diff options
Diffstat (limited to 'erts/emulator/beam/erl_bif_lists.c')
-rw-r--r-- | erts/emulator/beam/erl_bif_lists.c | 124 |
1 files changed, 93 insertions, 31 deletions
diff --git a/erts/emulator/beam/erl_bif_lists.c b/erts/emulator/beam/erl_bif_lists.c index 820ed2385d..73d327da3e 100644 --- a/erts/emulator/beam/erl_bif_lists.c +++ b/erts/emulator/beam/erl_bif_lists.c @@ -1,18 +1,19 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 1999-2011. All Rights Reserved. + * Copyright Ericsson AB 1999-2016. All Rights Reserved. * - * The contents of this file are subject to the Erlang Public License, - * Version 1.1, (the "License"); you may not use this file except in - * compliance with the License. You should have received a copy of the - * Erlang Public License along with this software. If not, it can be - * retrieved online at http://www.erlang.org/. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at * - * Software distributed under the License is distributed on an "AS IS" - * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See - * the License for the specific language governing rights and limitations - * under the License. + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. * * %CopyrightEnd% */ @@ -39,32 +40,93 @@ static BIF_RETTYPE append(Process* p, Eterm A, Eterm B) Eterm list; Eterm copy; Eterm last; - size_t need; - Eterm* hp; - int i; + Eterm* hp = NULL; + Sint i; - if ((i = erts_list_length(A)) < 0) { - BIF_ERROR(p, BADARG); + list = A; + + if (is_nil(list)) { + BIF_RET(B); } - if (i == 0) { - BIF_RET(B); - } else if (is_nil(B)) { - BIF_RET(A); + + if (is_not_list(list)) { + BIF_ERROR(p, BADARG); } - need = 2*i; - hp = HAlloc(p, need); - list = A; + /* optimistic append on heap first */ + + if ((i = HeapWordsLeft(p) / 2) < 4) { + goto list_tail; + } + + hp = HEAP_TOP(p); copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2)); list = CDR(list_val(list)); - hp += 2; + hp += 2; + i -= 2; /* don't use the last 2 words (extra i--;) */ + + while(i-- && is_list(list)) { + Eterm* listp = list_val(list); + last = CONS(hp, CAR(listp), make_list(hp+2)); + list = CDR(listp); + hp += 2; + } + + /* A is proper and B is NIL return A as-is, don't update HTOP */ + + if (is_nil(list) && is_nil(B)) { + BIF_RET(A); + } + + if (is_nil(list)) { + HEAP_TOP(p) = hp; + CDR(list_val(last)) = B; + BIF_RET(copy); + } + +list_tail: + + if ((i = erts_list_length(list)) < 0) { + BIF_ERROR(p, BADARG); + } + + /* remaining list was proper and B is NIL */ + if (is_nil(B)) { + BIF_RET(A); + } + + if (hp) { + /* Note: fall through case, already written + * on the heap. + * The last 2 words of the heap is not written yet + */ + Eterm *hp_save = hp; + ASSERT(i != 0); + HEAP_TOP(p) = hp + 2; + if (i == 1) { + hp[0] = CAR(list_val(list)); + hp[1] = B; + BIF_RET(copy); + } + hp = HAlloc(p, 2*(i - 1)); + last = CONS(hp_save, CAR(list_val(list)), make_list(hp)); + } else { + hp = HAlloc(p, 2*i); + copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2)); + hp += 2; + } + + list = CDR(list_val(list)); i--; + + ASSERT(i > -1); while(i--) { - Eterm* listp = list_val(list); - last = CONS(hp, CAR(listp), make_list(hp+2)); - list = CDR(listp); - hp += 2; + Eterm* listp = list_val(list); + last = CONS(hp, CAR(listp), make_list(hp+2)); + list = CDR(listp); + hp += 2; } + CDR(list_val(last)) = B; BIF_RET(copy); } @@ -98,9 +160,9 @@ static Eterm subtract(Process* p, Eterm A, Eterm B) Eterm small_vec[SMALL_VEC_SIZE]; /* Preallocated memory for small lists */ Eterm* vec_p; Eterm* vp; - int i; - int n; - int m; + Sint i; + Sint n; + Sint m; if ((n = erts_list_length(A)) < 0) { BIF_ERROR(p, BADARG); @@ -390,7 +452,7 @@ keyfind(int Bif, Process* p, Eterm Key, Eterm Pos, Eterm List) Eterm *tuple_ptr = tuple_val(term); if (pos <= arityval(*tuple_ptr)) { Eterm element = tuple_ptr[pos]; - if (CMP(Key, element) == 0) { + if (CMP_EQ(Key, element)) { return term; } } |