> From: Mattias Rönnblom [mailto:mattias.ronnb...@ericsson.com]
> Sent: Sunday, 13 October 2024 13.57
>
> The macros generating the parallel test for atomic test-and-
> [set|clear|flip] functions used a 64-bit reference word when assuring
> no neighbouring bits were modified, even when generating code for the
> 32-bit version of the test.
>
> This issue causes spurious test failures on GCC 12.2.0 (the default
> compiler on for example Debian 12 "bookworm"), when optimization level
> 2 or higher are used.
>
> The test failures do not occur with GCC 11, 12.3 and 13.2.
>
> To the author, this looks like a promotion-related compiler bug in GCC
> 12.2.
I am curious about the compiler bug...
Did the bug occur when the most significant bit was set, so it sign related?
Maybe this will reveal something:
TEST_ASSERT(expected_word == word,
"Untouched bits have changed value, %" PRIx ## size
" should be %" PRIx64,
word, expected_word);
>
> Fixes: 35326b61aecb ("bitops: add atomic bit operations in new API")
>
> Signed-off-by: Mattias Rönnblom <mattias.ronnb...@ericsson.com>
> ---
I took a deep look into this.
Regardless of what the compiler bug is,
Reviewed-by: Morten Brørup <m...@smartsharesystems.com>
