/* Calculate number of used stack slots in the current frame. */
static BCReg cur_topslot(GCproto *pt, const BCIns *pc, uint32_t nres)
{
BCIns ins = pc[-1];
if (bc_op(ins) == BC_UCLO)
ins = pc[bc_j(ins)];
switch (bc_op(ins)) {
case BC_CALLM: case BC_CALLMT: return bc_a(ins) + bc_c(ins) + nres-1+1;
case BC_RETM: return bc_a(ins) + bc_d(ins) + nres-1;
case BC_TSETM: return bc_a(ins) + nres-1;
default: return pt->framesize;
}
}
/* Unpatch the bytecode modified by a root trace. */
static void trace_unpatch(jit_State *J, GCtrace *T)
{
BCOp op = bc_op(T->startins);
BCIns *pc = mref(T->startpc, BCIns);
UNUSED(J);
if (op == BC_JMP)
return; /* No need to unpatch branches in parent traces (yet). */
switch (bc_op(*pc)) {
case BC_JFORL:
lua_assert(traceref(J, bc_d(*pc)) == T);
*pc = T->startins;
pc += bc_j(T->startins);
lua_assert(bc_op(*pc) == BC_JFORI);
setbc_op(pc, BC_FORI);
break;
case BC_JITERL:
case BC_JLOOP:
lua_assert(op == BC_ITERL || op == BC_LOOP || bc_isret(op));
*pc = T->startins;
break;
case BC_JMP:
lua_assert(op == BC_ITERL);
pc += bc_j(*pc)+2;
if (bc_op(*pc) == BC_JITERL) {
lua_assert(traceref(J, bc_d(*pc)) == T);
*pc = T->startins;
}
break;
case BC_JFUNCF:
lua_assert(op == BC_FUNCF);
*pc = T->startins;
break;
default: /* Already unpatched. */
break;
}
}
/* Find unused slots with reaching-definitions bytecode data-flow analysis. */
static BCReg snap_usedef(jit_State *J, uint8_t *udf,
const BCIns *pc, BCReg maxslot)
{
BCReg s;
GCobj *o;
if (maxslot == 0) return 0;
#ifdef LUAJIT_USE_VALGRIND
/* Avoid errors for harmless reads beyond maxslot. */
memset(udf, 1, SNAP_USEDEF_SLOTS);
#else
memset(udf, 1, maxslot);
#endif
/* Treat open upvalues as used. */
o = gcref(J->L->openupval);
while (o) {
if (uvval(gco2uv(o)) < J->L->base) break;
udf[uvval(gco2uv(o)) - J->L->base] = 0;
o = gcref(o->gch.nextgc);
}
#define USE_SLOT(s) udf[(s)] &= ~1
#define DEF_SLOT(s) udf[(s)] *= 3
/* Scan through following bytecode and check for uses/defs. */
lua_assert(pc >= proto_bc(J->pt) && pc < proto_bc(J->pt) + J->pt->sizebc);
for (;;) {
BCIns ins = *pc++;
BCOp op = bc_op(ins);
switch (bcmode_b(op)) {
case BCMvar: USE_SLOT(bc_b(ins)); break;
default: break;
}
switch (bcmode_c(op)) {
case BCMvar: USE_SLOT(bc_c(ins)); break;
case BCMrbase:
lua_assert(op == BC_CAT);
for (s = bc_b(ins); s <= bc_c(ins); s++) USE_SLOT(s);
for (; s < maxslot; s++) DEF_SLOT(s);
break;
case BCMjump:
handle_jump: {
BCReg minslot = bc_a(ins);
if (op >= BC_FORI && op <= BC_JFORL) minslot += FORL_EXT;
else if (op >= BC_ITERL && op <= BC_JITERL) minslot += bc_b(pc[-2])-1;
else if (op == BC_UCLO) { pc += bc_j(ins); break; }
for (s = minslot; s < maxslot; s++) DEF_SLOT(s);
return minslot < maxslot ? minslot : maxslot;
}
case BCMlit:
if (op == BC_JFORL || op == BC_JITERL || op == BC_JLOOP) {
goto handle_jump;
} else if (bc_isret(op)) {
BCReg top = op == BC_RETM ? maxslot : (bc_a(ins) + bc_d(ins)-1);
for (s = 0; s < bc_a(ins); s++) DEF_SLOT(s);
for (; s < top; s++) USE_SLOT(s);
for (; s < maxslot; s++) DEF_SLOT(s);
return 0;
}
break;
case BCMfunc: return maxslot; /* NYI: will abort, anyway. */
default: break;
}
switch (bcmode_a(op)) {
case BCMvar: USE_SLOT(bc_a(ins)); break;
case BCMdst:
if (!(op == BC_ISTC || op == BC_ISFC)) DEF_SLOT(bc_a(ins));
break;
case BCMbase:
if (op >= BC_CALLM && op <= BC_VARG) {
BCReg top = (op == BC_CALLM || op == BC_CALLMT || bc_c(ins) == 0) ?
