Feature request: an API to register externally defined tapir target

llvm/include/llvm/Analysis/TargetLibraryInfo.h

@@ -9,6 +9,7 @@
 #ifndef LLVM_ANALYSIS_TARGETLIBRARYINFO_H
 #define LLVM_ANALYSIS_TARGETLIBRARYINFO_H
 
+#include <functional>
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/Triple.h"
@@ -18,6 +19,7 @@
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
 #include "llvm/Transforms/Tapir/TapirTargetIDs.h"
+#include "llvm/Transforms/Tapir/LoweringUtils.h"
 
 namespace llvm {
 template <typename T> class ArrayRef;
@@ -38,6 +40,8 @@ struct VecDesc {
     NumLibFuncs
   };
 
+using TapirTargetFactory = std::function<TapirTarget *(Module &)>;
+
 /// Implementation of the target library information.
 ///
 /// This class constructs tables that hold the target library information and
@@ -204,6 +208,8 @@ class TargetLibraryInfoImpl {
     TapirTarget = TargetID;
   }
 
+  void setTapirTarget(TapirTargetFactory target);
+
   /// Return the ID of the target for Tapir lowering.
   TapirTargetID getTapirTarget() const {
     return TapirTarget;

llvm/include/llvm/Transforms/Tapir/LoweringUtils.h

@@ -13,6 +13,7 @@
 #ifndef LOWERING_UTILS_H_
 #define LOWERING_UTILS_H_
 
+#include <functional>
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SetVector.h"
@@ -409,6 +410,8 @@ class LoopOutlineProcessor {
 /// Generate a TapirTarget object for the specified TapirTargetID.
 TapirTarget *getTapirTargetFromID(Module &M, TapirTargetID TargetID);
 
+void setCustomTapirTarget(std::function<TapirTarget *(Module &)>);
+
 /// Find all inputs to tasks within a function \p F, including nested tasks.
 TaskValueSetMap findAllTaskInputs(Function &F, const DominatorTree &DT,
                                   const TaskInfo &TI);

llvm/include/llvm/Transforms/Tapir/TapirTargetIDs.h

@@ -25,6 +25,7 @@ enum class TapirTargetID {
   OpenCilk, // Lower to OpenCilk ABI
   OpenMP,   // Lower to OpenMP
   Qthreads, // Lower to Qthreads
+  Custom,
   Last_TapirTargetID
 };
 

llvm/lib/Transforms/Tapir/LoweringUtils.cpp

@@ -36,6 +36,13 @@ using namespace llvm;
 static const char TimerGroupName[] = DEBUG_TYPE;
 static const char TimerGroupDescription[] = "Tapir lowering";
 
+static TapirTargetFactory CUSTOM_TAPIR_TARGET;
+
+void llvm::TargetLibraryInfoImpl::setTapirTarget(TapirTargetFactory target) {
+  TapirTarget = TapirTargetID::Custom;
+  CUSTOM_TAPIR_TARGET = target;
+}
+
 TapirTarget *llvm::getTapirTargetFromID(Module &M, TapirTargetID ID) {
   switch (ID) {
   case TapirTargetID::None:
@@ -53,6 +60,8 @@ TapirTarget *llvm::getTapirTargetFromID(Module &M, TapirTargetID ID) {
     return new OpenMPABI(M);
   case TapirTargetID::Qthreads:
     return new QthreadsABI(M);
+  case TapirTargetID::Custom:
+    return CUSTOM_TAPIR_TARGET(M);
   default:
     llvm_unreachable("Invalid TapirTargetID");
   }