[mips][rtdyld] Move MIPS relocation resolution to a subclass and implement N32 relocations

N32 relocations are only correct for individual relocations at the moment.
Support for relocation composition will follow in a later patch.

Patch By: Daniel Sanders

Reviwers: vkalintiris, atanasyan

Differential Revision: https://reviews.llvm.org/D27467

llvm-svn: 289532

lib/ExecutionEngine/RuntimeDyld/CMakeLists.txt

@@ -6,6 +6,7 @@ add_llvm_library(LLVMRuntimeDyld
   RuntimeDyldCOFF.cpp
   RuntimeDyldELF.cpp
   RuntimeDyldMachO.cpp
+  Targets/RuntimeDyldELFMips.cpp
 
   DEPENDS
   intrinsics_gen

lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -1023,10 +1023,11 @@ createRuntimeDyldCOFF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
 }
 
 static std::unique_ptr<RuntimeDyldELF>
-createRuntimeDyldELF(RuntimeDyld::MemoryManager &MM,
+createRuntimeDyldELF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
                      JITSymbolResolver &Resolver, bool ProcessAllSections,
                      RuntimeDyldCheckerImpl *Checker) {
-  std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM, Resolver));
+  std::unique_ptr<RuntimeDyldELF> Dyld =
+      RuntimeDyldELF::create(Arch, MM, Resolver);
   Dyld->setProcessAllSections(ProcessAllSections);
   Dyld->setRuntimeDyldChecker(Checker);
   return Dyld;
@@ -1048,7 +1049,9 @@ std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
 RuntimeDyld::loadObject(const ObjectFile &Obj) {
   if (!Dyld) {
     if (Obj.isELF())
-      Dyld = createRuntimeDyldELF(MemMgr, Resolver, ProcessAllSections, Checker);
+      Dyld =
+          createRuntimeDyldELF(static_cast<Triple::ArchType>(Obj.getArch()),
+                               MemMgr, Resolver, ProcessAllSections, Checker);
     else if (Obj.isMachO())
       Dyld = createRuntimeDyldMachO(
                static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,

lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp

@@ -13,6 +13,7 @@
 
 #include "RuntimeDyldELF.h"
 #include "RuntimeDyldCheckerImpl.h"
+#include "Targets/RuntimeDyldELFMips.h"
 #include "llvm/ADT/IntervalMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
@@ -211,6 +212,21 @@ void RuntimeDyldELF::deregisterEHFrames() {
   RegisteredEHFrameSections.clear();
 }
 
+std::unique_ptr<RuntimeDyldELF>
+llvm::RuntimeDyldELF::create(Triple::ArchType Arch,
+                             RuntimeDyld::MemoryManager &MemMgr,
+                             JITSymbolResolver &Resolver) {
+  switch (Arch) {
+  default:
+    return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
+  case Triple::mips:
+  case Triple::mipsel:
+  case Triple::mips64:
+  case Triple::mips64el:
+    return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
+  }
+}
+
 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
   if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
@@ -498,24 +514,6 @@ void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
   }
 }
 
-void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
-                                           uint64_t Offset, uint32_t Value,
-                                           uint32_t Type, int32_t Addend) {
-  uint8_t *TargetPtr = Section.getAddressWithOffset(Offset);
-  Value += Addend;
-
-  DEBUG(dbgs() << "resolveMIPSRelocation, LocalAddress: "
-               << Section.getAddressWithOffset(Offset) << " FinalAddress: "
-               << format("%p", Section.getLoadAddressWithOffset(Offset))
-               << " Value: " << format("%x", Value)
-               << " Type: " << format("%x", Type)
-               << " Addend: " << format("%x", Addend) << "\n");
-
-  Value = evaluateMIPS32Relocation(Section, Offset, Value, Type);
-
-  applyMIPSRelocation(TargetPtr, Value, Type);
-}
-
 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
   if (Arch == Triple::UnknownArch ||
       !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
@@ -531,254 +529,6 @@ void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
   IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
 }
 
