[SelectionDAG] Improve support for promotion of <1 x fX> floating point argument types (PR31088)

PR31088 demonstrated that we were assuming that only integers require promotion from <1 x iX> types, when in fact float types may require it as well - in this case half floats.

This patch adds support for extension/truncation for both integer and float types.

Differential Revision: https://reviews.llvm.org/D32391

llvm-svn: 301910

3 files changed, 20 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 247470b4425..97a7fab6efd 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -523,16 +523,17 @@ SDValue DAGTypeLegalizer::ScalarizeVecOp_CONCAT_VECTORS(SDNode *N) {
   return DAG.getBuildVector(N->getValueType(0), SDLoc(N), Ops);
 }
 
-/// If the input is a vector that needs to be scalarized, it must be <1 x ty>,

-/// so just return the element, ignoring the index.

-SDValue DAGTypeLegalizer::ScalarizeVecOp_EXTRACT_VECTOR_ELT(SDNode *N) {

-  EVT VT = N->getValueType(0);

-  SDValue Res = GetScalarizedVector(N->getOperand(0));

-  if (Res.getValueType() != VT)

-    Res = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Res);

-  return Res;

-}

-

+/// If the input is a vector that needs to be scalarized, it must be <1 x ty>,
+/// so just return the element, ignoring the index.
+SDValue DAGTypeLegalizer::ScalarizeVecOp_EXTRACT_VECTOR_ELT(SDNode *N) {
+  EVT VT = N->getValueType(0);
+  SDValue Res = GetScalarizedVector(N->getOperand(0));
+  if (Res.getValueType() != VT)
+    Res = VT.isFloatingPoint()
+              ? DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, Res)
+              : DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Res);
+  return Res;
+}
 
 /// If the input condition is a vector that needs to be scalarized, it must be
 /// <1 x i1>, so just convert to a normal ISD::SELECT
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 209abf9234d..9d949a2bbfa 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -959,6 +959,12 @@ void SelectionDAG::clear() {
   DbgInfo->clear();
 }
 
+SDValue SelectionDAG::getFPExtendOrRound(SDValue Op, const SDLoc &DL, EVT VT) {
+  return VT.bitsGT(Op.getValueType())
+             ? getNode(ISD::FP_EXTEND, DL, VT, Op)
+             : getNode(ISD::FP_ROUND, DL, VT, Op, getIntPtrConstant(0, DL));
+}
+
 SDValue SelectionDAG::getAnyExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT) {
   return VT.bitsGT(Op.getValueType()) ?
     getNode(ISD::ANY_EXTEND, DL, VT, Op) :
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 866cff1cda5..ba9e11798f1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -350,7 +350,8 @@ static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL,
 
   EVT ValueSVT = ValueVT.getVectorElementType();
   if (ValueVT.getVectorNumElements() == 1 && ValueSVT != PartEVT)
-    Val = DAG.getAnyExtOrTrunc(Val, DL, ValueSVT);
+    Val = ValueVT.isFloatingPoint() ? DAG.getFPExtendOrRound(Val, DL, ValueSVT)
+                                    : DAG.getAnyExtOrTrunc(Val, DL, ValueSVT);
 
   return DAG.getBuildVector(ValueVT, DL, Val);
 }
@@ -543,10 +544,9 @@ static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &DL,
       Val = DAG.getNode(
           ISD::EXTRACT_VECTOR_ELT, DL, PartVT, Val,
           DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
-
-      Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT);
     }
 
+    assert(Val.getValueType() == PartVT && "Unexpected vector part value type");
     Parts[0] = Val;
     return;
   }