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, 8 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp
index 527f19b..1ceb1b2 100644
--- a/llvm/lib/Analysis/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/GlobalsModRef.cpp
@@ -344,6 +344,14 @@ bool GlobalsAAResult::AnalyzeUsesOfPointer(Value *V,
       if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
         return true;
     } else if (auto *Call = dyn_cast<CallBase>(I)) {
+      if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
+        if (II->getIntrinsicID() == Intrinsic::threadlocal_address &&
+            V == II->getArgOperand(0)) {
+          if (AnalyzeUsesOfPointer(II, Readers, Writers))
+            return true;
+          continue;
+        }
+      }
       // Make sure that this is just the function being called, not that it is
       // passing into the function.
       if (Call->isDataOperand(&U)) {