State *J, TraceNo lnk)
{
cTValue *frame = J->L->base - 1;
void *pc = mref(frame_func(frame)->l.pc, void);
int32_t depth = J->framedepth;
int32_t count = 0;
if ((J->pt->flags & PROTO_VARARG)) depth--; /* Vararg frame still missing. */
for (; depth > 0; depth--) { /* Count frames with same prototype. */
if (frame_iscont(frame)) depth--;
frame = frame_prev(frame);
if (mref(frame_func(frame)->l.pc, void) == pc)
count++;
}
if (J->pc == J->startpc) {
if (count + J->tailcalled > J->param[JIT_P_recunroll]) {
J->pc++;
if (J->framedepth + J->retdepth == 0)
rec_stop(J, LJ_TRLINK_TAILREC, J->cur.traceno); /* Tail-recursion. */
else
rec_stop(J, LJ_TRLINK_UPREC, J->cur.traceno); /* Up-recursion. */
}
} else {
if (count > J->param[JIT_P_callunroll]) {
if (lnk) { /* Possible tail- or up-recursion. */
lj_trace_flush(J, lnk); /* Flush trace that only returns. */
/* Set a small, pseudo-random hotcount for a quick retry of JFUNC*. */
hotcount_set(J2GG(J), J->pc+1, LJ_PRNG_BITS(J, 4));
}
lj_trace_err(J, LJ_TRERR_CUNROLL);
}
}
}
/* Record Lua function setup. */
static void rec_func_setup(jit_State *J)
{
GCproto *pt = J->pt;
BCReg s, numparams = pt->numparams;
if ((pt->flags & PROTO_NOJIT))
lj_trace_err(J, LJ_TRERR_CJITOFF);
if (J->baseslot + pt->framesize >= LJ_MAX_JSLOTS)
lj_trace_err(J, LJ_TRERR_STACKOV);
/* Fill up missing parameters with nil. */
for (s = J->maxslot; s < numparams; s++)
J->base[s] = TREF_NIL;
/* The remaining slots should never be read before they are written. */
J->maxslot = numparams;
}
/* Record Lua vararg function setup. */
static void rec_func_vararg(jit_State *J)
{
GCproto *pt = J->pt;
BCReg s, fixargs, vframe = J->maxslot+1;
lua_assert((pt->flags & PROTO_VARARG));
if (J->baseslot + vframe + pt->framesize >= LJ_MAX_JSLOTS)
lj_trace_err(J, LJ_TRERR_STACKOV);
J->base[vframe-1] = J->base[-1]; /* Copy function up. */
/* Copy fixarg slots up and set their original slots to nil. */
fixargs = pt->numparams < J->maxslot ? pt->numparams : J->maxslot;
for (s = 0; s < fixargs; s++) {
J->base[vframe+s] = J->base[s];
J->base[s] = TREF_NIL;
}
J->maxslot = fixargs;
J->framedepth++;
J->base += vframe;
J->baseslot += vframe;
}
/* Record entry to a Lua function. */
static void rec_func_lua(jit_State *J)
{
rec_func_setup(J);
check_call_unroll(J, 0);
}
/* Record entry to an already compiled function. */
static void rec_func_jit(jit_State *J, TraceNo lnk)
{
GCtrace *T;
rec_func_setup(J);
T = traceref(J, lnk);
if (T->linktype == LJ_TRLINK_RETURN) { /* Trace returns to interpreter? */
check_call_unroll(J, lnk);
/* Temporarily unpatch JFUNC* to continue recording across function. */
J->patchins = *J->pc;
J->patchpc = (BCIns *)J->pc;
*J->patchpc = T->startins;
return;
}
J->instunroll = 0; /* Cannot continue across a compiled function. */
if (J->pc == J->startpc && J->framedepth + J->retdepth == 0)
rec_stop(J, LJ_TRLINK_TAILREC, J->cur.traceno); /* Extra tail-recursion. */
else
rec_stop(J, LJ_TRLINK_ROOT, lnk); /* Link to the function. */
}
/* -- Vararg handling ----------------------------------------------------- */
