From: | Andres Freund <andres(at)anarazel(dot)de> |
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To: | pgsql-committers(at)postgresql(dot)org |
Subject: | pgsql: Mark x86's memory barrier inline assembly as clobbering the cpu |
Date: | 2014-09-19 15:15:43 |
Message-ID: | E1XUzuR-0003Gt-Dq@gemulon.postgresql.org |
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Lists: | pgsql-committers |
Mark x86's memory barrier inline assembly as clobbering the cpu flags.
x86's memory barrier assembly was marked as clobbering "memory" but
not "cc" even though 'addl' sets various flags. As it turns out gcc on
x86 implicitly assumes "cc" on every inline assembler statement, so
it's not a bug. But as that's poorly documented and might get copied
to architectures or compilers where that's not the case, it seems
better to be precise.
Discussion: 20140919100016(dot)GH4277(at)alap3(dot)anarazel(dot)de
To keep the code common, backpatch to 9.2 where explicit memory
barriers were introduced.
Branch
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master
Details
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http://git.postgresql.org/pg/commitdiff/e5603a2f35baa0bc9d61b16373383fdd37e49509
Modified Files
--------------
src/include/storage/barrier.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
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