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author | Stefan Liebler <stli@linux.ibm.com> | 2018-07-26 17:09:44 +0200 |
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committer | Stefan Liebler <stli@linux.ibm.com> | 2018-07-26 17:09:44 +0200 |
commit | c9dc4d5117afea7283d5fd80c80be8cc09cde84d (patch) | |
tree | 915d2f3ac4ab5e720455f777a5fe378835095421 /string/tst-xbzero-opt.c | |
parent | cfba5dbb10cc3abde632b46c60c10b2843917035 (diff) | |
download | glibc-c9dc4d5117afea7283d5fd80c80be8cc09cde84d.tar.gz |
Fix string/tst-xbzero-opt if build with gcc head.
On s390x, the test string/tst-xbzero-opt is failing if build with gcc head:
FAIL: no clear/prepare: expected 32 got 0
FAIL: no clear/test: expected some got 0
FAIL: ordinary clear/prepare: expected 32 got 0
INFO: ordinary clear/test: found 0 patterns (memset not eliminated)
PASS: explicit clear/prepare: expected 32 got 32
PASS: explicit clear/test: expected 0 got 0
In setup_no_clear / setup_ordinary_clear, GCC is omitting the memcpy loop
in prepare_test_buffer. Thus count_test_patterns does not find any of the
test_pattern.
This patch calls use_test_buffer in order to force the compiler to really copy
the pattern to buf.
ChangeLog:
* string/tst-xbzero-opt.c (use_test_buffer): New function.
(prepare_test_buffer): Call use_test_buffer as compiler barrier.
Diffstat (limited to 'string/tst-xbzero-opt.c')
-rw-r--r-- | string/tst-xbzero-opt.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/string/tst-xbzero-opt.c b/string/tst-xbzero-opt.c index aab4a7f715..898345b288 100644 --- a/string/tst-xbzero-opt.c +++ b/string/tst-xbzero-opt.c @@ -97,6 +97,17 @@ static const unsigned char test_pattern[16] = static ucontext_t uc_main, uc_co; +static __attribute__ ((noinline, noclone)) int +use_test_buffer (unsigned char *buf) +{ + unsigned int sum = 0; + + for (unsigned int i = 0; i < PATTERN_REPS; i++) + sum += buf[i * PATTERN_SIZE]; + + return (sum == 2 * PATTERN_REPS) ? 0 : 1; +} + /* Always check the test buffer immediately after filling it; this makes externally visible side effects depend on the buffer existing and having been filled in. */ @@ -116,6 +127,10 @@ prepare_test_buffer (unsigned char *buf) if (swapcontext (&uc_co, &uc_main)) abort (); + + /* Force the compiler to really copy the pattern to buf. */ + if (use_test_buffer (buf)) + abort (); } static void |