maxslot : (bc_a(ins) + bc_c(ins)+LJ_FR2);
if (LJ_FR2) DEF_SLOT(bc_a(ins)+1);
s = bc_a(ins) - ((op == BC_ITERC || op == BC_ITERN) ? 3 : 0);
for (; s < top; s++) USE_SLOT(s);
for (; s < maxslot; s++) DEF_SLOT(s);
if (op == BC_CALLT || op == BC_CALLMT) {
for (s = 0; s < bc_a(ins); s++) DEF_SLOT(s);
return 0;
}
} else if (op == BC_KNIL) {
for (s = bc_a(ins); s <= bc_d(ins); s++) DEF_SLOT(s);
} else if (op == BC_TSETM) {
for (s = bc_a(ins)-1; s < maxslot; s++) USE_SLOT(s);
}
break;
default: break;
}
lua_assert(pc >= proto_bc(J->pt) && pc < proto_bc(J->pt) + J->pt->sizebc);
}
#undef USE_SLOT
#undef DEF_SLOT
return 0; /* unreachable */
}
u4
printInstruction_aux(FILE *stream, const BCIns *ins /*in*/, int oneline)
{
const BCIns *ins0 = ins;
u4 j;
const BCIns i = *ins;
const char *name = ins_name[bc_op(i)];
fprintf(stream, "%p: ", ins);
++ ins;
switch(ins_format[bc_op(i)]) {
case IFM_R:
fprintf(stream, "%s\tr%d\n", name, bc_a(i)); break;
case IFM_RR:
fprintf(stream, "%s\tr%d, r%d\n", name, bc_a(i), bc_d(i)); break;
case IFM_RRR:
fprintf(stream, "%s\tr%d, r%d, r%d\n", name, bc_a(i), bc_b(i), bc_c(i));
break;
case IFM_RN:
fprintf(stream, "%s\tr%d, %d\n", name, bc_a(i), bc_d(i)); break;
case IFM_RRN:
fprintf(stream, "%s\tr%d, r%d, %d\n", name, bc_a(i), bc_b(i), bc_c(i));
break;
case IFM_RS:
fprintf(stream, "%s\tr%d, %d\n", name, bc_a(i), bc_sd(i)); break;
case IFM_J:
fprintf(stream, "%s\t%p\n", name, ins + bc_j(i)); break;
case IFM_RRJ:
fprintf(stream, "%s\tr%d, r%d, %p\n", name, bc_a(i), bc_d(i),
ins + 1 + bc_j(*ins));
ins++;
break;
case IFM____:
switch (bc_op(i)) {
case BC_EVAL:
{ fprintf(stream, "EVAL\tr%d", bc_a(i));
printInlineBitmap(stream, ins);
ins++;
}
break;
case BC_CASE:
{ u2 *tgt = (u2*)ins; u4 ncases = bc_d(i);
ins += (ncases + 1) / 2;
fprintf(stream, "CASE\tr%d\n", bc_a(i));
if (!oneline) {
for (j = 0; j < ncases; j++, tgt++) {
fprintf(stream, " %d: %p\n", j + 1, ins + bc_j_from_d(*tgt));
}
}
}
break;
case BC_CASE_S:
fprintf(stream, "CASE_S\tr%d ...TODO...\n", bc_a(i));
ins += bc_d(i);
break;
case BC_ALLOC1:
fprintf(stream, "ALLOC1\tr%d, r%d, r%d", bc_a(i), bc_b(i), bc_c(i));
printInlineBitmap(stream, ins);
ins += 1;
break;
case BC_ALLOC:
{
u1 *arg = (u1*)ins; ins += 1 + BC_ROUND(bc_c(i));
fprintf(stream, "ALLOC\tr%d, r%d", bc_a(i), bc_b(i));
for (j = 0; j < bc_c(i); j++, arg++)
fprintf(stream, ", r%d", *arg);
printInlineBitmap(stream, ins - 1);
}
break;
case BC_ALLOCAP:
{
u1 *arg = (u1*)ins; ins += 1 + BC_ROUND(bc_c(i) + 1);
fprintf(stream, "ALLOCAP\tr%d", bc_a(i));
u1 ptrmask = bc_b(i);
fprintf(stream, ", r%d", *arg++);
for (j = 1; j < bc_c(i); j++, arg++) {
fprintf(stream, ", r%d%c", *arg, ptrmask & 1 ? '*' : ' ');
ptrmask >>= 1;
}
printInlineBitmap(stream, ins - 1);
}
break;
case BC_CALL:
{ u1 *arg = (u1*)ins; ins += BC_ROUND(bc_c(i)) + 1;
fprintf(stream, "%s\tr%d", name, bc_a(i));
char comma = '(';
for (j = 0; j < bc_c(i); j++, arg++) {
fprintf(stream, "%cr%d", comma, *arg);
comma = ',';
}
fprintf(stream, ") [%x]", bc_b(i));
printInlineBitmap(stream, ins - 1);
}
break;
case BC_CALLT:
{
int j;
u1 bitmask = bc_b(i);
fprintf(stream, "CALLT r%d", bc_a(i));
for (j = 0; j < bc_c(i); j++) {
fprintf(stream, "%cr%d%c", j == 0 ? '(' : ',', j, bitmask & 1 ? '*' : ' ');
bitmask >>= 1;
}
fprintf(stream, ")\n");
}
break;
default:
fprintf(stream, "%s ...TODO...\n", name);
}
break;
default:
fprintf(stderr, "FATAL: Unknown intruction format: %d\n",
ins_format[bc_op(i)]);
exit(1);
}
return (u4)(ins - ins0);
}
