[llvm] 4dada8d - [DAG] Remove DAGTypeLegalizer::GenWidenVectorTruncStores (PR42046)

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-09-22T17:24:45+01:00
New Revision: 4dada8d617d81cd00e4028e09f7093f5b10a8a41

URL: https://github.com/llvm/llvm-project/commit/4dada8d617d81cd00e4028e09f7093f5b10a8a41
DIFF: https://github.com/llvm/llvm-project/commit/4dada8d617d81cd00e4028e09f7093f5b10a8a41.diff

LOG: [DAG] Remove DAGTypeLegalizer::GenWidenVectorTruncStores (PR42046)

Just scalarize trunc stores - GenWidenVectorTruncStores does the same thing but is flawed (PR42046) and unused.

Differential Revision: https://reviews.llvm.org/D87708

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
    llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index fbbb35cb905f..4264f8f650c0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -944,13 +944,6 @@ class LLVM_LIBRARY_VISIBILITY DAGTypeLegalizer {
   ///   ST:      store of a widen value
   void GenWidenVectorStores(SmallVectorImpl<SDValue> &StChain, StoreSDNode *ST);
 
-  /// Helper function to generate a set of stores to store a truncate widen
-  /// vector into non-widen memory.
-  ///   StChain: list of chains for the stores we have generated
-  ///   ST:      store of a widen value
-  void GenWidenVectorTruncStores(SmallVectorImpl<SDValue> &StChain,
-                                 StoreSDNode *ST);
-
   /// Modifies a vector input (widen or narrows) to a vector of NVT.  The
   /// input vector must have the same element type as NVT.
   /// When FillWithZeroes is "on" the vector will be widened with zeroes.

diff  --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index b09303e5219e..e67717b81e4e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -4580,11 +4580,11 @@ SDValue DAGTypeLegalizer::WidenVecOp_STORE(SDNode *N) {
   if (!ST->getMemoryVT().getScalarType().isByteSized())
     return TLI.scalarizeVectorStore(ST, DAG);
 
-  SmallVector<SDValue, 16> StChain;
   if (ST->isTruncatingStore())
-    GenWidenVectorTruncStores(StChain, ST);
-  else
-    GenWidenVectorStores(StChain, ST);
+    return TLI.scalarizeVectorStore(ST, DAG);
+
+  SmallVector<SDValue, 16> StChain;
+  GenWidenVectorStores(StChain, ST);
 
   if (StChain.size() == 1)
     return StChain[0];
@@ -5225,54 +5225,6 @@ void DAGTypeLegalizer::GenWidenVectorStores(SmallVectorImpl<SDValue> &StChain,
   }
 }
 
-void
-DAGTypeLegalizer::GenWidenVectorTruncStores(SmallVectorImpl<SDValue> &StChain,
-                                            StoreSDNode *ST) {
-  // For extension loads, it may not be more efficient to truncate the vector
-  // and then store it. Instead, we extract each element and then store it.
-  SDValue Chain = ST->getChain();
-  SDValue BasePtr = ST->getBasePtr();
-  MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
-  AAMDNodes AAInfo = ST->getAAInfo();
-  SDValue ValOp = GetWidenedVector(ST->getValue());
-  SDLoc dl(ST);
-
-  EVT StVT = ST->getMemoryVT();
-  EVT ValVT = ValOp.getValueType();
-
-  // It must be true that the wide vector type is bigger than where we need to
-  // store.
-  assert(StVT.isVector() && ValOp.getValueType().isVector());
-  assert(StVT.isScalableVector() == ValOp.getValueType().isScalableVector());
-  assert(StVT.bitsLT(ValOp.getValueType()));
-
-  if (StVT.isScalableVector())
-    report_fatal_error("Generating widen scalable vector truncating stores not "
-                       "yet supported");
-
-  // For truncating stores, we can not play the tricks of chopping legal vector
-  // types and bitcast it to the right type. Instead, we unroll the store.
-  EVT StEltVT  = StVT.getVectorElementType();
-  EVT ValEltVT = ValVT.getVectorElementType();
-  unsigned Increment = ValEltVT.getSizeInBits() / 8;
-  unsigned NumElts = StVT.getVectorNumElements();
-  SDValue EOp = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ValEltVT, ValOp,
-                            DAG.getVectorIdxConstant(0, dl));
-  StChain.push_back(
-      DAG.getTruncStore(Chain, dl, EOp, BasePtr, ST->getPointerInfo(), StEltVT,
-                        ST->getOriginalAlign(), MMOFlags, AAInfo));
-  unsigned Offset = Increment;
-  for (unsigned i=1; i < NumElts; ++i, Offset += Increment) {
-    SDValue NewBasePtr =
-        DAG.getObjectPtrOffset(dl, BasePtr, TypeSize::Fixed(Offset));
-    SDValue EOp = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ValEltVT, ValOp,
-                              DAG.getVectorIdxConstant(0, dl));
-    StChain.push_back(DAG.getTruncStore(
-        Chain, dl, EOp, NewBasePtr, ST->getPointerInfo().getWithOffset(Offset),
-        StEltVT, ST->getOriginalAlign(), MMOFlags, AAInfo));
-  }
-}
-
 /// Modifies a vector input (widen or narrows) to a vector of NVT.  The
 /// input vector must have the same element type as NVT.
 /// FillWithZeroes specifies that the vector should be widened with zeroes.