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Aegisub/subprojects/luajit/src/lj_opt_split.c

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/*
** SPLIT: Split 64 bit IR instructions into 32 bit IR instructions.
** Copyright (C) 2005-2017 Mike Pall. See Copyright Notice in luajit.h
*/
#define lj_opt_split_c
#define LUA_CORE
#include "lj_obj.h"
#if LJ_HASJIT && (LJ_SOFTFP || (LJ_32 && LJ_HASFFI))
#include "lj_err.h"
#include "lj_str.h"
#include "lj_ir.h"
#include "lj_jit.h"
#include "lj_ircall.h"
#include "lj_iropt.h"
#include "lj_vm.h"
/* SPLIT pass:
**
** This pass splits up 64 bit IR instructions into multiple 32 bit IR
** instructions. It's only active for soft-float targets or for 32 bit CPUs
** which lack native 64 bit integer operations (the FFI is currently the
** only emitter for 64 bit integer instructions).
**
** Splitting the IR in a separate pass keeps each 32 bit IR assembler
** backend simple. Only a small amount of extra functionality needs to be
** implemented. This is much easier than adding support for allocating
** register pairs to each backend (believe me, I tried). A few simple, but
** important optimizations can be performed by the SPLIT pass, which would
** be tedious to do in the backend.
**
** The basic idea is to replace each 64 bit IR instruction with its 32 bit
** equivalent plus an extra HIOP instruction. The splitted IR is not passed
** through FOLD or any other optimizations, so each HIOP is guaranteed to
** immediately follow it's counterpart. The actual functionality of HIOP is
** inferred from the previous instruction.
**
** The operands of HIOP hold the hiword input references. The output of HIOP
** is the hiword output reference, which is also used to hold the hiword
** register or spill slot information. The register allocator treats this
** instruction independently of any other instruction, which improves code
** quality compared to using fixed register pairs.
**
** It's easier to split up some instructions into two regular 32 bit
** instructions. E.g. XLOAD is split up into two XLOADs with two different
** addresses. Obviously 64 bit constants need to be split up into two 32 bit
** constants, too. Some hiword instructions can be entirely omitted, e.g.
** when zero-extending a 32 bit value to 64 bits. 64 bit arguments for calls
** are split up into two 32 bit arguments each.
**
** On soft-float targets, floating-point instructions are directly converted
** to soft-float calls by the SPLIT pass (except for comparisons and MIN/MAX).
** HIOP for number results has the type IRT_SOFTFP ("sfp" in -jdump).
**
** Here's the IR and x64 machine code for 'x.b = x.a + 1' for a struct with
** two int64_t fields:
**
** 0100 p32 ADD base +8
** 0101 i64 XLOAD 0100
** 0102 i64 ADD 0101 +1
** 0103 p32 ADD base +16
** 0104 i64 XSTORE 0103 0102
**
** mov rax, [esi+0x8]
** add rax, +0x01
** mov [esi+0x10], rax
**
** Here's the transformed IR and the x86 machine code after the SPLIT pass:
**
** 0100 p32 ADD base +8
** 0101 int XLOAD 0100
** 0102 p32 ADD base +12
** 0103 int XLOAD 0102
** 0104 int ADD 0101 +1
** 0105 int HIOP 0103 +0
** 0106 p32 ADD base +16
** 0107 int XSTORE 0106 0104
** 0108 int HIOP 0106 0105
**
** mov eax, [esi+0x8]
** mov ecx, [esi+0xc]
** add eax, +0x01
** adc ecx, +0x00
** mov [esi+0x10], eax
** mov [esi+0x14], ecx
**
** You may notice the reassociated hiword address computation, which is
** later fused into the mov operands by the assembler.
*/
