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author | Björn-Egil Dahlberg <[email protected]> | 2015-04-10 15:51:05 +0200 |
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committer | Björn-Egil Dahlberg <[email protected]> | 2015-04-10 15:51:05 +0200 |
commit | 42b1ee09491706cd255f8c146e07c1cb2cd939cc (patch) | |
tree | e1f59086bbf8d6f969fe258b5425bc8a449b4d00 /erts/emulator | |
parent | b5f3973cc50a193be868e672b2ced6dd619427c4 (diff) | |
parent | 2a0ff8b50a68d51e44fddf36867f390b64a4f2bf (diff) | |
download | otp-42b1ee09491706cd255f8c146e07c1cb2cd939cc.tar.gz otp-42b1ee09491706cd255f8c146e07c1cb2cd939cc.tar.bz2 otp-42b1ee09491706cd255f8c146e07c1cb2cd939cc.zip |
Merge branch 'egil/fix-hash-float-zero/OTP-12641'
* egil/fix-hash-float-zero/OTP-12641:
erts: Ensure hashing of zero is consistent
Diffstat (limited to 'erts/emulator')
-rw-r--r-- | erts/emulator/beam/utils.c | 29 | ||||
-rw-r--r-- | erts/emulator/test/hash_SUITE.erl | 27 |
2 files changed, 44 insertions, 12 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c index bf6d9fff50..aecfe04a75 100644 --- a/erts/emulator/beam/utils.c +++ b/erts/emulator/beam/utils.c @@ -955,12 +955,14 @@ tail_recur: UINT32_HASH_RET(external_ref_numbers(term)[0],FUNNY_NUMBER9,FUNNY_NUMBER10); case FLOAT_DEF: { - FloatDef ff; - GET_DOUBLE(term, ff); - hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]); - break; + FloatDef ff; + GET_DOUBLE(term, ff); + if (ff.fd == 0.0f) { + ff.fd = 0.0f; /* ensure pos. 0.0 */ + } + hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]); + break; } - case MAKE_HASH_CDR_PRE_OP: term = (Eterm) WSTACK_POP(stack); if (is_not_list(term)) { @@ -1474,6 +1476,9 @@ make_hash2(Eterm term) { FloatDef ff; GET_DOUBLE(term, ff); + if (ff.fd == 0.0f) { + ff.fd = 0.0f; /* ensure pos. 0.0 */ + } #if defined(WORDS_BIGENDIAN) || defined(DOUBLE_MIDDLE_ENDIAN) UINT32_HASH_2(ff.fw[0], ff.fw[1], HCONST_12); #else @@ -1893,8 +1898,8 @@ make_internal_hash(Eterm term) { FloatDef ff; GET_DOUBLE(term, ff); - if (ff.fd == 0.0) { - ff.fd = 0.0; /* ensure pos. 0.0 */ + if (ff.fd == 0.0f) { + ff.fd = 0.0f; /* ensure pos. 0.0 */ } UINT32_HASH_2(ff.fw[0], ff.fw[1], HCONST_12); goto pop_next; @@ -2079,12 +2084,14 @@ tail_recur: break; case FLOAT_DEF: { - FloatDef ff; - GET_DOUBLE(term, ff); - hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]); + FloatDef ff; + GET_DOUBLE(term, ff); + if (ff.fd == 0.0f) { + ff.fd = 0.0f; /* ensure pos. 0.0 */ + } + hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]); } break; - case MAKE_HASH_CDR_PRE_OP: term = (Eterm) WSTACK_POP(stack); if (is_not_list(term)) { diff --git a/erts/emulator/test/hash_SUITE.erl b/erts/emulator/test/hash_SUITE.erl index 647bb45049..5fa45f772d 100644 --- a/erts/emulator/test/hash_SUITE.erl +++ b/erts/emulator/test/hash_SUITE.erl @@ -73,6 +73,7 @@ config(priv_dir,_) -> init_per_group/2,end_per_group/2, test_basic/1,test_cmp/1,test_range/1,test_spread/1, test_phash2/1,otp_5292/1,bit_level_binaries/1,otp_7127/1, + test_hash_zero/1, end_per_testcase/2,init_per_testcase/2]). init_per_testcase(_Case, Config) -> Dog=test_server:timetrap(test_server:minutes(10)), @@ -86,7 +87,9 @@ suite() -> [{ct_hooks,[ts_install_cth]}]. all() -> [test_basic, test_cmp, test_range, test_spread, - test_phash2, otp_5292, bit_level_binaries, otp_7127]. + test_phash2, otp_5292, bit_level_binaries, otp_7127, + test_hash_zero + ]. groups() -> []. @@ -160,6 +163,8 @@ otp_7127(doc) -> otp_7127(Config) when is_list(Config) -> otp_7127_test(). +test_hash_zero(Config) when is_list(Config) -> + hash_zero_test(). -endif. @@ -591,6 +596,26 @@ otp_7127_test() -> 38990304 = erlang:phash2(<<"Scott9">>), ok. +hash_zero_test() -> + Zs = [0.0, -0.0, 0/-1, 0.0/-1, 0/-(1 bsl 65), + binary_to_term(<<131,70,0,0,0,0,0,0,0,0>>), %% +0.0 + binary_to_term(<<131,70,128,0,0,0,0,0,0,0>>)], %% -0.0 + ok = hash_zero_test(Zs,fun(T) -> erlang:phash2(T, 1 bsl 32) end), + ok = hash_zero_test(Zs,fun(T) -> erlang:phash(T, 1 bsl 32) end), + ok = hash_zero_test(Zs,fun(T) -> erlang:hash(T, (1 bsl 27) - 1) end), + ok. + +hash_zero_test([Z|Zs],F) -> + hash_zero_test(Zs,Z,F(Z),F). +hash_zero_test([Z|Zs],Z0,V,F) -> + true = Z0 =:= Z, %% assert exact equal + Z0 = Z, %% assert matching + V = F(Z), %% assert hash + hash_zero_test(Zs,Z0,V,F); +hash_zero_test([],_,_,_) -> + ok. + + %% %% Reference implementation of integer hashing %% |