[llvm] [JumpThreading] Copy metadata when inserting preload into preds (PR #134403)

[Nikita Popov via llvm-commits]

================
@@ -1409,6 +1409,13 @@ bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) {
     if (AATags)
       NewVal->setAAMetadata(AATags);
 
+    if (auto *MD = LoadI->getMetadata(LLVMContext::MD_invariant_load))
+      NewVal->setMetadata(LLVMContext::MD_invariant_load, MD);
+    if (auto *InvGroupMD = LoadI->getMetadata(LLVMContext::MD_invariant_group))
+      NewVal->setMetadata(LLVMContext::MD_invariant_group, InvGroupMD);
+    if (auto *RangeMD = LoadI->getMetadata(LLVMContext::MD_range))
+      NewVal->setMetadata(LLVMContext::MD_range, RangeMD);
----------------
nikic wrote:

Can we copy all metadata and then call dropUBImplyingAttrsAndMetadata()? We could only call it for the !isGuaranteedToTransferExecutionToSuccessor case.

I don't think preserving invariant_load is valid for the non-guaranteed-to-transfer case, at least with the currently specified semantics.

https://github.com/llvm/llvm-project/pull/134403