-void RuntimeDyldELF::resolveMIPSN32Relocation(const SectionEntry &Section,
-                                              uint64_t Offset, uint64_t Value,
-                                              uint32_t Type, int64_t Addend,
-                                              uint64_t SymOffset,
-                                              SID SectionID) {
-  int64_t CalculatedValue = evaluateMIPS64Relocation(
-      Section, Offset, Value, Type, Addend, SymOffset, SectionID);
-  applyMIPSRelocation(Section.getAddressWithOffset(Offset), CalculatedValue,
-                      Type);
-}
-
-void RuntimeDyldELF::resolveMIPSN64Relocation(const SectionEntry &Section,
-                                              uint64_t Offset, uint64_t Value,
-                                              uint32_t Type, int64_t Addend,
-                                              uint64_t SymOffset,
-                                              SID SectionID) {
-  uint32_t r_type = Type & 0xff;
-  uint32_t r_type2 = (Type >> 8) & 0xff;
-  uint32_t r_type3 = (Type >> 16) & 0xff;
-
-  // RelType is used to keep information for which relocation type we are
-  // applying relocation.
-  uint32_t RelType = r_type;
-  int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
-                                                     RelType, Addend,
-                                                     SymOffset, SectionID);
-  if (r_type2 != ELF::R_MIPS_NONE) {
-    RelType = r_type2;
-    CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
-                                               CalculatedValue, SymOffset,
-                                               SectionID);
-  }
-  if (r_type3 != ELF::R_MIPS_NONE) {
-    RelType = r_type3;
-    CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
-                                               CalculatedValue, SymOffset,
-                                               SectionID);
-  }
-  applyMIPSRelocation(Section.getAddressWithOffset(Offset), CalculatedValue,
-                      RelType);
-}
-
-int64_t RuntimeDyldELF::evaluateMIPS32Relocation(const SectionEntry &Section,
-                                                 uint64_t Offset,
-                                                 uint64_t Value,
-                                                 uint32_t Type) {
-
-  DEBUG(dbgs() << "evaluateMIPS32Relocation, LocalAddress: 0x"
-               << format("%llx", Section.getAddressWithOffset(Offset))
-               << " FinalAddress: 0x"
-               << format("%llx", Section.getLoadAddressWithOffset(Offset))
-               << " Value: 0x" << format("%llx", Value) << " Type: 0x"
-               << format("%x", Type) << "\n");
-
-  switch (Type) {
-  default:
-    llvm_unreachable("Unknown relocation type!");
-    return Value;
-  case ELF::R_MIPS_32:
-    return Value;
-  case ELF::R_MIPS_26:
-    return Value >> 2;
-  case ELF::R_MIPS_HI16:
-    // Get the higher 16-bits. Also add 1 if bit 15 is 1.
-    return (Value + 0x8000) >> 16;
-  case ELF::R_MIPS_LO16:
-    return Value;
-  case ELF::R_MIPS_PC32: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return Value - FinalAddress;
-  }
-  case ELF::R_MIPS_PC16: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value - FinalAddress) >> 2;
-  }
-  case ELF::R_MIPS_PC19_S2: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value - (FinalAddress & ~0x3)) >> 2;
-  }
-  case ELF::R_MIPS_PC21_S2: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value - FinalAddress) >> 2;
-  }
-  case ELF::R_MIPS_PC26_S2: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value - FinalAddress) >> 2;
-  }
-  case ELF::R_MIPS_PCHI16: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value - FinalAddress + 0x8000) >> 16;
-  }
-  case ELF::R_MIPS_PCLO16: {
-    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return Value - FinalAddress;
-  }
-  }
-}
-
-int64_t
-RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
-                                         uint64_t Offset, uint64_t Value,
-                                         uint32_t Type, int64_t Addend,
-                                         uint64_t SymOffset, SID SectionID) {
-
-  DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
-               << format("%llx", Section.getAddressWithOffset(Offset))
-               << " FinalAddress: 0x"
-               << format("%llx", Section.getLoadAddressWithOffset(Offset))
-               << " Value: 0x" << format("%llx", Value) << " Type: 0x"
-               << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
-               << " SymOffset: " << format("%x", SymOffset) << "\n");
-
-  switch (Type) {
-  default:
-    llvm_unreachable("Not implemented relocation type!");
-    break;
-  case ELF::R_MIPS_JALR:
-  case ELF::R_MIPS_NONE:
-    break;
-  case ELF::R_MIPS_32:
-  case ELF::R_MIPS_64:
-    return Value + Addend;
-  case ELF::R_MIPS_26:
-    return ((Value + Addend) >> 2) & 0x3ffffff;