/* Detect y = select(x, ...) idiom. */
static int select_detect(jit_State *J)
{
BCIns ins = J->pc[1];
if (bc_op(ins) == BC_CALLM && bc_b(ins) == 2 && bc_c(ins) == 1) {
cTValue *func = &J->L->base[bc_a(ins)];
if (tvisfunc(func) && funcV(func)->c.ffid == FF_select) {
TRef kfunc = lj_ir_kfunc(J, funcV(func));
emitir(IRTG(IR_EQ, IRT_FUNC), getslot(J, bc_a(ins)), kfunc);
return 1;
}
}
return 0;
}
/* Record vararg instruction. */
static void rec_varg(jit_State *J, BCReg dst, ptrdiff_t nresults)
{
int32_t numparams = J->pt->numparams;
ptrdiff_t nvararg = frame_delta(J->L->base-1) - numparams - 1;
lua_assert(frame_isvarg(J->L->base-1));
if (J->framedepth > 0) { /* Simple case: varargs defined on-trace. */
ptrdiff_t i;
if (nvararg < 0) nvararg = 0;
if (nresults == -1) {
nresults = nvararg;
J->maxslot = dst + (BCReg)nvararg;
} else if (dst + nresults > J->maxslot) {
J->maxslot = dst + (BCReg)nresults;
}
for (i = 0; i < nresults; i++)
J->base[dst+i] = i < nvararg ? getslot(J, i - nvararg - 1) : TREF_NIL;
} else { /* Unknown number of varargs passed to trace. */
TRef fr = emitir(IRTI(IR_SLOAD), 0, IRSLOAD_READONLY|IRSLOAD_FRAME);
int32_t frofs = 8*(1+numparams)+FRAME_VARG;
if (nresults >= 0) { /* Known fixed number of results. */
ptrdiff_t i;
if (nvararg > 0) {
ptrdiff_t nload = nvararg >= nresults ? nresults : nvararg;
TRef vbase;
if (nvararg >= nresults)
emitir(IRTGI(IR_GE), fr, lj_ir_kint(J, frofs+8*(int32_t)nresults));
else
emitir(IRTGI(IR_EQ), fr, lj_ir_kint(J, frame_ftsz(J->L->base-1)));
vbase = emitir(IRTI(IR_SUB), REF_BASE, fr);
vbase = emitir(IRT(IR_ADD, IRT_P32), vbase, lj_ir_kint(J, frofs-8));
for (i = 0; i < nload; i++) {
IRType t = itype2irt(&J->L->base[i-1-nvararg]);
TRef aref = emitir(IRT(IR_AREF, IRT_P32),
vbase, lj_ir_kint(J, (int32_t)i));
TRef tr = emitir(IRTG(IR_VLOAD, t), aref, 0);
if (irtype_ispri(t)) tr = TREF_PRI(t); /* Canonicalize primitives. */
J->base[dst+i] = tr;
}
} else {
emitir(IRTGI(IR_LE), fr, lj_ir_kint(J, frofs));
nvararg = 0;
}
for (i = nvararg; i < nresults; i++)
J->base[dst+i] = TREF_NIL;
if (dst + (BCReg)nresults > J->maxslot)
J->maxslot = dst + (BCReg)nresults;
} else if (select_detect(J)) { /* y = select(x, ...) */
TRef tridx = J->base[dst-1];
TRef tr = TREF_NIL;
ptrdiff_t idx = lj_ffrecord_select_mode(J, tridx, &J->L->base[dst-1]);
if (idx < 0) goto nyivarg;
if (idx != 0 && !tref_isinteger(tridx))
tridx = emitir(IRTGI(IR_CONV), tridx, IRCONV_INT_NUM|IRCONV_INDEX);
if (idx != 0 && tref_isk(tridx)) {
emitir(IRTGI(idx <= nvararg ? IR_GE : IR_LT),
fr, lj_ir_kint(J, frofs+8*(int32_t)idx));
frofs -= 8; /* Bias for 1-based index. */
} else if (idx <= nvararg) { /* Compute size. */
TRef tmp = emitir(IRTI(IR_ADD), fr, lj_ir_kint(J, -frofs));
if (numparams)
emitir(IRTGI(IR_GE), tmp, lj_ir_kint(J, 0));
tr = emitir(IRTI(IR_BSHR), tmp, lj_ir_kint(J, 3));
if (idx != 0) {
tridx = emitir(IRTI(IR_ADD), tridx, lj_ir_kint(J, -1));
rec_idx_abc(J, tr, tridx, (uint32_t)nvararg);
}
} else {
TRef tmp = lj_ir_kint(J, frofs);
if (idx != 0) {
TRef tmp2 = emitir(IRTI(IR_BSHL), tridx, lj_ir_kint(J, 3));
tmp = emitir(IRTI(IR_ADD), tmp2, tmp);
