[PowerPC] Always use "assembler dialect" 1

A setting in MCAsmInfo defines the "assembler dialect" to use.  This is used
by common code to choose between alternatives in a multi-alternative GNU
inline asm statement like the following:

  __asm__ ("{sfe|subfe} %0,%1,%2" : "=r" (out) : "r" (in1), "r" (in2));

The meaning of these dialects is platform specific, and GCC defines those
for PowerPC to use dialect 0 for old-style (POWER) mnemonics and 1 for
new-style (PowerPC) mnemonics, like in the example above.

To be compatible with inline asm used with GCC, LLVM ought to do the same.
Specifically, this means we should always use assembler dialect 1 since
old-style mnemonics really aren't supported on any current platform.

However, the current LLVM back-end uses:
  AssemblerDialect = 1;           // New-Style mnemonics.
in PPCMCAsmInfoDarwin, and
  AssemblerDialect = 0;           // Old-Style mnemonics.
in PPCLinuxMCAsmInfo.

The Linux setting really isn't correct, we should be using new-style
mnemonics everywhere.  This is changed by this commit.

Unfortunately, the setting of this variable is overloaded in the back-end
to decide whether or not we are on a Darwin target.  This is done in
PPCInstPrinter (the "SyntaxVariant" is initialized from the MCAsmInfo
AssemblerDialect setting), and also in PPCMCExpr.  Setting AssemblerDialect
to 1 for both Darwin and Linux no longer allows us to make this distinction.

Instead, this patch uses the MCSubtargetInfo passed to createPPCMCInstPrinter
to distinguish Darwin targets, and ignores the SyntaxVariant parameter.
As to PPCMCExpr, this patch adds an explicit isDarwin argument that needs
to be passed in by the caller when creating a target MCExpr.  (To do so
this patch implicitly also reverts commit 184441.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185858 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp

@@ -1015,7 +1015,7 @@ ParseExpression(const MCExpr *&EVal) {
   PPCMCExpr::VariantKind Variant;
   const MCExpr *E = ExtractModifierFromExpr(EVal, Variant);
   if (E)
-    EVal = PPCMCExpr::Create(Variant, E, getParser().getContext());
+    EVal = PPCMCExpr::Create(Variant, E, false, getParser().getContext());
 
   return false;
 }

lib/Target/PowerPC/InstPrinter/PPCInstPrinter.h

@@ -21,15 +21,14 @@ namespace llvm {
 class MCOperand;
 
 class PPCInstPrinter : public MCInstPrinter {
-  // 0 -> AIX, 1 -> Darwin.
+  bool IsDarwin;
-  unsigned SyntaxVariant;
 public:
   PPCInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII,
-                 const MCRegisterInfo &MRI, unsigned syntaxVariant)
+                 const MCRegisterInfo &MRI, bool isDarwin)
-    : MCInstPrinter(MAI, MII, MRI), SyntaxVariant(syntaxVariant) {}
+    : MCInstPrinter(MAI, MII, MRI), IsDarwin(isDarwin) {}
   
   bool isDarwinSyntax() const {
-    return SyntaxVariant == 1;
+    return IsDarwin;
   }
   
   virtual void printRegName(raw_ostream &OS, unsigned RegNo) const;

lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp

@@ -66,6 +66,6 @@ PPCLinuxMCAsmInfo::PPCLinuxMCAsmInfo(bool is64Bit) {
     
   ZeroDirective = "\t.space\t";
   Data64bitsDirective = is64Bit ? "\t.quad\t" : 0;
-  AssemblerDialect = 0;           // Old-Style mnemonics.
+  AssemblerDialect = 1;           // New-Style mnemonics.
 }
 

lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp

@@ -17,9 +17,8 @@ using namespace llvm;
 
 const PPCMCExpr*
 PPCMCExpr::Create(VariantKind Kind, const MCExpr *Expr,
-                       MCContext &Ctx) {
+                  bool isDarwin, MCContext &Ctx) {
-  int AssemblerDialect = Ctx.getAsmInfo()->getAssemblerDialect();
+  return new (Ctx) PPCMCExpr(Kind, Expr, isDarwin);
-  return new (Ctx) PPCMCExpr(Kind, Expr, AssemblerDialect);
 }
 
 void PPCMCExpr::PrintImpl(raw_ostream &OS) const {

lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.h

@@ -32,29 +32,32 @@ public:
 private:
   const VariantKind Kind;
   const MCExpr *Expr;
-  const int AssemblerDialect;
+  bool IsDarwin;
 
   explicit PPCMCExpr(VariantKind _Kind, const MCExpr *_Expr,
-                     int _AssemblerDialect)
+                     bool _IsDarwin)
-    : Kind(_Kind), Expr(_Expr), AssemblerDialect(_AssemblerDialect) {}
+    : Kind(_Kind), Expr(_Expr), IsDarwin(_IsDarwin) {}
 
 public:
   /// @name Construction
   /// @{
 
   static const PPCMCExpr *Create(VariantKind Kind, const MCExpr *Expr,
-                                      MCContext &Ctx);
+                                 bool isDarwin, MCContext &Ctx);
 
