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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2018-05-02 17:32:40 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2018-05-02 17:32:40 -0400 |
| commit | f74d83b3034f830bd68489b4aba99a4dee29c565 (patch) | |
| tree | 36391b2c01e9fcbf64727f3e3e0bafabf132c796 /src/backend/utils/adt/float.c | |
| parent | cec9d03d9165fd62544b63b7f236b9039f1adbe5 (diff) | |
| download | postgresql-f74d83b3034f830bd68489b4aba99a4dee29c565.tar.gz postgresql-f74d83b3034f830bd68489b4aba99a4dee29c565.zip | |
Revert back-branch changes in power()'s behavior for NaN inputs.
Per discussion, the value of fixing these bugs in the back branches
doesn't outweigh the downsides of changing corner-case behavior in
a minor release. Hence, revert commits 217d8f3a1 and 4d864de48 in
the v10 branch and the corresponding commits in 9.3-9.6.
Discussion: https://postgr.es/m/75DB81BEEA95B445AE6D576A0A5C9E936A73E741@BPXM05GP.gisp.nec.co.jp
Diffstat (limited to 'src/backend/utils/adt/float.c')
| -rw-r--r-- | src/backend/utils/adt/float.c | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index 45a62f26161..18b3b949acb 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -1462,25 +1462,6 @@ dpow(PG_FUNCTION_ARGS) float8 result; /* - * The POSIX spec says that NaN ^ 0 = 1, and 1 ^ NaN = 1, while all other - * cases with NaN inputs yield NaN (with no error). Many older platforms - * get one or more of these cases wrong, so deal with them via explicit - * logic rather than trusting pow(3). - */ - if (isnan(arg1)) - { - if (isnan(arg2) || arg2 != 0.0) - PG_RETURN_FLOAT8(get_float8_nan()); - PG_RETURN_FLOAT8(1.0); - } - if (isnan(arg2)) - { - if (arg1 != 1.0) - PG_RETURN_FLOAT8(get_float8_nan()); - PG_RETURN_FLOAT8(1.0); - } - - /* * The SQL spec requires that we emit a particular SQLSTATE error code for * certain error conditions. Specifically, we don't return a * divide-by-zero error code for 0 ^ -1. @@ -1498,7 +1479,7 @@ dpow(PG_FUNCTION_ARGS) * pow() sets errno only on some platforms, depending on whether it * follows _IEEE_, _POSIX_, _XOPEN_, or _SVID_, so we try to avoid using * errno. However, some platform/CPU combinations return errno == EDOM - * and result == NaN for negative arg1 and very large arg2 (they must be + * and result == Nan for negative arg1 and very large arg2 (they must be * using something different from our floor() test to decide it's * invalid). Other platforms (HPPA) return errno == ERANGE and a large * (HUGE_VAL) but finite result to signal overflow. |