} else {
tr = lj_ir_kint(J, 0);
}
emitir(IRTGI(IR_LT), fr, tmp);
}
if (idx != 0 && idx <= nvararg) {
IRType t;
TRef aref, vbase = emitir(IRTI(IR_SUB), REF_BASE, fr);
vbase = emitir(IRT(IR_ADD, IRT_P32), vbase, lj_ir_kint(J, frofs-8));
t = itype2irt(&J->L->base[idx-2-nvararg]);
aref = emitir(IRT(IR_AREF, IRT_P32), vbase, tridx);
tr = emitir(IRTG(IR_VLOAD, t), aref, 0);
if (irtype_ispri(t)) tr = TREF_PRI(t); /* Canonicalize primitives. */
}
J->base[dst-2] = tr;
J->maxslot = dst-1;
J->bcskip = 2; /* Skip CALLM + select. */
} else {
nyivarg:
setintV(&J->errinfo, BC_VARG);
lj_trace_err_info(J, LJ_TRERR_NYIBC);
}
}
if (J->baseslot + J->maxslot >= LJ_MAX_JSLOTS)
lj_trace_err(J, LJ_TRERR_STACKOV);
}
/* -- Record allocations -------------------------------------------------- */
static TRef rec_tnew(jit_State *J, uint32_t ah)
{
uint32_t asize = ah & 0x7ff;
uint32_t hbits = ah >> 11;
if (asize == 0x7ff) asize = 0x801;
return emitir(IRTG(IR_TNEW, IRT_TAB), asize, hbits);
}
/* -- Record bytecode ops ------------------------------------------------- */
/* Prepare for comparison. */
static void rec_comp_prep(jit_State *J)
{
/* Prevent merging with snapshot #0 (GC exit) since we fixup the PC. */
if (J->cur.nsnap == 1 && J->cur.snap[0].ref == J->cur.nins)
emitir_raw(IRT(IR_NOP, IRT_NIL), 0, 0);
lj_snap_add(J);
}
/* Fixup comparison. */
static void rec_comp_fixup(jit_State *J, const BCIns *pc, int cond)
{
BCIns jmpins = pc[1];
const BCIns *npc = pc + 2 + (cond ? bc_j(jmpins) : 0);
SnapShot *snap = &J->cur.snap[J->cur.nsnap-1];
/* Set PC to opposite target to avoid re-recording the comp. in side trace. */
J->cur.snapmap[snap->mapofs + snap->nent] = SNAP_MKPC(npc);
J->needsnap = 1;
if (bc_a(jmpins) < J->maxslot) J->maxslot = bc_a(jmpins);
lj_snap_shrink(J); /* Shrink last snapshot if possible. */
}
/* Record the next bytecode instruction (_before_ it's executed). */
void lj_record_ins(jit_State *J)
{
cTValue *lbase;
RecordIndex ix;
const BCIns *pc;
BCIns ins;
BCOp op;
TRef ra, rb, rc;
/* Perform post-processing action before recording the next instruction. */
if (LJ_UNLIKELY(J->postproc != LJ_POST_NONE)) {
switch (J->postproc) {
case LJ_POST_FIXCOMP: /* Fixup comparison. */
pc = frame_pc(&J2G(J)->tmptv);
rec_comp_fixup(J, pc, (!tvistruecond(&J2G(J)->tmptv2) ^ (bc_op(*pc)&1)));
/* fallthrough */
case LJ_POST_FIXGUARD: /* Fixup and emit pending guard. */
case LJ_POST_FIXGUARDSNAP: /* Fixup and emit pending guard and snapshot. */
if (!tvistruecond(&J2G(J)->tmptv2)) {
J->fold.ins.o ^= 1; /* Flip guard to opposite. */
if (J->postproc == LJ_POST_FIXGUARDSNAP) {
SnapShot *snap = &J->cur.snap[J->cur.nsnap-1];
J->cur.snapmap[snap->mapofs+snap->nent-1]--; /* False -> true. */
}
}
lj_opt_fold(J); /* Emit pending guard. */
/* fallthrough */
case LJ_POST_FIXBOOL:
if (!tvistruecond(&J2G(J)->tmptv2)) {
BCReg s;
TValue *tv = J->L->base;
for (s = 0; s < J->maxslot; s++) /* Fixup stack slot (if any). */
if (J->base[s] == TREF_TRUE && tvisfalse(&tv[s])) {
J->base[s] = TREF_FALSE;
break;
}
}
break;
case LJ_POST_FIXCONST:
{
BCReg s;
