Aegisub/vendor/luajit/src/lj_ir.c

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2014-04-28 04:45:14 +02:00
/*
** SSA IR (Intermediate Representation) emitter.
2018-05-12 08:58:15 +02:00
** Copyright (C) 2005-2017 Mike Pall. See Copyright Notice in luajit.h
2014-04-28 04:45:14 +02:00
*/
#define lj_ir_c
#define LUA_CORE
/* For pointers to libc/libm functions. */
#include <stdio.h>
#include <math.h>
#include "lj_obj.h"
#if LJ_HASJIT
#include "lj_gc.h"
#include "lj_str.h"
#include "lj_tab.h"
#include "lj_ir.h"
#include "lj_jit.h"
#include "lj_ircall.h"
#include "lj_iropt.h"
#include "lj_trace.h"
#if LJ_HASFFI
#include "lj_ctype.h"
#include "lj_cdata.h"
#include "lj_carith.h"
#endif
#include "lj_vm.h"
#include "lj_strscan.h"
#include "lj_lib.h"
/* Some local macros to save typing. Undef'd at the end. */
#define IR(ref) (&J->cur.ir[(ref)])
#define fins (&J->fold.ins)
/* 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))
/* -- IR tables ----------------------------------------------------------- */
/* IR instruction modes. */
LJ_DATADEF const uint8_t lj_ir_mode[IR__MAX+1] = {
IRDEF(IRMODE)
0
};
/* IR type sizes. */
LJ_DATADEF const uint8_t lj_ir_type_size[IRT__MAX+1] = {
#define IRTSIZE(name, size) size,
IRTDEF(IRTSIZE)
#undef IRTSIZE
0
};
/* C call info for CALL* instructions. */
LJ_DATADEF const CCallInfo lj_ir_callinfo[] = {
#define IRCALLCI(cond, name, nargs, kind, type, flags) \
{ (ASMFunction)IRCALLCOND_##cond(name), \
(nargs)|(CCI_CALL_##kind)|(IRT_##type<<CCI_OTSHIFT)|(flags) },
IRCALLDEF(IRCALLCI)
#undef IRCALLCI
{ NULL, 0 }
};
/* -- IR emitter ---------------------------------------------------------- */
/* Grow IR buffer at the top. */
void LJ_FASTCALL lj_ir_growtop(jit_State *J)
{
IRIns *baseir = J->irbuf + J->irbotlim;
MSize szins = J->irtoplim - J->irbotlim;
if (szins) {
baseir = (IRIns *)lj_mem_realloc(J->L, baseir, szins*sizeof(IRIns),
2*szins*sizeof(IRIns));
J->irtoplim = J->irbotlim + 2*szins;
} else {
baseir = (IRIns *)lj_mem_realloc(J->L, NULL, 0, LJ_MIN_IRSZ*sizeof(IRIns));
J->irbotlim = REF_BASE - LJ_MIN_IRSZ/4;
J->irtoplim = J->irbotlim + LJ_MIN_IRSZ;
}
J->cur.ir = J->irbuf = baseir - J->irbotlim;
}
/* Grow IR buffer at the bottom or shift it up. */
static void lj_ir_growbot(jit_State *J)
{
IRIns *baseir = J->irbuf + J->irbotlim;
MSize szins = J->irtoplim - J->irbotlim;
lua_assert(szins != 0);
lua_assert(J->cur.nk == J->irbotlim);
if (J->cur.nins + (szins >> 1) < J->irtoplim) {
/* More than half of the buffer is free on top: shift up by a quarter. */
MSize ofs = szins >> 2;
memmove(baseir + ofs, baseir, (J->cur.nins - J->irbotlim)*sizeof(IRIns));
J->irbotlim -= ofs;
J->irtoplim -= ofs;
J->cur.ir = J->irbuf = baseir - J->irbotlim;
} else {
/* Double the buffer size, but split the growth amongst top/bottom. */
IRIns *newbase = lj_mem_newt(J->L, 2*szins*sizeof(IRIns), IRIns);
MSize ofs = szins >= 256 ? 128 : (szins >> 1); /* Limit bottom growth. */
memcpy(newbase + ofs, baseir, (J->cur.nins - J->irbotlim)*sizeof(IRIns));
lj_mem_free(G(J->L), baseir, szins*sizeof(IRIns));
J->irbotlim -= ofs;
J->irtoplim = J->irbotlim + 2*szins;
J->cur.ir = J->irbuf = newbase - J->irbotlim;
}
}
/* Emit IR without any optimizations. */
TRef LJ_FASTCALL lj_ir_emit(jit_State *J)
{
IRRef ref = lj_ir_nextins(J);
IRIns *ir = IR(ref);
IROp op = fins->o;
ir->prev = J->chain[op];
J->chain[op] = (IRRef1)ref;
ir->o = op;
ir->op1 = fins->op1;
ir->op2 = fins->op2;
J->guardemit.irt |= fins->t.irt;
return TREF(ref, irt_t((ir->t = fins->t)));
}
/* Emit call to a C function. */
TRef lj_ir_call(jit_State *J, IRCallID id, ...)
