Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -7144,7 +7144,8 @@
   auto FRecordSwitches =
       Args.hasFlag(options::OPT_frecord_command_line,
                    options::OPT_fno_record_command_line, false);
-  if (FRecordSwitches && !Triple.isOSBinFormatELF())
+  if (FRecordSwitches && !Triple.isOSBinFormatELF() &&
+      !Triple.isOSBinFormatXCOFF())
     D.Diag(diag::err_drv_unsupported_opt_for_target)
         << Args.getLastArg(options::OPT_frecord_command_line)->getAsString(Args)
         << TripleStr;
Index: llvm/include/llvm/CodeGen/AsmPrinter.h
===================================================================
--- llvm/include/llvm/CodeGen/AsmPrinter.h
+++ llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -866,7 +866,7 @@
   /// Emit llvm.ident metadata in an '.ident' directive.
   void emitModuleIdents(Module &M);
   /// Emit bytes for llvm.commandline metadata.
-  void emitModuleCommandLines(Module &M);
+  virtual void emitModuleCommandLines(Module &M);
 
   GCMetadataPrinter *getOrCreateGCPrinter(GCStrategy &S);
   void emitGlobalAlias(Module &M, const GlobalAlias &GA);
Index: llvm/include/llvm/MC/MCStreamer.h
===================================================================
--- llvm/include/llvm/MC/MCStreamer.h
+++ llvm/include/llvm/MC/MCStreamer.h
@@ -647,6 +647,12 @@
   /// \param Sym - The symbol on the .ref directive.
   virtual void emitXCOFFRefDirective(const MCSymbol *Symbol);
 
+  /// Emit a C_INFO symbol with XCOFF embedded metadata to the .info section.
+  ///
+  /// \param Name - The embedded metadata name
+  /// \param Metadata - The embedded metadata
+  virtual void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata);
+
   /// Emit an ELF .size directive.
   ///
   /// This corresponds to an assembler statement such as:
Index: llvm/include/llvm/MC/MCXCOFFStreamer.h
===================================================================
--- llvm/include/llvm/MC/MCXCOFFStreamer.h
+++ llvm/include/llvm/MC/MCXCOFFStreamer.h
@@ -40,6 +40,10 @@
   void emitXCOFFExceptDirective(const MCSymbol *Symbol, const MCSymbol *Trap,
                                 unsigned Lang, unsigned Reason,
                                 unsigned FunctionSize, bool hasDebug) override;
+  void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) override {
+    report_fatal_error("emitXCOFFCInfoSym is not implemented yet on "
+                       "object generation path");
+  }
 };
 
 } // end namespace llvm
Index: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -486,6 +486,11 @@
     }
   }
 
+  // On AIX, emit bytes for llvm.commandline metadata after .file so that the
+  // C_INFO symbol is preserved if any csect is kept by the linker.
+  if (TM.getTargetTriple().isOSBinFormatXCOFF())
+    emitModuleCommandLines(M);
+
   GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
   assert(MI && "AsmPrinter didn't require GCModuleInfo?");
   for (const auto &I : *MI)
@@ -2330,7 +2335,9 @@
   emitModuleIdents(M);
 
   // Emit bytes for llvm.commandline metadata.
-  emitModuleCommandLines(M);
+  // The command line metadata is emitted earlier on XCOFF.
+  if (!TM.getTargetTriple().isOSBinFormatXCOFF())
+    emitModuleCommandLines(M);
 
   // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
   // split-stack is used.
Index: llvm/lib/MC/MCAsmStreamer.cpp
===================================================================
--- llvm/lib/MC/MCAsmStreamer.cpp
+++ llvm/lib/MC/MCAsmStreamer.cpp
@@ -37,6 +37,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Path.h"
 #include <optional>
+#include <algorithm>
 
 using namespace llvm;
 
@@ -200,6 +201,7 @@
                                 const MCSymbol *Trap,
                                 unsigned Lang, unsigned Reason,
                                 unsigned FunctionSize, bool hasDebug) override;
+  void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) override;
 
   void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
   void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
@@ -966,6 +968,65 @@
   EmitEOL();
 }
 