TValue *tv = J->L->base;
for (s = 0; s < J->maxslot; s++) /* Constify stack slots (if any). */
if (J->base[s] == TREF_NIL && !tvisnil(&tv[s]))
J->base[s] = lj_record_constify(J, &tv[s]);
}
break;
case LJ_POST_FFRETRY: /* Suppress recording of retried fast function. */
if (bc_op(*J->pc) >= BC__MAX)
return;
break;
default: lua_assert(0); break;
}
J->postproc = LJ_POST_NONE;
}
/* Need snapshot before recording next bytecode (e.g. after a store). */
if (J->needsnap) {
J->needsnap = 0;
lj_snap_purge(J);
lj_snap_add(J);
J->mergesnap = 1;
}
/* Skip some bytecodes. */
if (LJ_UNLIKELY(J->bcskip > 0)) {
J->bcskip--;
return;
}
/* Record only closed loops for root traces. */
pc = J->pc;
if (J->framedepth == 0 &&
(MSize)((char *)pc - (char *)J->bc_min) >= J->bc_extent)
lj_trace_err(J, LJ_TRERR_LLEAVE);
#ifdef LUA_USE_ASSERT
rec_check_slots(J);
rec_check_ir(J);
#endif
/* Keep a copy of the runtime values of var/num/str operands. */
#define rav (&ix.valv)
#define rbv (&ix.tabv)
#define rcv (&ix.keyv)
lbase = J->L->base;
ins = *pc;
op = bc_op(ins);
ra = bc_a(ins);
ix.val = 0;
switch (bcmode_a(op)) {
case BCMvar:
copyTV(J->L, rav, &lbase[ra]); ix.val = ra = getslot(J, ra); break;
default: break; /* Handled later. */
}
rb = bc_b(ins);
rc = bc_c(ins);
switch (bcmode_b(op)) {
case BCMnone: rb = 0; rc = bc_d(ins); break; /* Upgrade rc to 'rd'. */
case BCMvar:
copyTV(J->L, rbv, &lbase[rb]); ix.tab = rb = getslot(J, rb); break;
default: break; /* Handled later. */
}
switch (bcmode_c(op)) {
case BCMvar:
copyTV(J->L, rcv, &lbase[rc]); ix.key = rc = getslot(J, rc); break;
case BCMpri: setitype(rcv, ~rc); ix.key = rc = TREF_PRI(IRT_NIL+rc); break;
case BCMnum: { cTValue *tv = proto_knumtv(J->pt, rc);
copyTV(J->L, rcv, tv); ix.key = rc = tvisint(tv) ? lj_ir_kint(J, intV(tv)) :
lj_ir_knumint(J, numV(tv)); } break;
case BCMstr: { GCstr *s = gco2str(proto_kgc(J->pt, ~(ptrdiff_t)rc));
setstrV(J->L, rcv, s); ix.key = rc = lj_ir_kstr(J, s); } break;
default: break; /* Handled later. */
}
switch (op) {
/* -- Comparison ops ---------------------------------------------------- */
case BC_ISLT: case BC_ISGE: case BC_ISLE: case BC_ISGT:
#if LJ_HASFFI
if (tref_iscdata(ra) || tref_iscdata(rc)) {
rec_mm_comp_cdata(J, &ix, op, ((int)op & 2) ? MM_le : MM_lt);
break;
}
#endif
/* Emit nothing for two numeric or string consts. */
if (!(tref_isk2(ra,rc) && tref_isnumber_str(ra) && tref_isnumber_str(rc))) {
IRType ta = tref_isinteger(ra) ? IRT_INT : tref_type(ra);
IRType tc = tref_isinteger(rc) ? IRT_INT : tref_type(rc);
int irop;
if (ta != tc) {
/* Widen mixed number/int comparisons to number/number comparison. */
if (ta == IRT_INT && tc == IRT_NUM) {
ra = emitir(IRTN(IR_CONV), ra, IRCONV_NUM_INT);
ta = IRT_NUM;
} else if (ta == IRT_NUM && tc == IRT_INT) {
rc = emitir(IRTN(IR_CONV), rc, IRCONV_NUM_INT);
} else if (LJ_52) {
ta = IRT_NIL; /* Force metamethod for different types. */
} else if (!((ta == IRT_FALSE || ta == IRT_TRUE) &&
(tc == IRT_FALSE || tc == IRT_TRUE))) {
break; /* Interpreter will throw for two different types. */
}
}
rec_comp_prep(J);