{
const CCallInfo *ci = &lj_ir_callinfo[id];
uint32_t n = CCI_NARGS(ci);
TRef tr = TREF_NIL;
va_list argp;
va_start(argp, id);
if ((ci->flags & CCI_L)) n--;
if (n > 0)
tr = va_arg(argp, IRRef);
while (n-- > 1)
tr = emitir(IRT(IR_CARG, IRT_NIL), tr, va_arg(argp, IRRef));
va_end(argp);
if (CCI_OP(ci) == IR_CALLS)
J->needsnap = 1; /* Need snapshot after call with side effect. */
return emitir(CCI_OPTYPE(ci), tr, id);
}
/* -- Interning of constants ---------------------------------------------- */
/*
** IR instructions for constants are kept between J->cur.nk >= ref < REF_BIAS.
** They are chained like all other instructions, but grow downwards.
** The are interned (like strings in the VM) to facilitate reference
** comparisons. The same constant must get the same reference.
*/
/* Get ref of next IR constant and optionally grow IR.
** Note: this may invalidate all IRIns *!
*/
static LJ_AINLINE IRRef ir_nextk(jit_State *J)
{
IRRef ref = J->cur.nk;
if (LJ_UNLIKELY(ref <= J->irbotlim)) lj_ir_growbot(J);
J->cur.nk = --ref;
return ref;
}
/* Intern int32_t constant. */
TRef LJ_FASTCALL lj_ir_kint(jit_State *J, int32_t k)
{
IRIns *ir, *cir = J->cur.ir;
IRRef ref;
for (ref = J->chain[IR_KINT]; ref; ref = cir[ref].prev)
if (cir[ref].i == k)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
ir->i = k;
ir->t.irt = IRT_INT;
ir->o = IR_KINT;
ir->prev = J->chain[IR_KINT];
J->chain[IR_KINT] = (IRRef1)ref;
found:
return TREF(ref, IRT_INT);
}
/* The MRef inside the KNUM/KINT64 IR instructions holds the address of the
** 64 bit constant. The constants themselves are stored in a chained array
** and shared across traces.
**
** Rationale for choosing this data structure:
** - The address of the constants is embedded in the generated machine code
** and must never move. A resizable array or hash table wouldn't work.
** - Most apps need very few non-32 bit integer constants (less than a dozen).
** - Linear search is hard to beat in terms of speed and low complexity.
*/
typedef struct K64Array {
MRef next; /* Pointer to next list. */
MSize numk; /* Number of used elements in this array. */
TValue k[LJ_MIN_K64SZ]; /* Array of constants. */
} K64Array;
/* Free all chained arrays. */
void lj_ir_k64_freeall(jit_State *J)
{
K64Array *k;
for (k = mref(J->k64, K64Array); k; ) {
K64Array *next = mref(k->next, K64Array);
lj_mem_free(J2G(J), k, sizeof(K64Array));
k = next;
}
}
/* Find 64 bit constant in chained array or add it. */
cTValue *lj_ir_k64_find(jit_State *J, uint64_t u64)
{
K64Array *k, *kp = NULL;
TValue *ntv;
MSize idx;
/* Search for the constant in the whole chain of arrays. */
for (k = mref(J->k64, K64Array); k; k = mref(k->next, K64Array)) {
kp = k; /* Remember previous element in list. */
for (idx = 0; idx < k->numk; idx++) { /* Search one array. */
TValue *tv = &k->k[idx];
if (tv->u64 == u64) /* Needed for +-0/NaN/absmask. */
return tv;
}
}
/* Constant was not found, need to add it. */
if (!(kp && kp->numk < LJ_MIN_K64SZ)) { /* Allocate a new array. */
K64Array *kn = lj_mem_newt(J->L, sizeof(K64Array), K64Array);
setmref(kn->next, NULL);
kn->numk = 0;
if (kp)
