diff options
Diffstat (limited to 'libs/luajit-cmake/luajit/src/lj_opt_sink.c')
| -rw-r--r-- | libs/luajit-cmake/luajit/src/lj_opt_sink.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/libs/luajit-cmake/luajit/src/lj_opt_sink.c b/libs/luajit-cmake/luajit/src/lj_opt_sink.c new file mode 100644 index 0000000..4b9008b --- /dev/null +++ b/libs/luajit-cmake/luajit/src/lj_opt_sink.c @@ -0,0 +1,258 @@ +/* +** SINK: Allocation Sinking and Store Sinking. +** Copyright (C) 2005-2022 Mike Pall. See Copyright Notice in luajit.h +*/ + +#define lj_opt_sink_c +#define LUA_CORE + +#include "lj_obj.h" + +#if LJ_HASJIT + +#include "lj_ir.h" +#include "lj_jit.h" +#include "lj_iropt.h" +#include "lj_target.h" + +/* Some local macros to save typing. Undef'd at the end. */ +#define IR(ref) (&J->cur.ir[(ref)]) + +/* Check whether the store ref points to an eligible allocation. */ +static IRIns *sink_checkalloc(jit_State *J, IRIns *irs) +{ + IRIns *ir = IR(irs->op1); + if (!irref_isk(ir->op2)) + return NULL; /* Non-constant key. */ + if (ir->o == IR_HREFK || ir->o == IR_AREF) + ir = IR(ir->op1); + else if (!(ir->o == IR_HREF || ir->o == IR_NEWREF || + ir->o == IR_FREF || ir->o == IR_ADD)) + return NULL; /* Unhandled reference type (for XSTORE). */ + ir = IR(ir->op1); + if (!(ir->o == IR_TNEW || ir->o == IR_TDUP || ir->o == IR_CNEW)) + return NULL; /* Not an allocation. */ + return ir; /* Return allocation. */ +} + +/* Recursively check whether a value depends on a PHI. */ +static int sink_phidep(jit_State *J, IRRef ref, int *workp) +{ + IRIns *ir = IR(ref); + if (!*workp) return 1; /* Give up and pretend it does. */ + (*workp)--; + if (irt_isphi(ir->t)) return 1; + if (ir->op1 >= REF_FIRST && sink_phidep(J, ir->op1, workp)) return 1; + if (ir->op2 >= REF_FIRST && sink_phidep(J, ir->op2, workp)) return 1; + return 0; +} + +/* Check whether a value is a sinkable PHI or loop-invariant. */ +static int sink_checkphi(jit_State *J, IRIns *ira, IRRef ref) +{ + if (ref >= REF_FIRST) { + IRIns *ir = IR(ref); + if (irt_isphi(ir->t) || (ir->o == IR_CONV && ir->op2 == IRCONV_NUM_INT && + irt_isphi(IR(ir->op1)->t))) { + ira->prev++; + return 1; /* Sinkable PHI. */ + } + /* Otherwise the value must be loop-invariant. */ + if (ref < J->loopref) { + /* Check for PHI dependencies, but give up after reasonable effort. */ + int work = 64; + return !sink_phidep(J, ref, &work); + } else { + return 0; /* Loop-variant. */ + } + } + return 1; /* Constant (non-PHI). */ +} + +/* Mark non-sinkable allocations using single-pass backward propagation. +** +** Roots for the marking process are: +** - Some PHIs or snapshots (see below). +** - Non-PHI, non-constant values stored to PHI allocations. +** - All guards. +** - Any remaining loads not eliminated by store-to-load forwarding. +** - Stores with non-constant keys. +** - All stored values. +*/ +static void sink_mark_ins(jit_State *J) +{ + IRIns *ir, *irlast = IR(J->cur.nins-1); + for (ir = irlast ; ; ir--) { + switch (ir->o) { + case IR_BASE: + return; /* Finished. */ + case IR_ALOAD: case IR_HLOAD: case IR_XLOAD: case IR_TBAR: case IR_ALEN: + irt_setmark(IR(ir->op1)->t); /* Mark ref for remaining loads. */ + break; + case IR_FLOAD: + if (irt_ismarked(ir->t) || ir->op2 == IRFL_TAB_META) + irt_setmark(IR(ir->op1)->t); /* Mark table for remaining loads. */ + break; + case IR_ASTORE: case IR_HSTORE: case IR_FSTORE: case IR_XSTORE: { + IRIns *ira = sink_checkalloc(J, ir); + if (!ira || (irt_isphi(ira->t) && !sink_checkphi(J, ira, ir->op2))) + irt_setmark(IR(ir->op1)->t); /* Mark ineligible ref. */ + irt_setmark(IR(ir->op2)->t); /* Mark stored value. */ + break; + } +#if LJ_HASFFI + case IR_CNEWI: + if (irt_isphi(ir->t) && + (!sink_checkphi(J, ir, ir->op2) || + (LJ_32 && ir+1 < irlast && (ir+1)->o == IR_HIOP && + !sink_checkphi(J, ir, (ir+1)->op2)))) + irt_setmark(ir->t); /* Mark