irop = (int)op - (int)BC_ISLT + (int)IR_LT;
if (ta == IRT_NUM) {
if ((irop & 1)) irop ^= 4; /* ISGE/ISGT are unordered. */
if (!lj_ir_numcmp(numberVnum(rav), numberVnum(rcv), (IROp)irop))
irop ^= 5;
} else if (ta == IRT_INT) {
if (!lj_ir_numcmp(numberVnum(rav), numberVnum(rcv), (IROp)irop))
irop ^= 1;
} else if (ta == IRT_STR) {
if (!lj_ir_strcmp(strV(rav), strV(rcv), (IROp)irop)) irop ^= 1;
ra = lj_ir_call(J, IRCALL_lj_str_cmp, ra, rc);
rc = lj_ir_kint(J, 0);
ta = IRT_INT;
} else {
rec_mm_comp(J, &ix, (int)op);
break;
}
emitir(IRTG(irop, ta), ra, rc);
rec_comp_fixup(J, J->pc, ((int)op ^ irop) & 1);
}
break;
case BC_ISEQV: case BC_ISNEV:
case BC_ISEQS: case BC_ISNES:
case BC_ISEQN: case BC_ISNEN:
case BC_ISEQP: case BC_ISNEP:
#if LJ_HASFFI
if (tref_iscdata(ra) || tref_iscdata(rc)) {
rec_mm_comp_cdata(J, &ix, op, MM_eq);
break;
}
#endif
/* Emit nothing for two non-table, non-udata consts. */
if (!(tref_isk2(ra, rc) && !(tref_istab(ra) || tref_isudata(ra)))) {
int diff;
rec_comp_prep(J);
diff = lj_record_objcmp(J, ra, rc, rav, rcv);
if (diff == 2 || !(tref_istab(ra) || tref_isudata(ra)))
rec_comp_fixup(J, J->pc, ((int)op & 1) == !diff);
else if (diff == 1) /* Only check __eq if different, but same type. */
rec_mm_equal(J, &ix, (int)op);
}
break;
/* -- Unary test and copy ops ------------------------------------------- */
case BC_ISTC: case BC_ISFC:
if ((op & 1) == tref_istruecond(rc))
rc = 0; /* Don't store if condition is not true. */
/* fallthrough */
case BC_IST: case BC_ISF: /* Type specialization suffices. */
if (bc_a(pc[1]) < J->maxslot)
J->maxslot = bc_a(pc[1]); /* Shrink used slots. */
break;
/* -- Unary ops --------------------------------------------------------- */
case BC_NOT:
/* Type specialization already forces const result. */
rc = tref_istruecond(rc) ? TREF_FALSE : TREF_TRUE;
break;
case BC_LEN:
if (tref_isstr(rc))
rc = emitir(IRTI(IR_FLOAD), rc, IRFL_STR_LEN);
else if (!LJ_52 && tref_istab(rc))
rc = lj_ir_call(J, IRCALL_lj_tab_len, rc);
else
rc = rec_mm_len(J, rc, rcv);
break;
/* -- Arithmetic ops ---------------------------------------------------- */
case BC_UNM:
if (tref_isnumber_str(rc)) {
rc = lj_opt_narrow_unm(J, rc, rcv);
} else {
ix.tab = rc;
copyTV(J->L, &ix.tabv, rcv);
rc = rec_mm_arith(J, &ix, MM_unm);
}
break;
case BC_ADDNV: case BC_SUBNV: case BC_MULNV: case BC_DIVNV: case BC_MODNV:
/* Swap rb/rc and rbv/rcv. rav is temp. */
ix.tab = rc; ix.key = rc = rb; rb = ix.tab;
copyTV(J->L, rav, rbv);
copyTV(J->L, rbv, rcv);
copyTV(J->L, rcv, rav);
if (op == BC_MODNV)
goto recmod;
/* fallthrough */
case BC_ADDVN: case BC_SUBVN: case BC_MULVN: case BC_DIVVN:
case BC_ADDVV: case BC_SUBVV: case BC_MULVV: case BC_DIVVV: {
MMS mm = bcmode_mm(op);
if (tref_isnumber_str(rb) && tref_isnumber_str(rc))
rc = lj_opt_narrow_arith(J, rb, rc, rbv, rcv,
(int)mm - (int)MM_add + (int)IR_ADD);
else
rc = rec_mm_arith(J, &ix, mm);
break;
}
case BC_MODVN: case BC_MODVV:
recmod:
if (tref_isnumber_str(rb) && tref_isnumber_str(rc))
rc = lj_opt_narrow_mod(J, rb, rc, rbv, rcv);
else
rc = rec_mm_arith(J, &ix, MM_mod);
break;
