[Inlining] Delete redundant optnone/alwaysinline check

[lxfind]

Summary

The same check is done in InlineCost: https://github.com/llvm/llvm-project/blob/8b0bd54d0ec968df28ccc58bbb537a7b7c074ef2/llvm/lib/Analysis/InlineCost.cpp#L2537-L2552
Also, doing a check on the callee here is confusing, because anything that deals with callee should be done in the inner loop where we proecss all calls from the same caller.

[aeubanks]

I've thought about doing this a couple times already :)

[wenlei]

The same check is done in InlineCost: https://github.com/llvm/llvm-project/blob/8b0bd54d0ec968df28ccc58bbb537a7b7c074ef2/llvm/lib/Analysis/InlineCost.cpp#L2537-L2552

The check in InlineCost is on Caller, so it's not strictly redundant.

[wenlei]

On the other hand, I expect this to be captured as incompatible attributes (caller without it, but callee has it), so removing the check here should be fine.

[lxfind]

In D95186#2514080, @wenlei wrote:

The same check is done in InlineCost: https://github.com/llvm/llvm-project/blob/8b0bd54d0ec968df28ccc58bbb537a7b7c074ef2/llvm/lib/Analysis/InlineCost.cpp#L2537-L2552

The check in InlineCost is on Caller, so it's not strictly redundant.

It checks both there:

if (Call.hasFnAttr(Attribute::AlwaysInline)) ...
...
if (Caller->hasOptNone())

[wenlei]

Ah, you're right.. sorry for confusion..

llvm/lib/Transforms/IPO/Inliner.cpp

for (int I = 0; I < (int)Calls.size(); ++I) {
     // We expect the calls to typically be batched with sequences of calls that
     // have the same caller, so we first set up some shared infrastructure for
     // this caller. We also do any pruning we can at this layer on the caller
     // alone.
     Function &F = *Calls[I].first->getCaller();
     LazyCallGraph::Node &N = *CG.lookup(F);
     if (CG.lookupSCC(N) != C)
       continue;
-    if (!Calls[I].first->getCalledFunction()->hasFnAttribute(
-            Attribute::AlwaysInline) &&
-        F.hasOptNone()) {
-      setInlineRemark(*Calls[I].first, "optnone attribute");
-      continue;
-    }
 
     LLVM_DEBUG(dbgs() << "Inlining calls in: " << F.getName() << "\n");
 
     auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & {
       return FAM.getResult<AssumptionAnalysis>(F);
     };
 
     // Now process as many calls as we have within this caller in the sequence.