Reapply 132424 with fixes. This fixes PR10068.

[oota-llvm.git] / lib / Target / X86 / X86AsmBackend.cpp

diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp
index 3c1c4592dcbcadb5786ad6247cd1ce005def139e..4d7d96dcb36bd9150ceae86304626bab8a6bd936 100644 (file)
--- a/lib/Target/X86/X86AsmBackend.cpp
+++ b/lib/Target/X86/X86AsmBackend.cpp
@@ -12,15 +12,16 @@
 #include "X86FixupKinds.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCELFObjectWriter.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/MC/MCMachObjectWriter.h"
-#include "llvm/MC/MCObjectFormat.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/Object/MachOFormat.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
@@ -28,6 +29,13 @@
 #include "llvm/Target/TargetAsmBackend.h"
 using namespace llvm;
 
+// Option to allow disabling arithmetic relaxation to workaround PR9807, which
+// is useful when running bitwise comparison experiments on Darwin. We should be
+// able to remove this once PR9807 is resolved.
+static cl::opt<bool>
+MCDisableArithRelaxation("mc-x86-disable-arith-relaxation",
+         cl::desc("Disable relaxation of arithmetic instruction for X86"));
+
 static unsigned getFixupKindLog2Size(unsigned Kind) {
   switch (Kind) {
   default: assert(0 && "invalid fixup kind!");
@@ -41,12 +49,18 @@ static unsigned getFixupKindLog2Size(unsigned Kind) {
   case X86::reloc_signed_4byte:
   case X86::reloc_global_offset_table:
   case FK_Data_4: return 2;
+  case FK_PCRel_8:
   case FK_Data_8: return 3;
   }
 }
 
 namespace {
-class X86MachObjectWriter : public MCMachObjectTargetWriter {
+
+class X86ELFObjectWriter : public MCELFObjectTargetWriter {
+public:
+  X86ELFObjectWriter(bool is64Bit, Triple::OSType OSType, uint16_t EMachine,
+                     bool HasRelocationAddend)
+    : MCELFObjectTargetWriter(is64Bit, OSType, EMachine, HasRelocationAddend) {}
 };
 
 class X86AsmBackend : public TargetAsmBackend {
@@ -177,6 +191,9 @@ static unsigned getRelaxedOpcodeArith(unsigned Op) {
   case X86::CMP32mi8: return X86::CMP32mi;
   case X86::CMP64ri8: return X86::CMP64ri32;
   case X86::CMP64mi8: return X86::CMP64mi32;
+
+    // PUSH
+  case X86::PUSHi8: return X86::PUSHi32;
   }
 }
 
@@ -192,6 +209,9 @@ bool X86AsmBackend::MayNeedRelaxation(const MCInst &Inst) const {
   if (getRelaxedOpcodeBranch(Inst.getOpcode()) != Inst.getOpcode())
     return true;
 
+  if (MCDisableArithRelaxation)
+    return false;
+
   // Check if this instruction is ever relaxable.
   if (getRelaxedOpcodeArith(Inst.getOpcode()) == Inst.getOpcode())
     return false;
@@ -279,23 +299,16 @@ bool X86AsmBackend::WriteNopData(uint64_t Count, MCObjectWriter *OW) const {
 
 namespace {
 class ELFX86AsmBackend : public X86AsmBackend {
-  MCELFObjectFormat Format;
-
 public:
   Triple::OSType OSType;
   ELFX86AsmBackend(const Target &T, Triple::OSType _OSType)
     : X86AsmBackend(T), OSType(_OSType) {
-    HasScatteredSymbols = true;
     HasReliableSymbolDifference = true;
   }
 
-  virtual const MCObjectFormat &getObjectFormat() const {
-    return Format;
-  }
-
   virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
     const MCSectionELF &ES = static_cast<const MCSectionELF&>(Section);
-    return ES.getFlags() & MCSectionELF::SHF_MERGE;
+    return ES.getFlags() & ELF::SHF_MERGE;
   }
 };
 
@@ -305,10 +318,12 @@ public:
     : ELFX86AsmBackend(T, OSType) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createELFObjectWriter(OS, /*Is64Bit=*/false,
-                                 OSType, ELF::EM_386,
-                                 /*IsLittleEndian=*/true,
-                                 /*HasRelocationAddend=*/false);
+    return createELFObjectWriter(createELFObjectTargetWriter(),
+                                 OS, /*IsLittleEndian*/ true);
+  }
+
+  MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
+    return new X86ELFObjectWriter(false, OSType, ELF::EM_386, false);
   }
 };
 