case BC_POW:
if (tref_isnumber_str(rb) && tref_isnumber_str(rc))
rc = lj_opt_narrow_pow(J, rb, rc, rbv, rcv);
else
rc = rec_mm_arith(J, &ix, MM_pow);
break;
/* -- Constant and move ops --------------------------------------------- */
case BC_MOV:
/* Clear gap of method call to avoid resurrecting previous refs. */
if (ra > J->maxslot) J->base[ra-1] = 0;
break;
case BC_KSTR: case BC_KNUM: case BC_KPRI:
break;
case BC_KSHORT:
rc = lj_ir_kint(J, (int32_t)(int16_t)rc);
break;
case BC_KNIL:
while (ra <= rc)
J->base[ra++] = TREF_NIL;
if (rc >= J->maxslot) J->maxslot = rc+1;
break;
#if LJ_HASFFI
case BC_KCDATA:
rc = lj_ir_kgc(J, proto_kgc(J->pt, ~(ptrdiff_t)rc), IRT_CDATA);
break;
#endif
/* -- Upvalue and function ops ------------------------------------------ */
case BC_UGET:
rc = rec_upvalue(J, rc, 0);
break;
case BC_USETV: case BC_USETS: case BC_USETN: case BC_USETP:
rec_upvalue(J, ra, rc);
break;
/* -- Table ops --------------------------------------------------------- */
case BC_GGET: case BC_GSET:
settabV(J->L, &ix.tabv, tabref(J->fn->l.env));
ix.tab = emitir(IRT(IR_FLOAD, IRT_TAB), getcurrf(J), IRFL_FUNC_ENV);
ix.idxchain = LJ_MAX_IDXCHAIN;
rc = lj_record_idx(J, &ix);
break;
case BC_TGETB: case BC_TSETB:
setintV(&ix.keyv, (int32_t)rc);
ix.key = lj_ir_kint(J, (int32_t)rc);
/* fallthrough */
case BC_TGETV: case BC_TGETS: case BC_TSETV: case BC_TSETS:
ix.idxchain = LJ_MAX_IDXCHAIN;
rc = lj_record_idx(J, &ix);
break;
case BC_TNEW:
rc = rec_tnew(J, rc);
break;
case BC_TDUP:
rc = emitir(IRTG(IR_TDUP, IRT_TAB),
lj_ir_ktab(J, gco2tab(proto_kgc(J->pt, ~(ptrdiff_t)rc))), 0);
break;
/* -- Calls and vararg handling ----------------------------------------- */
case BC_ITERC:
J->base[ra] = getslot(J, ra-3);
J->base[ra+1] = getslot(J, ra-2);
J->base[ra+2] = getslot(J, ra-1);
{ /* Do the actual copy now because lj_record_call needs the values. */
TValue *b = &J->L->base[ra];
copyTV(J->L, b, b-3);
copyTV(J->L, b+1, b-2);
copyTV(J->L, b+2, b-1);
}
lj_record_call(J, ra, (ptrdiff_t)rc-1);
break;
/* L->top is set to L->base+ra+rc+NARGS-1+1. See lj_dispatch_ins(). */
case BC_CALLM:
rc = (BCReg)(J->L->top - J->L->base) - ra;
/* fallthrough */
case BC_CALL:
lj_record_call(J, ra, (ptrdiff_t)rc-1);
break;
case BC_CALLMT:
rc = (BCReg)(J->L->top - J->L->base) - ra;
/* fallthrough */
case BC_CALLT:
lj_record_tailcall(J, ra, (ptrdiff_t)rc-1);
break;
case BC_VARG:
rec_varg(J, ra, (ptrdiff_t)rb-1);
break;
/* -- Returns ----------------------------------------------------------- */
case BC_RETM:
/* L->top is set to L->base+ra+rc+NRESULTS-1, see lj_dispatch_ins(). */
rc = (BCReg)(J->L->top - J->L->base) - ra + 1;
/* fallthrough */
case BC_RET: case BC_RET0: case BC_RET1:
lj_record_ret(J, ra, (ptrdiff_t)rc-1);
break;
/* -- Loops and branches ------------------------------------------------ */
case BC_FORI:
if (rec_for(J, pc, 0) != LOOPEV_LEAVE)
J->loopref = J->cur.nins;
break;
case BC_JFORI:
lua_assert(bc_op(pc[(ptrdiff_t)rc-BCBIAS_J]) == BC_JFORL);
if (rec_for(J, pc, 0) != LOOPEV_LEAVE) /* Link to existing loop. */
rec_stop(J, LJ_TRLINK_ROOT, bc_d(pc[(ptrdiff_t)rc-BCBIAS_J]));
