[Alignment][NFC] Use Align for getMemcpy/Memmove/Memset

[gchatelet]

Summary

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

[gchatelet]

• Improve documentation

[courbet]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

4230

getByValAlign() can return zero, can you add a comment ?

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

2867

ditto.

llvm/lib/Target/Hexagon/HexagonISelLowering.cpp

171

ditto

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

2143

ditto

[gchatelet]

• Introduce getNonZeroByValAlign()

[gchatelet]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

4230

I've introduced getNonZeroByValAlign() which cannot return zero,
As a matter of fact getByValAlign() is now useless and deprecated.

llvm/include/llvm/CodeGen/SelectionDAG.h

#endif
   SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N1,
                   SDValue N2, SDValue N3, SDValue N4, SDValue N5);
 
   /// Compute a TokenFactor to force all the incoming stack arguments to be
   /// loaded from the stack. This is used in tail call lowering to protect
   /// stack arguments from being clobbered.
   SDValue getStackArgumentTokenFactor(SDValue Chain);
 
+  LLVM_ATTRIBUTE_DEPRECATED(SDValue getMemcpy(SDValue Chain, const SDLoc &dl,
+                                              SDValue Dst, SDValue Src,
+                                              SDValue Size, unsigned Align,
+                                              bool isVol, bool AlwaysInline,
+                                              bool isTailCall,
+                                              MachinePointerInfo DstPtrInfo,
+                                              MachinePointerInfo SrcPtrInfo),
+                            "Use the version that takes Align instead") {
+    return getMemcpy(Chain, dl, Dst, Src, Size, llvm::Align(Align), isVol,
+                     AlwaysInline, isTailCall, DstPtrInfo, SrcPtrInfo);
+  }
+
   SDValue getMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
-                    SDValue Size, unsigned Align, bool isVol, bool AlwaysInline,
-                    bool isTailCall, MachinePointerInfo DstPtrInfo,
+                    SDValue Size, Align Alignment, bool isVol,
+                    bool AlwaysInline, bool isTailCall,
+                    MachinePointerInfo DstPtrInfo,
                     MachinePointerInfo SrcPtrInfo);
 
+  LLVM_ATTRIBUTE_DEPRECATED(SDValue getMemmove(SDValue Chain, const SDLoc &dl,
+                                               SDValue Dst, SDValue Src,
+                                               SDValue Size, unsigned Align,
+                                               bool isVol, bool isTailCall,
+                                               MachinePointerInfo DstPtrInfo,
+                                               MachinePointerInfo SrcPtrInfo),
+                            "Use the version that takes Align instead") {
+    return getMemmove(Chain, dl, Dst, Src, Size, llvm::Align(Align), isVol,
+                      isTailCall, DstPtrInfo, SrcPtrInfo);
+  }
   SDValue getMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
-                     SDValue Size, unsigned Align, bool isVol, bool isTailCall,
+                     SDValue Size, Align Alignment, bool isVol, bool isTailCall,
                      MachinePointerInfo DstPtrInfo,
                      MachinePointerInfo SrcPtrInfo);
 
+  LLVM_ATTRIBUTE_DEPRECATED(SDValue getMemset(SDValue Chain, const SDLoc &dl,
+                                              SDValue Dst, SDValue Src,
+                                              SDValue Size, unsigned Align,
+                                              bool isVol, bool isTailCall,
+                                              MachinePointerInfo DstPtrInfo),
+                            "Use the version that takes Align instead") {
+    return getMemset(Chain, dl, Dst, Src, Size, llvm::Align(Align), isVol,
+                     isTailCall, DstPtrInfo);
+  }
   SDValue getMemset(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
-                    SDValue Size, unsigned Align, bool isVol, bool isTailCall,
+                    SDValue Size, Align Alignment, bool isVol, bool isTailCall,
                     MachinePointerInfo DstPtrInfo);
 
   SDValue getAtomicMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst,
                           unsigned DstAlign, SDValue Src, unsigned SrcAlign,
                           SDValue Size, Type *SizeTy, unsigned ElemSz,
                           bool isTailCall, MachinePointerInfo DstPtrInfo,
                           MachinePointerInfo SrcPtrInfo);
 

llvm/include/llvm/CodeGen/TargetCallingConv.h

public:
     void setSplitEnd()  { IsSplitEnd = 1; }
 
     bool isCopyElisionCandidate()  const { return IsCopyElisionCandidate; }
     void setCopyElisionCandidate() { IsCopyElisionCandidate = 1; }
 
     bool isPointer()  const { return IsPointer; }
     void setPointer() { IsPointer = 1; }
 
-    unsigned getByValAlign() const {
+    LLVM_ATTRIBUTE_DEPRECATED(unsigned getByValAlign() const,
+                              "Use getNonZeroByValAlign() instead") {
       MaybeAlign A = decodeMaybeAlign(ByValAlign);
       return A ? A->value() : 0;
     }
+    Align getNonZeroByValAlign() const {
+      MaybeAlign A = decodeMaybeAlign(ByValAlign);
+      assert(A && "ByValAlign must be defined");
+      return *A;
+    }
     void setByValAlign(Align A) {
       ByValAlign = encode(A);
-      assert(getByValAlign() == A.value() && "bitfield overflow");
+      assert(getNonZeroByValAlign() == A && "bitfield overflow");
     }
 
     unsigned getOrigAlign() const {
       MaybeAlign A = decodeMaybeAlign(OrigAlign);
       return A ? A->value() : 0;
     }
     void setOrigAlign(Align A) {
       OrigAlign = encode(A);

llvm/lib/CodeGen/CallingConvLower.cpp

 
 /// Allocate space on the stack large enough to pass an argument by value.
 /// The size and alignment information of the argument is encoded in
 /// its parameter attribute.
 void CCState::HandleByVal(unsigned ValNo, MVT ValVT, MVT LocVT,
                           CCValAssign::LocInfo LocInfo, int MinSize,
                           int MinAlignment, ISD::ArgFlagsTy ArgFlags) {
   Align MinAlign(MinAlignment);
-  Align Alignment(ArgFlags.getByValAlign());
+  Align Alignment = ArgFlags.getNonZeroByValAlign();
   unsigned Size  = ArgFlags.getByValSize();
   if (MinSize > (int)Size)
     Size = MinSize;
   if (MinAlign > Alignment)
     Alignment = MinAlign;
   ensureMaxAlignment(Alignment);
   MF.getSubtarget().getTargetLowering()->HandleByVal(this, Size,
                                                      Alignment.value());

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

static void checkAddrSpaceIsValidForLibcall(const TargetLowering *TLI,
   // pointer operands can be losslessly bitcasted to pointers of address space 0
   if (AS != 0 && !TLI->isNoopAddrSpaceCast(AS, 0)) {
     report_fatal_error("cannot lower memory intrinsic in address space " +
                        Twine(AS));
   }
 }
 
 SDValue SelectionDAG::getMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst,
-                                SDValue Src, SDValue Size, unsigned Alignment,
+                                SDValue Src, SDValue Size, Align Alignment,
                                 bool isVol, bool AlwaysInline, bool isTailCall,
                                 MachinePointerInfo DstPtrInfo,
                                 MachinePointerInfo SrcPtrInfo) {
-  assert(Alignment &&
-         "The SDAG layer expects explicit alignment and reserves 0");
-
   // Check to see if we should lower the memcpy to loads and stores first.
   // For cases within the target-specified limits, this is the best choice.
   ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
   if (ConstantSize) {
     // Memcpy with size zero? Just return the original chain.
     if (ConstantSize->isNullValue())
       return Chain;
 
     SDValue Result = getMemcpyLoadsAndStores(
-        *this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(),
-        Align(Alignment), isVol, false, DstPtrInfo, SrcPtrInfo);
+        *this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(), Alignment,
+        isVol, false, DstPtrInfo, SrcPtrInfo);
     if (Result.getNode())
       return Result;
   }
 
