[SVE][CodeGen] Add new EVT/MVT getFixedSizeInBits() functions

[david-arm]

Summary

When we know that a particular type is always going to be fixed
width we have so far been writing code like this:

getSizeInBits().getFixedSize()

Since we are doing this in quite a few places now it seems to make
sense to add a new helper function that allows us to replace
these calls with a single getFixedSizeInBits() call.

[efriedma]

LGTM, thanks

llvm/include/llvm/CodeGen/SelectionDAGNodes.h

public:
   /// If the value type is a scalable vector type, the scalable property will
   /// be set and the runtime size will be a positive integer multiple of the
   /// base size.
   TypeSize getValueSizeInBits() const {
     return getValueType().getSizeInBits();
   }
 
   uint64_t getScalarValueSizeInBits() const {
-    return getValueType().getScalarType().getSizeInBits().getFixedSize();
+    return getValueType().getScalarType().getFixedSizeInBits();
   }
 
   // Forwarding methods - These forward to the corresponding methods in SDNode.
   inline unsigned getOpcode() const;
   inline unsigned getNumOperands() const;
   inline const SDValue &getOperand(unsigned i) const;
   inline uint64_t getConstantOperandVal(unsigned i) const;
   inline const APInt &getConstantOperandAPInt(unsigned i) const;

llvm/include/llvm/CodeGen/ValueTypes.h

#endif
     /// be set and the runtime size will be a positive integer multiple of the
     /// base size.
     TypeSize getSizeInBits() const {
       if (isSimple())
         return V.getSizeInBits();
       return getExtendedSizeInBits();
     }
 
+    /// Return the size of the specified fixed width value type in bits. The
+    /// function will assert if the type is scalable.
+    uint64_t getFixedSizeInBits() const {
+      return getSizeInBits().getFixedSize();
+    }
+
     uint64_t getScalarSizeInBits() const {
       return getScalarType().getSizeInBits().getFixedSize();
     }
 
     /// Return the number of bytes overwritten by a store of the specified value
     /// type.
     ///
     /// If the value type is a scalable vector type, the scalable property will

llvm/include/llvm/Support/MachineValueType.h

TypeSize getSizeInBits() const {
       case v1024i32:
       case v1024f32:  return TypeSize::Fixed(32768);
       case v2048i32:
       case v2048f32:  return TypeSize::Fixed(65536);
       case exnref: return TypeSize::Fixed(0); // opaque type
       }
     }
 
+    /// Return the size of the specified fixed width value type in bits. The
+    /// function will assert if the type is scalable.
+    uint64_t getFixedSizeInBits() const {
+      return getSizeInBits().getFixedSize();
+    }
+
     uint64_t getScalarSizeInBits() const {
       return getScalarType().getSizeInBits().getFixedSize();
     }
 
     /// Return the number of bytes overwritten by a store of the specified value
     /// type.
     ///
     /// If the value type is a scalable vector type, the scalable property will

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo,
                                SmallestAlign);
 
   // Store the new element.  This may be larger than the vector element type,
   // so use a truncating store.
   SDValue EltPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
   Store = DAG.getTruncStore(
       Store, dl, Elt, EltPtr, MachinePointerInfo::getUnknownStack(MF), EltVT,
       commonAlignment(SmallestAlign,
-                      EltVT.getSizeInBits().getFixedSize() / 8));
+                      EltVT.getFixedSizeInBits() / 8));
 
   EVT LoVT, HiVT;
   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VecVT);
 
   // Load the Lo part from the stack slot.
   Lo = DAG.getLoad(LoVT, dl, Store, StackPtr, PtrInfo, SmallestAlign);
 
   // Increment the pointer to the other part.
if (N->getValueType(0).bitsLT(EltVT)) {
     SDValue Load = DAG.getLoad(EltVT, dl, Store, StackPtr,
       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()));
     return DAG.getZExtOrTrunc(Load, dl, N->getValueType(0));
   }
 
   return DAG.getExtLoad(
       ISD::EXTLOAD, dl, N->getValueType(0), Store, StackPtr,
       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()), EltVT,
-      commonAlignment(SmallestAlign, EltVT.getSizeInBits().getFixedSize() / 8));
+      commonAlignment(SmallestAlign, EltVT.getFixedSizeInBits() / 8));
 }
 
 SDValue DAGTypeLegalizer::SplitVecOp_ExtVecInRegOp(SDNode *N) {
   SDValue Lo, Hi;
 
