[clang] [Clang] Add builtins for masked vector loads / stores (PR #154464)

[Erich Keane via cfe-commits]

================
@@ -2266,6 +2266,87 @@ static bool BuiltinCountZeroBitsGeneric(Sema &S, CallExpr *TheCall) {
   return false;
 }
 
+static ExprResult BuiltinMaskedLoad(Sema &S, CallExpr *TheCall) {
+  if (S.checkArgCount(TheCall, 2))
+    return ExprError();
+
+  Expr *MaskArg = TheCall->getArg(0);
+  Expr *PtrArg = TheCall->getArg(1);
+
+  QualType MaskTy = MaskArg->getType();
+  if (!MaskTy->isExtVectorBoolType())
+    return ExprError(
+        S.Diag(MaskArg->getBeginLoc(), diag::err_builtin_invalid_arg_type)
+        << 1 << /* vector of */ 4 << /* booleans */ 6 << /* no fp */ 0
+        << MaskTy);
+
+  QualType PtrTy = PtrArg->getType();
+  if (!PtrTy->isPointerType() || !PtrTy->getPointeeType()->isVectorType())
+    return ExprError(
+        S.Diag(PtrArg->getExprLoc(), diag::err_vec_masked_load_store_ptr)
+        << 2 << "pointer to vector");
+
+  QualType PointeeTy = PtrTy->getPointeeType();
+  const VectorType *MaskVecTy = MaskTy->getAs<VectorType>();
+  const VectorType *DataVecTy = PointeeTy->getAs<VectorType>();
+  if (MaskVecTy->getNumElements() != DataVecTy->getNumElements())
+    return ExprError(
+        S.Diag(TheCall->getBeginLoc(), diag::err_vec_masked_load_store_size)
+        << "__builtin_masked_load" << MaskTy << PointeeTy);
+
+  TheCall->setType(PointeeTy);
+  return TheCall;
+}
+
+static ExprResult BuiltinMaskedStore(Sema &S, CallExpr *TheCall) {
+  if (S.checkArgCount(TheCall, 3))
----------------
erichkeane wrote:

Mask and pointer arg, which is about 2/3 of the fuctions, are the same, right?  Seems like a `CheckBuiltinMaskPointerArgs` function cleans this up a bunch, and would, IMO, improve readabilitiy.

https://github.com/llvm/llvm-project/pull/154464