   // Then check to see if we should lower the memcpy with target-specific
   // code. If the target chooses to do this, this is the next best.
   if (TSI) {
     SDValue Result = TSI->EmitTargetCodeForMemcpy(
-        *this, dl, Chain, Dst, Src, Size, Alignment, isVol, AlwaysInline,
-        DstPtrInfo, SrcPtrInfo);
+        *this, dl, Chain, Dst, Src, Size, Alignment.value(), isVol,
+        AlwaysInline, DstPtrInfo, SrcPtrInfo);
     if (Result.getNode())
       return Result;
   }
 
   // If we really need inline code and the target declined to provide it,
   // use a (potentially long) sequence of loads and stores.
   if (AlwaysInline) {
     assert(ConstantSize && "AlwaysInline requires a constant size!");
-    return getMemcpyLoadsAndStores(
-        *this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(),
-        Align(Alignment), isVol, true, DstPtrInfo, SrcPtrInfo);
+    return getMemcpyLoadsAndStores(*this, dl, Chain, Dst, Src,
+                                   ConstantSize->getZExtValue(), Alignment,
+                                   isVol, true, DstPtrInfo, SrcPtrInfo);
   }
 
   checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace());
   checkAddrSpaceIsValidForLibcall(TLI, SrcPtrInfo.getAddrSpace());
 
   // FIXME: If the memcpy is volatile (isVol), lowering it to a plain libc
   // memcpy is not guaranteed to be safe. libc memcpys aren't required to
   // respect volatile, so they may do things like read or write memory
CLI.setDebugLoc(dl)
       .setDiscardResult()
       .setTailCall(isTailCall);
 
   std::pair<SDValue, SDValue> CallResult = TLI->LowerCallTo(CLI);
   return CallResult.second;
 }
 
 SDValue SelectionDAG::getMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst,
-                                 SDValue Src, SDValue Size, unsigned Alignment,
+                                 SDValue Src, SDValue Size, Align Alignment,
                                  bool isVol, bool isTailCall,
                                  MachinePointerInfo DstPtrInfo,
                                  MachinePointerInfo SrcPtrInfo) {
-  assert(Alignment &&
-         "The SDAG layer expects explicit alignment and reserves 0");
-
   // Check to see if we should lower the memmove to loads and stores first.
   // For cases within the target-specified limits, this is the best choice.
   ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
   if (ConstantSize) {
     // Memmove with size zero? Just return the original chain.
     if (ConstantSize->isNullValue())
       return Chain;
 
     SDValue Result = getMemmoveLoadsAndStores(
-        *this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(),
-        Align(Alignment), isVol, false, DstPtrInfo, SrcPtrInfo);
+        *this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(), Alignment,
+        isVol, false, DstPtrInfo, SrcPtrInfo);
     if (Result.getNode())
       return Result;
   }
 
   // Then check to see if we should lower the memmove with target-specific
   // code. If the target chooses to do this, this is the next best.
   if (TSI) {
-    SDValue Result =
-        TSI->EmitTargetCodeForMemmove(*this, dl, Chain, Dst, Src, Size,
-                                      Alignment, isVol, DstPtrInfo, SrcPtrInfo);
+    SDValue Result = TSI->EmitTargetCodeForMemmove(
+        *this, dl, Chain, Dst, Src, Size, Alignment.value(), isVol, DstPtrInfo,
+        SrcPtrInfo);
     if (Result.getNode())
       return Result;
   }
 
   checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace());
   checkAddrSpaceIsValidForLibcall(TLI, SrcPtrInfo.getAddrSpace());
 
   // FIXME: If the memmove is volatile, lowering it to plain libc memmove may
CLI.setDebugLoc(dl)
       .setDiscardResult()
       .setTailCall(isTailCall);
 
   std::pair<SDValue, SDValue> CallResult = TLI->LowerCallTo(CLI);
   return CallResult.second;
 }
 
 SDValue SelectionDAG::getMemset(SDValue Chain, const SDLoc &dl, SDValue Dst,
-                                SDValue Src, SDValue Size, unsigned Alignment,
+                                SDValue Src, SDValue Size, Align Alignment,
                                 bool isVol, bool isTailCall,
                                 MachinePointerInfo DstPtrInfo) {
-  assert(Alignment &&
-         "The SDAG layer expects explicit alignment and reserves 0");
-
   // Check to see if we should lower the memset to stores first.
   // For cases within the target-specified limits, this is the best choice.
   ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
   if (ConstantSize) {
     // Memset with size zero? Just return the original chain.
     if (ConstantSize->isNullValue())
       return Chain;
 
     SDValue Result = getMemsetStores(*this, dl, Chain, Dst, Src,
-                                     ConstantSize->getZExtValue(),
-                                     Align(Alignment), isVol, DstPtrInfo);
+                                     ConstantSize->getZExtValue(), Alignment,
+                                     isVol, DstPtrInfo);
 
     if (Result.getNode())
       return Result;
   }
 
   // Then check to see if we should lower the memset with target-specific
   // code. If the target chooses to do this, this is the next best.
   if (TSI) {
     SDValue Result = TSI->EmitTargetCodeForMemset(
-        *this, dl, Chain, Dst, Src, Size, Alignment, isVol, DstPtrInfo);
+        *this, dl, Chain, Dst, Src, Size, Alignment.value(), isVol, DstPtrInfo);
     if (Result.getNode())
       return Result;
   }
 
   checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace());
 
   // Emit a library call.
   TargetLowering::ArgListTy Args;

