Only emit EM_SPARC32PLUS objects on explicit request

llvm/include/llvm/BinaryFormat/ELF.h

@@ -697,6 +697,19 @@ enum {
 #include "ELFRelocs/SystemZ.def"
 };
 
+// SPARC Specific e_flags
+enum : unsigned {
+  EF_SPARC_EXT_MASK = 0xffff00,
+  EF_SPARC_32PLUS = 0x000100,
+  EF_SPARC_SUN_US1 = 0x000200,
+  EF_SPARC_HAL_R1 = 0x000400,
+  EF_SPARC_SUN_US3 = 0x000800,
+  EF_SPARCV9_MM = 0x3,
+  EF_SPARCV9_TSO = 0x0,
+  EF_SPARCV9_PSO = 0x1,
+  EF_SPARCV9_RMO = 0x2,
+};
+
 // ELF Relocation type for Sparc.
 enum {
 #include "ELFRelocs/Sparc.def"

llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp

@@ -133,16 +133,14 @@ namespace {
   protected:
     bool Is64Bit;
     bool IsV8Plus;
-    bool HasV9;
 
   public:
     SparcAsmBackend(const MCSubtargetInfo &STI)
         : MCAsmBackend(STI.getTargetTriple().isLittleEndian()
                            ? llvm::endianness::little
                            : llvm::endianness::big),
           Is64Bit(STI.getTargetTriple().isArch64Bit()),
-          IsV8Plus(STI.hasFeature(Sparc::FeatureV8Plus)),
-          HasV9(STI.hasFeature(Sparc::FeatureV9)) {}
+          IsV8Plus(STI.hasFeature(Sparc::FeatureV8Plus)) {}
 
     unsigned getNumFixupKinds() const override {
       return Sparc::NumTargetFixupKinds;
@@ -361,7 +359,7 @@ namespace {
     std::unique_ptr<MCObjectTargetWriter>
     createObjectTargetWriter() const override {
       uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(OSType);
-      return createSparcELFObjectWriter(Is64Bit, IsV8Plus, HasV9, OSABI);
+      return createSparcELFObjectWriter(Is64Bit, IsV8Plus, OSABI);
     }
   };
 

llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp

@@ -21,16 +21,11 @@ using namespace llvm;
 namespace {
   class SparcELFObjectWriter : public MCELFObjectTargetWriter {
   public:
-    SparcELFObjectWriter(bool Is64Bit, bool IsV8Plus, bool HasV9, uint8_t OSABI)
+    SparcELFObjectWriter(bool Is64Bit, bool IsV8Plus, uint8_t OSABI)
         : MCELFObjectTargetWriter(
               Is64Bit, OSABI,
-              Is64Bit
-                  ? ELF::EM_SPARCV9
-                  // Note that we still need to emit an EM_SPARC32PLUS object
-                  // even when V8+ isn't explicitly requested, if we're
-                  // targeting a V9-capable CPU. This matches GAS behavior upon
-                  // encountering any V9 instructions in its input.
-                  : ((IsV8Plus || HasV9) ? ELF::EM_SPARC32PLUS : ELF::EM_SPARC),
+              Is64Bit ? ELF::EM_SPARCV9
+                      : (IsV8Plus ? ELF::EM_SPARC32PLUS : ELF::EM_SPARC),
               /*HasRelocationAddend*/ true) {}
 
     ~SparcELFObjectWriter() override = default;
@@ -153,8 +148,6 @@ bool SparcELFObjectWriter::needsRelocateWithSymbol(const MCValue &,
 }
 
 std::unique_ptr<MCObjectTargetWriter>
-llvm::createSparcELFObjectWriter(bool Is64Bit, bool IsV8Plus, bool HasV9,
-                                 uint8_t OSABI) {
-  return std::make_unique<SparcELFObjectWriter>(Is64Bit, IsV8Plus, HasV9,
-                                                OSABI);
+llvm::createSparcELFObjectWriter(bool Is64Bit, bool IsV8Plus, uint8_t OSABI) {
+  return std::make_unique<SparcELFObjectWriter>(Is64Bit, IsV8Plus, OSABI);
 }

llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp

@@ -86,7 +86,7 @@ createSparcMCSubtargetInfo(const Triple &TT, StringRef CPU, StringRef FS) {
 
 static MCTargetStreamer *
 createObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
-  return new SparcTargetELFStreamer(S);
+  return new SparcTargetELFStreamer(S, STI);
 }
 