/* Some local macros to save typing. Undef'd at the end. */
#define IR(ref) (&J->cur.ir[(ref)])
/* Directly emit the transformed IR without updating chains etc. */
static IRRef split_emit(jit_State *J, uint16_t ot, IRRef1 op1, IRRef1 op2)
{
IRRef nref = lj_ir_nextins(J);
IRIns *ir = IR(nref);
ir->ot = ot;
ir->op1 = op1;
ir->op2 = op2;
return nref;
}
#if LJ_SOFTFP
/* Emit a (checked) number to integer conversion. */
static IRRef split_num2int(jit_State *J, IRRef lo, IRRef hi, int check)
{
IRRef tmp, res;
#if LJ_LE
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), lo, hi);
#else
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hi, lo);
#endif
res = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_softfp_d2i);
if (check) {
tmp = split_emit(J, IRTI(IR_CALLN), res, IRCALL_softfp_i2d);
split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
split_emit(J, IRTGI(IR_EQ), tmp, lo);
split_emit(J, IRTG(IR_HIOP, IRT_SOFTFP), tmp+1, hi);
}
return res;
}
/* Emit a CALLN with one split 64 bit argument. */
static IRRef split_call_l(jit_State *J, IRRef1 *hisubst, IRIns *oir,
IRIns *ir, IRCallID id)
{
IRRef tmp, op1 = ir->op1;
J->cur.nins--;
#if LJ_LE
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), oir[op1].prev, hisubst[op1]);
#else
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hisubst[op1], oir[op1].prev);
#endif
ir->prev = tmp = split_emit(J, IRTI(IR_CALLN), tmp, id);
return split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
}
/* Emit a CALLN with one split 64 bit argument and a 32 bit argument. */
static IRRef split_call_li(jit_State *J, IRRef1 *hisubst, IRIns *oir,
IRIns *ir, IRCallID id)
{
IRRef tmp, op1 = ir->op1, op2 = ir->op2;
J->cur.nins--;
#if LJ_LE
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), oir[op1].prev, hisubst[op1]);
#else
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hisubst[op1], oir[op1].prev);
#endif
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, oir[op2].prev);
ir->prev = tmp = split_emit(J, IRTI(IR_CALLN), tmp, id);
return split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
}
#endif
/* Emit a CALLN with two split 64 bit arguments. */
static IRRef split_call_ll(jit_State *J, IRRef1 *hisubst, IRIns *oir,
IRIns *ir, IRCallID id)
{
IRRef tmp, op1 = ir->op1, op2 = ir->op2;
J->cur.nins--;
#if LJ_LE
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), oir[op1].prev, hisubst[op1]);
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, oir[op2].prev);
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, hisubst[op2]);
#else
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hisubst[op1], oir[op1].prev);
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, hisubst[op2]);