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

case Intrinsic::write_register: {
     return;
   }
   case Intrinsic::memcpy: {
     const auto &MCI = cast<MemCpyInst>(I);
     SDValue Op1 = getValue(I.getArgOperand(0));
     SDValue Op2 = getValue(I.getArgOperand(1));
     SDValue Op3 = getValue(I.getArgOperand(2));
     // @llvm.memcpy defines 0 and 1 to both mean no alignment.
-    unsigned DstAlign = std::max<unsigned>(MCI.getDestAlignment(), 1);
-    unsigned SrcAlign = std::max<unsigned>(MCI.getSourceAlignment(), 1);
-    unsigned Align = MinAlign(DstAlign, SrcAlign);
+    Align DstAlign = MCI.getDestAlign().valueOrOne();
+    Align SrcAlign = MCI.getSourceAlign().valueOrOne();
+    Align Alignment = commonAlignment(DstAlign, SrcAlign);
     bool isVol = MCI.isVolatile();
     bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
     // FIXME: Support passing different dest/src alignments to the memcpy DAG
     // node.
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
-    SDValue MC = DAG.getMemcpy(Root, sdl, Op1, Op2, Op3, Align, isVol,
+    SDValue MC = DAG.getMemcpy(Root, sdl, Op1, Op2, Op3, Alignment, isVol,
                                /* AlwaysInline */ false, isTC,
                                MachinePointerInfo(I.getArgOperand(0)),
                                MachinePointerInfo(I.getArgOperand(1)));
     updateDAGForMaybeTailCall(MC);
     return;
   }
   case Intrinsic::memcpy_inline: {
     const auto &MCI = cast<MemCpyInlineInst>(I);
     SDValue Dst = getValue(I.getArgOperand(0));
     SDValue Src = getValue(I.getArgOperand(1));
     SDValue Size = getValue(I.getArgOperand(2));
     assert(isa<ConstantSDNode>(Size) && "memcpy_inline needs constant size");
     // @llvm.memcpy.inline defines 0 and 1 to both mean no alignment.
     Align DstAlign = MCI.getDestAlign().valueOrOne();
     Align SrcAlign = MCI.getSourceAlign().valueOrOne();
     Align Alignment = commonAlignment(DstAlign, SrcAlign);
     bool isVol = MCI.isVolatile();
     bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
     // FIXME: Support passing different dest/src alignments to the memcpy DAG
     // node.
-    SDValue MC = DAG.getMemcpy(
-        getRoot(), sdl, Dst, Src, Size, Alignment.value(), isVol,
-        /* AlwaysInline */ true, isTC, MachinePointerInfo(I.getArgOperand(0)),
+    SDValue MC = DAG.getMemcpy(getRoot(), sdl, Dst, Src, Size, Alignment, isVol,
+                               /* AlwaysInline */ true, isTC,
+                               MachinePointerInfo(I.getArgOperand(0)),
                                MachinePointerInfo(I.getArgOperand(1)));
     updateDAGForMaybeTailCall(MC);
     return;
   }
   case Intrinsic::memset: {
     const auto &MSI = cast<MemSetInst>(I);
     SDValue Op1 = getValue(I.getArgOperand(0));
     SDValue Op2 = getValue(I.getArgOperand(1));
     SDValue Op3 = getValue(I.getArgOperand(2));
     // @llvm.memset defines 0 and 1 to both mean no alignment.
-    unsigned Align = std::max<unsigned>(MSI.getDestAlignment(), 1);
+    Align Alignment = MSI.getDestAlign().valueOrOne();
     bool isVol = MSI.isVolatile();
     bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
-    SDValue MS = DAG.getMemset(Root, sdl, Op1, Op2, Op3, Align, isVol,
-                               isTC, MachinePointerInfo(I.getArgOperand(0)));
+    SDValue MS = DAG.getMemset(Root, sdl, Op1, Op2, Op3, Alignment, isVol, isTC,
+                               MachinePointerInfo(I.getArgOperand(0)));
     updateDAGForMaybeTailCall(MS);
     return;
   }
   case Intrinsic::memmove: {
     const auto &MMI = cast<MemMoveInst>(I);
     SDValue Op1 = getValue(I.getArgOperand(0));
     SDValue Op2 = getValue(I.getArgOperand(1));
     SDValue Op3 = getValue(I.getArgOperand(2));
     // @llvm.memmove defines 0 and 1 to both mean no alignment.
-    unsigned DstAlign = std::max<unsigned>(MMI.getDestAlignment(), 1);
-    unsigned SrcAlign = std::max<unsigned>(MMI.getSourceAlignment(), 1);
-    unsigned Align = MinAlign(DstAlign, SrcAlign);
+    Align DstAlign = MMI.getDestAlign().valueOrOne();
+    Align SrcAlign = MMI.getSourceAlign().valueOrOne();
+    Align Alignment = commonAlignment(DstAlign, SrcAlign);
     bool isVol = MMI.isVolatile();
     bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
     // FIXME: Support passing different dest/src alignments to the memmove DAG
     // node.
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
-    SDValue MM = DAG.getMemmove(Root, sdl, Op1, Op2, Op3, Align, isVol,
+    SDValue MM = DAG.getMemmove(Root, sdl, Op1, Op2, Op3, Alignment, isVol,
                                 isTC, MachinePointerInfo(I.getArgOperand(0)),
                                 MachinePointerInfo(I.getArgOperand(1)));
     updateDAGForMaybeTailCall(MM);
     return;
   }
   case Intrinsic::memcpy_element_unordered_atomic: {
     const AtomicMemCpyInst &MI = cast<AtomicMemCpyInst>(I);
     SDValue Dst = getValue(MI.getRawDest());

 /// correct prototype.
 bool SelectionDAGBuilder::visitMemPCpyCall(const CallInst &I) {
   SDValue Dst = getValue(I.getArgOperand(0));
   SDValue Src = getValue(I.getArgOperand(1));
   SDValue Size = getValue(I.getArgOperand(2));
 
   unsigned DstAlign = DAG.InferPtrAlignment(Dst);
   unsigned SrcAlign = DAG.InferPtrAlignment(Src);
-  unsigned Align = std::min(DstAlign, SrcAlign);
-  if (Align == 0) // Alignment of one or both could not be inferred.
-    Align = 1; // 0 and 1 both specify no alignment, but 0 is reserved.
+  // DAG::getMemcpy needs Alignment to be defined.
+  Align Alignment = assumeAligned(std::min(DstAlign, SrcAlign));
 
   bool isVol = false;
   SDLoc sdl = getCurSDLoc();
 
   // In the mempcpy context we need to pass in a false value for isTailCall
   // because the return pointer needs to be adjusted by the size of
   // the copied memory.
   SDValue Root = isVol ? getRoot() : getMemoryRoot();
-  SDValue MC = DAG.getMemcpy(Root, sdl, Dst, Src, Size, Align, isVol,
-                             false, /*isTailCall=*/false,
+  SDValue MC = DAG.getMemcpy(Root, sdl, Dst, Src, Size, Alignment, isVol, false,
+                             /*isTailCall=*/false,
                              MachinePointerInfo(I.getArgOperand(0)),
                              MachinePointerInfo(I.getArgOperand(1)));
   assert(MC.getNode() != nullptr &&
          "** memcpy should not be lowered as TailCall in mempcpy context **");
   DAG.setRoot(MC);
 
   // Check if Size needs to be truncated or extended.
   Size = DAG.getSExtOrTrunc(Size, sdl, Dst.getValueType());

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

if (VA.isRegLoc()) {
         DstInfo = MachinePointerInfo::getStack(DAG.getMachineFunction(),
                                                LocMemOffset);
       }
 
       if (Outs[i].Flags.isByVal()) {
         SDValue SizeNode =
             DAG.getConstant(Outs[i].Flags.getByValSize(), DL, MVT::i64);
         SDValue Cpy = DAG.getMemcpy(
-            Chain, DL, DstAddr, Arg, SizeNode, Outs[i].Flags.getByValAlign(),
+            Chain, DL, DstAddr, Arg, SizeNode,
+            Outs[i].Flags.getNonZeroByValAlign(),
             /*isVol = */ false, /*AlwaysInline = */ false,
-            /*isTailCall = */ false,
-            DstInfo, MachinePointerInfo());
+            /*isTailCall = */ false, DstInfo, MachinePointerInfo());
 
         MemOpChains.push_back(Cpy);
       } else {
         // Since we pass i1/i8/i16 as i1/i8/i16 on stack and Arg is already
         // promoted to a legal register type i32, we should truncate Arg back to
         // i1/i8/i16.
         if (VA.getValVT() == MVT::i1 || VA.getValVT() == MVT::i8 ||
             VA.getValVT() == MVT::i16)
SDValue AArch64TargetLowering::LowerVACOPY(SDValue Op,
   SDLoc DL(Op);
   unsigned PtrSize = Subtarget->isTargetILP32() ? 4 : 8;
   unsigned VaListSize = (Subtarget->isTargetDarwin() ||
                          Subtarget->isTargetWindows()) ? PtrSize : 32;
   const Value *DestSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
 
   return DAG.getMemcpy(Op.getOperand(0), DL, Op.getOperand(1), Op.getOperand(2),
-                       DAG.getConstant(VaListSize, DL, MVT::i32), PtrSize,
-                       false, false, false, MachinePointerInfo(DestSV),
-                       MachinePointerInfo(SrcSV));
+                       DAG.getConstant(VaListSize, DL, MVT::i32),
+                       Align(PtrSize), false, false, false,
+                       MachinePointerInfo(DestSV), MachinePointerInfo(SrcSV));
 }
 
 SDValue AArch64TargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
   assert(Subtarget->isTargetDarwin() &&
          "automatic va_arg instruction only works on Darwin");
 
   const Value *V = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
   EVT VT = Op.getValueType();

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

if (VA.isRegLoc()) {
       if (IsTailCall) {
         ISD::ArgFlagsTy Flags = Outs[i].Flags;
         unsigned OpSize = Flags.isByVal() ?
           Flags.getByValSize() : VA.getValVT().getStoreSize();
 
         // FIXME: We can have better than the minimum byval required alignment.
         Alignment =
             Flags.isByVal()
-                ? MaybeAlign(Flags.getByValAlign())
+                ? Flags.getNonZeroByValAlign()
                 : commonAlignment(Subtarget->getStackAlignment(), Offset);
 
         Offset = Offset + FPDiff;
         int FI = MFI.CreateFixedObject(OpSize, Offset, true);
 
