From e793c052f9d9548442a46817998a46cbca4ccb70 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 2 Nov 2017 12:48:44 -0600 Subject: [PATCH] Simplify the psymbol hash function This patch simplifies the psymbol_hash function, by changing it not to examine the contents of the symbol's name. This change just mirrors what psymbol_compare already does -- it is checking for name equality, which is ok because symbol names are interned in symbol_set_names. This change speeds up psymbol reading. "gdb -nx -batch gdb" previously took ~1.8 seconds on my machine, and with this patch it now takes ~1.7 seconds. gdb/ChangeLog 2017-11-09 Tom Tromey * psymtab.c (psymbol_hash): Do not hash string contents. (psymbol_compare): Add comment. --- gdb/ChangeLog | 5 +++++ gdb/psymtab.c | 7 ++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f3c77cd28d7..22434aa3434 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2017-11-09 Tom Tromey + + * psymtab.c (psymbol_hash): Do not hash string contents. + (psymbol_compare): Add comment. + 2017-11-09 Tom Tromey * dictionary.c (dict_hash): Move "TKB" check into the "switch". diff --git a/gdb/psymtab.c b/gdb/psymtab.c index 29d40dcc04c..06a65bf26ea 100644 --- a/gdb/psymtab.c +++ b/gdb/psymtab.c @@ -1548,7 +1548,9 @@ psymbol_hash (const void *addr, int length) h = hash_continue (&lang, sizeof (unsigned int), h); h = hash_continue (&domain, sizeof (unsigned int), h); h = hash_continue (&theclass, sizeof (unsigned int), h); - h = hash_continue (psymbol->ginfo.name, strlen (psymbol->ginfo.name), h); + /* Note that psymbol names are interned via symbol_set_names, so + there's no need to hash the contents of the name here. */ + h = hash_continue (&psymbol->ginfo.name, sizeof (psymbol->ginfo.name), h); return h; } @@ -1568,6 +1570,9 @@ psymbol_compare (const void *addr1, const void *addr2, int length) && sym1->ginfo.language == sym2->ginfo.language && PSYMBOL_DOMAIN (sym1) == PSYMBOL_DOMAIN (sym2) && PSYMBOL_CLASS (sym1) == PSYMBOL_CLASS (sym2) + /* Note that psymbol names are interned via + symbol_set_names, so there's no need to compare the + contents of the name here. */ && sym1->ginfo.name == sym2->ginfo.name); } -- 2.30.2