From a8e391f3baf2cfbcfa57e46d4cfe95c089921100 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 7 Sep 2017 17:51:43 +0200 Subject: Rewrite select_val_bins so that its labels can be packed --- erts/emulator/beam/beam_debug.c | 16 ++--------- erts/emulator/beam/beam_load.c | 52 +++++++++--------------------------- erts/emulator/beam/select_instrs.tab | 19 ++++++------- 3 files changed, 24 insertions(+), 63 deletions(-) (limited to 'erts/emulator/beam') diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c index 9ba65e2464..df152f1605 100644 --- a/erts/emulator/beam/beam_debug.c +++ b/erts/emulator/beam/beam_debug.c @@ -632,6 +632,8 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr) switch (op) { case op_i_select_val_lins_xfI: case op_i_select_val_lins_yfI: + case op_i_select_val_bins_xfI: + case op_i_select_val_bins_yfI: { int n = ap[-1]; int ix = n; @@ -651,20 +653,6 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr) size += (n+1) / 2; } break; - case op_i_select_val_bins_xfI: - case op_i_select_val_bins_yfI: - { - int n = ap[-1]; - - while (n > 0) { - BeamInstr* target = f_to_addr(addr, op, ap+1); - erts_print(to, to_arg, "%T f(" HEXF ") ", (Eterm) ap[0], target); - ap += 2; - size += 2; - n--; - } - } - break; case op_i_select_tuple_arity_xfI: case op_i_select_tuple_arity_yfI: { diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c index 9bb5866cb3..944ff7bc4c 100644 --- a/erts/emulator/beam/beam_load.c +++ b/erts/emulator/beam/beam_load.c @@ -4039,7 +4039,6 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail, int i, j, align = 0; if (size == 2) { - /* * Use a special-cased instruction if there are only two values. */ @@ -4056,47 +4055,19 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail, op->a[5] = Rest[3]; return op; - - } else if (size > 10) { - - /* binary search instruction */ - - NEW_GENOP(stp, op); - op->next = NULL; - op->op = genop_i_select_val_bins_3; - GENOP_ARITY(op, arity); - op->a[0] = S; - op->a[1] = Fail; - op->a[2].type = TAG_u; - op->a[2].val = size; - for (i = 3; i < arity; i++) { - op->a[i] = Rest[i-3]; - } - - /* - * Sort the values to make them useful for a binary search. - */ - - qsort(op->a+3, size, 2*sizeof(GenOpArg), - (int (*)(const void *, const void *)) genopargcompare); -#ifdef DEBUG - for (i = 3; i < arity-2; i += 2) { - ASSERT(op->a[i].val < op->a[i+2].val); - } -#endif - return op; } - /* linear search instruction */ - - align = 1; + if (size <= 10) { + /* Use linear search. Reserve place for a sentinel. */ + align = 1; + } arity += 2*align; size += align; NEW_GENOP(stp, op); op->next = NULL; - op->op = genop_i_select_val_lins_3; + op->op = (align == 0) ? genop_i_select_val_bins_3 : genop_i_select_val_lins_3; GENOP_ARITY(op, arity); op->a[0] = S; op->a[1] = Fail; @@ -4110,7 +4081,7 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail, } /* - * Sort the values to make them useful for a sentinel search + * Sort the values to make them useful for a binary or sentinel search. */ qsort(tmp, size - align, 2*sizeof(GenOpArg), @@ -4125,11 +4096,12 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail, erts_free(ERTS_ALC_T_LOADER_TMP, (void *) tmp); - /* add sentinel */ - - op->a[j].type = TAG_u; - op->a[j].val = ~((BeamInstr)0); - op->a[j+size] = Fail; + if (align) { + /* Add sentinel for linear search. */ + op->a[j].type = TAG_u; + op->a[j].val = ~((BeamInstr)0); + op->a[j+size] = Fail; + } #ifdef DEBUG for (i = 0; i < size - 1; i++) { diff --git a/erts/emulator/beam/select_instrs.tab b/erts/emulator/beam/select_instrs.tab index 6b59f02925..4a8d9cce96 100644 --- a/erts/emulator/beam/select_instrs.tab +++ b/erts/emulator/beam/select_instrs.tab @@ -30,16 +30,15 @@ select_val_bins.fetch(Src) { } select_val_bins.select(Fail, NumElements) { - struct Pairs { + struct Singleton { BeamInstr val; - Eterm offset; }; - struct Pairs* low; - struct Pairs* high; - struct Pairs* mid; + struct Singleton* low; + struct Singleton* high; + struct Singleton* mid; int bdiff; /* int not long because the arrays aren't that large */ - low = (struct Pairs *) (&$NumElements + 1); + low = (struct Singleton *) ($NEXT_INSTRUCTION); high = low + $NumElements; /* The pointer subtraction (high-low) below must produce @@ -60,15 +59,17 @@ select_val_bins.select(Fail, NumElements) { * */ while ((bdiff = (int)((char*)high - (char*)low)) > 0) { - unsigned int boffset = ((unsigned int)bdiff >> 1) & ~(sizeof(struct Pairs)-1); + unsigned int boffset = ((unsigned int)bdiff >> 1) & ~(sizeof(struct Singleton)-1); - mid = (struct Pairs*)((char*)low + boffset); + mid = (struct Singleton*)((char*)low + boffset); if (select_val < mid->val) { high = mid; } else if (select_val > mid->val) { low = mid + 1; } else { - $JUMP(mid->offset); + Sint32* jump_tab = (Sint32 *) ($NEXT_INSTRUCTION + $NumElements); + Sint32 offset = jump_tab[mid - (struct Singleton *)($NEXT_INSTRUCTION)]; + $JUMP(offset); } } $JUMP($Fail); -- cgit v1.2.3