         DstAddr = DAG.getFrameIndex(FI, PtrVT);
         DstInfo = MachinePointerInfo::getFixedStack(MF, FI);
 
if (VA.isRegLoc()) {
         DstInfo = MachinePointerInfo::getStack(MF, LocMemOffset);
         Alignment =
             commonAlignment(Subtarget->getStackAlignment(), LocMemOffset);
       }
 
       if (Outs[i].Flags.isByVal()) {
         SDValue SizeNode =
             DAG.getConstant(Outs[i].Flags.getByValSize(), DL, MVT::i32);
-        SDValue Cpy = DAG.getMemcpy(
-            Chain, DL, DstAddr, Arg, SizeNode, Outs[i].Flags.getByValAlign(),
+        SDValue Cpy =
+            DAG.getMemcpy(Chain, DL, DstAddr, Arg, SizeNode,
+                          Outs[i].Flags.getNonZeroByValAlign(),
                           /*isVol = */ false, /*AlwaysInline = */ true,
                           /*isTailCall = */ false, DstInfo,
                           MachinePointerInfo(AMDGPUAS::PRIVATE_ADDRESS));
 
         MemOpChains.push_back(Cpy);
       } else {
         SDValue Store = DAG.getStore(Chain, DL, Arg, DstAddr, DstInfo,
                                      Alignment ? Alignment->value() : 0);
         MemOpChains.push_back(Store);
       }
     }

llvm/lib/Target/ARC/ARCISelLowering.cpp

SDValue ARCTargetLowering::LowerCallArguments(
 
   // 3. Memcpy 'byVal' args & push final InVals.
   // Aggregates passed "byVal" need to be copied by the callee.
   // The callee will use a pointer to this copy, rather than the original
   // pointer.
   for (const auto &ArgDI : ArgData) {
     if (ArgDI.Flags.isByVal() && ArgDI.Flags.getByValSize()) {
       unsigned Size = ArgDI.Flags.getByValSize();
-      unsigned Align = std::max(StackSlotSize, ArgDI.Flags.getByValAlign());
+      Align Alignment =
+          std::max(Align(StackSlotSize), ArgDI.Flags.getNonZeroByValAlign());
       // Create a new object on the stack and copy the pointee into it.
-      int FI = MFI.CreateStackObject(Size, Align, false);
+      int FI = MFI.CreateStackObject(Size, Alignment, false);
       SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
       InVals.push_back(FIN);
       MemOps.push_back(DAG.getMemcpy(
-          Chain, dl, FIN, ArgDI.SDV, DAG.getConstant(Size, dl, MVT::i32), Align,
-          false, false, false, MachinePointerInfo(), MachinePointerInfo()));
+          Chain, dl, FIN, ArgDI.SDV, DAG.getConstant(Size, dl, MVT::i32),
+          Alignment, false, false, false, MachinePointerInfo(),
+          MachinePointerInfo()));
     } else {
       InVals.push_back(ArgDI.SDV);
     }
   }
 
   // 4. Chain mem ops nodes into a TokenFactor.
   if (!MemOps.empty()) {
     MemOps.push_back(Chain);

llvm/lib/Target/ARM/ARMISelLowering.cpp

if (VA.needsCustom()) {
         auto PtrVT = getPointerTy(DAG.getDataLayout());
         unsigned LocMemOffset = VA.getLocMemOffset();
         SDValue StkPtrOff = DAG.getIntPtrConstant(LocMemOffset, dl);
         SDValue Dst = DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr, StkPtrOff);
         SDValue SrcOffset = DAG.getIntPtrConstant(4*offset, dl);
         SDValue Src = DAG.getNode(ISD::ADD, dl, PtrVT, Arg, SrcOffset);
         SDValue SizeNode = DAG.getConstant(Flags.getByValSize() - 4*offset, dl,
                                            MVT::i32);
-        SDValue AlignNode = DAG.getConstant(Flags.getByValAlign(), dl,
-                                            MVT::i32);
+        SDValue AlignNode =
+            DAG.getConstant(Flags.getNonZeroByValAlign().value(), dl, MVT::i32);
 
         SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Glue);
         SDValue Ops[] = { Chain, Dst, Src, SizeNode, AlignNode};
         MemOpChains.push_back(DAG.getNode(ARMISD::COPY_STRUCT_BYVAL, dl, VTs,
                                           Ops));
       }
     } else if (!isTailCall) {
       assert(VA.isMemLoc());

llvm/lib/Target/Hexagon/HexagonISelLowering.cpp

 /// by "Src" to address "Dst" of size "Size".  Alignment information is
 /// specified by the specific parameter attribute. The copy will be passed as
 /// a byval function parameter.  Sometimes what we are copying is the end of a
 /// larger object, the part that does not fit in registers.
 static SDValue CreateCopyOfByValArgument(SDValue Src, SDValue Dst,
                                          SDValue Chain, ISD::ArgFlagsTy Flags,
                                          SelectionDAG &DAG, const SDLoc &dl) {
   SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i32);
-  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
-                       /*isVolatile=*/false, /*AlwaysInline=*/false,
-                       /*isTailCall=*/false,
-                       MachinePointerInfo(), MachinePointerInfo());
+  return DAG.getMemcpy(
+      Chain, dl, Dst, Src, SizeNode, Flags.getNonZeroByValAlign(),
+      /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
 }
 
 bool
 HexagonTargetLowering::CanLowerReturn(
     CallingConv::ID CallConv, MachineFunction &MF, bool IsVarArg,
     const SmallVectorImpl<ISD::OutputArg> &Outs,
     LLVMContext &Context) const {
   SmallVector<CCValAssign, 16> RVLocs;
HexagonTargetLowering::LowerVACOPY(SDValue Op, SelectionDAG &DAG) const {
   SDValue DestPtr = Op.getOperand(1);
   SDValue SrcPtr = Op.getOperand(2);
   const Value *DestSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
   SDLoc DL(Op);
   // Size of the va_list is 12 bytes as it has 3 pointers. Therefore,
   // we need to memcopy 12 bytes from va_list to another similar list.
   return DAG.getMemcpy(Chain, DL, DestPtr, SrcPtr,
-                       DAG.getIntPtrConstant(12, DL), 4, /*isVolatile*/false,
-                       false, false,
+                       DAG.getIntPtrConstant(12, DL), Align(4),
+                       /*isVolatile*/ false, false, false,
                        MachinePointerInfo(DestSV), MachinePointerInfo(SrcSV));
-
 }
 
 SDValue HexagonTargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
   const SDLoc &dl(Op);
   SDValue LHS = Op.getOperand(0);
   SDValue RHS = Op.getOperand(1);
   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
   MVT ResTy = ty(Op);

llvm/lib/Target/Lanai/LanaiISelLowering.cpp

SDValue LanaiTargetLowering::LowerCCCCallTo(
   SmallVector<SDValue, 8> ByValArgs;
   for (unsigned I = 0, E = Outs.size(); I != E; ++I) {
     ISD::ArgFlagsTy Flags = Outs[I].Flags;
     if (!Flags.isByVal())
       continue;
 
     SDValue Arg = OutVals[I];
     unsigned Size = Flags.getByValSize();
-    unsigned Align = Flags.getByValAlign();
+    Align Alignment = Flags.getNonZeroByValAlign();
 
-    int FI = MFI.CreateStackObject(Size, Align, false);
+    int FI = MFI.CreateStackObject(Size, Alignment, false);
     SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
     SDValue SizeNode = DAG.getConstant(Size, DL, MVT::i32);
 
-    Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Align,
+    Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Alignment,
                           /*IsVolatile=*/false,
                           /*AlwaysInline=*/false,
                           /*isTailCall=*/false, MachinePointerInfo(),
                           MachinePointerInfo());
     ByValArgs.push_back(FIPtr);
   }
 
   Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, DL);

llvm/lib/Target/MSP430/MSP430ISelLowering.cpp

if (VA.isRegLoc()) {
           DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr,
                       DAG.getIntPtrConstant(VA.getLocMemOffset(), dl));
 
