From 5ec7465fec8bceb477732d6757112fe162116eb8 Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Tue, 2 Jun 2020 21:00:35 +0100 Subject: libctf: having debugging enabled is unlikely The deduplicator can emit enormous amounts of debugging output, so much so that a later commit will introduce a new configure flag that configures most of it out (and configures it out by default). It became clear that when this configure flag is on, but debugging is not enabled via the LIBCTF_DEBUG environment variable, up to 10% of runtime can be spent on branch mispredictions checking the _libctf_debug variable. Mark it unlikely to be set (when it is set, performance is likely to be the least of your concerns). libctf/ * ctf-subr.c (ctf_dprintf): _libctf_debug is unlikely to be set. --- libctf/ctf-subr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'libctf/ctf-subr.c') diff --git a/libctf/ctf-subr.c b/libctf/ctf-subr.c index 114df84..a5cde9d 100644 --- a/libctf/ctf-subr.c +++ b/libctf/ctf-subr.c @@ -183,7 +183,7 @@ int ctf_getdebug (void) _libctf_printflike_ (1, 2) void ctf_dprintf (const char *format, ...) { - if (_libctf_debug) + if (_libctf_unlikely_ (_libctf_debug)) { va_list alist; -- cgit v1.1