[AArch64] Do not use ABI alignment for mops.memset.tag

Pointer element types do not imply that the pointer is ABI aligned.
We should be using either an explicit align attribute here, or fall
back to an alignment of 1. This fixes a new element type access
introduced in D117764.

I don't think this makes any practical difference though, as the
lowering does not depend on alignment.

Differential Revision: https://reviews.llvm.org/D118681

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -11928,12 +11928,11 @@ bool AArch64TargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
   case Intrinsic::aarch64_mops_memset_tag: {
     Value *Dst = I.getArgOperand(0);
     Value *Val = I.getArgOperand(1);
-    PointerType *PtrTy = cast<PointerType>(Dst->getType());
     Info.opc = ISD::INTRINSIC_W_CHAIN;
     Info.memVT = MVT::getVT(Val->getType());
     Info.ptrVal = Dst;
     Info.offset = 0;
-    Info.align = DL.getABITypeAlign(PtrTy->getPointerElementType());
+    Info.align = I.getParamAlign(0).valueOrOne();
     Info.flags = MachineMemOperand::MOStore;
     // The size of the memory being operated on is unknown at this point
     Info.size = MemoryLocation::UnknownSize;

llvm/test/CodeGen/AArch64/aarch64-mops-mte.ll

@@ -324,3 +324,34 @@ entry:
   %r = tail call i8* @llvm.aarch64.mops.memset.tag(i8* %dst, i8 %value_trunc, i64 %size)
   ret i8* %r
 }
+
+define i8* @memset_tagged_size_aligned(i8* %dst, i64 %size, i32 %value) {
+; GISel-O0-LABEL: memset_tagged_size_aligned:
+; GISel-O0:       // %bb.0: // %entry
+; GISel-O0-NEXT:    // implicit-def: $x8
+; GISel-O0-NEXT:    mov w8, w2
+; GISel-O0-NEXT:    setgp [x0]!, x1!, x8
+; GISel-O0-NEXT:    setgm [x0]!, x1!, x8
+; GISel-O0-NEXT:    setge [x0]!, x1!, x8
+; GISel-O0-NEXT:    ret
+;
+; GISel-LABEL: memset_tagged_size_aligned:
+; GISel:       // %bb.0: // %entry
+; GISel-NEXT:    // kill: def $w2 killed $w2 def $x2
+; GISel-NEXT:    setgp [x0]!, x1!, x2
+; GISel-NEXT:    setgm [x0]!, x1!, x2
+; GISel-NEXT:    setge [x0]!, x1!, x2
+; GISel-NEXT:    ret
+;
+; SDAG-LABEL: memset_tagged_size_aligned:
+; SDAG:       // %bb.0: // %entry
+; SDAG-NEXT:    // kill: def $w2 killed $w2 def $x2
+; SDAG-NEXT:    setgp [x0]!, x1!, x2
+; SDAG-NEXT:    setgm [x0]!, x1!, x2
+; SDAG-NEXT:    setge [x0]!, x1!, x2
+; SDAG-NEXT:    ret
+entry:
+  %value_trunc = trunc i32 %value to i8
+  %r = tail call i8* @llvm.aarch64.mops.memset.tag(i8* align 16 %dst, i8 %value_trunc, i64 %size)
+  ret i8* %r
+}