[llvm-branch-commits] [IR] Introduce `llvm.experimental.hot()` (PR #84850)

[Arthur Eubanks via llvm-branch-commits]

================
@@ -7276,6 +7276,12 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     setValue(&I, getValue(I.getArgOperand(0)));
     return;
 
+  case Intrinsic::experimental_hot:
+    // Default lowering to false. It's intended to be lowered as soon as profile
+    // is avalible to unblock other optimizations.
----------------
aeubanks wrote:

we shouldn't even get to isel, this should be unconditionally lowered in the optimization pipeline and any instance of this intrinsic getting to isel should be considered a bug (e.g. coroutines, LowerMatrixIntrinsicsPass)

https://github.com/llvm/llvm-project/pull/84850