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| author | Christian Biesinger <cbiesinger@google.com> | 2019-12-02 18:58:35 -0600 |
|---|---|---|
| committer | Christian Biesinger <cbiesinger@google.com> | 2019-12-03 15:27:15 -0600 |
| commit | 4cbd39b289b012782df2fdda9adc7eacdcfc6ad7 (patch) | |
| tree | f52aba927c48c83dca2923c7c3c0c55657ca29c1 /gdb/bcache.c | |
| parent | 82f910ea9cce04b0faabfcd022d9d8949567541e (diff) | |
| download | binutils-4cbd39b289b012782df2fdda9adc7eacdcfc6ad7.zip binutils-4cbd39b289b012782df2fdda9adc7eacdcfc6ad7.tar.gz binutils-4cbd39b289b012782df2fdda9adc7eacdcfc6ad7.tar.bz2 | |
Replace hash function from bcache with fast_hash
This function is not just slower than xxhash, it is slower than
even libiberty's iterative_hash, so there does not seem to be
a reason for it to exist.
------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------
BM_xxh3 11 ns 11 ns 66127192
BM_xxh32 19 ns 19 ns 36792609
BM_xxh64 16 ns 16 ns 42941328
BM_city32 26 ns 26 ns 27028370
BM_city64 17 ns 17 ns 40472793
BM_iterative_hash 77 ns 77 ns 9088854
BM_bcache_hash 125 ns 125 ns 5599232
gdb/ChangeLog:
2019-12-03 Christian Biesinger <cbiesinger@google.com>
* bcache.c (hash): Remove.
(hash_continue): Remove.
* bcache.h (hash): Remove.
(hash_continue): Remove.
(struct bcache) <ctor>: Update.
* psymtab.c (psymbol_hash): Update.
* stabsread.c (hashname): Update.
* utils.h (fast_hash): Add an argument for a start value,
defaulting to zero.
Change-Id: I107f013eda5fdd3293326b5a206be43155dae0f8
Diffstat (limited to 'gdb/bcache.c')
| -rw-r--r-- | gdb/bcache.c | 25 |
1 files changed, 0 insertions, 25 deletions
diff --git a/gdb/bcache.c b/gdb/bcache.c index 3f0a63b..497efe9 100644 --- a/gdb/bcache.c +++ b/gdb/bcache.c @@ -51,31 +51,6 @@ struct bstring d; }; -/* The old hash function was stolen from SDBM. This is what DB 3.0 - uses now, and is better than the old one. */ - -unsigned long -hash(const void *addr, int length) -{ - return hash_continue (addr, length, 0); -} - -/* Continue the calculation of the hash H at the given address. */ - -unsigned long -hash_continue (const void *addr, int length, unsigned long h) -{ - const unsigned char *k, *e; - - k = (const unsigned char *)addr; - e = k+length; - for (; k< e;++k) - { - h *=16777619; - h ^= *k; - } - return (h); -} /* Growing the bcache's hash table. */ |