[llvm][CodeGen][SVE] Constrain prefetch intrinsic argument to immediate values.

[fpetrogalli]

Summary

The argument that sets the prefetch type of a prefetch intrinsic must
be an immediate value.

[efriedma]

LGTM

llvm/include/llvm/IR/IntrinsicsAArch64.td

 //
 
 def int_aarch64_sve_stnt1 : AdvSIMD_1Vec_PredStore_Intrinsic;
 
 //
 // Prefetch
 //
 
-def int_aarch64_sve_prf : Intrinsic<[], [llvm_anyvector_ty,
-                                         llvm_ptr_ty,
-                                         llvm_i32_ty], [IntrArgMemOnly]>;
+def int_aarch64_sve_prf
+  : Intrinsic<[], [llvm_anyvector_ty, llvm_ptr_ty, llvm_i32_ty],
+                  [IntrArgMemOnly, ImmArg<2>]>;
 
 //
 // Scalar to vector operations
 //
 
 def int_aarch64_sve_dup : AdvSIMD_SVE_DUP_Intrinsic;
 
 def int_aarch64_sve_index : AdvSIMD_SVE_Index_Intrinsic;

llvm/lib/Target/AArch64/SVEInstrFormats.td

 
 def SVEPrefetchOperand : AsmOperandClass {
   let Name = "SVEPrefetch";
   let ParserMethod = "tryParsePrefetch<true>";
   let PredicateMethod = "isPrefetch";
   let RenderMethod = "addPrefetchOperands";
 }
 
-def sve_prfop : Operand<i32>, ImmLeaf<i32, [{
+def sve_prfop : Operand<i32>, TImmLeaf<i32, [{
     return (((uint32_t)Imm) <= 15);
   }]> {
   let PrintMethod = "printPrefetchOp<true>";
   let ParserMatchClass = SVEPrefetchOperand;
 }
 
 class SVELogicalImmOperand<int Width> : AsmOperandClass {
   let Name = "SVELogicalImm" # Width;