mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-04-28 18:16:06 +00:00
Code Issues Projects Releases Wiki Activity

[mlir] Remove the Identifier ThreadLocalCache from MLIRContext

Browse Source 
This used to be important for reducing lock contention when accessing identifiers, but
the cost of the cache can be quite large if parsing in a multi-threaded context. After
D104167, the win of keeping a cache is not worth the cost.

Differential Revision: https://reviews.llvm.org/D104737
This commit is contained in:
River Riddle 2021-06-22 19:13:57 +00:00
parent e4e31e19bb
commit 87e59e47e9
1 changed files with 3 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
mlir/lib/IR/MLIRContext.cpp
View File

@ -24,7 +24,6 @@
#include "mlir/IR/OpImplementation.h"
#include "mlir/IR/Types.h"
#include "mlir/Support/DebugAction.h"
#include "mlir/Support/ThreadLocalCache.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SetVector.h"
@ -275,10 +274,6 @@ public:
llvm::StringMap<PointerUnion<Dialect *, MLIRContext *>,
llvm::BumpPtrAllocator &>
identifiers;
/// A thread local cache of identifiers to reduce lock contention.
ThreadLocalCache<llvm::StringMap<
llvm::StringMapEntry<PointerUnion<Dialect *, MLIRContext *>> *>>
localIdentifierCache;
/// An allocator used for AbstractAttribute and AbstractType objects.
llvm::BumpPtrAllocator abstractDialectSymbolAllocator;
@ -811,26 +806,18 @@ Identifier Identifier::get(const Twine &string, MLIRContext *context) {
return Identifier(&*insertedIt.first);
}
// Check for an existing instance in the local cache.
auto *&localEntry = (*impl.localIdentifierCache)[str];
if (localEntry)
return Identifier(localEntry);
// Check for an existing identifier in read-only mode.
{
llvm::sys::SmartScopedReader<true> contextLock(impl.identifierMutex);
auto it = impl.identifiers.find(str);
if (it != impl.identifiers.end()) {
localEntry = &*it;
return Identifier(localEntry);
}
if (it != impl.identifiers.end())
return Identifier(&*it);
}
// Acquire a writer-lock so that we can safely create the new instance.
llvm::sys::SmartScopedWriter<true> contextLock(impl.identifierMutex);
auto it = impl.identifiers.insert({str, getDialectOrContext()}).first;
localEntry = &*it;
return Identifier(localEntry);
return Identifier(&*it);
}
Dialect *Identifier::getDialect() {