       SDValue MemOp;
       ISD::ArgFlagsTy Flags = Outs[i].Flags;
 
       if (Flags.isByVal()) {
         SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i16);
-        MemOp = DAG.getMemcpy(Chain, dl, PtrOff, Arg, SizeNode,
-                              Flags.getByValAlign(),
-                              /*isVolatile*/false,
-                              /*AlwaysInline=*/true,
-                              /*isTailCall=*/false,
-                              MachinePointerInfo(),
-                              MachinePointerInfo());
+        MemOp = DAG.getMemcpy(
+            Chain, dl, PtrOff, Arg, SizeNode, Flags.getNonZeroByValAlign(),
+            /*isVolatile*/ false,
+            /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
       } else {
         MemOp = DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo());
       }
 
       MemOpChains.push_back(MemOp);
     }
   }
 

llvm/lib/Target/Mips/MipsISelLowering.cpp

void MipsTargetLowering::passByValArg(
     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
     const CCValAssign &VA) const {
   unsigned ByValSizeInBytes = Flags.getByValSize();
   unsigned OffsetInBytes = 0; // From beginning of struct
   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
-  unsigned Alignment = std::min(Flags.getByValAlign(), RegSizeInBytes);
+  Align Alignment =
+      std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
   unsigned NumRegs = LastReg - FirstReg;
 
   if (NumRegs) {
     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
     unsigned I = 0;
 
     // Copy words to registers.
     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
-                                    MachinePointerInfo(), Alignment);
+                                    MachinePointerInfo(), Alignment.value());
       MemOpChains.push_back(LoadVal.getValue(1));
       unsigned ArgReg = ArgRegs[FirstReg + I];
       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
     }
 
     // Return if the struct has been fully copied.
     if (ByValSizeInBytes == OffsetInBytes)
       return;
if (LeftoverBytes) {
           continue;
 
         // Load subword.
         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
                                       DAG.getConstant(OffsetInBytes, DL,
                                                       PtrTy));
         SDValue LoadVal = DAG.getExtLoad(
             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
-            MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
+            MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment.value());
         MemOpChains.push_back(LoadVal.getValue(1));
 
         // Shift the loaded value.
         unsigned Shamt;
 
         if (isLittle)
           Shamt = TotalBytesLoaded * 8;
         else
           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
 
         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
                                     DAG.getConstant(Shamt, DL, MVT::i32));
 
         if (Val.getNode())
           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
         else
           Val = Shift;
 
         OffsetInBytes += LoadSizeInBytes;
         TotalBytesLoaded += LoadSizeInBytes;
-        Alignment = std::min(Alignment, LoadSizeInBytes);
+        Alignment = std::min(Alignment, Align(LoadSizeInBytes));
       }
 
       unsigned ArgReg = ArgRegs[FirstReg + I];
       RegsToPass.push_back(std::make_pair(ArgReg, Val));
       return;
     }
   }
 
   // Copy remainder of byval arg to it with memcpy.
   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
-  Chain = DAG.getMemcpy(Chain, DL, Dst, Src,
-                        DAG.getConstant(MemCpySize, DL, PtrTy),
-                        Alignment, /*isVolatile=*/false, /*AlwaysInline=*/false,
-                        /*isTailCall=*/false,
-                        MachinePointerInfo(), MachinePointerInfo());
+  Chain = DAG.getMemcpy(
+      Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
+      Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
+      /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
   MemOpChains.push_back(Chain);
 }
 
 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
                                          SDValue Chain, const SDLoc &DL,
                                          SelectionDAG &DAG,
                                          CCState &State) const {
   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();

llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp

if (!Outs[OIdx].Flags.isByVal()) {
       O << ".param .b" << sz << " ";
       O << "_";
       continue;
     }
     auto *PTy = dyn_cast<PointerType>(Ty);
     assert(PTy && "Param with byval attribute should be a pointer type");
     Type *ETy = PTy->getElementType();
 
-    unsigned align = Outs[OIdx].Flags.getByValAlign();
+    Align align = Outs[OIdx].Flags.getNonZeroByValAlign();
     unsigned sz = DL.getTypeAllocSize(ETy);
-    O << ".param .align " << align << " .b8 ";
+    O << ".param .align " << align.value() << " .b8 ";
     O << "_";
     O << "[" << sz << "]";
   }
   O << ");";
   return O.str();
 }
 
 unsigned NVPTXTargetLowering::getArgumentAlignment(SDValue Callee,
for (unsigned i = 0, e = Args.size(); i != e; ++i, ++OIdx) {
     SmallVector<uint64_t, 16> Offsets;
     auto *PTy = dyn_cast<PointerType>(Args[i].Ty);
     assert(PTy && "Type of a byval parameter should be pointer");
     ComputePTXValueVTs(*this, DL, PTy->getElementType(), VTs, &Offsets, 0);
 
     // declare .param .align <align> .b8 .param<n>[<size>];
     unsigned sz = Outs[OIdx].Flags.getByValSize();
     SDVTList DeclareParamVTs = DAG.getVTList(MVT::Other, MVT::Glue);
-    unsigned ArgAlign = Outs[OIdx].Flags.getByValAlign();
+    Align ArgAlign = Outs[OIdx].Flags.getNonZeroByValAlign();
     // The ByValAlign in the Outs[OIdx].Flags is alway set at this point,
     // so we don't need to worry about natural alignment or not.
     // See TargetLowering::LowerCallTo().
 
     // Enforce minumum alignment of 4 to work around ptxas miscompile
     // for sm_50+. See corresponding alignment adjustment in
     // emitFunctionParamList() for details.
-    if (ArgAlign < 4)
-      ArgAlign = 4;
-    SDValue DeclareParamOps[] = {Chain, DAG.getConstant(ArgAlign, dl, MVT::i32),
-                                 DAG.getConstant(paramCount, dl, MVT::i32),
-                                 DAG.getConstant(sz, dl, MVT::i32), InFlag};
+    if (ArgAlign < Align(4))
+      ArgAlign = Align(4);
+    SDValue DeclareParamOps[] = {
+        Chain, DAG.getConstant(ArgAlign.value(), dl, MVT::i32),
     Chain = DAG.getNode(NVPTXISD::DeclareParam, dl, DeclareParamVTs,
                         DeclareParamOps);
     InFlag = Chain.getValue(1);
     for (unsigned j = 0, je = VTs.size(); j != je; ++j) {
       EVT elemtype = VTs[j];
       int curOffset = Offsets[j];
-      unsigned PartAlign = GreatestCommonDivisor64(ArgAlign, curOffset);
+      unsigned PartAlign = GreatestCommonDivisor64(ArgAlign.value(), curOffset);
       auto PtrVT = getPointerTy(DL);
       SDValue srcAddr = DAG.getNode(ISD::ADD, dl, PtrVT, OutVals[OIdx],
                                     DAG.getConstant(curOffset, dl, PtrVT));
       SDValue theVal = DAG.getLoad(elemtype, dl, tempChain, srcAddr,
                                    MachinePointerInfo(), PartAlign);
       if (elemtype.getSizeInBits() < 16) {
         theVal = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i16, theVal);
       }

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

SDValue PPCTargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
   return DAG.getLoad(VT, dl, InChain, Result, MachinePointerInfo());
 }
 
 SDValue PPCTargetLowering::LowerVACOPY(SDValue Op, SelectionDAG &DAG) const {
   assert(!Subtarget.isPPC64() && "LowerVACOPY is PPC32 only");
 
   // We have to copy the entire va_list struct:
   // 2*sizeof(char) + 2 Byte alignment + 2*sizeof(char*) = 12 Byte
-  return DAG.getMemcpy(Op.getOperand(0), Op,
-                       Op.getOperand(1), Op.getOperand(2),
-                       DAG.getConstant(12, SDLoc(Op), MVT::i32), 8, false, true,
-                       false, MachinePointerInfo(), MachinePointerInfo());
+  return DAG.getMemcpy(Op.getOperand(0), Op, Op.getOperand(1), Op.getOperand(2),
+                       DAG.getConstant(12, SDLoc(Op), MVT::i32), Align(8),
+                       false, true, false, MachinePointerInfo(),
+                       MachinePointerInfo());
 }
 
