[llvm] [BOLT][AArch64] Fix strict usage during ADR Relax (PR #71377)

[Denis Revunov via llvm-commits]

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@@ -72,14 +72,17 @@ void ADRRelaxationPass::runOnFunction(BinaryFunction &BF) {
 
       if (It != BB.begin() && BC.MIB->isNoop(*std::prev(It))) {
         It = BB.eraseInstruction(std::prev(It));
-      } else if (opts::StrictMode && !BF.isSimple()) {
+      } else if (std::next(It) != BB.end() && BC.MIB->isNoop(*std::next(It))) {
+        BB.eraseInstruction(std::next(It));
+      } else if (!opts::StrictMode && !BF.isSimple()) {
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treapster wrote:

This change is very confusing because it has relaxed behavior with strict option and strict behavior without it. I think the only way to make it make sense is to fail regardless of --strict mode as @maksfb suggested. But you have to evaluate whether it's worth making bolt always fail on binaries with non-simple functions without nops. If there's no jump table, it is fine so a failure may be false positive.

https://github.com/llvm/llvm-project/pull/71377