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, oir[op2].prev);
#endif
ir->prev = tmp = split_emit(J, IRTI(IR_CALLN), tmp, id);
return split_emit(J,
IRT(IR_HIOP, (LJ_SOFTFP && irt_isnum(ir->t)) ? IRT_SOFTFP : IRT_INT),
tmp, tmp);
}
/* Get a pointer to the other 32 bit word (LE: hiword, BE: loword). */
static IRRef split_ptr(jit_State *J, IRIns *oir, IRRef ref)
{
IRRef nref = oir[ref].prev;
IRIns *ir = IR(nref);
int32_t ofs = 4;
if (ir->o == IR_KPTR)
return lj_ir_kptr(J, (char *)ir_kptr(ir) + ofs);
if (ir->o == IR_ADD && irref_isk(ir->op2) && !irt_isphi(oir[ref].t)) {
/* Reassociate address. */
ofs += IR(ir->op2)->i;
nref = ir->op1;
if (ofs == 0) return nref;
}
return split_emit(J, IRTI(IR_ADD), nref, lj_ir_kint(J, ofs));
}
/* Substitute references of a snapshot. */
static void split_subst_snap(jit_State *J, SnapShot *snap, IRIns *oir)
{
SnapEntry *map = &J->cur.snapmap[snap->mapofs];
MSize n, nent = snap->nent;
for (n = 0; n < nent; n++) {
SnapEntry sn = map[n];
IRIns *ir = &oir[snap_ref(sn)];
if (!(LJ_SOFTFP && (sn & SNAP_SOFTFPNUM) && irref_isk(snap_ref(sn))))
map[n] = ((sn & 0xffff0000) | ir->prev);
}
}
/* Transform the old IR to the new IR. */
static void split_ir(jit_State *J)
{
IRRef nins = J->cur.nins, nk = J->cur.nk;
MSize irlen = nins - nk;
MSize need = (irlen+1)*(sizeof(IRIns) + sizeof(IRRef1));
IRIns *oir = (IRIns *)lj_str_needbuf(J->L, &G(J->L)->tmpbuf, need);
IRRef1 *hisubst;
IRRef ref, snref;
SnapShot *snap;
/* Copy old IR to buffer. */
memcpy(oir, IR(nk), irlen*sizeof(IRIns));
/* Bias hiword substitution table and old IR. Loword kept in field prev. */
hisubst = (IRRef1 *)&oir[irlen] - nk;
oir -= nk;
/* Remove all IR instructions, but retain IR constants. */
J->cur.nins = REF_FIRST;
J->loopref = 0;
/* Process constants and fixed references. */
for (ref = nk; ref <= REF_BASE; ref++) {
IRIns *ir = &oir[ref];
if ((LJ_SOFTFP && ir->o == IR_KNUM) || ir->o == IR_KINT64) {
/* Split up 64 bit constant. */
TValue tv = *ir_k64(ir);
ir->prev = lj_ir_kint(J, (int32_t)tv.u32.lo);
hisubst[ref] = lj_ir_kint(J, (int32_t)tv.u32.hi);
} else {
ir->prev = ref; /* Identity substitution for loword. */
hisubst[ref] = 0;
}
}
/* Process old IR instructions. */
snap = J->cur.snap;
snref = snap->ref;
for (ref = REF_FIRST; ref < nins; ref++) {
IRIns *ir = &oir[ref];
IRRef nref = lj_ir_nextins(J);
IRIns *nir = IR(nref);
IRRef hi = 0;
if (ref >= snref) {
snap->ref = nref;
split_subst_snap(J, snap++, oir);
snref = snap < &J->cur.snap[J->cur.nsnap] ? snap->ref : ~(IRRef)0;
}
/* Copy-substitute old instruction to new instruction. */
nir->op1 = ir->op1 < nk ? ir->op1 : oir[ir->op1].prev;
nir->op2 = ir->op2 < nk ? ir->op2 : oir[ir->op2].prev;
ir->prev = nref; /* Loword substitution. */
nir->o = ir->o;
nir->t.irt = ir->t.irt & ~(IRT_MARK|IRT_ISPHI);
hisubst[ref] = 0;
/* Split 64 bit instructions. */
#if LJ_SOFTFP
if (irt_isnum(ir->t)) {
nir->t.irt = IRT_INT | (nir->t.irt & IRT_GUARD); /* Turn into INT op. */
/* Note: hi ref = lo ref + 1! Required for SNAP_SOFTFPNUM logic. */
switch (ir->o) {
case IR_ADD:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_add);
break;
