Revert again

Author: TIHan

src/coreclr/jit/instr.cpp

@@ -1718,7 +1718,6 @@ instruction CodeGen::ins_Move_Extend(var_types srcType, bool srcInReg)
 #if defined(TARGET_XARCH)
         return INS_kmovq_msk;
 #elif defined(TARGET_ARM64)
-        //unreached(); // TODO-SVE: This needs testing
         return INS_sve_mov;
 #endif
     }

src/coreclr/jit/morph.cpp

@@ -2330,7 +2330,7 @@ void CallArgs::AddFinalArgsAndDetermineABIInfo(Compiler* comp, GenTreeCall* call
 
         bool      isBackFilled     = false;
         unsigned  nextFltArgRegNum = fltArgRegNum; // This is the next floating-point argument register number to use
-        bool      isStructArg      = varTypeIsStruct(argSigType);
+        bool      isStructArg      = varTypeIsStruct(argSigType) && !varTypeIsMask(argx->gtEffectiveVal());
         var_types structBaseType   = TYP_STRUCT;
         unsigned  structSize       = 0;
         bool      passStructByRef  = false;
@@ -3178,7 +3178,7 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* call)
             argx->gtType = TYP_I_IMPL;
         }
 
-        bool     isStructArg    = varTypeIsStruct(arg.GetSignatureType());
+        bool     isStructArg    = varTypeIsStruct(arg.GetSignatureType()) && !varTypeIsMask(arg.GetSignatureType());
         GenTree* argObj         = argx->gtEffectiveVal();
         bool     makeOutArgCopy = false;
 

src/coreclr/jit/rationalize.cpp

@@ -100,7 +100,11 @@ void Rationalizer::RewriteNodeAsCall(GenTree**             use,
             assert(!operand->OperIsFieldList());
 
             sigTyp = comp->impNormStructType(clsHnd);
-            arg    = NewCallArg::Struct(operand, sigTyp, clsHnd);
+            if (varTypeIsMask(operand) && varTypeIsSIMD(sigTyp))
+            {
+                sigTyp = TYP_MASK;
+            }
+            arg = NewCallArg::Struct(operand, sigTyp, clsHnd);
         }
         else
         {