setmref(kp->next, kn); /* Chain to the end of the list. */
else
setmref(J->k64, kn); /* Link first array. */
kp = kn;
}
ntv = &kp->k[kp->numk++]; /* Add to current array. */
ntv->u64 = u64;
return ntv;
}
/* Intern 64 bit constant, given by its address. */
TRef lj_ir_k64(jit_State *J, IROp op, cTValue *tv)
{
IRIns *ir, *cir = J->cur.ir;
IRRef ref;
IRType t = op == IR_KNUM ? IRT_NUM : IRT_I64;
for (ref = J->chain[op]; ref; ref = cir[ref].prev)
if (ir_k64(&cir[ref]) == tv)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
lua_assert(checkptr32(tv));
setmref(ir->ptr, tv);
ir->t.irt = t;
ir->o = op;
ir->prev = J->chain[op];
J->chain[op] = (IRRef1)ref;
found:
return TREF(ref, t);
}
/* Intern FP constant, given by its 64 bit pattern. */
TRef lj_ir_knum_u64(jit_State *J, uint64_t u64)
{
return lj_ir_k64(J, IR_KNUM, lj_ir_k64_find(J, u64));
}
/* Intern 64 bit integer constant. */
TRef lj_ir_kint64(jit_State *J, uint64_t u64)
{
return lj_ir_k64(J, IR_KINT64, lj_ir_k64_find(J, u64));
}
/* Check whether a number is int and return it. -0 is NOT considered an int. */
static int numistrueint(lua_Number n, int32_t *kp)
{
int32_t k = lj_num2int(n);
if (n == (lua_Number)k) {
if (kp) *kp = k;
if (k == 0) { /* Special check for -0. */
TValue tv;
setnumV(&tv, n);
if (tv.u32.hi != 0)
return 0;
}
return 1;
}
return 0;
}
/* Intern number as int32_t constant if possible, otherwise as FP constant. */
TRef lj_ir_knumint(jit_State *J, lua_Number n)
{
int32_t k;
if (numistrueint(n, &k))
return lj_ir_kint(J, k);
else
return lj_ir_knum(J, n);
}
/* Intern GC object "constant". */
TRef lj_ir_kgc(jit_State *J, GCobj *o, IRType t)
{
IRIns *ir, *cir = J->cur.ir;
IRRef ref;
lua_assert(!isdead(J2G(J), o));
for (ref = J->chain[IR_KGC]; ref; ref = cir[ref].prev)
if (ir_kgc(&cir[ref]) == o)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
/* NOBARRIER: Current trace is a GC root. */
setgcref(ir->gcr, o);
ir->t.irt = (uint8_t)t;
ir->o = IR_KGC;
ir->prev = J->chain[IR_KGC];
J->chain[IR_KGC] = (IRRef1)ref;
found:
return TREF(ref, t);
}
/* Intern 32 bit pointer constant. */
TRef lj_ir_kptr_(jit_State *J, IROp op, void *ptr)
{
IRIns *ir, *cir = J->cur.ir;
IRRef ref;
lua_assert((void *)(intptr_t)i32ptr(ptr) == ptr);
for (ref = J->chain[op]; ref; ref = cir[ref].prev)
if (mref(cir[ref].ptr, void) == ptr)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
setmref(ir->ptr, ptr);
ir->t.irt = IRT_P32;
ir->o = op;
ir->prev = J->chain[op];
J->chain[op] = (IRRef1)ref;
found:
return TREF(ref, IRT_P32);
}
/* Intern typed NULL constant. */
TRef lj_ir_knull(jit_State *J, IRType t)
{
IRIns *ir, *cir = J->cur.ir;
IRRef ref;
for (ref = J->chain[IR_KNULL]; ref; ref = cir[ref].prev)
if (irt_t(cir[ref].t) == t)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
ir->i = 0;
ir->t.irt = (uint8_t)t;
ir->o = IR_KNULL;
ir->prev = J->chain[IR_KNULL];
J->chain[IR_KNULL] = (IRRef1)ref;
found:
return TREF(ref, t);
}
/* Intern key slot. */
TRef lj_ir_kslot(jit_State *J, TRef key, IRRef slot)
{
IRIns *ir, *cir = J->cur.ir;
IRRef2 op12 = IRREF2((IRRef1)key, (IRRef1)slot);
IRRef ref;
