Richard Sandiford bc88711db8 Add TargetLowering::prepareVolatileOrAtomicLoad ...

One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.

Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.

The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences.  It is a no-op for targets other than SystemZ.

llvm-svn: 196905

2013-12-10 10:36:34 +00:00

..

llvm

Add TargetLowering::prepareVolatileOrAtomicLoad

2013-12-10 10:36:34 +00:00

llvm-c

Add a Scalarizer pass.

2013-11-22 16:58:05 +00:00