 SDValue PPCTargetLowering::LowerADJUST_TRAMPOLINE(SDValue Op,
                                                   SelectionDAG &DAG) const {
   if (Subtarget.isAIXABI())
     report_fatal_error("ADJUST_TRAMPOLINE operation is not supported on AIX.");
 
   return Op.getOperand(0);
static unsigned CalculateStackSlotSize(EVT ArgVT, ISD::ArgFlagsTy Flags,
   if (!Flags.isInConsecutiveRegs())
     ArgSize = ((ArgSize + PtrByteSize - 1)/PtrByteSize) * PtrByteSize;
 
   return ArgSize;
 }
 
 /// CalculateStackSlotAlignment - Calculates the alignment of this argument
 /// on the stack.
-static unsigned CalculateStackSlotAlignment(EVT ArgVT, EVT OrigVT,
-                                            ISD::ArgFlagsTy Flags,
-                                            unsigned PtrByteSize) {
-  unsigned Align = PtrByteSize;
+static Align CalculateStackSlotAlignment(EVT ArgVT, EVT OrigVT,
+  Align Alignment(PtrByteSize);
 
   // Altivec parameters are padded to a 16 byte boundary.
   if (ArgVT == MVT::v4f32 || ArgVT == MVT::v4i32 ||
       ArgVT == MVT::v8i16 || ArgVT == MVT::v16i8 ||
       ArgVT == MVT::v2f64 || ArgVT == MVT::v2i64 ||
       ArgVT == MVT::v1i128 || ArgVT == MVT::f128)
-    Align = 16;
+    Alignment = Align(16);
   // QPX vector types stored in double-precision are padded to a 32 byte
   // boundary.
   else if (ArgVT == MVT::v4f64 || ArgVT == MVT::v4i1)
-    Align = 32;
+    Alignment = Align(32);
 
   // ByVal parameters are aligned as requested.
   if (Flags.isByVal()) {
-    unsigned BVAlign = Flags.getByValAlign();
+    auto BVAlign = Flags.getNonZeroByValAlign();
     if (BVAlign > PtrByteSize) {
-      if (BVAlign % PtrByteSize != 0)
-          llvm_unreachable(
+      if (BVAlign.value() % PtrByteSize != 0)
             "ByVal alignment is not a multiple of the pointer size");
 
-      Align = BVAlign;
+      Alignment = BVAlign;
     }
   }
 
   // Array members are always packed to their original alignment.
   if (Flags.isInConsecutiveRegs()) {
     // If the array member was split into multiple registers, the first
     // needs to be aligned to the size of the full type.  (Except for
     // ppcf128, which is only aligned as its f64 components.)
     if (Flags.isSplit() && OrigVT != MVT::ppcf128)
-      Align = OrigVT.getStoreSize();
+      Alignment = Align(OrigVT.getStoreSize());
     else
-      Align = ArgVT.getStoreSize();
+      Alignment = Align(ArgVT.getStoreSize());
   }
 
-  return Align;
+  return Alignment;
 }
 
 /// CalculateStackSlotUsed - Return whether this argument will use its
 /// stack slot (instead of being passed in registers).  ArgOffset,
 /// AvailableFPRs, and AvailableVRs must hold the current argument
 /// position, and will be updated to account for this argument.
 static bool CalculateStackSlotUsed(EVT ArgVT, EVT OrigVT,
                                    ISD::ArgFlagsTy Flags,
                                    unsigned PtrByteSize,
                                    unsigned LinkageSize,
                                    unsigned ParamAreaSize,
                                    unsigned &ArgOffset,
                                    unsigned &AvailableFPRs,
                                    unsigned &AvailableVRs, bool HasQPX) {
   bool UseMemory = false;
 
   // Respect alignment of argument on the stack.
-  unsigned Align =
+  Align Alignment =
       CalculateStackSlotAlignment(ArgVT, OrigVT, Flags, PtrByteSize);
-  ArgOffset = ((ArgOffset + Align - 1) / Align) * Align;
+  ArgOffset = alignTo(ArgOffset, Alignment);
   // If there's no space left in the argument save area, we must
   // use memory (this check also catches zero-sized arguments).
   if (ArgOffset >= LinkageSize + ParamAreaSize)
     UseMemory = true;
 
   // Allocate argument on the stack.
   ArgOffset += CalculateStackSlotSize(ArgVT, Flags, PtrByteSize);
   if (Flags.isInConsecutiveRegsLast())
for (unsigned ArgNo = 0, e = Ins.size(); ArgNo != e; ++ArgNo) {
     ISD::ArgFlagsTy Flags = Ins[ArgNo].Flags;
     if (Ins[ArgNo].isOrigArg()) {
       std::advance(FuncArg, Ins[ArgNo].getOrigArgIndex() - CurArgIdx);
       CurArgIdx = Ins[ArgNo].getOrigArgIndex();
     }
     // We re-align the argument offset for each argument, except when using the
     // fast calling convention, when we need to make sure we do that only when
     // we'll actually use a stack slot.
-    unsigned CurArgOffset, Align;
+    unsigned CurArgOffset;
+    Align Alignment;
     auto ComputeArgOffset = [&]() {
       /* Respect alignment of argument on the stack.  */
-      Align = CalculateStackSlotAlignment(ObjectVT, OrigVT, Flags, PtrByteSize);
-      ArgOffset = ((ArgOffset + Align - 1) / Align) * Align;
+      Alignment =
+          CalculateStackSlotAlignment(ObjectVT, OrigVT, Flags, PtrByteSize);
+      ArgOffset = alignTo(ArgOffset, Alignment);
       CurArgOffset = ArgOffset;
     };
 
     if (CallConv != CallingConv::Fast) {
       ComputeArgOffset();
 
       /* Compute GPR index associated with argument offset.  */
       GPR_idx = (ArgOffset - LinkageSize) / PtrByteSize;
if (Flags.isByVal()) {
       // caller has allocated the parameter save anyway, we can refer
       // directly to the caller's stack frame.  Otherwise, create a
       // local copy in our own frame.
       int FI;
       if (HasParameterArea ||
           ArgSize + ArgOffset > LinkageSize + Num_GPR_Regs * PtrByteSize)
         FI = MFI.CreateFixedObject(ArgSize, ArgOffset, false, true);
       else
-        FI = MFI.CreateStackObject(ArgSize, Align, false);
+        FI = MFI.CreateStackObject(ArgSize, Alignment, false);
       SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
 
       // Handle aggregates smaller than 8 bytes.
       if (ObjSize < PtrByteSize) {
         // The value of the object is its address, which differs from the
         // address of the enclosing doubleword on big-endian systems.
         SDValue Arg = FIN;
         if (!isLittleEndian) {

 /// specified by the specific parameter attribute. The copy will be passed as
 /// a byval function parameter.
 /// Sometimes what we are copying is the end of a larger object, the part that
 /// does not fit in registers.
 static SDValue CreateCopyOfByValArgument(SDValue Src, SDValue Dst,
                                          SDValue Chain, ISD::ArgFlagsTy Flags,
                                          SelectionDAG &DAG, const SDLoc &dl) {
   SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i32);
-  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
-                       false, false, false, MachinePointerInfo(),
-                       MachinePointerInfo());
+  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode,
+                       Flags.getNonZeroByValAlign(), false, false, false,
+                       MachinePointerInfo(), MachinePointerInfo());
 }
 
 /// LowerMemOpCallTo - Store the argument to the stack or remember it in case of
 /// tail calls.
 static void LowerMemOpCallTo(
     SelectionDAG &DAG, MachineFunction &MF, SDValue Chain, SDValue Arg,
     SDValue PtrOff, int SPDiff, unsigned ArgOffset, bool isPPC64,
     bool isTailCall, bool isVector, SmallVectorImpl<SDValue> &MemOpChains,
if (IsFastCall) {
             continue;
           break;
         }
         HasParameterArea = true;
       }
     }
 