/* Continue tracing if the loop is not entered. */
break;
case BC_FORL:
rec_loop_interp(J, pc, rec_for(J, pc+((ptrdiff_t)rc-BCBIAS_J), 1));
break;
case BC_ITERL:
rec_loop_interp(J, pc, rec_iterl(J, *pc));
break;
case BC_LOOP:
rec_loop_interp(J, pc, rec_loop(J, ra));
break;
case BC_JFORL:
rec_loop_jit(J, rc, rec_for(J, pc+bc_j(traceref(J, rc)->startins), 1));
break;
case BC_JITERL:
rec_loop_jit(J, rc, rec_iterl(J, traceref(J, rc)->startins));
break;
case BC_JLOOP:
rec_loop_jit(J, rc, rec_loop(J, ra));
break;
case BC_IFORL:
case BC_IITERL:
case BC_ILOOP:
case BC_IFUNCF:
case BC_IFUNCV:
lj_trace_err(J, LJ_TRERR_BLACKL);
break;
case BC_JMP:
if (ra < J->maxslot)
J->maxslot = ra; /* Shrink used slots. */
break;
/* -- Function headers -------------------------------------------------- */
case BC_FUNCF:
rec_func_lua(J);
break;
case BC_JFUNCF:
rec_func_jit(J, rc);
break;
case BC_FUNCV:
rec_func_vararg(J);
rec_func_lua(J);
break;
case BC_JFUNCV:
lua_assert(0); /* Cannot happen. No hotcall counting for varag funcs. */
break;
case BC_FUNCC:
case BC_FUNCCW:
lj_ffrecord_func(J);
break;
default:
if (op >= BC__MAX) {
lj_ffrecord_func(J);
break;
}
/* fallthrough */
case BC_ITERN:
case BC_ISNEXT:
case BC_CAT:
case BC_UCLO:
case BC_FNEW:
case BC_TSETM:
setintV(&J->errinfo, (int32_t)op);
lj_trace_err_info(J, LJ_TRERR_NYIBC);
break;
}
/* rc == 0 if we have no result yet, e.g. pending __index metamethod call. */
if (bcmode_a(op) == BCMdst && rc) {
J->base[ra] = rc;
if (ra >= J->maxslot) J->maxslot = ra+1;
}
#undef rav
#undef rbv
#undef rcv
/* Limit the number of recorded IR instructions. */
if (J->cur.nins > REF_FIRST+(IRRef)J->param[JIT_P_maxrecord])
lj_trace_err(J, LJ_TRERR_TRACEOV);
}
/* -- Recording setup ----------------------------------------------------- */
/* Setup recording for a root trace started by a hot loop. */
static const BCIns *rec_setup_root(jit_State *J)
{
/* Determine the next PC and the bytecode range for the loop. */
const BCIns *pcj, *pc = J->pc;
BCIns ins = *pc;
BCReg ra = bc_a(ins);
switch (bc_op(ins)) {
case BC_FORL:
J->bc_extent = (MSize)(-bc_j(ins))*sizeof(BCIns);
pc += 1+bc_j(ins);
J->bc_min = pc;
break;
case BC_ITERL:
lua_assert(bc_op(pc[-1]) == BC_ITERC);
J->maxslot = ra + bc_b(pc[-1]) - 1;
J->bc_extent = (MSize)(-bc_j(ins))*sizeof(BCIns);
pc += 1+bc_j(ins);
lua_assert(bc_op(pc[-1]) == BC_JMP);
J->bc_min = pc;
break;
case BC_LOOP:
/* Only check BC range for real loops, but not for "repeat until true". */
pcj = pc + bc_j(ins);
ins = *pcj;
if (bc_op(ins) == BC_JMP && bc_j(ins) < 0) {
J->bc_min = pcj+1 + bc_j(ins);
J->bc_extent = (MSize)(-bc_j(ins))*sizeof(BCIns);
}
J->maxslot = ra;
pc++;
break;
case BC_RET:
case BC_RET0:
case BC_RET1:
/* No bytecode range check for down-recursive root traces. */
J->maxslot = ra + bc_d(ins) - 1;
break;
case BC_FUNCF:
/* No bytecode range check for root traces started by a hot call. */
J->maxslot = J->pt->numparams;
pc++;
break;
default:
lua_assert(0);
break;
}
return pc;
}
/* Setup for recording a new trace. */
void lj_record_setup(jit_State *J)
