From b12c84c74c1749e40b27c498829195b85bffa2db Mon Sep 17 00:00:00 2001
From: Ivan Radanov Ivanov <ivanov.i.aa@m.titech.ac.jp>
Date: Fri, 12 Jan 2024 10:19:05 +0900
Subject: [PATCH] Util function for intrinsic creation

---
 enzyme/Enzyme/EnzymeLogic.cpp | 25 ++-----------------------
 enzyme/Enzyme/Utils.cpp       | 28 ++++++++++++++++++++++++++++
 enzyme/Enzyme/Utils.h         |  6 ++++++
 3 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/enzyme/Enzyme/EnzymeLogic.cpp b/enzyme/Enzyme/EnzymeLogic.cpp
index 31e4b45ca7b9..5000ed34bcaa 100644
--- a/enzyme/Enzyme/EnzymeLogic.cpp
+++ b/enzyme/Enzyme/EnzymeLogic.cpp
@@ -5094,29 +5094,8 @@ class TruncateGenerator : public llvm::InstVisitor<TruncateGenerator> {
     // TODO check that the intrinsic is overloaded
 
     CallInst *intr;
-#if LLVM_VERSION_MAJOR >= 16
-    Value *nres = intr = B.CreateIntrinsic(retTy, II.getIntrinsicID(), new_ops,
-                                           &II, II.getName());
-#else
-    // Older version do not automatically mangle the intrinsic for us - we need
-    // to provide the types to mangle with
-    SmallVector<Intrinsic::IITDescriptor, 8> Table;
-    getIntrinsicInfoTableEntries(II.getIntrinsicID(), Table);
-    ArrayRef<Intrinsic::IITDescriptor> TableRef = Table;
-    SmallVector<Type *, 2> ArgTys;
-    Intrinsic::MatchIntrinsicTypesResult Res =
-        Intrinsic::matchIntrinsicSignature(II.getFunctionType(), TableRef,
-                                           ArgTys);
-    assert(Res != Intrinsic::MatchIntrinsicTypes_NoMatchRet &&
-           "Intrinsic has incorrect return type!");
-    assert(Res != Intrinsic::MatchIntrinsicTypes_NoMatchArg &&
-           "Intrinsic has incorrect argument type!");
-    for (unsigned i = 0; i < ArgTys.size(); i++)
-      if (ArgTys[i] == getFromType())
-        ArgTys[i] = getToType();
-    Value *nres = intr = B.CreateIntrinsic(II.getIntrinsicID(), ArgTys, new_ops,
-                                           &II, II.getName());
-#endif
+    Value *nres = intr = createIntrinsicCall(B, II.getIntrinsicID(), retTy,
+                                             new_ops, &II, II.getName());
     if (II.getType() == getFromType())
       nres = expand(B, nres);
     intr->copyIRFlags(newI);
diff --git a/enzyme/Enzyme/Utils.cpp b/enzyme/Enzyme/Utils.cpp
index 455346addf21..1ee2e48c4033 100644
--- a/enzyme/Enzyme/Utils.cpp
+++ b/enzyme/Enzyme/Utils.cpp
@@ -2825,3 +2825,31 @@ bool collectOffset(GEPOperator *gep, const DataLayout &DL, unsigned BitWidth,
   return true;
 #endif
 }
+
+llvm::CallInst *createIntrinsicCall(llvm::IRBuilderBase &B,
+                                    llvm::Intrinsic::ID ID, llvm::Type *RetTy,
+                                    llvm::ArrayRef<llvm::Value *> Args,
+                                    llvm::Instruction *FMFSource,
+                                    const llvm::Twine &Name) {
+#if LLVM_VERSION_MAJOR >= 16
+  llvm::CallInst *nres = B.CreateIntrinsic(RetTy, ID, Args, FMFSource, Name);
+#else
+  SmallVector<Intrinsic::IITDescriptor> Table;
+  Intrinsic::getIntrinsicInfoTableEntries(ID, Table);
+  ArrayRef<Intrinsic::IITDescriptor> TableRef(Table);
+
+  SmallVector<Type *> ArgTys;
+  ArgTys.reserve(Args.size());
+  for (auto &I : Args)
+    ArgTys.push_back(I->getType());
+  FunctionType *FTy = FunctionType::get(RetTy, ArgTys, false);
+  SmallVector<Type *> OverloadTys;
+  Intrinsic::MatchIntrinsicTypesResult Res =
+      matchIntrinsicSignature(FTy, TableRef, OverloadTys);
+  (void)Res;
+  assert(Res == Intrinsic::MatchIntrinsicTypes_Match && TableRef.empty() &&
+         "Wrong types for intrinsic!");
+  llvm::CallInst *nres = B.CreateIntrinsic(ID, ArgTys, Args, FMFSource, Name);
+#endif
+  return nres;
+}
diff --git a/enzyme/Enzyme/Utils.h b/enzyme/Enzyme/Utils.h
index b7b7b5f31f29..32401d2f17e5 100644
--- a/enzyme/Enzyme/Utils.h
+++ b/enzyme/Enzyme/Utils.h
@@ -1807,4 +1807,10 @@ bool collectOffset(llvm::GEPOperator *gep, const llvm::DataLayout &DL,
                    unsigned BitWidth,
                    llvm::MapVector<llvm::Value *, llvm::APInt> &VariableOffsets,
                    llvm::APInt &ConstantOffset);
+
+llvm::CallInst *createIntrinsicCall(llvm::IRBuilderBase &B,
+                                    llvm::Intrinsic::ID ID, llvm::Type *RetTy,
+                                    llvm::ArrayRef<llvm::Value *> Args,
+                                    llvm::Instruction *FMFSource = nullptr,
+                                    const llvm::Twine &Name = "");
 #endif // ENZYME_UTILS_H