   // *_EXTEND_VECTOR_INREG only reference the lower half of the input, so
   // splitting the result has the same effect as splitting the input operand.
   SplitVecRes_ExtVecInRegOp(N, Lo, Hi);
for (VT = (unsigned)MVT::LAST_VECTOR_VALUETYPE;
     auto Action = TLI.getTypeAction(*DAG.getContext(), MemVT);
     if ((Action == TargetLowering::TypeLegal ||
          Action == TargetLowering::TypePromoteInteger) &&
         WidenEltVT == MemVT.getVectorElementType() &&
         (WidenWidth % MemVTWidth) == 0 &&
         isPowerOf2_32(WidenWidth / MemVTWidth) &&
         (MemVTWidth <= Width ||
          (Align!=0 && MemVTWidth<=AlignInBits && MemVTWidth<=Width+WidenEx))) {
-      if (RetVT.getSizeInBits().getFixedSize() < MemVTWidth || MemVT == WidenVT)
+      if (RetVT.getFixedSizeInBits() < MemVTWidth || MemVT == WidenVT)
         return MemVT;
     }
   }
 
   if (Scalable)
     report_fatal_error("Using element-wise loads and stores for widening "
                        "operations is not supported for scalable vectors");
   return RetVT;
void DAGTypeLegalizer::GenWidenVectorStores(SmallVectorImpl<SDValue> &StChain,
   SDValue  ValOp = GetWidenedVector(ST->getValue());
   SDLoc dl(ST);
 
   EVT StVT = ST->getMemoryVT();
   TypeSize StWidth = StVT.getSizeInBits();
   EVT ValVT = ValOp.getValueType();
   TypeSize ValWidth = ValVT.getSizeInBits();
   EVT ValEltVT = ValVT.getVectorElementType();
-  unsigned ValEltWidth = ValEltVT.getSizeInBits().getFixedSize();
+  unsigned ValEltWidth = ValEltVT.getFixedSizeInBits();
   assert(StVT.getVectorElementType() == ValEltVT);
   assert(StVT.isScalableVector() == ValVT.isScalableVector() &&
          "Mismatch between store and value types");
 
   int Idx = 0;          // current index to store
 
   MachinePointerInfo MPI = ST->getPointerInfo();
   uint64_t ScaledOffset = 0;

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

if (StoreMemVT.isFloatingPoint() || StoreMemVT.isVector()) {
     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
     return Result;
   }
 
   assert(StoreMemVT.isInteger() && !StoreMemVT.isVector() &&
          "Unaligned store of unknown type.");
   // Get the half-size VT
   EVT NewStoredVT = StoreMemVT.getHalfSizedIntegerVT(*DAG.getContext());
-  unsigned NumBits = NewStoredVT.getSizeInBits().getFixedSize();
+  unsigned NumBits = NewStoredVT.getFixedSizeInBits();
   unsigned IncrementSize = NumBits / 8;
 
   // Divide the stored value in two parts.
   SDValue ShiftAmount = DAG.getConstant(
       NumBits, dl, getShiftAmountTy(Val.getValueType(), DAG.getDataLayout()));
   SDValue Lo = Val;
   SDValue Hi = DAG.getNode(ISD::SRL, dl, VT, Val, ShiftAmount);
 
if (IsCompressedMemory) {
     Increment = DAG.getNode(ISD::CTPOP, DL, MaskIntVT, MaskInIntReg);
     Increment = DAG.getZExtOrTrunc(Increment, DL, AddrVT);
     // Scale is an element size in bytes.
     SDValue Scale = DAG.getConstant(DataVT.getScalarSizeInBits() / 8, DL,
                                     AddrVT);
     Increment = DAG.getNode(ISD::MUL, DL, AddrVT, Increment, Scale);
   } else if (DataVT.isScalableVector()) {
     Increment = DAG.getVScale(DL, AddrVT,
-                              APInt(AddrVT.getSizeInBits().getFixedSize(),
+                              APInt(AddrVT.getFixedSizeInBits(),
                                     DataVT.getStoreSize().getKnownMinSize()));
   } else
     Increment = DAG.getConstant(DataVT.getStoreSize(), DL, AddrVT);
 
   return DAG.getNode(ISD::ADD, DL, AddrVT, Addr, Increment);
 }
 
 static SDValue clampDynamicVectorIndex(SelectionDAG &DAG,
                                        SDValue Idx,
                                        EVT VecVT,
                                        const SDLoc &dl) {
   if (!VecVT.isScalableVector() && isa<ConstantSDNode>(Idx))
     return Idx;
 