 static MCTargetStreamer *createTargetAsmStreamer(MCStreamer &S,

llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.h

@@ -34,10 +34,8 @@ MCCodeEmitter *createSparcMCCodeEmitter(const MCInstrInfo &MCII,
 MCAsmBackend *createSparcAsmBackend(const Target &T, const MCSubtargetInfo &STI,
                                     const MCRegisterInfo &MRI,
                                     const MCTargetOptions &Options);
-std::unique_ptr<MCObjectTargetWriter> createSparcELFObjectWriter(bool Is64Bit,
-                                                                 bool IsV8Plus,
-                                                                 bool HasV9,
-                                                                 uint8_t OSABI);
+std::unique_ptr<MCObjectTargetWriter>
+createSparcELFObjectWriter(bool Is64Bit, bool IsV8Plus, uint8_t OSABI);
 
 // Defines symbolic names for Sparc v9 ASI tag names.
 namespace SparcASITag {

llvm/lib/Target/Sparc/MCTargetDesc/SparcTargetStreamer.cpp

@@ -12,11 +12,24 @@
 
 #include "SparcTargetStreamer.h"
 #include "SparcInstPrinter.h"
+#include "SparcMCTargetDesc.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCRegister.h"
+#include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/FormattedStream.h"
 
 using namespace llvm;
 
+static unsigned getEFlagsForFeatureSet(const MCSubtargetInfo &STI) {
+  unsigned EFlags = 0;
+
+  if (STI.hasFeature(Sparc::FeatureV8Plus))
+    EFlags |= ELF::EF_SPARC_32PLUS;
+
+  return EFlags;
+}
+
 // pin vtable to this file
 SparcTargetStreamer::SparcTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {}
 
@@ -38,8 +51,16 @@ void SparcTargetAsmStreamer::emitSparcRegisterScratch(unsigned reg) {
      << ", #scratch\n";
 }
 
-SparcTargetELFStreamer::SparcTargetELFStreamer(MCStreamer &S)
-    : SparcTargetStreamer(S) {}
+SparcTargetELFStreamer::SparcTargetELFStreamer(MCStreamer &S,
+                                               const MCSubtargetInfo &STI)
+    : SparcTargetStreamer(S) {
+  MCAssembler &MCA = getStreamer().getAssembler();
+  unsigned EFlags = MCA.getELFHeaderEFlags();
+
+  EFlags |= getEFlagsForFeatureSet(STI);
+
+  MCA.setELFHeaderEFlags(EFlags);
+}
 
 MCELFStreamer &SparcTargetELFStreamer::getStreamer() {
   return static_cast<MCELFStreamer &>(Streamer);

llvm/lib/Target/Sparc/MCTargetDesc/SparcTargetStreamer.h

@@ -40,7 +40,7 @@ class SparcTargetAsmStreamer : public SparcTargetStreamer {
 // This part is for ELF object output
 class SparcTargetELFStreamer : public SparcTargetStreamer {
 public:
-  SparcTargetELFStreamer(MCStreamer &S);
+  SparcTargetELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
   MCELFStreamer &getStreamer();
   void emitSparcRegisterIgnore(unsigned reg) override {}
   void emitSparcRegisterScratch(unsigned reg) override {}

llvm/test/MC/Sparc/elf-sparc-machine-type.s

@@ -1,10 +1,9 @@
 ## Emit correct machine type depending on triple and cpu options.
 ## - `-triple sparc` emits an object of type EM_SPARC;
-## - `-triple sparc -mcpu=v9` or `-triple sparc -mattr=+v8plus` emits EM_SPARC32PLUS; and
+## - `-triple sparc -mattr=+v8plus` emits EM_SPARC32PLUS; and
 ## - `-triple sparcv9` emits EM_SPARCV9.
 
 # RUN: llvm-mc -filetype=obj -triple sparc                  %s -o - | llvm-readobj -h - | FileCheck --check-prefixes=SPARC       %s
-# RUN: llvm-mc -filetype=obj -triple sparc         -mcpu=v9 %s -o - | llvm-readobj -h - | FileCheck --check-prefixes=SPARC32PLUS %s
 # RUN: llvm-mc -filetype=obj -triple sparc   -mattr=+v8plus %s -o - | llvm-readobj -h - | FileCheck --check-prefixes=SPARC32PLUS %s
 # RUN: llvm-mc -filetype=obj -triple sparcv9                %s -o - | llvm-readobj -h - | FileCheck --check-prefixes=SPARCV9     %s