case IR_SUB:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_sub);
break;
case IR_MUL:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_mul);
break;
case IR_DIV:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_div);
break;
case IR_POW:
hi = split_call_li(J, hisubst, oir, ir, IRCALL_lj_vm_powi);
break;
case IR_FPMATH:
/* Try to rejoin pow from EXP2, MUL and LOG2. */
if (nir->op2 == IRFPM_EXP2 && nir->op1 > J->loopref) {
IRIns *irp = IR(nir->op1);
if (irp->o == IR_CALLN && irp->op2 == IRCALL_softfp_mul) {
IRIns *irm4 = IR(irp->op1);
IRIns *irm3 = IR(irm4->op1);
IRIns *irm12 = IR(irm3->op1);
IRIns *irl1 = IR(irm12->op1);
if (irm12->op1 > J->loopref && irl1->o == IR_CALLN &&
irl1->op2 == IRCALL_lj_vm_log2) {
IRRef tmp = irl1->op1; /* Recycle first two args from LOG2. */
IRRef arg3 = irm3->op2, arg4 = irm4->op2;
J->cur.nins--;
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, arg3);
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, arg4);
ir->prev = tmp = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_pow);
hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
break;
}
}
}
hi = split_call_l(J, hisubst, oir, ir, IRCALL_lj_vm_floor + ir->op2);
break;
case IR_ATAN2:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_atan2);
break;
case IR_LDEXP:
hi = split_call_li(J, hisubst, oir, ir, IRCALL_ldexp);
break;
case IR_NEG: case IR_ABS:
nir->o = IR_CONV; /* Pass through loword. */
nir->op2 = (IRT_INT << 5) | IRT_INT;
hi = split_emit(J, IRT(ir->o == IR_NEG ? IR_BXOR : IR_BAND, IRT_SOFTFP),
hisubst[ir->op1], hisubst[ir->op2]);
break;
case IR_SLOAD:
if ((nir->op2 & IRSLOAD_CONVERT)) { /* Convert from int to number. */
nir->op2 &= ~IRSLOAD_CONVERT;
ir->prev = nref = split_emit(J, IRTI(IR_CALLN), nref,
IRCALL_softfp_i2d);
hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
break;
}
/* fallthrough */
case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
case IR_STRTO:
hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
break;
case IR_XLOAD: {
IRIns inslo = *nir; /* Save/undo the emit of the lo XLOAD. */
J->cur.nins--;
hi = split_ptr(J, oir, ir->op1); /* Insert the hiref ADD. */
nref = lj_ir_nextins(J);
nir = IR(nref);
*nir = inslo; /* Re-emit lo XLOAD immediately before hi XLOAD. */
hi = split_emit(J, IRT(IR_XLOAD, IRT_SOFTFP), hi, ir->op2);
#if LJ_LE
ir->prev = nref;
#else
ir->prev = hi; hi = nref;
#endif
break;
}
case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_XSTORE:
split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nir->op1, hisubst[ir->op2]);
break;
case IR_CONV: { /* Conversion to number. Others handled below. */
IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
UNUSED(st);
#if LJ_32 && LJ_HASFFI
if (st == IRT_I64 || st == IRT_U64) {
hi = split_call_l(J, hisubst, oir, ir,
st == IRT_I64 ? IRCALL_fp64_l2d : IRCALL_fp64_ul2d);
break;
}
#endif
lua_assert(st == IRT_INT ||
(LJ_32 && LJ_HASFFI && (st == IRT_U32 || st == IRT_FLOAT)));
nir->o = IR_CALLN;
#if LJ_32 && LJ_HASFFI
nir->op2 = st == IRT_INT ? IRCALL_softfp_i2d :
st == IRT_FLOAT ? IRCALL_softfp_f2d :
IRCALL_softfp_ui2d;
#else
