[AArch64] Add a Machine Value Type for 8 consecutive registers

Adds MVT::i64x8, a Machine Value Type needed for lowering inline assembly
operands which materialize a sequence of eight general purpose registers.

Differential Revision: https://reviews.llvm.org/D94096

Author: labrinea

llvm/include/llvm/CodeGen/ValueTypes.td

@@ -216,6 +216,7 @@ def untyped   : ValueType<8,    174>;  // Produces an untyped value
 def funcref   : ValueType<0,    175>;  // WebAssembly's funcref type
 def externref : ValueType<0,    176>;  // WebAssembly's externref type
 def x86amx    : ValueType<8192, 177>;  // X86 AMX value
+def i64x8     : ValueType<512,  178>;  // 8 Consecutive GPRs (AArch64)
 
 
 def token      : ValueType<0, 248>;  // TokenTy

llvm/include/llvm/Support/MachineValueType.h

@@ -270,9 +270,10 @@ namespace llvm {
       funcref        = 175,    // WebAssembly's funcref type
       externref      = 176,    // WebAssembly's externref type
       x86amx         = 177,    // This is an X86 AMX value
+      i64x8          = 178,    // 8 Consecutive GPRs (AArch64)
 
       FIRST_VALUETYPE =  1,    // This is always the beginning of the list.
-      LAST_VALUETYPE = x86amx, // This always remains at the end of the list.
+      LAST_VALUETYPE = i64x8,  // This always remains at the end of the list.
       VALUETYPE_SIZE = LAST_VALUETYPE + 1,
 
       // This is the current maximum for LAST_VALUETYPE.
@@ -987,6 +988,7 @@ namespace llvm {
       case nxv16f16:
       case nxv8f32:
       case nxv4f64: return TypeSize::Scalable(256);
+      case i64x8:
       case v512i1:
       case v64i8:
       case v32i16:

llvm/lib/CodeGen/ValueTypes.cpp

@@ -167,6 +167,7 @@ std::string EVT::getEVTString() const {
   case MVT::Glue:      return "glue";
   case MVT::x86mmx:    return "x86mmx";
   case MVT::x86amx:    return "x86amx";
+  case MVT::i64x8:     return "i64x8";
   case MVT::Metadata:  return "Metadata";
   case MVT::Untyped:   return "Untyped";
   case MVT::funcref:   return "funcref";
@@ -198,6 +199,7 @@ Type *EVT::getTypeForEVT(LLVMContext &Context) const {
   case MVT::ppcf128: return Type::getPPC_FP128Ty(Context);
   case MVT::x86mmx:  return Type::getX86_MMXTy(Context);
   case MVT::x86amx:  return Type::getX86_AMXTy(Context);
+  case MVT::i64x8:   return IntegerType::get(Context, 512);
   case MVT::externref:
     return PointerType::get(StructType::create(Context), 10);
   case MVT::funcref:

llvm/utils/TableGen/CodeGenTarget.cpp

@@ -77,6 +77,7 @@ StringRef llvm::getEnumName(MVT::SimpleValueType T) {
   case MVT::ppcf128:  return "MVT::ppcf128";
   case MVT::x86mmx:   return "MVT::x86mmx";
   case MVT::x86amx:   return "MVT::x86amx";
+  case MVT::i64x8:    return "MVT::i64x8";
   case MVT::Glue:     return "MVT::Glue";
   case MVT::isVoid:   return "MVT::isVoid";
   case MVT::v1i1:     return "MVT::v1i1";