pgsql: Mark x86's memory barrier inline assembly as clobbering the cpu - Mailing list pgsql-committers

From Andres Freund
Subject pgsql: Mark x86's memory barrier inline assembly as clobbering the cpu
Date
Msg-id E1XUzuR-0003Gt-Dq@gemulon.postgresql.org
Whole thread Raw
List 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.GH4277@alap3.anarazel.de

To keep the code common, backpatch to 9.2 where explicit memory
barriers were introduced.

Branch
------
master

Details
-------
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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