[Alignment] Use Align for TargetLowering::MinStackArgumentAlignment

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

Reviewers: courbet

Subscribers: sdardis, nemanjai, hiraditya, kbarton, jrtc27, MaskRay, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67288

llvm-svn: 371498

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -1578,8 +1578,8 @@ class TargetLoweringBase {
   }
 
   /// Return the minimum stack alignment of an argument.
-  unsigned getMinStackArgumentAlignment() const {
-    return MinStackArgumentAlignment.value();
+  llvm::Align getMinStackArgumentAlignment() const {
+    return MinStackArgumentAlignment;
   }
 
   /// Return the minimum function alignment.
@@ -2122,8 +2122,8 @@ class TargetLoweringBase {
   void setPrefLoopAlignment(llvm::Align Align) { PrefLoopAlignment = Align; }
 
   /// Set the minimum stack alignment of an argument.
-  void setMinStackArgumentAlignment(unsigned Align) {
-    MinStackArgumentAlignment = llvm::Align(Align);
+  void setMinStackArgumentAlignment(llvm::Align Align) {
+    MinStackArgumentAlignment = Align;
   }
 
   /// Set the maximum atomic operation size supported by the

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -1898,20 +1898,19 @@ SDValue SelectionDAG::expandVAArg(SDNode *Node) {
   EVT VT = Node->getValueType(0);
   SDValue Tmp1 = Node->getOperand(0);
   SDValue Tmp2 = Node->getOperand(1);
-  unsigned Align = Node->getConstantOperandVal(3);
+  const llvm::MaybeAlign MA(Node->getConstantOperandVal(3));
 
   SDValue VAListLoad = getLoad(TLI.getPointerTy(getDataLayout()), dl, Tmp1,
                                Tmp2, MachinePointerInfo(V));
   SDValue VAList = VAListLoad;
 
-  if (Align > TLI.getMinStackArgumentAlignment()) {
-    assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
-
+  if (MA && *MA > TLI.getMinStackArgumentAlignment()) {
     VAList = getNode(ISD::ADD, dl, VAList.getValueType(), VAList,
-                     getConstant(Align - 1, dl, VAList.getValueType()));
+                     getConstant(MA->value() - 1, dl, VAList.getValueType()));
 
-    VAList = getNode(ISD::AND, dl, VAList.getValueType(), VAList,
-                     getConstant(-(int64_t)Align, dl, VAList.getValueType()));
+    VAList =
+        getNode(ISD::AND, dl, VAList.getValueType(), VAList,
+                getConstant(-(int64_t)MA->value(), dl, VAList.getValueType()));
   }
 
   // Increment the pointer, VAList, to the next vaarg

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -1416,7 +1416,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
 
   // On ARM arguments smaller than 4 bytes are extended, so all arguments
   // are at least 4 bytes aligned.
-  setMinStackArgumentAlignment(4);
+  setMinStackArgumentAlignment(llvm::Align(4));
 
   // Prefer likely predicted branches to selects on out-of-order cores.
   PredictableSelectIsExpensive = Subtarget->getSchedModel().isOutOfOrder();

llvm/lib/Target/Mips/MipsISelLowering.cpp

@@ -523,7 +523,8 @@ MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
 
   // The arguments on the stack are defined in terms of 4-byte slots on O32
   // and 8-byte slots on N32/N64.
-  setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? 8 : 4);
+  setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? llvm::Align(8)
+                                                            : llvm::Align(4));
 
   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
 
@@ -2150,7 +2151,8 @@ SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
   EVT VT = Node->getValueType(0);
   SDValue Chain = Node->getOperand(0);
   SDValue VAListPtr = Node->getOperand(1);
-  unsigned Align = Node->getConstantOperandVal(3);
+  const llvm::Align Align =
+      llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
   SDLoc DL(Node);
   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
@@ -2167,14 +2169,13 @@ SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
   //        when the pointer is still aligned from the last va_arg (or pair of
   //        va_args for the i64 on O32 case).
   if (Align > getMinStackArgumentAlignment()) {
-    assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
+    VAList = DAG.getNode(
+        ISD::ADD, DL, VAList.getValueType(), VAList,
+        DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
 
-    VAList = DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
-                         DAG.getConstant(Align - 1, DL, VAList.getValueType()));
-
-    VAList = DAG.getNode(ISD::AND, DL, VAList.getValueType(), VAList,
-                         DAG.getConstant(-(int64_t)Align, DL,
-                                         VAList.getValueType()));
+    VAList = DAG.getNode(
+        ISD::AND, DL, VAList.getValueType(), VAList,
+        DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
   }
 
   // Increment the pointer, VAList, to the next vaarg.

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

@@ -139,7 +139,7 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
   // On PPC32/64, arguments smaller than 4/8 bytes are extended, so all
   // arguments are at least 4/8 bytes aligned.
   bool isPPC64 = Subtarget.isPPC64();
-  setMinStackArgumentAlignment(isPPC64 ? 8:4);
+  setMinStackArgumentAlignment(isPPC64 ? llvm::Align(8) : llvm::Align(4));
 
   // Set up the register classes.
   addRegisterClass(MVT::i32, &PPC::GPRCRegClass);