From: "Clément Vasseur" <clement.vasseur@gmail.com>
To: musl@lists.openwall.com
Subject: broken gcc optimization for facilitynames
Date: Wed, 18 Jun 2014 16:31:58 +0000 (UTC) [thread overview]
Message-ID: <lnsett$5et$2@ger.gmane.org> (raw)
Hello,
I might have found a gcc code generation problem with the facilitynames
implementation used in musl. See the following reduced test case:
$ cat test-facilitynames.c
#define SYSLOG_NAMES
#include <syslog.h>
int main(void)
{
for (int i = 0; facilitynames[i].c_name; i++)
if (facilitynames[i].c_name)
return facilitynames[i].c_val;
}
$ musl-gcc -std=gnu99 -O1 test-facilitynames.c && ./a.out; echo $?
32
$ musl-gcc -std=gnu99 -O2 test-facilitynames.c && ./a.out; echo $?
1
I see similar results with gcc versions 4.6.1, 4.8.3 and 4.9.0 (with a
different return value with -O2).
next reply other threads:[~2014-06-18 16:31 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-18 16:31 Clément Vasseur [this message]
2014-06-19 3:34 ` Rich Felker
2014-06-20 10:14 ` Christopher Meng
2014-06-20 22:13 ` Clément Vasseur
2014-06-20 22:09 ` Clément Vasseur
2014-06-20 22:51 ` Szabolcs Nagy
2014-06-21 0:34 ` Rich Felker
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