/* Const part is not touched by CSE/DCE, so 0-65535 is ok for IRMlit here. */
lua_assert(tref_isk(key) && slot == (IRRef)(IRRef1)slot);
for (ref = J->chain[IR_KSLOT]; ref; ref = cir[ref].prev)
if (cir[ref].op12 == op12)
goto found;
ref = ir_nextk(J);
ir = IR(ref);
ir->op12 = op12;
ir->t.irt = IRT_P32;
ir->o = IR_KSLOT;
ir->prev = J->chain[IR_KSLOT];
J->chain[IR_KSLOT] = (IRRef1)ref;
found:
return TREF(ref, IRT_P32);
}
/* -- Access to IR constants ---------------------------------------------- */
/* Copy value of IR constant. */
void lj_ir_kvalue(lua_State *L, TValue *tv, const IRIns *ir)
{
UNUSED(L);
lua_assert(ir->o != IR_KSLOT); /* Common mistake. */
switch (ir->o) {
case IR_KPRI: setitype(tv, irt_toitype(ir->t)); break;
case IR_KINT: setintV(tv, ir->i); break;
case IR_KGC: setgcV(L, tv, ir_kgc(ir), irt_toitype(ir->t)); break;
case IR_KPTR: case IR_KKPTR: case IR_KNULL:
setlightudV(tv, mref(ir->ptr, void));
break;
case IR_KNUM: setnumV(tv, ir_knum(ir)->n); break;
#if LJ_HASFFI
case IR_KINT64: {
GCcdata *cd = lj_cdata_new_(L, CTID_INT64, 8);
*(uint64_t *)cdataptr(cd) = ir_kint64(ir)->u64;
setcdataV(L, tv, cd);
break;
}
#endif
default: lua_assert(0); break;
}
}
/* -- Convert IR operand types -------------------------------------------- */
/* Convert from string to number. */
TRef LJ_FASTCALL lj_ir_tonumber(jit_State *J, TRef tr)
{
if (!tref_isnumber(tr)) {
if (tref_isstr(tr))
tr = emitir(IRTG(IR_STRTO, IRT_NUM), tr, 0);
else
lj_trace_err(J, LJ_TRERR_BADTYPE);
}
return tr;
}
/* Convert from integer or string to number. */
TRef LJ_FASTCALL lj_ir_tonum(jit_State *J, TRef tr)
{
if (!tref_isnum(tr)) {
if (tref_isinteger(tr))
tr = emitir(IRTN(IR_CONV), tr, IRCONV_NUM_INT);
else if (tref_isstr(tr))
tr = emitir(IRTG(IR_STRTO, IRT_NUM), tr, 0);
else
lj_trace_err(J, LJ_TRERR_BADTYPE);
}
return tr;
}
/* Convert from integer or number to string. */
TRef LJ_FASTCALL lj_ir_tostr(jit_State *J, TRef tr)
{
if (!tref_isstr(tr)) {
if (!tref_isnumber(tr))
lj_trace_err(J, LJ_TRERR_BADTYPE);
tr = emitir(IRT(IR_TOSTR, IRT_STR), tr, 0);
}
return tr;
}
/* -- Miscellaneous IR ops ------------------------------------------------ */
/* Evaluate numeric comparison. */
int lj_ir_numcmp(lua_Number a, lua_Number b, IROp op)
{
switch (op) {
case IR_EQ: return (a == b);
case IR_NE: return (a != b);
case IR_LT: return (a < b);
case IR_GE: return (a >= b);
case IR_LE: return (a <= b);
case IR_GT: return (a > b);
case IR_ULT: return !(a >= b);
case IR_UGE: return !(a < b);
case IR_ULE: return !(a > b);
case IR_UGT: return !(a <= b);
default: lua_assert(0); return 0;
}
}
/* Evaluate string comparison. */
int lj_ir_strcmp(GCstr *a, GCstr *b, IROp op)
{
int res = lj_str_cmp(a, b);
switch (op) {
case IR_LT: return (res < 0);
case IR_GE: return (res >= 0);
case IR_LE: return (res <= 0);
case IR_GT: return (res > 0);
default: lua_assert(0); return 0;
}
}
/* Rollback IR to previous state. */
void lj_ir_rollback(jit_State *J, IRRef ref)
{
IRRef nins = J->cur.nins;
while (nins > ref) {
IRIns *ir;
nins--;
ir = IR(nins);
J->chain[ir->o] = ir->prev;
}
J->cur.nins = nins;
}
#undef IR
#undef fins
#undef emitir
#endif