From 23916fffce6bac40347fc5a061c9e073e462f943 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 3 Apr 2012 03:37:26 +0000 Subject: [PATCH] ld: optimize vfinfo output slightly ld atm ends up calling the write() syscall on every char when displaying an error message. For example: $ echo 'main(){foo();}' | strace -f -ewrite gcc -x c -o /dev/null - ... [pid 13035] write(2, ":", 1) = 1 [pid 13035] write(2, " ", 1) = 1 [pid 13035] write(2, "I", 1) = 1 [pid 13035] write(2, "n", 1) = 1 [pid 13035] write(2, " ", 1) = 1 [pid 13035] write(2, "f", 1) = 1 [pid 13035] write(2, "u", 1) = 1 [pid 13035] write(2, "n", 1) = 1 [pid 13035] write(2, "c", 1) = 1 [pid 13035] write(2, "t", 1) = 1 [pid 13035] write(2, "i", 1) = 1 [pid 13035] write(2, "o", 1) = 1 [pid 13035] write(2, "n", 1) = 1 [pid 13035] write(2, " ", 1) = 1 [pid 13035] write(2, "`", 1) = 1 ... That's just to write ": In function `main':". A slight optimization in the vfinfo() func gives a much more reasonable syscall footprint: ... write(2, ": In function `", 15) = 15 ... Signed-off-by: Mike Frysinger --- ld/ChangeLog | 6 ++++++ ld/ldmisc.c | 11 +++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/ld/ChangeLog b/ld/ChangeLog index 9801bda539..203f986159 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,9 @@ +2012-04-02 Mike Frysinger + + * ldmisc.c (vfinfo): Assign new local str to fmt. Delete + putc call. If str and fmt are different, call fwrite on + the difference. + 2012-03-30 Nick Clifton * po/vi.po: Updated Vietnamese translation. diff --git a/ld/ldmisc.c b/ld/ldmisc.c index 5112c716a4..ca1896ff1c 100644 --- a/ld/ldmisc.c +++ b/ld/ldmisc.c @@ -72,11 +72,14 @@ vfinfo (FILE *fp, const char *fmt, va_list arg, bfd_boolean is_warning) while (*fmt != '\0') { + const char *str = fmt; while (*fmt != '%' && *fmt != '\0') - { - putc (*fmt, fp); - fmt++; - } + fmt++; + if (fmt != str) + if (fwrite (str, 1, fmt - str, fp)) + { + /* Ignore. */ + } if (*fmt == '%') { -- 2.34.1