[llvm] [BOLT] Correctly print preferred disassembly for annotated instructions (PR #120564)

[Kristof Beyls via llvm-commits]

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@@ -1961,7 +1961,15 @@ void BinaryContext::printInstruction(raw_ostream &OS, const MCInst &Instruction,
     OS << "\tjit\t" << MIB->getTargetSymbol(Instruction)->getName()
        << " # ID: " << DynamicID;
   } else {
-    InstPrinter->printInst(&Instruction, 0, "", *STI, OS);
+    // If there are annotations on the instruction, the MCInstPrinter will fail
+    // to print the preferred alias as it only does so when the number of
+    // operands is as expected. See
+    // https://github.com/llvm/llvm-project/blob/782f1a0d895646c364a53f9dcdd6d4ec1f3e5ea0/llvm/lib/MC/MCInstPrinter.cpp#L142
+    // Therefore, create a temporary copy of the Inst from which the annotations
+    // are removed, and print that Inst.
+    MCInst InstNoAnnot = Instruction;
+    MIB->stripAnnotations(InstNoAnnot);
+    InstPrinter->printInst(&InstNoAnnot, 0, "", *STI, OS);
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kbeyls wrote:

Yes, I am also expecting the bottleneck to be I/O here, so thought it would be good to keep the code simple and not make it more complicated to avoid the copy.

https://github.com/llvm/llvm-project/pull/120564