nir->op2 = IRCALL_softfp_i2d;
#endif
hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
break;
}
case IR_CALLN:
case IR_CALLL:
case IR_CALLS:
case IR_CALLXS:
goto split_call;
case IR_PHI:
if (nir->op1 == nir->op2)
J->cur.nins--; /* Drop useless PHIs. */
if (hisubst[ir->op1] != hisubst[ir->op2])
split_emit(J, IRT(IR_PHI, IRT_SOFTFP),
hisubst[ir->op1], hisubst[ir->op2]);
break;
case IR_HIOP:
J->cur.nins--; /* Drop joining HIOP. */
ir->prev = nir->op1;
hi = nir->op2;
break;
default:
lua_assert(ir->o <= IR_NE || ir->o == IR_MIN || ir->o == IR_MAX);
hi = split_emit(J, IRTG(IR_HIOP, IRT_SOFTFP),
hisubst[ir->op1], hisubst[ir->op2]);
break;
}
} else
#endif
#if LJ_32 && LJ_HASFFI
if (irt_isint64(ir->t)) {
IRRef hiref = hisubst[ir->op1];
nir->t.irt = IRT_INT | (nir->t.irt & IRT_GUARD); /* Turn into INT op. */
switch (ir->o) {
case IR_ADD:
case IR_SUB:
/* Use plain op for hiword if loword cannot produce a carry/borrow. */
if (irref_isk(nir->op2) && IR(nir->op2)->i == 0) {
ir->prev = nir->op1; /* Pass through loword. */
nir->op1 = hiref; nir->op2 = hisubst[ir->op2];
hi = nref;
break;
}
/* fallthrough */
case IR_NEG:
hi = split_emit(J, IRTI(IR_HIOP), hiref, hisubst[ir->op2]);
break;
case IR_MUL:
hi = split_call_ll(J, hisubst, oir, ir, IRCALL_lj_carith_mul64);
break;
case IR_DIV:
hi = split_call_ll(J, hisubst, oir, ir,
irt_isi64(ir->t) ? IRCALL_lj_carith_divi64 :
IRCALL_lj_carith_divu64);
break;
case IR_MOD:
hi = split_call_ll(J, hisubst, oir, ir,
irt_isi64(ir->t) ? IRCALL_lj_carith_modi64 :
IRCALL_lj_carith_modu64);
break;
case IR_POW:
hi = split_call_ll(J, hisubst, oir, ir,
irt_isi64(ir->t) ? IRCALL_lj_carith_powi64 :
IRCALL_lj_carith_powu64);
break;
case IR_FLOAD:
lua_assert(ir->op2 == IRFL_CDATA_INT64);
hi = split_emit(J, IRTI(IR_FLOAD), nir->op1, IRFL_CDATA_INT64_4);
#if LJ_BE
ir->prev = hi; hi = nref;
#endif
break;
case IR_XLOAD:
hi = split_emit(J, IRTI(IR_XLOAD), split_ptr(J, oir, ir->op1), ir->op2);
#if LJ_BE
ir->prev = hi; hi = nref;
#endif
break;
case IR_XSTORE:
split_emit(J, IRTI(IR_HIOP), nir->op1, hisubst[ir->op2]);
break;
case IR_CONV: { /* Conversion to 64 bit integer. Others handled below. */
IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
#if LJ_SOFTFP
if (st == IRT_NUM) { /* NUM to 64 bit int conv. */
hi = split_call_l(J, hisubst, oir, ir,
irt_isi64(ir->t) ? IRCALL_fp64_d2l : IRCALL_fp64_d2ul);
} else if (st == IRT_FLOAT) { /* FLOAT to 64 bit int conv. */
nir->o = IR_CALLN;
nir->op2 = irt_isi64(ir->t) ? IRCALL_fp64_f2l : IRCALL_fp64_f2ul;
hi = split_emit(J, IRTI(IR_HIOP), nref, nref);
}
#else
if (st == IRT_NUM || st == IRT_FLOAT) { /* FP to 64 bit int conv. */
hi = split_emit(J, IRTI(IR_HIOP), nir->op1, nref);
}
#endif
else if (st == IRT_I64 || st == IRT_U64) { /* 64/64 bit cast. */
/* Drop cast, since assembler doesn't care. But fwd both parts. */
hi = hiref;
goto fwdlo;
} else if ((ir->op2 & IRCONV_SEXT)) { /* Sign-extend to 64 bit. */
IRRef k31 = lj_ir_kint(J, 31);
nir = IR(nref); /* May have been reallocated. */
ir->prev = nir->op1; /* Pass through loword. */
nir->o = IR_BSAR; /* hi = bsar(lo, 31). */
nir->op2 = k31;
hi = nref;