+void MCAsmStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
+  const char *InfoDirective = "\t.info ";
+  const char *Separator = ", ";
+  constexpr int WordSize = sizeof(uint32_t);
+
+  // Start by emitting the .info pseudo-op and C_INFO symbol name.
+  OS << InfoDirective;
+  PrintQuotedString(Name, OS);
+  OS << Separator;
+
+  size_t MetadataSize = Metadata.size();
+
+  // Emit the 4-byte length of the metadata.
+  OS << format_hex(MetadataSize, 10) << Separator;
+
+  // Nothing left to do if there's no metadata.
+  if (MetadataSize == 0) {
+    EmitEOL();
+    return;
+  }
+
+  // Metadata needs to be padded out to an even word size.
+  uint32_t PaddedSize = alignTo(std::max((int)MetadataSize, 1), 4);
+  uint32_t PaddingSize = PaddedSize - MetadataSize;
+
+  // Write out the payload a word at a time.
+  //
+  // The assembler has a limit on the number of operands in an expression,
+  // so we need multiple .info pseudo-ops. We choose a small number of words
+  // per pseudo-op to keep the assembly readable.
+  constexpr int WordsPerDirective = 5;
+  // Force emitting a new directive to keep the first directive purely about the name and size of the note.
+  int WordsBeforeNextDirective = 0;
+  auto PrintWord = [&](const uint8_t *WordPtr) {
+    if (WordsBeforeNextDirective-- == 0) {
+      EmitEOL();
+      OS << InfoDirective;
+      WordsBeforeNextDirective = WordsPerDirective;
+    }
+    OS << Separator;
+    uint32_t Word = llvm::support::endian::read32be(WordPtr);
+    OS << format_hex(Word, 10);
+  };
+  
+  size_t Index = 0;
+  for (; Index + WordSize <= MetadataSize; Index += WordSize)
+    PrintWord((const uint8_t *)Metadata.data() + Index);
+
+  // If there is padding, then we have at least one byte of payload left
+  // to emit.
+  if (PaddingSize) {
+    assert(PaddedSize - Index == WordSize);
+    std::array<uint8_t, WordSize> LastWord = {0};
+    ::memcpy(LastWord.data(), Metadata.data() + Index, MetadataSize - Index);
+    PrintWord(LastWord.data());
+  }
+  EmitEOL();
+}
+
 void MCAsmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
   assert(MAI->hasDotTypeDotSizeDirective());
   OS << "\t.size\t";
Index: llvm/lib/MC/MCStreamer.cpp
===================================================================
--- llvm/lib/MC/MCStreamer.cpp
+++ llvm/lib/MC/MCStreamer.cpp
@@ -1208,6 +1208,11 @@
                      "XCOFF targets");
 }
 
+void MCStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
+  llvm_unreachable("emitXCOFFCInfoSym is only supported on"
+                   "XCOFF targets");
+}
+
 void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
 void MCStreamer::emitELFSymverDirective(const MCSymbol *OriginalSym,
                                         StringRef Name, bool KeepOriginalSym) {}
Index: llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -290,6 +290,8 @@
   bool doFinalization(Module &M) override;
 
   void emitTTypeReference(const GlobalValue *GV, unsigned Encoding) override;
+
+  void emitModuleCommandLines(Module &M) override;
 };
 
 } // end anonymous namespace
@@ -2954,6 +2956,26 @@
   return new PPCLinuxAsmPrinter(tm, std::move(Streamer));
 }
 
+void PPCAIXAsmPrinter::emitModuleCommandLines(Module &M) {
+  const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
+  if (!NMD || !NMD->getNumOperands())
+    return;
+
+  std::string S;
+  raw_string_ostream RSOS(S);
+  for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
+    const MDNode *N = NMD->getOperand(i);
+    assert(N->getNumOperands() == 1 &&
+           "llvm.commandline metadata entry can have only one operand");
+    const MDString *MDS = cast<MDString>(N->getOperand(0));
+    // Add "@(#)" to support retrieving the command line information with the
+    // AIX "what" command
+    RSOS << "@(#)opt " << MDS->getString() << "\n";
+    RSOS.write('\0');
+  }
+  OutStreamer->emitXCOFFCInfoSym(".GCC.command.line", RSOS.str());
+}
+
 // Force static initialization.
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializePowerPCAsmPrinter() {
   TargetRegistry::RegisterAsmPrinter(getThePPC32Target(),
Index: llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll
@@ -0,0 +1,23 @@
+; RUN: llc -mtriple powerpc-ibm-aix-xcoff < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+
+; RUN: not --crash llc -mtriple powerpc-ibm-aix-xcoff -filetype=obj  < %s 2>&1 | \
+; RUN: FileCheck --check-prefix=OBJ %s
+; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj  < %s 2>&1 | \
+; RUN: FileCheck --check-prefix=OBJ %s
+
+; Verify that llvm.commandline metadata is emitted to .info sections and that the
+; metadata is padded if necessary.
+
+; OBJ: LLVM ERROR: emitXCOFFCInfoSym is not implemented yet on object generation path
+
+; ASM: .info ".GCC.command.line", 0x0000003a,
+; ASM: .info , 0x40282329, 0x6f707420, 0x636c616e, 0x67202d63, 0x6f6d6d61, 0x6e64202d
+; ASM: .info , 0x6c696e65, 0x0a004028, 0x23296f70, 0x7420736f, 0x6d657468, 0x696e6720
+; ASM: .info , 0x656c7365, 0x20313233, 0x0a000000
+
+!llvm.commandline = !{!0, !1}
+!0 = !{!"clang -command -line"}
+!1 = !{!"something else 123"}