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From: Fangrui Song <maskray@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/google/grte/v5-2.27/master] More aggressively prevent a buffer from being optimized out Date: Sat, 28 Aug 2021 00:38:54 +0000 (GMT) [thread overview] Message-ID: <20210828003854.332C93857C7B@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=df64d523104d05a17c9ef66345077154588a5424 commit df64d523104d05a17c9ef66345077154588a5424 Author: Shu-Chun Weng <scw@google.com> Date: Mon May 3 16:12:44 2021 -0700 More aggressively prevent a buffer from being optimized out The volatile global variable was first introduced in e86f9654c. I have noticed the compiler still optimizing the buffer out on AArch64 presumably because the assignment is after all other observable behaviors so it's still valid to eliminate it. Diff: --- string/tst-xbzero-opt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/string/tst-xbzero-opt.c b/string/tst-xbzero-opt.c index e9c411b2ef..4f16c4d678 100644 --- a/string/tst-xbzero-opt.c +++ b/string/tst-xbzero-opt.c @@ -119,17 +119,17 @@ static void setup_no_clear (void) { unsigned char buf[TEST_BUFFER_SIZE]; - prepare_test_buffer (buf); vol_glob = buf; + prepare_test_buffer (buf); } static void setup_ordinary_clear (void) { unsigned char buf[TEST_BUFFER_SIZE]; + vol_glob = buf; prepare_test_buffer (buf); memset (buf, 0, TEST_BUFFER_SIZE); - vol_glob = buf; } static void
next reply other threads:[~2021-08-28 0:38 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-28 0:38 Fangrui Song [this message] -- strict thread matches above, loose matches on Subject: below -- 2021-07-15 19:42 Shu-Chun Weng
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