[llvm] [RISCV] [MachineOutliner] Analyze all candidates (PR #127659)

[Sudharsan Veeravalli via llvm-commits]

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@@ -3047,35 +3042,32 @@ RISCVInstrInfo::getOutliningCandidateInfo(
     std::vector<outliner::Candidate> &RepeatedSequenceLocs,
     unsigned MinRepeats) const {
 
-  // Each RepeatedSequenceLoc is identical.
-  outliner::Candidate &Candidate = RepeatedSequenceLocs[0];
-  auto CandidateInfo = analyzeCandidate(Candidate);
-  if (!CandidateInfo)
-    RepeatedSequenceLocs.clear();
+  // Analyze each candidate and erase the ones that are not viable.
+  llvm::erase_if(RepeatedSequenceLocs, analyzeCandidate);
 
   // If the sequence doesn't have enough candidates left, then we're done.
   if (RepeatedSequenceLocs.size() < MinRepeats)
     return std::nullopt;
 
+  // Each RepeatedSequenceLoc is identical.
+  outliner::Candidate &Candidate = RepeatedSequenceLocs[0];
   unsigned InstrSizeCExt =
       Candidate.getMF()->getSubtarget<RISCVSubtarget>().hasStdExtCOrZca() ? 2
                                                                           : 4;
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svs-quic wrote:

> I think we do have to care a little about which call we can use because the call instruction will not show up in the candidate sequence (which is a bit different to what's pointed out in that comment).

Yeah this is true for the MachineOutlinerTailCall case but for the MachineOutlinerDefault case we have a `jr t0` in the outlined function that can be compressed.



https://github.com/llvm/llvm-project/pull/127659