Add Alignment argument to IRBuilder CreateAtomicRMW and CreateAtomicCmpXchg.

And then push those change throughout LLVM.

Keep the old signature in Clang's CGBuilder for now -- that will be
updated in a follow-on patch (D97224).

The MLIR LLVM-IR dialect is not updated to support the new alignment
attribute, but preserves its existing behavior.

Differential Revision: https://reviews.llvm.org/D97223

Author: jyknight

clang/lib/CodeGen/CGBuilder.h

@@ -132,6 +132,28 @@ class CGBuilderTy : public CGBuilderBaseTy {
     return CreateAlignedStore(getInt1(Value), Addr, CharUnits::One());
   }
 
+  // Temporarily use old signature; clang will be updated to an Address overload
+  // in a subsequent patch.
+  llvm::AtomicCmpXchgInst *
+  CreateAtomicCmpXchg(llvm::Value *Ptr, llvm::Value *Cmp, llvm::Value *New,
+                      llvm::AtomicOrdering SuccessOrdering,
+                      llvm::AtomicOrdering FailureOrdering,
+                      llvm::SyncScope::ID SSID = llvm::SyncScope::System) {
+    return CGBuilderBaseTy::CreateAtomicCmpXchg(
+        Ptr, Cmp, New, llvm::MaybeAlign(), SuccessOrdering, FailureOrdering,
+        SSID);
+  }
+
+  // Temporarily use old signature; clang will be updated to an Address overload
+  // in a subsequent patch.
+  llvm::AtomicRMWInst *
+  CreateAtomicRMW(llvm::AtomicRMWInst::BinOp Op, llvm::Value *Ptr,
+                  llvm::Value *Val, llvm::AtomicOrdering Ordering,
+                  llvm::SyncScope::ID SSID = llvm::SyncScope::System) {
+    return CGBuilderBaseTy::CreateAtomicRMW(Op, Ptr, Val, llvm::MaybeAlign(),
+                                            Ordering, SSID);
+  }
+
   using CGBuilderBaseTy::CreateBitCast;
   Address CreateBitCast(Address Addr, llvm::Type *Ty,
                         const llvm::Twine &Name = "") {

llvm/include/llvm/CodeGen/AtomicExpandUtils.h

@@ -22,8 +22,8 @@ class Value;
 /// (the builder, %addr, %loaded, %new_val, ordering,
 ///  /* OUT */ %success, /* OUT */ %new_loaded)
 using CreateCmpXchgInstFun =
-    function_ref<void(IRBuilder<> &, Value *, Value *, Value *, AtomicOrdering,
-                      Value *&, Value *&)>;
+    function_ref<void(IRBuilder<> &, Value *, Value *, Value *, Align,
+                      AtomicOrdering, Value *&, Value *&)>;
 
 /// Expand an atomic RMW instruction into a loop utilizing
 /// cmpxchg. You'll want to make sure your target machine likes cmpxchg

llvm/include/llvm/IR/IRBuilder.h

@@ -1704,21 +1704,30 @@ class IRBuilderBase {
     return Insert(new FenceInst(Context, Ordering, SSID), Name);
   }
 
-  AtomicCmpXchgInst *CreateAtomicCmpXchg(
-      Value *Ptr, Value *Cmp, Value *New, AtomicOrdering SuccessOrdering,
-      AtomicOrdering FailureOrdering, SyncScope::ID SSID = SyncScope::System) {
-    const DataLayout &DL = BB->getModule()->getDataLayout();
-    Align Alignment(DL.getTypeStoreSize(New->getType()));
-    return Insert(new AtomicCmpXchgInst(
-        Ptr, Cmp, New, Alignment, SuccessOrdering, FailureOrdering, SSID));
+  AtomicCmpXchgInst *
+  CreateAtomicCmpXchg(Value *Ptr, Value *Cmp, Value *New, MaybeAlign Align,
+                      AtomicOrdering SuccessOrdering,
+                      AtomicOrdering FailureOrdering,
+                      SyncScope::ID SSID = SyncScope::System) {
+    if (!Align) {
+      const DataLayout &DL = BB->getModule()->getDataLayout();
+      Align = llvm::Align(DL.getTypeStoreSize(New->getType()));
+    }
+
+    return Insert(new AtomicCmpXchgInst(Ptr, Cmp, New, *Align, SuccessOrdering,
+                                        FailureOrdering, SSID));
   }
 
-  AtomicRMWInst *CreateAtomicRMW(AtomicRMWInst::BinOp Op, Value *Ptr, Value *Val,
+  AtomicRMWInst *CreateAtomicRMW(AtomicRMWInst::BinOp Op, Value *Ptr,
+                                 Value *Val, MaybeAlign Align,
                                  AtomicOrdering Ordering,
                                  SyncScope::ID SSID = SyncScope::System) {
-    const DataLayout &DL = BB->getModule()->getDataLayout();
-    Align Alignment(DL.getTypeStoreSize(Val->getType()));
-    return Insert(new AtomicRMWInst(Op, Ptr, Val, Alignment, Ordering, SSID));
+    if (!Align) {
+      const DataLayout &DL = BB->getModule()->getDataLayout();
+      Align = llvm::Align(DL.getTypeStoreSize(Val->getType()));
+    }
+
+    return Insert(new AtomicRMWInst(Op, Ptr, Val, *Align, Ordering, SSID));
   }
 
   Value *CreateGEP(Value *Ptr, ArrayRef<Value *> IdxList,