{
uint32_t i;
/* Initialize state related to current trace. */
memset(J->slot, 0, sizeof(J->slot));
memset(J->chain, 0, sizeof(J->chain));
memset(J->bpropcache, 0, sizeof(J->bpropcache));
J->scev.idx = REF_NIL;
setmref(J->scev.pc, NULL);
J->baseslot = 1; /* Invoking function is at base[-1]. */
J->base = J->slot + J->baseslot;
J->maxslot = 0;
J->framedepth = 0;
J->retdepth = 0;
J->instunroll = J->param[JIT_P_instunroll];
J->loopunroll = J->param[JIT_P_loopunroll];
J->tailcalled = 0;
J->loopref = 0;
J->bc_min = NULL; /* Means no limit. */
J->bc_extent = ~(MSize)0;
/* Emit instructions for fixed references. Also triggers initial IR alloc. */
emitir_raw(IRT(IR_BASE, IRT_P32), J->parent, J->exitno);
for (i = 0; i <= 2; i++) {
IRIns *ir = IR(REF_NIL-i);
ir->i = 0;
ir->t.irt = (uint8_t)(IRT_NIL+i);
ir->o = IR_KPRI;
ir->prev = 0;
}
J->cur.nk = REF_TRUE;
J->startpc = J->pc;
setmref(J->cur.startpc, J->pc);
if (J->parent) { /* Side trace. */
GCtrace *T = traceref(J, J->parent);
TraceNo root = T->root ? T->root : J->parent;
J->cur.root = (uint16_t)root;
J->cur.startins = BCINS_AD(BC_JMP, 0, 0);
/* Check whether we could at least potentially form an extra loop. */
if (J->exitno == 0 && T->snap[0].nent == 0) {
/* We can narrow a FORL for some side traces, too. */
if (J->pc > proto_bc(J->pt) && bc_op(J->pc[-1]) == BC_JFORI &&
bc_d(J->pc[bc_j(J->pc[-1])-1]) == root) {
lj_snap_add(J);
rec_for_loop(J, J->pc-1, &J->scev, 1);
goto sidecheck;
}
} else {
J->startpc = NULL; /* Prevent forming an extra loop. */
}
lj_snap_replay(J, T);
sidecheck:
if (traceref(J, J->cur.root)->nchild >= J->param[JIT_P_maxside] ||
T->snap[J->exitno].count >= J->param[JIT_P_hotexit] +
J->param[JIT_P_tryside]) {
rec_stop(J, LJ_TRLINK_INTERP, 0);
}
} else { /* Root trace. */
J->cur.root = 0;
J->cur.startins = *J->pc;
J->pc = rec_setup_root(J);
/* Note: the loop instruction itself is recorded at the end and not
** at the start! So snapshot #0 needs to point to the *next* instruction.
*/
lj_snap_add(J);
if (bc_op(J->cur.startins) == BC_FORL)
rec_for_loop(J, J->pc-1, &J->scev, 1);
if (1 + J->pt->framesize >= LJ_MAX_JSLOTS)
lj_trace_err(J, LJ_TRERR_STACKOV);
}
#ifdef LUAJIT_ENABLE_CHECKHOOK
/* Regularly check for instruction/line hooks from compiled code and
** exit to the interpreter if the hooks are set.
**
** This is a compile-time option and disabled by default, since the
** hook checks may be quite expensive in tight loops.
**
** Note this is only useful if hooks are *not* set most of the time.
** Use this only if you want to *asynchronously* interrupt the execution.
**
** You can set the instruction hook via lua_sethook() with a count of 1
** from a signal handler or another native thread. Please have a look
** at the first few functions in luajit.c for an example (Ctrl-C handler).
*/
{
TRef tr = emitir(IRT(IR_XLOAD, IRT_U8),
lj_ir_kptr(J, &J2G(J)->hookmask), IRXLOAD_VOLATILE);
tr = emitir(IRTI(IR_BAND), tr, lj_ir_kint(J, (LUA_MASKLINE|LUA_MASKCOUNT)));
emitir(IRTGI(IR_EQ), tr, lj_ir_kint(J, 0));
}
#endif
}
#undef IR
#undef emitir_raw
#undef emitir
#endif