[IntrinsicEmitter] Extend argument overloading with forward references.

Extend the mechanism to overload intrinsic arguments by using either
backward or forward references to the overloadable arguments.

In for example:

  def int_something : Intrinsic<[LLVMPointerToElt<0>],
                                [llvm_anyvector_ty], []>;

LLVMPointerToElt<0> is a forward reference to the overloadable operand
of type 'llvm_anyvector_ty' and would allow intrinsics such as:

  declare i32* @llvm.something.v4i32(<4 x i32>);
  declare i64* @llvm.something.v2i64(<2 x i64>);

where the result pointer type is deduced from the element type of the
first argument.

If the returned pointer is not a pointer to the element type, LLVM will
give an error:

  Intrinsic has incorrect return type!
  i64* (<4 x i32>)* @llvm.something.v4i32

Reviewers: RKSimon, arsenm, rnk, greened

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D62995

llvm-svn: 363233

1 files changed, 3 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 42406e27e35..e0d85c4b49a 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -1019,13 +1019,12 @@ Value *InstCombiner::simplifyAMDGCNMemoryIntrinsicDemanded(IntrinsicInst *II,
   getIntrinsicInfoTableEntries(IID, Table);
   ArrayRef<Intrinsic::IITDescriptor> TableRef = Table;
 
+  // Validate function argument and return types, extracting overloaded types
+  // along the way.
   FunctionType *FTy = II->getCalledFunction()->getFunctionType();
   SmallVector<Type *, 6> OverloadTys;
-  Intrinsic::matchIntrinsicType(FTy->getReturnType(), TableRef, OverloadTys);
-  for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
-    Intrinsic::matchIntrinsicType(FTy->getParamType(i), TableRef, OverloadTys);
+  Intrinsic::matchIntrinsicSignature(FTy, TableRef, OverloadTys);
 
-  // Get the new return type overload of the intrinsic.
   Module *M = II->getParent()->getParent()->getParent();
   Type *EltTy = II->getType()->getVectorElementType();
   Type *NewTy = (NewNumElts == 1) ? EltTy : VectorType::get(EltTy, NewNumElts);