Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> On 05/09/2018 02:51, Andres Freund wrote:
>> My current proposal is thus to do add a check that does
>> #if defined(__clang__) && defined(__i386__) && !defined(__SSE2_MATH__)
>> something-that-fails
>> #endif
>> in an autoconf test, and have configure complain if that fails.
> Would this not be invalidated if the bug you have filed gets fixed?
Perhaps, but how would autoconf tell that? I wouldn't have any confidence
in a runtime test, as it might or might not trigger the bug depending on
all sorts of factors like -O level.
In any case, it seems like "use -msse2 on x86" is good advice from a
performance standpoint even if it doesn't prevent a compiler bug.
One thought is that maybe we should provide a way to override this,
in case somebody really can't or doesn't want to use -msse2, and
is willing to put up with platform-dependent float behavior.
regards, tom lane