ineligible allocation. */ +#endif + /* fallthrough */ + case IR_USTORE: + irt_setmark(IR(ir->op2)->t); /* Mark stored value. */ + break; +#if LJ_HASFFI + case IR_CALLXS: +#endif + case IR_CALLS: + irt_setmark(IR(ir->op1)->t); /* Mark (potentially) stored values. */ + break; + case IR_PHI: { + IRIns *irl = IR(ir->op1), *irr = IR(ir->op2); + irl->prev = irr->prev = 0; /* Clear PHI value counts. */ + if (irl->o == irr->o && + (irl->o == IR_TNEW || irl->o == IR_TDUP || + (LJ_HASFFI && (irl->o == IR_CNEW || irl->o == IR_CNEWI)))) + break; + irt_setmark(irl->t); + irt_setmark(irr->t); + break; + } + default: + if (irt_ismarked(ir->t) || irt_isguard(ir->t)) { /* Propagate mark. */ + if (ir->op1 >= REF_FIRST) irt_setmark(IR(ir->op1)->t); + if (ir->op2 >= REF_FIRST) irt_setmark(IR(ir->op2)->t); + } + break; + } + } +} + +/* Mark all instructions referenced by a snapshot. */ +static void sink_mark_snap(jit_State *J, SnapShot *snap) +{ + SnapEntry *map = &J->cur.snapmap[snap->mapofs]; + MSize n, nent = snap->nent; + for (n = 0; n < nent; n++) { + IRRef ref = snap_ref(map[n]); + if (!irref_isk(ref)) + irt_setmark(IR(ref)->t); + } +} + +/* Iteratively remark PHI refs with differing marks or PHI value counts. */ +static void sink_remark_phi(jit_State *J) +{ + IRIns *ir; + int remark; + do { + remark = 0; + for (ir = IR(J->cur.nins-1); ir->o == IR_PHI; ir--) { + IRIns *irl = IR(ir->op1), *irr = IR(ir->op2); + if (!((irl->t.irt ^ irr->t.irt) & IRT_MARK) && irl->prev == irr->prev) + continue; + remark |= (~(irl->t.irt & irr->t.irt) & IRT_MARK); + irt_setmark(IR(ir->op1)->t); + irt_setmark(IR(ir->op2)->t); + } + } while (remark); +} + +/* Sweep instructions and tag sunken allocations and stores. */ +static void sink_sweep_ins(jit_State *J) +{ + IRIns *ir, *irbase = IR(REF_BASE); + for (ir = IR(J->cur.nins-1) ; ir >= irbase; ir--) { + switch (ir->o) { + case IR_ASTORE: case IR_HSTORE: case IR_FSTORE: case IR_XSTORE: { + IRIns *ira = sink_checkalloc(J, ir); + if (ira && !irt_ismarked(ira->t)) { + int delta = (int)(ir - ira); + ir->prev = REGSP(RID_SINK, delta > 255 ? 255 : delta); + } else { + ir->prev = REGSP_INIT; + } + break; + } + case IR_NEWREF: + if (!irt_ismarked(IR(ir->op1)->t)) { + ir->prev = REGSP(RID_SINK, 0); + } else { + irt_clearmark(ir->t); + ir->prev = REGSP_INIT; + } + break; +#if LJ_HASFFI + case IR_CNEW: case IR_CNEWI: +#endif + case IR_TNEW: case IR_TDUP: + if (!irt_ismarked(ir->t)) { + ir->t.irt &= ~IRT_GUARD; + ir->prev = REGSP(RID_SINK, 0); + J->cur.sinktags = 1; /* Signal present SINK tags to assembler. */ + } else { + irt_clearmark(ir->t); + ir->prev = REGSP_INIT; + } + break; + case IR_PHI: { + IRIns *ira = IR(ir->op2); + if (!irt_ismarked(ira->t) && + (ira->o == IR_TNEW || ira->o == IR_TDUP || + (LJ_HASFFI && (ira->o == IR_CNEW || ira->o == IR_CNEWI)))) { + ir->prev = REGSP(RID_SINK, 0); + } else { + ir->prev = REGSP_INIT; + } + break; + } + default: + irt_clearmark(ir->t); + ir->prev = REGSP_INIT; + break; + } + } + for (ir = IR(J->cur.nk); ir < irbase; ir++) { + irt_clearmark(ir->t); + ir->prev = REGSP_INIT; + /* The false-positive of irt_is64() for ASMREF_L (REF_NIL) is OK here. */ + if (irt_is64(ir->t) && ir->o != IR_KNULL) + ir++; + } +} + +/* Allocation sinking and store sinking. +** +** 1. Mark all non-sinkable allocations. +** 2. Then sink all remaining allocations and the related stores. +*/ +void lj_opt_sink(jit_State *J) +{ + const uint32_t need = (JIT_F_OPT_SINK|JIT_F_OPT_FWD| + JIT_F_OPT_DCE|JIT_F_OPT_CSE|JIT_F_OPT_FOLD); + if ((J->flags & need) == need && + (J->chain[IR_TNEW] || J->chain[IR_TDUP] || + (LJ_HASFFI && (J->chain[IR_CNEW] || J->chain[IR_CNEWI])))) { + if (!J->loopref) + sink_mark_snap(J, &J->cur.snap[J->cur.nsnap-1]); + sink_mark_ins(J); + if (J->loopref) + sink_remark_phi(J); + sink_sweep_ins(J); + } +} + +#undef IR + +#endif |