This should be the last bit of refactoring in preparation for a patch that would
finally fix PR37494.
This patch introduces the concept of memory dependency groups (class
MemoryGroup) and "Load/Store Unit token" (LSUToken) to track the status of a
memory operation.
A MemoryGroup is a node of a memory dependency graph. It is used internally to
classify memory operations based on the memory operations they depend on. Let I
and J be two memory operations, we say that I and J equivalent (for the purpose
of mapping instructions to memory dependency groups) if the set of memory
operations they depend depend on is identical.
MemoryGroups are identified by so-called LSUToken (a unique group identifier
assigned by the LSUnit to every group). When an instruction I is dispatched to
the LSUnit, the LSUnit maps I to a group, and then returns a LSUToken.
LSUTokens are used by class Scheduler to track memory dependencies.
This patch simplifies the LSUnit interface and moves most of the implementation
details to its base class (LSUnitBase). There is no user visible change to the
output.
llvm-svn: 361950
Class LSUnitBase provides a abstract interface for all the concrete LS units in
llvm-mca.
Methods exposed by the public abstract LSUnitBase interface are:
- Status isAvailable(const InstRef&);
- void dispatch(const InstRef &);
- const InstRef &isReady(const InstRef &);
LSUnitBase standardises the API, but not the data structures internally used by
LS units. This allows for more flexibility.
Previously, only method `isReady()` was declared virtual by class LSUnit.
Also, derived classes had to inherit all the internal data members of LSUnit.
No functional change intended.
llvm-svn: 361496
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Andrea Di Biagio