I wrote: > What I conclude is that Red Hat hot-wired gcc to assume -msse4.2, > but they didn't hot-wire clang the same way.
In confirmation of that: everything goes through fine if I manually
add -msse4.2 to configure's choice of BITCODE_CFLAGS. Not sure if
that line of thought can lead to a usable solution, or if it's
superior to messing with the attributes on relevant functions as
you mooted upthread.
regards, tom lane
