author | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | |
Tue, 10 Dec 2013 10:36:34 +0000 (10:36 +0000) | ||
committer | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | |
Tue, 10 Dec 2013 10:36:34 +0000 (10:36 +0000) | ||
commit | 086791eca2260c03c7bbdd37a53626d16656f0ca | |
tree | 338587b3a572be6708a71a39c22332bea08ca0a4 | tree | snapshot (tar.xz tar.gz zip) |
parent | faeef98cbcd1b8e1830b3ced48e85dd77c1b71b8 | commit | diff |
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196905 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196905 91177308-0d34-0410-b5e6-96231b3b80d8
24 files changed: