[Orc] Refactor the compile-on-demand layer to make module partitioning lazy,

and avoid cloning unused decls into every partition.

Module partitioning showed up as a source of significant overhead when I
profiled some trivial test cases. Avoiding the overhead of partitionging
for uncalled functions helps to mitigate this.

This change also means that it is no longer necessary to have a
LazyEmittingLayer underneath the CompileOnDemand layer, since the
CompileOnDemandLayer will not extract or emit function bodies until they are
called.

llvm-svn: 236465

1 files changed, 2 insertions, 7 deletions

diff --git a/llvm/tools/lli/OrcLazyJIT.h b/llvm/tools/lli/OrcLazyJIT.h
index 2b2db6e668c..bff2eca26a5 100644
--- a/llvm/tools/lli/OrcLazyJIT.h
+++ b/llvm/tools/lli/OrcLazyJIT.h
@@ -21,7 +21,6 @@
 #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
 #include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
 #include "llvm/ExecutionEngine/Orc/IRTransformLayer.h"
-#include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
 #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
 #include "llvm/IR/LLVMContext.h"
@@ -37,9 +36,7 @@ public:
   typedef std::function<std::unique_ptr<Module>(std::unique_ptr<Module>)>
     TransformFtor;
   typedef orc::IRTransformLayer<CompileLayerT, TransformFtor> IRDumpLayerT;
-  typedef orc::LazyEmittingLayer<IRDumpLayerT> LazyEmitLayerT;
-  typedef orc::CompileOnDemandLayer<LazyEmitLayerT,
-                                    CompileCallbackMgr> CODLayerT;
+  typedef orc::CompileOnDemandLayer<IRDumpLayerT, CompileCallbackMgr> CODLayerT;
   typedef CODLayerT::ModuleSetHandleT ModuleHandleT;
 
   typedef std::function<
@@ -57,9 +54,8 @@ public:
       ObjectLayer(),
       CompileLayer(ObjectLayer, orc::SimpleCompiler(*this->TM)),
       IRDumpLayer(CompileLayer, createDebugDumper()),
-      LazyEmitLayer(IRDumpLayer),
       CCMgr(BuildCallbackMgr(IRDumpLayer, CCMgrMemMgr, Context)),
-      CODLayer(LazyEmitLayer, *CCMgr),
+      CODLayer(IRDumpLayer, *CCMgr),
       CXXRuntimeOverrides([this](const std::string &S) { return mangle(S); }) {}
 
   ~OrcLazyJIT() {
@@ -154,7 +150,6 @@ private:
   ObjLayerT ObjectLayer;
   CompileLayerT CompileLayer;
   IRDumpLayerT IRDumpLayer;
-  LazyEmitLayerT LazyEmitLayer;
   std::unique_ptr<CompileCallbackMgr> CCMgr;
   CODLayerT CODLayer;