Add a mechanism for optimisation plugins to register passes that all front ends can use without needing to be aware of the plugin (or the plugin be aware of the front end).

Before 3.0, I'd like to add a mechanism for automatically loading a set of plugins from a config file.  API suggestions welcome...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137717 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/IPO/PassManagerBuilder.h

@@ -98,6 +98,10 @@ private:
 public:
   PassManagerBuilder();
   ~PassManagerBuilder();
+  /// Adds an extension that will be used by all PassManagerBuilder instances.
+  /// This is intended to be used by plugins, to register a set of
+  /// optimisations to run automatically.
+  static void addGlobalExtension(ExtensionPointTy Ty, ExtensionFn Fn);
   void addExtension(ExtensionPointTy Ty, ExtensionFn Fn);
 
 private:
@@ -115,6 +119,15 @@ public:
   void populateLTOPassManager(PassManagerBase &PM, bool Internalize,
                               bool RunInliner);
 };
-
+/// Registers a function for adding a standard set of passes.  This should be
+/// used by optimizer plugins to allow all front ends to transparently use
+/// them.  Create a static instance of this class in your plugin, providing a
+/// private function that the PassManagerBuilder can use to add your passes.
+struct RegisterStandardPasses {
+  RegisterStandardPasses(PassManagerBuilder::ExtensionPointTy Ty,
+                         PassManagerBuilder::ExtensionFn Fn) {
+    PassManagerBuilder::addGlobalExtension(Ty, Fn);
+  }
+};
 } // end namespace llvm
 #endif

lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -25,6 +25,8 @@
 #include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/IPO.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/ManagedStatic.h"
 
 using namespace llvm;
 
@@ -43,12 +45,25 @@ PassManagerBuilder::~PassManagerBuilder() {
   delete Inliner;
 }
 
+/// Set of global extensions, automatically added as part of the standard set.
+static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
+   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
+
+void PassManagerBuilder::addGlobalExtension(
+    PassManagerBuilder::ExtensionPointTy Ty,
+    PassManagerBuilder::ExtensionFn Fn) {
+  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
+}
+
 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
   Extensions.push_back(std::make_pair(Ty, Fn));
 }
 
 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
                                            PassManagerBase &PM) const {
+  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
+    if ((*GlobalExtensions)[i].first == ETy)
+      (*GlobalExtensions)[i].second(*this, PM);
   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
     if (Extensions[i].first == ETy)
       Extensions[i].second(*this, PM);