[NFC] Add extra documentation for GetSymbolFromOperand() in PPCMCInstLower.cpp

Add a missing comment from D155600, where we note that we get the symbol
from a global, due to XCOFF-specific intricacies.

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
index ba5465f..c9797fd 100644
--- a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -32,6 +32,8 @@ using namespace llvm;
 static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO,
                                       AsmPrinter &AP) {
   if (MO.isGlobal()) {
+    // Get the symbol from the global, accounting for XCOFF-specific
+    // intricacies (see TargetLoweringObjectFileXCOFF::getTargetSymbol).
     const GlobalValue *GV = MO.getGlobal();
     return AP.getSymbol(GV);
   }