1 files changed, 461 insertions, 0 deletions

diff --git a/src/lj_ir.c b/src/lj_ir.c
new file mode 100644
index 00000000..2ff54821
--- /dev/null
+++ b/src/lj_ir.c
@@ -0,0 +1,461 @@
+/*
+** SSA IR (Intermediate Representation) emitter.
+** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lj_ir_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+
+#if LJ_HASJIT
+
+#include "lj_gc.h"
+#include "lj_str.h"
+#include "lj_ir.h"
+#include "lj_jit.h"
+#include "lj_iropt.h"
+#include "lj_trace.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 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)));
+}
+
+/* -- 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 IR instruction holds the address of the constant
+** (an aligned double or a special 64 bit pattern). The KNUM 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-integer constants (less than a dozen).
+** - Linear search is hard to beat in terms of speed and low complexity.
+*/
+typedef struct KNumArray {
+  MRef next;                    /* Pointer to next list. */
+  MSize numk;                   /* Number of used elements in this array. */
+  TValue k[LJ_MIN_KNUMSZ];      /* Array of constants. */
+} KNumArray;
+
+/* Free all chained arrays. */
+void lj_ir_knum_freeall(jit_State *J)
+{
+  KNumArray *kn;
+  for (kn = mref(J->knum, KNumArray); kn; ) {
+    KNumArray *next = mref(kn->next, KNumArray);
+    lj_mem_free(J2G(J), kn, sizeof(KNumArray));
+    kn = next;
+  }
+}
+
+/* Find KNUM constant in chained array or add it. */
+static cTValue *ir_knum_find(jit_State *J, uint64_t nn)
+{
+  KNumArray *kn, *knp = NULL;
+  TValue *ntv;
+  MSize idx;
+  /* Search for the constant in the whole chain of arrays. */
+  for (kn = mref(J->knum, KNumArray); kn; kn = mref(kn->next, KNumArray)) {
+    knp = kn;  /* Remember previous element in list. */
+    for (idx = 0; idx < kn->numk; idx++) {  /* Search one array. */
+      TValue *tv = &kn->k[idx];
+      if (tv->u64 == nn)  /* Needed for +-0/NaN/absmask. */
+        return tv;
+    }
+  }
+  /* Constant was not found, need to add it. */
+  if (!(knp && knp->numk < LJ_MIN_KNUMSZ)) {  /* Allocate a new array. */
+    KNumArray *nkn = lj_mem_newt(J->L, sizeof(KNumArray), KNumArray);
+    setmref(nkn->next, NULL);
+    nkn->numk = 0;
+    if (knp)
+      setmref(knp->next, nkn);  /* Chain to the end of the list. */
+    else
+      setmref(J->knum, nkn);  /* Link first array. */
+    knp = nkn;
+  }
+  ntv = &knp->k[knp->numk++];  /* Add to current array. */
+  ntv->u64 = nn;
+  return ntv;
+}
+
+/* Intern FP constant, given by its address. */
+TRef lj_ir_knum_addr(jit_State *J, cTValue *tv)
+{
+  IRIns *ir, *cir = J->cur.ir;
+  IRRef ref;
+  for (ref = J->chain[IR_KNUM]; ref; ref = cir[ref].prev)
+    if (ir_knum(&cir[ref]) == tv)
+      goto found;
+  ref = ir_nextk(J);
+  ir = IR(ref);
+  setmref(ir->ptr, tv);
+  ir->t.irt = IRT_NUM;
+  ir->o = IR_KNUM;
+  ir->prev = J->chain[IR_KNUM];
+  J->chain[IR_KNUM] = (IRRef1)ref;
+found:
+  return TREF(ref, IRT_NUM);
+}
+
+/* Intern FP constant, given by its 64 bit pattern. */
+TRef lj_ir_knum_nn(jit_State *J, uint64_t nn)
+{
+  return lj_ir_knum_addr(J, ir_knum_find(J, nn));
+}
+
+/* Special 16 byte aligned SIMD constants. */
+LJ_DATADEF LJ_ALIGN(16) cTValue lj_ir_knum_tv[4] = {
+  { U64x(7fffffff,ffffffff) }, { U64x(7fffffff,ffffffff) },
+  { U64x(80000000,00000000) }, { U64x(80000000,00000000) }
+};
+
+/* 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 == cast_num(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;
+  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, void *ptr)
+{
+  IRIns *ir, *cir = J->cur.ir;
+  IRRef ref;
+  lua_assert((void *)(intptr_t)i32ptr(ptr) == ptr);
+  for (ref = J->chain[IR_KPTR]; 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_PTR;
+  ir->o = IR_KPTR;
+  ir->prev = J->chain[IR_KPTR];
+  J->chain[IR_KPTR] = (IRRef1)ref;
+found:
+  return TREF(ref, IRT_PTR);
+}
+
+/* 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_PTR;
+  ir->o = IR_KSLOT;
+  ir->prev = J->chain[IR_KSLOT];
+  J->chain[IR_KSLOT] = (IRRef1)ref;
+found:
+  return TREF(ref, IRT_PTR);
+}
+
+/* -- 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. */
+  if (irt_isint(ir->t)) {
+    lua_assert(ir->o == IR_KINT);
+    setintV(tv, ir->i);
+  } else if (irt_isnum(ir->t)) {
+    lua_assert(ir->o == IR_KNUM);
+    setnumV(tv, ir_knum(ir)->n);
+  } else if (irt_ispri(ir->t)) {
+    lua_assert(ir->o == IR_KPRI);
+    setitype(tv, irt_toitype(ir->t));
+  } else {
+    if (ir->o == IR_KGC) {
+      lua_assert(irt_isgcv(ir->t));
+      setgcV(L, tv, &ir_kgc(ir)->gch, irt_toitype(ir->t));
+    } else {
+      lua_assert(ir->o == IR_KPTR || ir->o == IR_KNULL);
+      setlightudV(tv, mref(ir->ptr, void));
+    }
+  }
+}
+
+/* -- Convert IR operand types -------------------------------------------- */
+
+/* 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_TONUM), tr, 0);
+    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;
+}
+
+/* Convert from number or string to bitop operand (overflow wrapped). */
+TRef LJ_FASTCALL lj_ir_tobit(jit_State *J, TRef tr)
+{
+  if (!tref_isinteger(tr)) {
+    if (tref_isstr(tr))
+      tr = emitir(IRTG(IR_STRTO, IRT_NUM), tr, 0);
+    else if (!tref_isnum(tr))
+      lj_trace_err(J, LJ_TRERR_BADTYPE);
+    tr = emitir(IRTI(IR_TOBIT), tr, lj_ir_knum_tobit(J));
+  }
+  return tr;
+}
+
+/* Convert from number or string to integer (overflow undefined). */
+TRef LJ_FASTCALL lj_ir_toint(jit_State *J, TRef tr)
+{
+  if (!tref_isinteger(tr)) {
+    if (tref_isstr(tr))
+      tr = emitir(IRTG(IR_STRTO, IRT_NUM), tr, 0);
+    else if (!tref_isnum(tr))
+      lj_trace_err(J, LJ_TRERR_BADTYPE);
+    tr = emitir(IRTI(IR_TOINT), tr, IRTOINT_ANY);
+  }
+  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