-  static const PPCMCExpr *CreateLo(const MCExpr *Expr, MCContext &Ctx) {
+  static const PPCMCExpr *CreateLo(const MCExpr *Expr,
-    return Create(VK_PPC_LO, Expr, Ctx);
+                                   bool isDarwin, MCContext &Ctx) {
+    return Create(VK_PPC_LO, Expr, isDarwin, Ctx);
   }
 
-  static const PPCMCExpr *CreateHi(const MCExpr *Expr, MCContext &Ctx) {
+  static const PPCMCExpr *CreateHi(const MCExpr *Expr,
-    return Create(VK_PPC_HI, Expr, Ctx);
+                                   bool isDarwin, MCContext &Ctx) {
+    return Create(VK_PPC_HI, Expr, isDarwin, Ctx);
   }
 
-  static const PPCMCExpr *CreateHa(const MCExpr *Expr, MCContext &Ctx) {
+  static const PPCMCExpr *CreateHa(const MCExpr *Expr,
-    return Create(VK_PPC_HA, Expr, Ctx);
+                                   bool isDarwin, MCContext &Ctx) {
+    return Create(VK_PPC_HA, Expr, isDarwin, Ctx);
   }
 
   /// @}
@@ -68,7 +71,7 @@ public:
   const MCExpr *getSubExpr() const { return Expr; }
 
   /// isDarwinSyntax - True if expression is to be printed using Darwin syntax.
-  bool isDarwinSyntax() const { return AssemblerDialect == 1; }
+  bool isDarwinSyntax() const { return IsDarwin; }
 
 
   /// @}

lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp

@@ -117,7 +117,8 @@ static MCInstPrinter *createPPCMCInstPrinter(const Target &T,
                                              const MCInstrInfo &MII,
                                              const MCRegisterInfo &MRI,
                                              const MCSubtargetInfo &STI) {
-  return new PPCInstPrinter(MAI, MII, MRI, SyntaxVariant);
+  bool isDarwin = Triple(STI.getTargetTriple()).isOSDarwin();
+  return new PPCInstPrinter(MAI, MII, MRI, isDarwin);
 }
 
 extern "C" void LLVMInitializePowerPCTargetMC() {

lib/Target/PowerPC/PPC.h

@@ -40,7 +40,7 @@ namespace llvm {
   FunctionPass *createPPCJITCodeEmitterPass(PPCTargetMachine &TM,
                                             JITCodeEmitter &MCE);
   void LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
-                                    AsmPrinter &AP);
+                                    AsmPrinter &AP, bool isDarwin);
 
   /// \brief Creates an PPC-specific Target Transformation Info pass.
   ImmutablePass *createPPCTargetTransformInfoPass(const PPCTargetMachine *TM);

lib/Target/PowerPC/PPCAsmPrinter.cpp

@@ -352,7 +352,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   case PPC::LDtocCPT:
   case PPC::LDtoc: {
     // Transform %X3 = LDtoc <ga:@min1>, %X2
-    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
 
     // Change the opcode to LD, and the global address operand to be a
     // reference to the TOC entry we will synthesize later.
@@ -381,7 +381,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
       
   case PPC::ADDIStocHA: {
     // Transform %Xd = ADDIStocHA %X2, <ga:@sym>
-    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
 
     // Change the opcode to ADDIS8.  If the global address is external,
     // has common linkage, is a function address, or is a jump table
@@ -425,7 +425,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   }
   case PPC::LDtocL: {
     // Transform %Xd = LDtocL <ga:@sym>, %Xs
-    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
 
     // Change the opcode to LD.  If the global address is external, has
     // common linkage, or is a jump table address, then reference the
@@ -462,7 +462,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   }
   case PPC::ADDItocL: {
     // Transform %Xd = ADDItocL %Xs, <ga:@sym>
-    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
 
     // Change the opcode to ADDI8.  If the global address is external, then
     // generate a TOC entry and reference that.  Otherwise reference the
@@ -514,7 +514,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   }
   case PPC::LDgotTprelL: {
     // Transform %Xd = LDgotTprelL <ga:@sym>, %Xs
-    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+    LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
 
     // Change the opcode to LD.
     TmpInst.setOpcode(PPC::LD);
@@ -720,7 +720,7 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   }
   }
 
-  LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
+  LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
   OutStreamer.EmitInstruction(TmpInst);
 }
 