} else { /* Zero-extend to 64 bit. */
hi = lj_ir_kint(J, 0);
goto fwdlo;
}
break;
}
case IR_CALLXS:
goto split_call;
case IR_PHI: {
IRRef hiref2;
if ((irref_isk(nir->op1) && irref_isk(nir->op2)) ||
nir->op1 == nir->op2)
J->cur.nins--; /* Drop useless PHIs. */
hiref2 = hisubst[ir->op2];
if (!((irref_isk(hiref) && irref_isk(hiref2)) || hiref == hiref2))
split_emit(J, IRTI(IR_PHI), hiref, hiref2);
break;
}
case IR_HIOP:
J->cur.nins--; /* Drop joining HIOP. */
ir->prev = nir->op1;
hi = nir->op2;
break;
default:
lua_assert(ir->o <= IR_NE); /* Comparisons. */
split_emit(J, IRTGI(IR_HIOP), hiref, hisubst[ir->op2]);
break;
}
} else
#endif
#if LJ_SOFTFP
if (ir->o == IR_SLOAD) {
if ((nir->op2 & IRSLOAD_CONVERT)) { /* Convert from number to int. */
nir->op2 &= ~IRSLOAD_CONVERT;
if (!(nir->op2 & IRSLOAD_TYPECHECK))
nir->t.irt = IRT_INT; /* Drop guard. */
split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
ir->prev = split_num2int(J, nref, nref+1, irt_isguard(ir->t));
}
} else if (ir->o == IR_TOBIT) {
IRRef tmp, op1 = ir->op1;
J->cur.nins--;
#if LJ_LE
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), oir[op1].prev, hisubst[op1]);
#else
tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hisubst[op1], oir[op1].prev);
#endif
ir->prev = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_lj_vm_tobit);
} else if (ir->o == IR_TOSTR) {
if (hisubst[ir->op1]) {
if (irref_isk(ir->op1))
nir->op1 = ir->op1;
else
split_emit(J, IRT(IR_HIOP, IRT_NIL), hisubst[ir->op1], nref);
}
} else if (ir->o == IR_HREF || ir->o == IR_NEWREF) {
if (irref_isk(ir->op2) && hisubst[ir->op2])
nir->op2 = ir->op2;
} else
#endif
if (ir->o == IR_CONV) { /* See above, too. */
IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
#if LJ_32 && LJ_HASFFI
if (st == IRT_I64 || st == IRT_U64) { /* Conversion from 64 bit int. */
#if LJ_SOFTFP
if (irt_isfloat(ir->t)) {
split_call_l(J, hisubst, oir, ir,
st == IRT_I64 ? IRCALL_fp64_l2f : IRCALL_fp64_ul2f);
J->cur.nins--; /* Drop unused HIOP. */
}
#else
if (irt_isfp(ir->t)) { /* 64 bit integer to FP conversion. */
ir->prev = split_emit(J, IRT(IR_HIOP, irt_type(ir->t)),
hisubst[ir->op1], nref);
}
#endif
else { /* Truncate to lower 32 bits. */
fwdlo:
ir->prev = nir->op1; /* Forward loword. */
/* Replace with NOP to avoid messing up the snapshot logic. */
nir->ot = IRT(IR_NOP, IRT_NIL);
nir->op1 = nir->op2 = 0;
}
}
#endif
#if LJ_SOFTFP && LJ_32 && LJ_HASFFI
else if (irt_isfloat(ir->t)) {
if (st == IRT_NUM) {
split_call_l(J, hisubst, oir, ir, IRCALL_softfp_d2f);
J->cur.nins--; /* Drop unused HIOP. */
} else {
nir->o = IR_CALLN;
nir->op2 = st == IRT_INT ? IRCALL_softfp_i2f : IRCALL_softfp_ui2f;
}
} else if (st == IRT_FLOAT) {
nir->o = IR_CALLN;
nir->op2 = irt_isint(ir->t) ? IRCALL_softfp_f2i : IRCALL_softfp_f2ui;
} else
#endif
#if LJ_SOFTFP
if (st == IRT_NUM || (LJ_32 && LJ_HASFFI && st == IRT_FLOAT)) {
if (irt_isguard(ir->t)) {
lua_assert(st == IRT_NUM && irt_isint(ir->t));
J->cur.nins--;
ir->prev = split_num2int(J, nir->op1, hisubst[ir->op1], 1);
} else {
split_call_l(J, hisubst, oir, ir,
#if LJ_32 && LJ_HASFFI
st == IRT_NUM ?
