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Diffstat (limited to 'erts/emulator/test/small_SUITE.erl')
-rw-r--r-- | erts/emulator/test/small_SUITE.erl | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/erts/emulator/test/small_SUITE.erl b/erts/emulator/test/small_SUITE.erl new file mode 100644 index 0000000000..00a02e5560 --- /dev/null +++ b/erts/emulator/test/small_SUITE.erl @@ -0,0 +1,115 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2019. All Rights Reserved. +%% +%% 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 +%% +%% 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% +%% +-module(small_SUITE). + +-export([all/0, suite/0]). +-export([edge_cases/1]). + +-include_lib("common_test/include/ct.hrl"). + +suite() -> + [{ct_hooks,[ts_install_cth]}, + {timetrap, {minutes, 1}}]. + +all() -> + [edge_cases]. + +edge_cases(Config) when is_list(Config) -> + {MinSmall, MaxSmall} = Limits = determine_small_limits(0), + ct:pal("Limits = ~p", [Limits]), + + true = (MaxSmall + 1) =:= MaxSmall + id(1), + true = (MinSmall - 1) =:= MinSmall - id(1), + true = (MaxSmall + 1) > id(MaxSmall), + true = (MinSmall - 1) < id(MinSmall), + -1 = MinSmall + id(MaxSmall), + -1 = MaxSmall + id(MinSmall), + + false = is_small(MinSmall * -1), + false = is_small(MinSmall - id(1)), + false = is_small(MinSmall - 1), + false = is_small(MaxSmall + id(1)), + + Lower = lists:seq(MinSmall, MinSmall + 128), + Upper = lists:seq(MaxSmall, MaxSmall - 128, -1), + Pow2 = seq_pow2(MinSmall, MaxSmall), + NearZero = lists:seq(-128, 128), + + ok = test_combinations([Lower, Upper, Pow2, NearZero], MinSmall, MaxSmall), + + ok. + +test_combinations([As | Rest]=TestVectors, MinS, MaxS) -> + [begin + _ = [arith_test(A, B, MinS, MaxS) || B <- Bs] + end || A <- As, Bs <- TestVectors], + test_combinations(Rest, MinS, MaxS); +test_combinations([], _MinS, _MaxS) -> + ok. + +%% Builds a sequence of all powers of 2 between MinSmall and MaxSmall +seq_pow2(MinSmall, MaxSmall) -> + sp2_1(MinSmall, MinSmall, MaxSmall). + +sp2_1(N, _MinS, MaxS) when N >= MaxS -> + []; +sp2_1(-1, MinS, MaxS) -> + [-1 | sp2_1(1, MinS, MaxS)]; +sp2_1(N, MinS, MaxS) when N < 0 -> + [N | sp2_1(N bsr 1, MinS, MaxS)]; +sp2_1(N, MinS, MaxS) when N > 0 -> + [N | sp2_1(N bsl 1, MinS, MaxS)]. + +arith_test(A, B, MinS, MaxS) -> + verify_kind(A + B, MinS, MaxS), + verify_kind(B + A, MinS, MaxS), + verify_kind(A - B, MinS, MaxS), + verify_kind(B - A, MinS, MaxS), + verify_kind(A * B, MinS, MaxS), + verify_kind(B * A, MinS, MaxS), + + true = A + B =:= apply(erlang, id('+'), [A, B]), + true = A - B =:= apply(erlang, id('-'), [A, B]), + true = A * B =:= apply(erlang, id('*'), [A, B]), + + true = A + B =:= B + id(A), + true = A - B =:= A + id(-B), + true = B - A =:= B + id(-A), + true = A * B =:= B * id(A), + + true = B =:= 0 orelse ((A * B) div id(B) =:= A), + true = A =:= 0 orelse ((B * A) div id(A) =:= B), + + ok. + +%% Verifies that N is a small when it should be +verify_kind(N, MinS, MaxS) -> + true = is_small(N) =:= (N >= MinS andalso N =< MaxS). + +is_small(N) when is_integer(N) -> + 0 =:= erts_debug:flat_size(N). + +determine_small_limits(N) -> + case is_small(-1 bsl N) of + true -> determine_small_limits(N + 1); + false -> {-1 bsl (N - 1), (1 bsl (N - 1)) - 1} + end. + +id(I) -> I. |