GlobalsModRef, ValueTracking: Look through threadlocal.address intrinsic (#88418)

This improves handling of `threadlocal.address` intrinsic in analyses:

The thread-id cannot change within a function with the exception of
suspend points of pre-split coroutines. This changes
`llvm::getUnderlyingObject` to look through `threadlocal.address` in
these cases.

`GlobalsAAResult::AnalyzeUsesOfPointer` checks whether an address can be
traced to simple loads/stores or escapes to other places. Starting the
analysis from a thread-local `GlobalValue` the `threadlocal.address`
intrinsic is safe to skip here.

This improves issue #87437

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index b87bba7..c038f7e 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -6255,6 +6255,10 @@ bool llvm::isIntrinsicReturningPointerAliasingArgumentWithoutCapturing(
     return true;
   case Intrinsic::ptrmask:
     return !MustPreserveNullness;
+  case Intrinsic::threadlocal_address:
+    // The underlying variable changes with thread ID. The Thread ID may change
+    // at coroutine suspend points.
+    return !Call->getParent()->getParent()->isPresplitCoroutine();
   default:
     return false;
   }