From 1a6ff1a96b302283d517b3cdeae7310adecbe859 Mon Sep 17 00:00:00 2001 From: Christian Biesinger Date: Fri, 27 Sep 2019 13:08:25 -0500 Subject: [PATCH] Add a fast_hash function in common-utils Also updates a caller in symtab.c. For now this just calls htab_hash_string but the next patch will change it to xxhash, if available. gdb/ChangeLog: 2019-10-22 Christian Biesinger * utils.h (fast_hash): New function. * symtab.c (hash_demangled_name_entry): Call new function fast_hash. Change-Id: I77cac0d9aa78fc65316a2af449f52edcae72dc9b --- gdb/ChangeLog | 6 ++++++ gdb/symtab.c | 3 ++- gdb/utils.h | 10 ++++++++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index d271330400e..bbf5d0897dc 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-10-22 Christian Biesinger + + * utils.h (fast_hash): New function. + * symtab.c (hash_demangled_name_entry): Call new function + fast_hash. + 2019-10-22 Christian Biesinger * symtab.c (struct demangled_name_entry): Change type of mangled diff --git a/gdb/symtab.c b/gdb/symtab.c index 567d09d355b..dff92ca203c 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -70,6 +70,7 @@ #include #include "gdbsupport/gdb_string_view.h" #include "gdbsupport/pathstuff.h" +#include "gdbsupport/common-utils.h" /* Forward declarations for local functions. */ @@ -727,7 +728,7 @@ hash_demangled_name_entry (const void *data) const struct demangled_name_entry *e = (const struct demangled_name_entry *) data; - return iterative_hash (e->mangled.data (), e->mangled.length (), 0); + return fast_hash (e->mangled.data (), e->mangled.length ()); } /* Equality function for the demangled name hash. */ diff --git a/gdb/utils.h b/gdb/utils.h index af8b461b6e1..478c485e664 100644 --- a/gdb/utils.h +++ b/gdb/utils.h @@ -567,4 +567,14 @@ extern void copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, const gdb_byte *source, ULONGEST source_offset, ULONGEST nbits, int bits_big_endian); +/* A fast hashing function. This can be used to hash strings in a fast way + when the length is known. If no fast hashing library is available, falls + back to iterative_hash from libiberty. */ + +static inline unsigned int +fast_hash (const char* str, size_t len) +{ + return iterative_hash (str, len, 0); +} + #endif /* UTILS_H */ -- 2.30.2