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[binutils-gdb] Simplify the psymbol hash function
- From: Tom Tromey <tromey at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 9 Nov 2017 15:37:50 -0000
- Subject: [binutils-gdb] Simplify the psymbol hash function
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e793c052f9d9548442a46817998a46cbca4ccb70
commit e793c052f9d9548442a46817998a46cbca4ccb70
Author: Tom Tromey <tom@tromey.com>
Date: Thu Nov 2 12:48:44 2017 -0600
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 <tom@tromey.com>
* psymtab.c (psymbol_hash): Do not hash string contents.
(psymbol_compare): Add comment.
Diff:
---
gdb/ChangeLog | 5 +++++
gdb/psymtab.c | 7 ++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f3c77cd..22434aa 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
2017-11-09 Tom Tromey <tom@tromey.com>
+ * psymtab.c (psymbol_hash): Do not hash string contents.
+ (psymbol_compare): Add comment.
+
+2017-11-09 Tom Tromey <tom@tromey.com>
+
* dictionary.c (dict_hash): Move "TKB" check into the "switch".
2017-11-08 Joel Brobecker <brobecker@adacore.com>
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 29d40dc..06a65bf 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);
}