Fix HexagonGenExtract return statu

[serge-sans-paille]

Summary

Correctly reflect change in the return status.

Patch needed to land https://reviews.llvm.org/D80916

[foad]

Looks obviously correct to me but I'd prefer a Hexagon maintainer to review it.

[serge-sans-paille]

ping @kparzysz for the final review then :-)

[serge-sans-paille]

In order to land the pass return status check before branching for LLVM-11, and given the trivial nature of that patch, I'll merge it in a day or so if there's no more activity there.

[kparzysz]

LGTM. Thanks!

[serge-sans-paille]

Thanks!

llvm/lib/Target/Hexagon/HexagonGenExtract.cpp

bool HexagonGenExtract::convert(Instruction *In) {
   Value *NewIn = IRB.CreateCall(ExtF, {BF, IRB.getInt32(W), IRB.getInt32(SR)});
   if (SL != 0)
     NewIn = IRB.CreateShl(NewIn, SL, CSL->getName());
   In->replaceAllUsesWith(NewIn);
   return true;
 }
 
 bool HexagonGenExtract::visitBlock(BasicBlock *B) {
+  bool Changed = false;
+
   // Depth-first, bottom-up traversal.
   for (auto *DTN : children<DomTreeNode*>(DT->getNode(B)))
-    visitBlock(DTN->getBlock());
+    Changed |= visitBlock(DTN->getBlock());
 
   // Allow limiting the number of generated extracts for debugging purposes.
   bool HasCutoff = ExtractCutoff.getPosition();
   unsigned Cutoff = ExtractCutoff;
 
-  bool Changed = false;
   BasicBlock::iterator I = std::prev(B->end()), NextI, Begin = B->begin();
   while (true) {
     if (HasCutoff && (ExtractCount >= Cutoff))
       return Changed;
     bool Last = (I == Begin);
     if (!Last)
       NextI = std::prev(I);
     Instruction *In = &*I;