[PATCH] D72778: [Matrix] Add __builtin_matrix_transpose to Clang.

[John McCall via Phabricator via cfe-commits]

rjmccall added inline comments.


================
Comment at: clang/lib/Sema/SemaChecking.cpp:15051
+
+  Expr *Arg = TheCall->getArg(0);
+  if (!Arg->getType()->isConstantMatrixType()) {
----------------
fhahn wrote:
> rjmccall wrote:
> > When a builtin has custom type-checking (`t`), you need to handle placeholders in the operands yourself, just like you would for an operator.
> I added placeholder handling and added additional tests.
Oh, I'm sorry, I gave you poor advice: you do need to handle placeholders, but more generally than that, you need an r-value.   Since you aren't doing any further conversions, you just need to call DefaultLValueConversion, which will also handle placeholders for you.

You will also need to store the checked argument back into the call, which you can only really test with an IRGen test.  This is one of the few places where we do actually directly mutate the AST.


================
Comment at: clang/lib/Sema/SemaChecking.cpp:1918
+    switch (BuiltinID) {
+    case Builtin::BI__builtin_matrix_transpose:
+      return SemaBuiltinMatrixTransposeOverload(TheCall, TheCallResult);
----------------
I didn't notice this before, but I think a single level of switch is fine; there's probably nothing common about matrix builtins that you're going to want to handle like this.


================
Comment at: clang/lib/Sema/SemaChecking.cpp:15063
+  // matrix type.
+  auto *MType = Matrix->getType()->getAs<ConstantMatrixType>();
+  QualType ResultType = Context.getConstantMatrixType(
----------------
Please call `getAs` once and then check the result above instead of calling `isConstantMatrixType()` (which does most of the same work as `getAs`).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72778/new/

https://reviews.llvm.org/D72778