(irt_isint(ir->t) ? IRCALL_softfp_d2i : IRCALL_softfp_d2ui) :
(irt_isint(ir->t) ? IRCALL_softfp_f2i : IRCALL_softfp_f2ui)
#else
IRCALL_softfp_d2i
#endif
);
J->cur.nins--; /* Drop unused HIOP. */
}
}
#endif
} else if (ir->o == IR_CALLXS) {
IRRef hiref;
split_call:
hiref = hisubst[ir->op1];
if (hiref) {
IROpT ot = nir->ot;
IRRef op2 = nir->op2;
nir->ot = IRT(IR_CARG, IRT_NIL);
#if LJ_LE
nir->op2 = hiref;
#else
nir->op2 = nir->op1; nir->op1 = hiref;
#endif
ir->prev = nref = split_emit(J, ot, nref, op2);
}
if (LJ_SOFTFP ? irt_is64(ir->t) : irt_isint64(ir->t))
hi = split_emit(J,
IRT(IR_HIOP, (LJ_SOFTFP && irt_isnum(ir->t)) ? IRT_SOFTFP : IRT_INT),
nref, nref);
} else if (ir->o == IR_CARG) {
IRRef hiref = hisubst[ir->op1];
if (hiref) {
IRRef op2 = nir->op2;
#if LJ_LE
nir->op2 = hiref;
#else
nir->op2 = nir->op1; nir->op1 = hiref;
#endif
ir->prev = nref = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, op2);
nir = IR(nref);
}
hiref = hisubst[ir->op2];
if (hiref) {
#if !LJ_TARGET_X86
int carg = 0;
IRIns *cir;
for (cir = IR(nir->op1); cir->o == IR_CARG; cir = IR(cir->op1))
carg++;
if ((carg & 1) == 0) { /* Align 64 bit arguments. */
IRRef op2 = nir->op2;
nir->op2 = REF_NIL;
nref = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, op2);
nir = IR(nref);
}
#endif
#if LJ_BE
{ IRRef tmp = nir->op2; nir->op2 = hiref; hiref = tmp; }
#endif
ir->prev = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, hiref);
}
} else if (ir->o == IR_CNEWI) {
if (hisubst[ir->op2])
split_emit(J, IRT(IR_HIOP, IRT_NIL), nref, hisubst[ir->op2]);
} else if (ir->o == IR_LOOP) {
J->loopref = nref; /* Needed by assembler. */
}
hisubst[ref] = hi; /* Store hiword substitution. */
}
if (snref == nins) { /* Substitution for last snapshot. */
snap->ref = J->cur.nins;
split_subst_snap(J, snap, oir);
}
/* Add PHI marks. */
for (ref = J->cur.nins-1; ref >= REF_FIRST; ref--) {
IRIns *ir = IR(ref);
if (ir->o != IR_PHI) break;
if (!irref_isk(ir->op1)) irt_setphi(IR(ir->op1)->t);
if (ir->op2 > J->loopref) irt_setphi(IR(ir->op2)->t);
}
}
/* Protected callback for split pass. */
static TValue *cpsplit(lua_State *L, lua_CFunction dummy, void *ud)
{
jit_State *J = (jit_State *)ud;
split_ir(J);
UNUSED(L); UNUSED(dummy);
return NULL;
}
#if defined(LUA_USE_ASSERT) || LJ_SOFTFP
/* Slow, but sure way to check whether a SPLIT pass is needed. */
static int split_needsplit(jit_State *J)
{
IRIns *ir, *irend;
IRRef ref;
for (ir = IR(REF_FIRST), irend = IR(J->cur.nins); ir < irend; ir++)
if (LJ_SOFTFP ? irt_is64orfp(ir->t) : irt_isint64(ir->t))
return 1;
if (LJ_SOFTFP) {
for (ref = J->chain[IR_SLOAD]; ref; ref = IR(ref)->prev)
if ((IR(ref)->op2 & IRSLOAD_CONVERT))
return 1;
if (J->chain[IR_TOBIT])
return 1;
}
for (ref = J->chain[IR_CONV]; ref; ref = IR(ref)->prev) {
IRType st = (IR(ref)->op2 & IRCONV_SRCMASK);
if ((LJ_SOFTFP && (st == IRT_NUM || st == IRT_FLOAT)) ||
st == IRT_I64 || st == IRT_U64)
return 1;
}
return 0; /* Nope. */
}
#endif
/* SPLIT pass. */
void lj_opt_split(jit_State *J)
{
#if LJ_SOFTFP
if (!J->needsplit)
J->needsplit = split_needsplit(J);
#else
lua_assert(J->needsplit >= split_needsplit(J)); /* Verify flag. */
#endif
if (J->needsplit) {
int errcode = lj_vm_cpcall(J->L, NULL, J, cpsplit);
if (errcode) {
/* Completely reset the trace to avoid inconsistent dump on abort. */
J->cur.nins = J->cur.nk = REF_BASE;
J->cur.nsnap = 0;
lj_err_throw(J->L, errcode); /* Propagate errors. */
}
}
}
#undef IR
#endif
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