[XCOFF] Adjust .rename emission sequence

[jasonliu]

Summary

AIX assembler does not generate correct relocation when .rename appear between tc entry label and .tc directive.
So only emit .rename after .tc/.comm or other linkage is emitted.

[hubert.reinterpretcast]

@jasonliu, I would expect that this affects labels in general and not just TOC entries.

[jasonliu]

Adjust all .rename emission sequence.

[jasonliu]

In D85317#2196922, @hubert.reinterpretcast wrote:

@jasonliu, I would expect that this affects labels in general and not just TOC entries.

I'm not sure if there is a way to trigger that in our assembly code generation. But I think it's still a good idea to emit .rename after something is "defined" consistently. So I reversed all the other .rename emission sequence.

[daltenty]

LGTM, thanks!

llvm/lib/MC/MCAsmStreamer.cpp

void MCAsmStreamer::emitXCOFFLocalCommonSymbol(MCSymbol *LabelSym,
   CsectSym->print(OS, MAI);
   OS << ',' << Log2_32(ByteAlignment);
 
   EmitEOL();
 }
 
 void MCAsmStreamer::emitXCOFFSymbolLinkageWithVisibility(
     MCSymbol *Symbol, MCSymbolAttr Linkage, MCSymbolAttr Visibility) {
-  // Print symbol's rename (original name contains invalid character(s)) if
-  // there is one.
-  if (cast<MCSymbolXCOFF>(Symbol)->hasRename())
-    emitXCOFFRenameDirective(Symbol,
-                             cast<MCSymbolXCOFF>(Symbol)->getSymbolTableName());
 
   switch (Linkage) {
   case MCSA_Global:
     OS << MAI->getGlobalDirective();
     break;
   case MCSA_Weak:
     OS << MAI->getWeakDirective();
     break;
case MCSA_Hidden:
     break;
   case MCSA_Protected:
     OS << ",protected";
     break;
   default:
     report_fatal_error("unexpected value for Visibility type");
   }
   EmitEOL();
+
+  // Print symbol's rename (original name contains invalid character(s)) if
+  // there is one.
+  if (cast<MCSymbolXCOFF>(Symbol)->hasRename())
+    emitXCOFFRenameDirective(Symbol,
+                             cast<MCSymbolXCOFF>(Symbol)->getSymbolTableName());
 }
 
 void MCAsmStreamer::emitXCOFFRenameDirective(const MCSymbol *Name,
                                              StringRef Rename) {
   OS << "\t.rename\t";
   Name->print(OS, MAI);
   const char DQ = '"';
   OS << ',' << DQ;
void MCAsmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
   Symbol->print(OS, MAI);
   OS << ", ";
   Value->print(OS, MAI);
   EmitEOL();
 }
 
 void MCAsmStreamer::emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                      unsigned ByteAlignment) {
-  // Print symbol's rename (original name contains invalid character(s)) if
-  // there is one.
-  MCSymbolXCOFF *XSym = dyn_cast<MCSymbolXCOFF>(Symbol);
-  if (XSym && XSym->hasRename())
-    emitXCOFFRenameDirective(XSym, XSym->getSymbolTableName());
-
   OS << "\t.comm\t";
   Symbol->print(OS, MAI);
   OS << ',' << Size;
 
   if (ByteAlignment != 0) {
     if (MAI->getCOMMDirectiveAlignmentIsInBytes())
       OS << ',' << ByteAlignment;
     else
       OS << ',' << Log2_32(ByteAlignment);
   }
   EmitEOL();
+
+  // Print symbol's rename (original name contains invalid character(s)) if
+  // there is one.
+  MCSymbolXCOFF *XSym = dyn_cast<MCSymbolXCOFF>(Symbol);
+  if (XSym && XSym->hasRename())
+    emitXCOFFRenameDirective(XSym, XSym->getSymbolTableName());
+
 }
 
 void MCAsmStreamer::emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                           unsigned ByteAlign) {
   OS << "\t.lcomm\t";
   Symbol->print(OS, MAI);
   OS << ',' << Size;
 

llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp

public:
   PPCTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS)
       : PPCTargetStreamer(S), OS(OS) {}
 
   void emitTCEntry(const MCSymbol &S) override {
     if (const MCSymbolXCOFF *XSym = dyn_cast<MCSymbolXCOFF>(&S)) {
       MCSymbolXCOFF *TCSym =
           cast<MCSymbolXCOFF>(Streamer.getContext().getOrCreateSymbol(
               XSym->getSymbolTableName() + "[TC]"));
+      OS << "\t.tc " << TCSym->getName() << "," << XSym->getName() << '\n';
+
       if (TCSym->hasRename())
         Streamer.emitXCOFFRenameDirective(TCSym, TCSym->getSymbolTableName());
-      OS << "\t.tc " << TCSym->getName() << "," << XSym->getName() << '\n';
       return;
     }
 
     OS << "\t.tc " << S.getName() << "[TC]," << S.getName() << '\n';
   }
 
   void emitMachine(StringRef CPU) override {
     OS << "\t.machine " << CPU << '\n';

llvm/test/CodeGen/PowerPC/aix-xcoff-symbol-rename.ll

 define i32 (...)* @"f\26_o"() {
 entry:
   ret i32 (...)* @"f\40o"
 }
 
 ; This is f@o
 declare i32 @"f\40o"(...)
 