   EVT IdxVT = Idx.getValueType();
   unsigned NElts = VecVT.getVectorMinNumElements();
   if (VecVT.isScalableVector()) {
     SDValue VS = DAG.getVScale(dl, IdxVT,
-                               APInt(IdxVT.getSizeInBits().getFixedSize(),
+                               APInt(IdxVT.getFixedSizeInBits(),
                                      NElts));
     SDValue Sub = DAG.getNode(ISD::SUB, dl, IdxVT, VS,
                               DAG.getConstant(1, dl, IdxVT));
 
     return DAG.getNode(ISD::UMIN, dl, IdxVT, Idx, Sub);
   } else {
     if (isPowerOf2_32(NElts)) {
       APInt Imm = APInt::getLowBitsSet(IdxVT.getSizeInBits(),
SDValue TargetLowering::getVectorElementPointer(SelectionDAG &DAG,
                                                 SDValue Index) const {
   SDLoc dl(Index);
   // Make sure the index type is big enough to compute in.
   Index = DAG.getZExtOrTrunc(Index, dl, VecPtr.getValueType());
 
   EVT EltVT = VecVT.getVectorElementType();
 
   // Calculate the element offset and add it to the pointer.
-  unsigned EltSize = EltVT.getSizeInBits().getFixedSize() / 8; // FIXME: should be ABI size.
-  assert(EltSize * 8 == EltVT.getSizeInBits().getFixedSize() &&
+  unsigned EltSize = EltVT.getFixedSizeInBits() / 8; // FIXME: should be ABI size.
+  assert(EltSize * 8 == EltVT.getFixedSizeInBits() &&
          "Converting bits to bytes lost precision");
 
   Index = clampDynamicVectorIndex(DAG, Index, VecVT, dl);
 
   EVT IdxVT = Index.getValueType();
 
   Index = DAG.getNode(ISD::MUL, dl, IdxVT, Index,
                       DAG.getConstant(EltSize, dl, IdxVT));

llvm/lib/CodeGen/TargetLoweringBase.cpp

void TargetLoweringBase::initActions() {
   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
   memset(CondCodeActions, 0, sizeof(CondCodeActions));
   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
   std::fill(std::begin(TargetDAGCombineArray),
             std::end(TargetDAGCombineArray), 0);
 
   for (MVT VT : MVT::fp_valuetypes()) {
-    MVT IntVT = MVT::getIntegerVT(VT.getSizeInBits().getFixedSize());
+    MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
     if (IntVT.isValid()) {
       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
     }
   }
 
   // Set default actions for various operations.
   for (MVT VT : MVT::all_valuetypes()) {

llvm/lib/Target/Hexagon/HexagonISelLoweringHVX.cpp

HexagonTargetLowering::initializeHVXLowering() {
   }
 
   // Handle store widening for short vectors.
   std::vector<MVT> ShortTys;
   unsigned HwLen = Subtarget.getVectorLength();
   for (MVT ElemTy : Subtarget.getHVXElementTypes()) {
     if (ElemTy == MVT::i1)
       continue;
-    int ElemWidth = ElemTy.getSizeInBits().getFixedSize();
+    int ElemWidth = ElemTy.getFixedSizeInBits();
     int MaxElems = (8*HwLen) / ElemWidth;
     for (int N = 2; N < MaxElems; N *= 2) {
       MVT VecTy = MVT::getVectorVT(ElemTy, N);
       auto Action = getPreferredVectorAction(VecTy);
       if (Action == TargetLoweringBase::TypeWidenVector) {
         setOperationAction(ISD::LOAD,         VecTy, Custom);
         setOperationAction(ISD::STORE,        VecTy, Custom);
         setOperationAction(ISD::TRUNCATE,     VecTy, Custom);

llvm/unittests/CodeGen/ScalableVectorMVTsTest.cpp

TEST(ScalableVectorMVTsTest, SizeQueries) {
 
   // Check that scalable and non-scalable types with the same minimum size
   // are not considered equal.
   ASSERT_TRUE(v4i32.getSizeInBits() != nxv4i32.getSizeInBits());
   ASSERT_FALSE(v2i64.getSizeInBits() == nxv2f64.getSizeInBits());
 
   // Check that we can obtain a known-exact size from a non-scalable type.
   EXPECT_EQ(v4i32.getSizeInBits(), 128U);
-  EXPECT_EQ(v2i64.getSizeInBits().getFixedSize(), 128U);
+  EXPECT_EQ(v2i64.getFixedSizeInBits(), 128U);
 
   // Check that we can query the known minimum size for both scalable and
   // fixed length types.
   EXPECT_EQ(nxv2i32.getSizeInBits().getKnownMinSize(), 64U);
   EXPECT_EQ(nxv2f64.getSizeInBits().getKnownMinSize(), 128U);
   EXPECT_EQ(v2i32.getSizeInBits().getKnownMinSize(),
             nxv2i32.getSizeInBits().getKnownMinSize());