     /* Respect alignment of argument on the stack.  */
-    unsigned Align =
+    auto Alignement =
         CalculateStackSlotAlignment(ArgVT, OrigVT, Flags, PtrByteSize);
-    NumBytes = ((NumBytes + Align - 1) / Align) * Align;
+    NumBytes = alignTo(NumBytes, Alignement);
 
     NumBytes += CalculateStackSlotSize(ArgVT, Flags, PtrByteSize);
     if (Flags.isInConsecutiveRegsLast())
       NumBytes = ((NumBytes + PtrByteSize - 1)/PtrByteSize) * PtrByteSize;
   }
 
   unsigned NumBytesActuallyUsed = NumBytes;
 
for (unsigned i = 0; i != NumOps; ++i) {
     // register cannot be found for it.
     SDValue PtrOff;
 
     // We re-align the argument offset for each argument, except when using the
     // fast calling convention, when we need to make sure we do that only when
     // we'll actually use a stack slot.
     auto ComputePtrOff = [&]() {
       /* Respect alignment of argument on the stack.  */
-      unsigned Align =
+      auto Alignment =
           CalculateStackSlotAlignment(ArgVT, OrigVT, Flags, PtrByteSize);
-      ArgOffset = ((ArgOffset + Align - 1) / Align) * Align;
+      ArgOffset = alignTo(ArgOffset, Alignment);
 
       PtrOff = DAG.getConstant(ArgOffset, dl, StackPtr.getValueType());
 
       PtrOff = DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr, PtrOff);
     };
 
     if (!IsFastCall) {
       ComputePtrOff();

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

SDValue RISCVTargetLowering::LowerCall(CallLoweringInfo &CLI,
   SmallVector<SDValue, 8> ByValArgs;
   for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
     ISD::ArgFlagsTy Flags = Outs[i].Flags;
     if (!Flags.isByVal())
       continue;
 
     SDValue Arg = OutVals[i];
     unsigned Size = Flags.getByValSize();
-    unsigned Align = Flags.getByValAlign();
+    Align Alignment = Flags.getNonZeroByValAlign();
 
-    int FI = MF.getFrameInfo().CreateStackObject(Size, Align, /*isSS=*/false);
+    int FI =
+        MF.getFrameInfo().CreateStackObject(Size, Alignment, /*isSS=*/false);
     SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
     SDValue SizeNode = DAG.getConstant(Size, DL, XLenVT);
 
-    Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Align,
+    Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Alignment,
                           /*IsVolatile=*/false,
-                          /*AlwaysInline=*/false,
-                          IsTailCall, MachinePointerInfo(),
-                          MachinePointerInfo());
+                          /*AlwaysInline=*/false, IsTailCall,
+                          MachinePointerInfo(), MachinePointerInfo());
     ByValArgs.push_back(FIPtr);
   }
 
   if (!IsTailCall)
     Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, CLI.DL);
 
   // Copy argument values to their designated locations.
   SmallVector<std::pair<Register, SDValue>, 8> RegsToPass;

llvm/lib/Target/Sparc/SparcISelLowering.cpp

SparcTargetLowering::LowerCall_32(TargetLowering::CallLoweringInfo &CLI,
   SmallVector<SDValue, 8> ByValArgs;
   for (unsigned i = 0,  e = Outs.size(); i != e; ++i) {
     ISD::ArgFlagsTy Flags = Outs[i].Flags;
     if (!Flags.isByVal())
       continue;
 
     SDValue Arg = OutVals[i];
     unsigned Size = Flags.getByValSize();
-    unsigned Align = Flags.getByValAlign();
+    Align Alignment = Flags.getNonZeroByValAlign();
 
     if (Size > 0U) {
-      int FI = MFI.CreateStackObject(Size, Align, false);
+      int FI = MFI.CreateStackObject(Size, Alignment, false);
       SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
       SDValue SizeNode = DAG.getConstant(Size, dl, MVT::i32);
 
-      Chain = DAG.getMemcpy(Chain, dl, FIPtr, Arg, SizeNode, Align,
+      Chain = DAG.getMemcpy(Chain, dl, FIPtr, Arg, SizeNode, Alignment,
                             false,        // isVolatile,
                             (Size <= 32), // AlwaysInline if size <= 32,
                             false,        // isTailCall
                             MachinePointerInfo(), MachinePointerInfo());
       ByValArgs.push_back(FIPtr);
     }
     else {
       SDValue nullVal;

llvm/lib/Target/SystemZ/SystemZISelLowering.cpp

SDValue SystemZTargetLowering::lowerVACOPY(SDValue Op,
   SDValue Chain      = Op.getOperand(0);
   SDValue DstPtr     = Op.getOperand(1);
   SDValue SrcPtr     = Op.getOperand(2);
   const Value *DstSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
   SDLoc DL(Op);
 
   return DAG.getMemcpy(Chain, DL, DstPtr, SrcPtr, DAG.getIntPtrConstant(32, DL),
-                       /*Align*/8, /*isVolatile*/false, /*AlwaysInline*/false,
-                       /*isTailCall*/false,
-                       MachinePointerInfo(DstSV), MachinePointerInfo(SrcSV));
+                       Align(8), /*isVolatile*/ false, /*AlwaysInline*/ false,
+                       /*isTailCall*/ false, MachinePointerInfo(DstSV),
+                       MachinePointerInfo(SrcSV));
 }
 
 SDValue SystemZTargetLowering::
 lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
   const TargetFrameLowering *TFI = Subtarget.getFrameLowering();
   MachineFunction &MF = DAG.getMachineFunction();
   bool RealignOpt = !MF.getFunction().hasFnAttribute("no-realign-stack");
   bool StoreBackchain = MF.getFunction().hasFnAttribute("backchain");

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

if (Out.Flags.isInAlloca())
       fail(DL, DAG, "WebAssembly hasn't implemented inalloca arguments");
     if (Out.Flags.isInConsecutiveRegs())
       fail(DL, DAG, "WebAssembly hasn't implemented cons regs arguments");
     if (Out.Flags.isInConsecutiveRegsLast())
       fail(DL, DAG, "WebAssembly hasn't implemented cons regs last arguments");
     if (Out.Flags.isByVal() && Out.Flags.getByValSize() != 0) {
       auto &MFI = MF.getFrameInfo();
       int FI = MFI.CreateStackObject(Out.Flags.getByValSize(),
-                                     Out.Flags.getByValAlign(),
+                                     Out.Flags.getNonZeroByValAlign(),
                                      /*isSS=*/false);
       SDValue SizeNode =
           DAG.getConstant(Out.Flags.getByValSize(), DL, MVT::i32);
       SDValue FINode = DAG.getFrameIndex(FI, getPointerTy(Layout));
       Chain = DAG.getMemcpy(
-          Chain, DL, FINode, OutVal, SizeNode, Out.Flags.getByValAlign(),
+          Chain, DL, FINode, OutVal, SizeNode, Out.Flags.getNonZeroByValAlign(),
           /*isVolatile*/ false, /*AlwaysInline=*/false,
           /*isTailCall*/ false, MachinePointerInfo(), MachinePointerInfo());
       OutVal = FINode;
     }
     // Count the number of fixed args *after* legalization.
     NumFixedArgs += Out.IsFixed;
   }
 

llvm/lib/Target/X86/X86ISelLowering.cpp

 /// Make a copy of an aggregate at address specified by "Src" to address
 /// "Dst" with size and alignment information specified by the specific
 /// parameter attribute. The copy will be passed as a byval function parameter.
 static SDValue CreateCopyOfByValArgument(SDValue Src, SDValue Dst,
                                          SDValue Chain, ISD::ArgFlagsTy Flags,
                                          SelectionDAG &DAG, const SDLoc &dl) {
   SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i32);
 