@@ -891,6 +891,7 @@ static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
 void PPCDarwinAsmPrinter::
 EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
   bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
+  bool isDarwin = Subtarget.isDarwin();
   
   const TargetLoweringObjectFileMachO &TLOFMacho = 
     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
@@ -930,7 +931,7 @@ EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
       // mflr r11
       OutStreamer.EmitInstruction(MCInstBuilder(PPC::MFLR).addReg(PPC::R11));
       // addis r11, r11, ha16(LazyPtr - AnonSymbol)
-      const MCExpr *SubHa16 = PPCMCExpr::CreateHa(Sub, OutContext);
+      const MCExpr *SubHa16 = PPCMCExpr::CreateHa(Sub, isDarwin, OutContext);
       OutStreamer.EmitInstruction(MCInstBuilder(PPC::ADDIS)
         .addReg(PPC::R11)
         .addReg(PPC::R11)
@@ -940,7 +941,7 @@ EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
 
       // ldu r12, lo16(LazyPtr - AnonSymbol)(r11)
       // lwzu r12, lo16(LazyPtr - AnonSymbol)(r11)
-      const MCExpr *SubLo16 = PPCMCExpr::CreateLo(Sub, OutContext);
+      const MCExpr *SubLo16 = PPCMCExpr::CreateLo(Sub, isDarwin, OutContext);
       OutStreamer.EmitInstruction(MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
         .addReg(PPC::R12)
         .addExpr(SubLo16).addExpr(SubLo16)
@@ -985,14 +986,16 @@ EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
 
     // lis r11, ha16(LazyPtr)
-    const MCExpr *LazyPtrHa16 = PPCMCExpr::CreateHa(LazyPtrExpr, OutContext);
+    const MCExpr *LazyPtrHa16 =
+      PPCMCExpr::CreateHa(LazyPtrExpr, isDarwin, OutContext);
     OutStreamer.EmitInstruction(MCInstBuilder(PPC::LIS)
       .addReg(PPC::R11)
       .addExpr(LazyPtrHa16));
 
     // ldu r12, lo16(LazyPtr)(r11)
     // lwzu r12, lo16(LazyPtr)(r11)
-    const MCExpr *LazyPtrLo16 = PPCMCExpr::CreateLo(LazyPtrExpr, OutContext);
+    const MCExpr *LazyPtrLo16 =
+      PPCMCExpr::CreateLo(LazyPtrExpr, isDarwin, OutContext);
     OutStreamer.EmitInstruction(MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
       .addReg(PPC::R12)
       .addExpr(LazyPtrLo16).addExpr(LazyPtrLo16)

lib/Target/PowerPC/PPCMCInstLower.cpp

@@ -105,7 +105,7 @@ static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO, AsmPrinter &AP){
 }
 
 static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
-                              AsmPrinter &Printer) {
+                              AsmPrinter &Printer, bool isDarwin) {
   MCContext &Ctx = Printer.OutContext;
   MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None;
 
@@ -150,10 +150,10 @@ static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
   // Add ha16() / lo16() markers if required.
   switch (access) {
     case PPCII::MO_LO:
-      Expr = PPCMCExpr::CreateLo(Expr, Ctx);
+      Expr = PPCMCExpr::CreateLo(Expr, isDarwin, Ctx);
       break;
     case PPCII::MO_HA:
-      Expr = PPCMCExpr::CreateHa(Expr, Ctx);
+      Expr = PPCMCExpr::CreateHa(Expr, isDarwin, Ctx);
       break;
   }
 
@@ -161,7 +161,7 @@ static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
 }
 
 void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
-                                        AsmPrinter &AP) {
+                                        AsmPrinter &AP, bool isDarwin) {
   OutMI.setOpcode(MI->getOpcode());
   
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
@@ -185,17 +185,17 @@ void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
       break;
     case MachineOperand::MO_GlobalAddress:
     case MachineOperand::MO_ExternalSymbol:
-      MCOp = GetSymbolRef(MO, GetSymbolFromOperand(MO, AP), AP);
+      MCOp = GetSymbolRef(MO, GetSymbolFromOperand(MO, AP), AP, isDarwin);
       break;
     case MachineOperand::MO_JumpTableIndex:
-      MCOp = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP);
+      MCOp = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP, isDarwin);
       break;
     case MachineOperand::MO_ConstantPoolIndex:
-      MCOp = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP);
+      MCOp = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP, isDarwin);
       break;
     case MachineOperand::MO_BlockAddress:
-      MCOp = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()),
+      MCOp = GetSymbolRef(MO,AP.GetBlockAddressSymbol(MO.getBlockAddress()),AP,
-                          AP);
+                          isDarwin);
       break;
     case MachineOperand::MO_RegisterMask:
       continue;

test/CodeGen/PowerPC/asm-dialect.ll

@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=powerpc-unknown-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc-apple-darwin | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64-apple-darwin | FileCheck %s
+
+; This test verifies that we choose "assembler variant 1" (which GCC
+; uses for "new-style mnemonics" as opposed to POWER mnemonics) when
+; processing multi-variant inline asm statements, on all subtargets.
+
+; CHECK: subfe
+; CHECK-NOT: sfe
+
+define i32 @test(i32 %in1, i32 %in2) {
+entry:
+  %0 = tail call i32 asm "$(sfe$|subfe$) $0,$1,$2", "=r,r,r"(i32 %in1, i32 %in2)
+  ret i32 %0
+}
+