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-rw-r--r--src/backend/access/hash/hashfunc.c21
1 files changed, 21 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);
}