@@ -318,26 +333,22 @@ public:
     : ELFX86AsmBackend(T, OSType) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createELFObjectWriter(OS, /*Is64Bit=*/true,
-                                 OSType, ELF::EM_X86_64,
-                                 /*IsLittleEndian=*/true,
-                                 /*HasRelocationAddend=*/true);
+    return createELFObjectWriter(createELFObjectTargetWriter(),
+                                 OS, /*IsLittleEndian*/ true);
+  }
+
+  MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
+    return new X86ELFObjectWriter(true, OSType, ELF::EM_X86_64, true);
   }
 };
 
 class WindowsX86AsmBackend : public X86AsmBackend {
   bool Is64Bit;
-  MCCOFFObjectFormat Format;
 
 public:
   WindowsX86AsmBackend(const Target &T, bool is64Bit)
     : X86AsmBackend(T)
     , Is64Bit(is64Bit) {
-    HasScatteredSymbols = true;
-  }
-
-  virtual const MCObjectFormat &getObjectFormat() const {
-    return Format;
   }
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
@@ -346,17 +357,9 @@ public:
 };
 
 class DarwinX86AsmBackend : public X86AsmBackend {
-  MCMachOObjectFormat Format;
-
 public:
   DarwinX86AsmBackend(const Target &T)
-    : X86AsmBackend(T) {
-    HasScatteredSymbols = true;
-  }
-
-  virtual const MCObjectFormat &getObjectFormat() const {
-    return Format;
-  }
+    : X86AsmBackend(T) { }
 };
 
 class DarwinX86_32AsmBackend : public DarwinX86AsmBackend {
@@ -365,11 +368,9 @@ public:
     : DarwinX86AsmBackend(T) {}
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createMachObjectWriter(new X86MachObjectWriter,
-                                  OS, /*Is64Bit=*/false,
-                                  object::mach::CTM_i386,
-                                  object::mach::CSX86_ALL,
-                                  /*IsLittleEndian=*/true);
+    return createX86MachObjectWriter(OS, /*Is64Bit=*/false,
+                                     object::mach::CTM_i386,
+                                     object::mach::CSX86_ALL);
   }
 };
 
@@ -381,11 +382,9 @@ public:
   }
 
   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
-    return createMachObjectWriter(new X86MachObjectWriter,
-                                  OS, /*Is64Bit=*/true,
-                                  object::mach::CTM_x86_64,
-                                  object::mach::CSX86_ALL,
-                                  /*IsLittleEndian=*/true);
+    return createX86MachObjectWriter(OS, /*Is64Bit=*/true,
+                                     object::mach::CTM_x86_64,
+                                     object::mach::CSX86_ALL);
   }
 
   virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
@@ -426,28 +425,26 @@ public:
 
 TargetAsmBackend *llvm::createX86_32AsmBackend(const Target &T,
                                                const std::string &TT) {
-  switch (Triple(TT).getOS()) {
-  case Triple::Darwin:
+  Triple TheTriple(TT);
+
+  if (TheTriple.isOSDarwin() || TheTriple.getEnvironment() == Triple::MachO)
     return new DarwinX86_32AsmBackend(T);
-  case Triple::MinGW32:
-  case Triple::Cygwin:
-  case Triple::Win32:
+
+  if (TheTriple.isOSWindows())
     return new WindowsX86AsmBackend(T, false);
-  default:
-    return new ELFX86_32AsmBackend(T, Triple(TT).getOS());
-  }
+
+  return new ELFX86_32AsmBackend(T, TheTriple.getOS());
 }
 
 TargetAsmBackend *llvm::createX86_64AsmBackend(const Target &T,
                                                const std::string &TT) {
-  switch (Triple(TT).getOS()) {
-  case Triple::Darwin:
+  Triple TheTriple(TT);
+
+  if (TheTriple.isOSDarwin() || TheTriple.getEnvironment() == Triple::MachO)
     return new DarwinX86_64AsmBackend(T);
-  case Triple::MinGW64:
-  case Triple::Cygwin:
-  case Triple::Win32:
+
+  if (TheTriple.isOSWindows())
     return new WindowsX86AsmBackend(T, true);
-  default:
-    return new ELFX86_64AsmBackend(T, Triple(TT).getOS());
-  }
+
+  return new ELFX86_64AsmBackend(T, TheTriple.getOS());
 }