-  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
-                       /*isVolatile*/false, /*AlwaysInline=*/true,
-                       /*isTailCall*/false,
-                       MachinePointerInfo(), MachinePointerInfo());
+  return DAG.getMemcpy(
+      Chain, dl, Dst, Src, SizeNode, Flags.getNonZeroByValAlign(),
+      /*isVolatile*/ false, /*AlwaysInline=*/true,
+      /*isTailCall*/ false, MachinePointerInfo(), MachinePointerInfo());
 }
 
 /// Return true if the calling convention is one that we can guarantee TCO for.
 static bool canGuaranteeTCO(CallingConv::ID CC) {
   return (CC == CallingConv::Fast || CC == CallingConv::GHC ||
           CC == CallingConv::X86_RegCall || CC == CallingConv::HiPE ||
           CC == CallingConv::HHVM || CC == CallingConv::Tail);
 }
case CCValAssign::BCvt:
       Arg = DAG.getBitcast(RegVT, Arg);
       break;
     case CCValAssign::Indirect: {
       if (isByVal) {
         // Memcpy the argument to a temporary stack slot to prevent
         // the caller from seeing any modifications the callee may make
         // as guaranteed by the `byval` attribute.
         int FrameIdx = MF.getFrameInfo().CreateStackObject(
-            Flags.getByValSize(), std::max(16, (int)Flags.getByValAlign()),
-            false);
+            Flags.getByValSize(),
+            std::max(Align(16), Flags.getNonZeroByValAlign()), false);
         SDValue StackSlot =
             DAG.getFrameIndex(FrameIdx, getPointerTy(DAG.getDataLayout()));
         Chain =
             CreateCopyOfByValArgument(Arg, StackSlot, Chain, Flags, DAG, dl);
         // From now on treat this as a regular pointer
         Arg = StackSlot;
         isByVal = false;
       } else {
static SDValue LowerVACOPY(SDValue Op, const X86Subtarget &Subtarget,
 
   SDValue Chain = Op.getOperand(0);
   SDValue DstPtr = Op.getOperand(1);
   SDValue SrcPtr = Op.getOperand(2);
   const Value *DstSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
   SDLoc DL(Op);
 
-  return DAG.getMemcpy(Chain, DL, DstPtr, SrcPtr,
-                       DAG.getIntPtrConstant(24, DL), 8, /*isVolatile*/false,
-                       false, false,
+  return DAG.getMemcpy(Chain, DL, DstPtr, SrcPtr, DAG.getIntPtrConstant(24, DL),
+                       Align(8), /*isVolatile*/ false, false, false,
                        MachinePointerInfo(DstSV), MachinePointerInfo(SrcSV));
 }
 
 // Helper to get immediate/variable SSE shift opcode from other shift opcodes.
 static unsigned getTargetVShiftUniformOpcode(unsigned Opc, bool IsVariable) {
   switch (Opc) {
   case ISD::SHL:
   case X86ISD::VSHL:

llvm/lib/Target/X86/X86SelectionDAGInfo.cpp

if (BytesLeft) {
     // Handle the last 1 - 7 bytes.
     unsigned Offset = SizeVal - BytesLeft;
     EVT AddrVT = Dst.getValueType();
     EVT SizeVT = Size.getValueType();
 
     Chain = DAG.getMemset(Chain, dl,
                           DAG.getNode(ISD::ADD, dl, AddrVT, Dst,
                                       DAG.getConstant(Offset, dl, AddrVT)),
-                          Val,
-                          DAG.getConstant(BytesLeft, dl, SizeVT),
-                          Align, isVolatile, false,
+                          Val, DAG.getConstant(BytesLeft, dl, SizeVT),
+                          llvm::Align(Align), isVolatile, false,
                           DstPtrInfo.getWithOffset(Offset));
   }
 
   // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain.
   return Chain;
 }
 
 /// Emit a single REP MOVS{B,W,D,Q} instruction.
static SDValue emitConstantSizeRepmov(
   Results.push_back(RepMovs);
   unsigned Offset = Size - BytesLeft;
   EVT DstVT = Dst.getValueType();
   EVT SrcVT = Src.getValueType();
   Results.push_back(DAG.getMemcpy(
       Chain, dl,
       DAG.getNode(ISD::ADD, dl, DstVT, Dst, DAG.getConstant(Offset, dl, DstVT)),
       DAG.getNode(ISD::ADD, dl, SrcVT, Src, DAG.getConstant(Offset, dl, SrcVT)),
-      DAG.getConstant(BytesLeft, dl, SizeVT), Align, isVolatile,
+      DAG.getConstant(BytesLeft, dl, SizeVT), llvm::Align(Align), isVolatile,
       /*AlwaysInline*/ true, /*isTailCall*/ false,
       DstPtrInfo.getWithOffset(Offset), SrcPtrInfo.getWithOffset(Offset)));
   return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Results);
 }
 
 SDValue X86SelectionDAGInfo::EmitTargetCodeForMemcpy(
     SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
     SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,

llvm/lib/Target/XCore/XCoreISelLowering.cpp

#endif
   // Aggregates passed "byVal" need to be copied by the callee.
   // The callee will use a pointer to this copy, rather than the original
   // pointer.
   for (SmallVectorImpl<ArgDataPair>::const_iterator ArgDI = ArgData.begin(),
                                                     ArgDE = ArgData.end();
        ArgDI != ArgDE; ++ArgDI) {
     if (ArgDI->Flags.isByVal() && ArgDI->Flags.getByValSize()) {
       unsigned Size = ArgDI->Flags.getByValSize();
-      unsigned Align = std::max(StackSlotSize, ArgDI->Flags.getByValAlign());
+      Align Alignment =
+          std::max(Align(StackSlotSize), ArgDI->Flags.getNonZeroByValAlign());
       // Create a new object on the stack and copy the pointee into it.
-      int FI = MFI.CreateStackObject(Size, Align, false);
+      int FI = MFI.CreateStackObject(Size, Alignment, false);
       SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
       InVals.push_back(FIN);
-      MemOps.push_back(DAG.getMemcpy(Chain, dl, FIN, ArgDI->SDV,
-                                     DAG.getConstant(Size, dl, MVT::i32),
-                                     Align, false, false, false,
-                                     MachinePointerInfo(),
-                                     MachinePointerInfo()));
+      MemOps.push_back(DAG.getMemcpy(
+          Chain, dl, FIN, ArgDI->SDV, DAG.getConstant(Size, dl, MVT::i32),
+          Alignment, false, false, false, MachinePointerInfo(),
     } else {
       InVals.push_back(ArgDI->SDV);
     }
   }
 
   // 4, chain mem ops nodes into a TokenFactor.
   if (!MemOps.empty()) {
     MemOps.push_back(Chain);
case ISD::STORE: {
     unsigned Alignment = ST->getAlignment();
 
     if (LoadSDNode *LD = dyn_cast<LoadSDNode>(ST->getValue())) {
       if (LD->hasNUsesOfValue(1, 0) && ST->getMemoryVT() == LD->getMemoryVT() &&
         LD->getAlignment() == Alignment &&
         !LD->isVolatile() && !LD->isIndexed() &&
         Chain.reachesChainWithoutSideEffects(SDValue(LD, 1))) {
         bool isTail = isInTailCallPosition(DAG, ST, Chain);
-        return DAG.getMemmove(Chain, dl, ST->getBasePtr(),
-                              LD->getBasePtr(),
-                              DAG.getConstant(StoreBits/8, dl, MVT::i32),
-                              Alignment, false, isTail, ST->getPointerInfo(),
-                              LD->getPointerInfo());
+        return DAG.getMemmove(Chain, dl, ST->getBasePtr(), LD->getBasePtr(),
+                              DAG.getConstant(StoreBits / 8, dl, MVT::i32),
+                              Align(Alignment), false, isTail,
+                              ST->getPointerInfo(), LD->getPointerInfo());
       }
     }
     break;
   }
   }
   return SDValue();
 }