-; ASM:         .rename _Renamed..24f_o[DS],"f$o" # -- Begin function f$o
-; ASM-NEXT:    .lglobl _Renamed..24f_o[DS]
-; ASM-NEXT:    .rename ._Renamed..24f_o,".f$o"
+; ASM:         .lglobl _Renamed..24f_o[DS] # -- Begin function f$o
+; ASM-NEXT:    .rename _Renamed..24f_o[DS],"f$o"
 ; ASM-NEXT:    .lglobl ._Renamed..24f_o
+; ASM-NEXT:    .rename ._Renamed..24f_o,".f$o"
 ; ASM-NEXT:    .align  4
 ; ASM-NEXT:    .csect _Renamed..24f_o[DS],2
 ; ASM-NEXT:    .vbyte  4, ._Renamed..24f_o     # @"f$o"
 ; ASM-NEXT:    .vbyte  4, TOC[TC0]
 ; ASM-NEXT:    .vbyte  4, 0
 ; ASM-NEXT:    .csect .text[PR],2
 ; ASM-NEXT:  ._Renamed..24f_o:
 ; ASM:         bl ._Renamed..40f_o
 ; ASM-NEXT:    nop
-; ASM:         .rename _Renamed..26f_o[DS],"f&o" # -- Begin function f&o
-; ASM-NEXT:    .globl  _Renamed..26f_o[DS]
-; ASM-NEXT:    .rename ._Renamed..26f_o,".f&o"
+; ASM:         .globl  _Renamed..26f_o[DS] # -- Begin function f&o
+; ASM-NEXT:    .rename _Renamed..26f_o[DS],"f&o"
 ; ASM-NEXT:    .globl  ._Renamed..26f_o
+; ASM-NEXT:    .rename ._Renamed..26f_o,".f&o"
 ; ASM-NEXT:    .align  4
 ; ASM-NEXT:    .csect _Renamed..26f_o[DS],2
 ; ASM-NEXT:    .vbyte  4, ._Renamed..26f_o     # @"f&o"
 ; ASM-NEXT:    .vbyte  4, TOC[TC0]
 ; ASM-NEXT:    .vbyte  4, 0
 ; ASM-NEXT:    .csect .text[PR],2
 ; ASM-NEXT:  ._Renamed..26f_o:
 ; ASM:         bl ._Renamed..24f_o
-; ASM:         .rename _Renamed..265ff__o[DS],"f&_o" # -- Begin function f&_o
-; ASM-NEXT:    .globl  _Renamed..265ff__o[DS]
-; ASM-NEXT:    .rename ._Renamed..265ff__o,".f&_o"
+; ASM:         .globl  _Renamed..265ff__o[DS] # -- Begin function f&_o
+; ASM-NEXT:    .rename _Renamed..265ff__o[DS],"f&_o"
 ; ASM-NEXT:    .globl  ._Renamed..265ff__o
+; ASM-NEXT:    .rename ._Renamed..265ff__o,".f&_o"
 ; ASM-NEXT:    .align  4
 ; ASM-NEXT:    .csect _Renamed..265ff__o[DS],2
 ; ASM-NEXT:    .vbyte  4, ._Renamed..265ff__o  # @"f&_o"
 ; ASM-NEXT:    .vbyte  4, TOC[TC0]
 ; ASM-NEXT:    .vbyte  4, 0
 ; ASM-NEXT:    .csect .text[PR],2
 ; ASM-NEXT:  ._Renamed..265ff__o:
 ; ASM:         .csect .data[RW],2
-; ASM-NEXT:    .rename _Renamed..60f_o,"f`o"
 ; ASM-NEXT:    .globl  _Renamed..60f_o
+; ASM-NEXT:    .rename _Renamed..60f_o,"f`o"
 ; ASM-NEXT:    .align  2
 ; ASM-NEXT:  _Renamed..60f_o:
 ; ASM-NEXT:    .vbyte  4, 10                   # 0xa
-; ASM-NEXT:    .rename _Renamed..2222f_o_[RW],"f""o"""
 ; ASM-NEXT:    .comm _Renamed..2222f_o_[RW],4,2
-; ASM-NEXT:    .rename ._Renamed..40f_o,".f@o"
+; ASM-NEXT:    .rename _Renamed..2222f_o_[RW],"f""o"""
 ; ASM-NEXT:    .extern ._Renamed..40f_o
-; ASM-NEXT:    .rename _Renamed..40f_o[DS],"f@o"
+; ASM-NEXT:    .rename ._Renamed..40f_o,".f@o"
 ; ASM-NEXT:    .extern _Renamed..40f_o[DS]
+; ASM-NEXT:    .rename _Renamed..40f_o[DS],"f@o"
 ; ASM-NEXT:    .toc
 ; ASM-NEXT:  L..C0:
-; ASM-NEXT:    .rename _Renamed..40f_o[TC],"f@o"
 ; ASM-NEXT:    .tc _Renamed..40f_o[TC],_Renamed..40f_o[DS]
+; ASM-NEXT:    .rename _Renamed..40f_o[TC],"f@o"
 
 ; OBJ:       Disassembly of section .text:
 ; OBJ-EMPTY:
 ; OBJ-NEXT:  00000000 (idx: 6) .f$o:
 ; OBJ-NEXT:         0: 7c 08 02 a6   mflr 0
 ; OBJ-NEXT:         4: 90 01 00 08   stw 0, 8(1)
 ; OBJ-NEXT:         8: 94 21 ff c0   stwu 1, -64(1)
 ; OBJ-NEXT:         c: 4b ff ff f5   bl 0x0