diff options
| -rw-r--r-- | src/backend/access/hash/hashfunc.c | 21 | ||||
| -rw-r--r-- | src/test/regress/expected/hash_func.out | 33 | ||||
| -rw-r--r-- | src/test/regress/sql/hash_func.sql | 9 |
3 files changed, 63 insertions, 0 deletions
diff --git a/src/backend/access/hash/hashfunc.c b/src/backend/access/hash/hashfunc.c index db20d9d1c14..68c3ebb9bba 100644 --- a/src/backend/access/hash/hashfunc.c +++ b/src/backend/access/hash/hashfunc.c @@ -30,6 +30,7 @@ #include "catalog/pg_collation.h" #include "common/hashfn.h" #include "utils/builtins.h" +#include "utils/float.h" #include "utils/pg_locale.h" /* @@ -151,6 +152,14 @@ hashfloat4(PG_FUNCTION_ARGS) PG_RETURN_UINT32(0); /* + * Similarly, NaNs can have different bit patterns but they should all + * compare as equal. For backwards-compatibility reasons we force them to + * have the hash value of a standard NaN. + */ + if (isnan(key)) + key = get_float4_nan(); + + /* * To support cross-type hashing of float8 and float4, we want to return * the same hash value hashfloat8 would produce for an equal float8 value. * So, widen the value to float8 and hash that. (We must do this rather @@ -172,6 +181,8 @@ hashfloat4extended(PG_FUNCTION_ARGS) /* Same approach as hashfloat4 */ if (key == (float4) 0) PG_RETURN_UINT64(seed); + if (isnan(key)) + key = get_float4_nan(); key8 = key; return hash_any_extended((unsigned char *) &key8, sizeof(key8), seed); @@ -190,6 +201,14 @@ hashfloat8(PG_FUNCTION_ARGS) if (key == (float8) 0) PG_RETURN_UINT32(0); + /* + * Similarly, NaNs can have different bit patterns but they should all + * compare as equal. For backwards-compatibility reasons we force them to + * have the hash value of a standard NaN. + */ + if (isnan(key)) + key = get_float8_nan(); + return hash_any((unsigned char *) &key, sizeof(key)); } @@ -202,6 +221,8 @@ hashfloat8extended(PG_FUNCTION_ARGS) /* Same approach as hashfloat8 */ if (key == (float8) 0) PG_RETURN_UINT64(seed); + if (isnan(key)) + key = get_float8_nan(); return hash_any_extended((unsigned char *) &key, sizeof(key), seed); } diff --git a/src/test/regress/expected/hash_func.out b/src/test/regress/expected/hash_func.out index dca31365bcf..61c6cbbf109 100644 --- a/src/test/regress/expected/hash_func.out +++ b/src/test/regress/expected/hash_func.out @@ -339,3 +339,36 @@ SELECT v as value, hash_record_extended(v, 0)::bit(32) as extended0 FROM (VALUES (row(1, 'aaa')::hash_test_t2)) x(v); ERROR: could not identify an extended hash function for type money DROP TYPE hash_test_t2; +-- +-- Check special cases for specific data types +-- +SELECT hashfloat4('0'::float4) = hashfloat4('-0'::float4) AS t; + t +--- + t +(1 row) + +SELECT hashfloat4('NaN'::float4) = hashfloat4('-NaN'::float4) AS t; + t +--- + t +(1 row) + +SELECT hashfloat8('0'::float8) = hashfloat8('-0'::float8) AS t; + t +--- + t +(1 row) + +SELECT hashfloat8('NaN'::float8) = hashfloat8('-NaN'::float8) AS t; + t +--- + t +(1 row) + +SELECT hashfloat4('NaN'::float4) = hashfloat8('NaN'::float8) AS t; + t +--- + t +(1 row) + diff --git a/src/test/regress/sql/hash_func.sql b/src/test/regress/sql/hash_func.sql index 0292dedd15a..5c994f5de5e 100644 --- a/src/test/regress/sql/hash_func.sql +++ b/src/test/regress/sql/hash_func.sql @@ -253,3 +253,12 @@ FROM (VALUES (row(1, 'aaa')::hash_test_t2)) x(v); SELECT v as value, hash_record_extended(v, 0)::bit(32) as extended0 FROM (VALUES (row(1, 'aaa')::hash_test_t2)) x(v); DROP TYPE hash_test_t2; + +-- +-- Check special cases for specific data types +-- +SELECT hashfloat4('0'::float4) = hashfloat4('-0'::float4) AS t; +SELECT hashfloat4('NaN'::float4) = hashfloat4('-NaN'::float4) AS t; +SELECT hashfloat8('0'::float8) = hashfloat8('-0'::float8) AS t; +SELECT hashfloat8('NaN'::float8) = hashfloat8('-NaN'::float8) AS t; +SELECT hashfloat4('NaN'::float4) = hashfloat8('NaN'::float8) AS t; |