-  case ELF::R_MIPS_GPREL16: {
-    uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
-    return Value + Addend - (GOTAddr + 0x7ff0);
-  }
-  case ELF::R_MIPS_SUB:
-    return Value - Addend;
-  case ELF::R_MIPS_HI16:
-    // Get the higher 16-bits. Also add 1 if bit 15 is 1.
-    return ((Value + Addend + 0x8000) >> 16) & 0xffff;
-  case ELF::R_MIPS_LO16:
-    return (Value + Addend) & 0xffff;
-  case ELF::R_MIPS_CALL16:
-  case ELF::R_MIPS_GOT_DISP:
-  case ELF::R_MIPS_GOT_PAGE: {
-    uint8_t *LocalGOTAddr =
-        getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
-    uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, getGOTEntrySize());
-
-    Value += Addend;
-    if (Type == ELF::R_MIPS_GOT_PAGE)
-      Value = (Value + 0x8000) & ~0xffff;
-
-    if (GOTEntry)
-      assert(GOTEntry == Value &&
-                   "GOT entry has two different addresses.");
-    else
-      writeBytesUnaligned(Value, LocalGOTAddr, getGOTEntrySize());
-
-    return (SymOffset - 0x7ff0) & 0xffff;
-  }
-  case ELF::R_MIPS_GOT_OFST: {
-    int64_t page = (Value + Addend + 0x8000) & ~0xffff;
-    return (Value + Addend - page) & 0xffff;
-  }
-  case ELF::R_MIPS_GPREL32: {
-    uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
-    return Value + Addend - (GOTAddr + 0x7ff0);
-  }
-  case ELF::R_MIPS_PC16: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - FinalAddress) >> 2) & 0xffff;
-  }
-  case ELF::R_MIPS_PC32: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return Value + Addend - FinalAddress;
-  }
-  case ELF::R_MIPS_PC18_S3: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - (FinalAddress & ~0x7)) >> 3) & 0x3ffff;
-  }
-  case ELF::R_MIPS_PC19_S2: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - (FinalAddress & ~0x3)) >> 2) & 0x7ffff;
-  }
-  case ELF::R_MIPS_PC21_S2: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
-  }
-  case ELF::R_MIPS_PC26_S2: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
-  }
-  case ELF::R_MIPS_PCHI16: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
-  }
-  case ELF::R_MIPS_PCLO16: {
-    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
-    return (Value + Addend - FinalAddress) & 0xffff;
-  }
-  }
-  return 0;
-}
-
-void RuntimeDyldELF::applyMIPSRelocation(uint8_t *TargetPtr, int64_t Value,
-                                         uint32_t Type) {
-  uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
-
-  switch (Type) {
-  default:
-    llvm_unreachable("Unknown relocation type!");
-    break;
-  case ELF::R_MIPS_GPREL16:
-  case ELF::R_MIPS_HI16:
-  case ELF::R_MIPS_LO16:
-  case ELF::R_MIPS_PC16:
-  case ELF::R_MIPS_PCHI16:
-  case ELF::R_MIPS_PCLO16:
-  case ELF::R_MIPS_CALL16:
-  case ELF::R_MIPS_GOT_DISP:
-  case ELF::R_MIPS_GOT_PAGE:
-  case ELF::R_MIPS_GOT_OFST:
-    Insn = (Insn & 0xffff0000) | (Value & 0x0000ffff);
-    writeBytesUnaligned(Insn, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_PC18_S3:
-    Insn = (Insn & 0xfffc0000) | (Value & 0x0003ffff);
-    writeBytesUnaligned(Insn, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_PC19_S2:
-    Insn = (Insn & 0xfff80000) | (Value & 0x0007ffff);
-    writeBytesUnaligned(Insn, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_PC21_S2:
-    Insn = (Insn & 0xffe00000) | (Value & 0x001fffff);
-    writeBytesUnaligned(Insn, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_26:
-  case ELF::R_MIPS_PC26_S2:
-    Insn = (Insn & 0xfc000000) | (Value & 0x03ffffff);
-    writeBytesUnaligned(Insn, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_32:
-  case ELF::R_MIPS_GPREL32:
-  case ELF::R_MIPS_PC32:
-    writeBytesUnaligned(Value & 0xffffffff, TargetPtr, 4);
-    break;
-  case ELF::R_MIPS_64:
-  case ELF::R_MIPS_SUB:
-    writeBytesUnaligned(Value, TargetPtr, 8);
-    break;
-  }
-}
-
 // Return the .TOC. section and offset.
 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
                                           ObjSectionToIDMap &LocalSections,
@@ -1123,22 +873,6 @@ void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
     resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
                          (uint32_t)(Addend & 0xffffffffL));
     break;
-  case Triple::mips: // Fall through.
-  case Triple::mipsel:
-  case Triple::mips64:
-  case Triple::mips64el:
-    if (IsMipsO32ABI)
-      resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
-                            Type, (uint32_t)(Addend & 0xffffffffL));
-    else if (IsMipsN32ABI)
-      resolveMIPSN32Relocation(Section, Offset, Value, Type, Addend, SymOffset,
-                               SectionID);
-    else if (IsMipsN64ABI)
-      resolveMIPSN64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
-                               SectionID);
-    else
-      llvm_unreachable("Mips ABI not handled");
-    break;
   case Triple::ppc:
     resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
     break;

lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h

@@ -43,9 +43,6 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
   void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,
                             uint32_t Value, uint32_t Type, int32_t Addend);
 
-  void resolveMIPSRelocation(const SectionEntry &Section, uint64_t Offset,
-                             uint32_t Value, uint32_t Type, int32_t Addend);
-
   void resolvePPC32Relocation(const SectionEntry &Section, uint64_t Offset,
                               uint64_t Value, uint32_t Type, int64_t Addend);
 
@@ -55,23 +52,6 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
   void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,
                                 uint64_t Value, uint32_t Type, int64_t Addend);
 
-  void resolveMIPSN32Relocation(const SectionEntry &Section, uint64_t Offset,
-                                uint64_t Value, uint32_t Type, int64_t Addend,
-                                uint64_t SymOffset, SID SectionID);
-  void resolveMIPSN64Relocation(const SectionEntry &Section, uint64_t Offset,
-                                uint64_t Value, uint32_t Type, int64_t Addend,
-                                uint64_t SymOffset, SID SectionID);
-
-  int64_t evaluateMIPS32Relocation(const SectionEntry &Section, uint64_t Offset,
-                                   uint64_t Value, uint32_t Type);
-  int64_t evaluateMIPS64Relocation(const SectionEntry &Section,
-                                   uint64_t Offset, uint64_t Value,
-                                   uint32_t Type,  int64_t Addend,
-                                   uint64_t SymOffset, SID SectionID);
-
-  void applyMIPSRelocation(uint8_t *TargetPtr, int64_t CalculatedValue,
-                           uint32_t Type);
-
   unsigned getMaxStubSize() override {
     if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be)
       return 20; // movz; movk; movk; movk; br
@@ -104,9 +84,10 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
   Error findOPDEntrySection(const ELFObjectFileBase &Obj,
                             ObjSectionToIDMap &LocalSections,
                             RelocationValueRef &Rel);
-
+protected:
   size_t getGOTEntrySize();
 
+private:
   SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
 
   // Allocate no GOT entries for use in the given section.
@@ -143,10 +124,12 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
   // that consume more than one slot)
   unsigned CurrentGOTIndex;
 
+protected:
   // A map from section to a GOT section that has entries for section's GOT
   // relocations. (Mips64 specific)
   DenseMap<SID, SID> SectionToGOTMap;
 
+private:
   // A map to avoid duplicate got entries (Mips64 specific)
   StringMap<uint64_t> GOTSymbolOffsets;
 
@@ -167,6 +150,10 @@ public:
                  JITSymbolResolver &Resolver);
   ~RuntimeDyldELF() override;
 
+  static std::unique_ptr<RuntimeDyldELF>
+  create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr,
+         JITSymbolResolver &Resolver);
+
   std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
   loadObject(const object::ObjectFile &O) override;
 

lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldELFMips.cpp

@@ -0,0 +1,312 @@
+//===-- RuntimeDyldELFMips.cpp ---- ELF/Mips specific code. -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RuntimeDyldELFMips.h"
+#include "llvm/Support/ELF.h"
+
+#define DEBUG_TYPE "dyld"
+
+void RuntimeDyldELFMips::resolveRelocation(const RelocationEntry &RE,
+                                           uint64_t Value) {
+  const SectionEntry &Section = Sections[RE.SectionID];
+  if (IsMipsO32ABI)
+    resolveMIPSO32Relocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
+  else if (IsMipsN32ABI) {
+    resolveMIPSN32Relocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
+                             RE.SymOffset, RE.SectionID);
+  } else if (IsMipsN64ABI)
+    resolveMIPSN64Relocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
+                             RE.SymOffset, RE.SectionID);
+  else
+    llvm_unreachable("Mips ABI not handled");
+}
+
+uint64_t RuntimeDyldELFMips::evaluateRelocation(const RelocationEntry &RE,
+                                                uint64_t Value,
+                                                uint64_t Addend) {
+  if (IsMipsN32ABI) {
+    const SectionEntry &Section = Sections[RE.SectionID];
+    Value = evaluateMIPS64Relocation(Section, RE.Offset, Value, RE.RelType,
+                                     Addend, RE.SymOffset, RE.SectionID);
+    return Value;
+  }
+  llvm_unreachable("Not reachable");
+}
+
+void RuntimeDyldELFMips::applyRelocation(const RelocationEntry &RE,
+                                         uint64_t Value) {
+  if (IsMipsN32ABI) {
+    const SectionEntry &Section = Sections[RE.SectionID];
+    applyMIPSRelocation(Section.getAddressWithOffset(RE.Offset), Value,
+                        RE.RelType);
+    return;
+  }
+  llvm_unreachable("Not reachable");
+}
+
+int64_t
+RuntimeDyldELFMips::evaluateMIPS32Relocation(const SectionEntry &Section,
+                                             uint64_t Offset, uint64_t Value,
+                                             uint32_t Type) {
+
+  DEBUG(dbgs() << "evaluateMIPS32Relocation, LocalAddress: 0x"
+               << format("%llx", Section.getAddressWithOffset(Offset))
+               << " FinalAddress: 0x"
+               << format("%llx", Section.getLoadAddressWithOffset(Offset))
+               << " Value: 0x" << format("%llx", Value) << " Type: 0x"
+               << format("%x", Type) << "\n");
+
+  switch (Type) {
+  default:
+    llvm_unreachable("Unknown relocation type!");
+    return Value;
+  case ELF::R_MIPS_32:
+    return Value;
+  case ELF::R_MIPS_26:
+    return Value >> 2;
+  case ELF::R_MIPS_HI16:
+    // Get the higher 16-bits. Also add 1 if bit 15 is 1.
+    return (Value + 0x8000) >> 16;
+  case ELF::R_MIPS_LO16:
+    return Value;
+  case ELF::R_MIPS_PC32: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return Value - FinalAddress;
+  }
+  case ELF::R_MIPS_PC16: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value - FinalAddress) >> 2;
+  }
+  case ELF::R_MIPS_PC19_S2: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value - (FinalAddress & ~0x3)) >> 2;
+  }
+  case ELF::R_MIPS_PC21_S2: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value - FinalAddress) >> 2;
+  }
+  case ELF::R_MIPS_PC26_S2: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value - FinalAddress) >> 2;
+  }
+  case ELF::R_MIPS_PCHI16: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value - FinalAddress + 0x8000) >> 16;
+  }
+  case ELF::R_MIPS_PCLO16: {
+    uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return Value - FinalAddress;
+  }
+  }
+}
+
+int64_t RuntimeDyldELFMips::evaluateMIPS64Relocation(
+    const SectionEntry &Section, uint64_t Offset, uint64_t Value, uint32_t Type,
+    int64_t Addend, uint64_t SymOffset, SID SectionID) {
+
+  DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
+               << format("%llx", Section.getAddressWithOffset(Offset))
+               << " FinalAddress: 0x"
+               << format("%llx", Section.getLoadAddressWithOffset(Offset))
+               << " Value: 0x" << format("%llx", Value) << " Type: 0x"
+               << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
+               << " SymOffset: " << format("%x", SymOffset) << "\n");
+
+  switch (Type) {
+  default:
+    llvm_unreachable("Not implemented relocation type!");
+    break;
+  case ELF::R_MIPS_JALR:
+  case ELF::R_MIPS_NONE:
+    break;
+  case ELF::R_MIPS_32:
+  case ELF::R_MIPS_64:
+    return Value + Addend;
+  case ELF::R_MIPS_26:
+    return ((Value + Addend) >> 2) & 0x3ffffff;
+  case ELF::R_MIPS_GPREL16: {
+    uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
+    return Value + Addend - (GOTAddr + 0x7ff0);
+  }
+  case ELF::R_MIPS_SUB:
+    return Value - Addend;
+  case ELF::R_MIPS_HI16:
+    // Get the higher 16-bits. Also add 1 if bit 15 is 1.
+    return ((Value + Addend + 0x8000) >> 16) & 0xffff;
+  case ELF::R_MIPS_LO16:
+    return (Value + Addend) & 0xffff;
+  case ELF::R_MIPS_CALL16:
+  case ELF::R_MIPS_GOT_DISP:
+  case ELF::R_MIPS_GOT_PAGE: {
+    uint8_t *LocalGOTAddr =
+        getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
+    uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, getGOTEntrySize());
+
+    Value += Addend;
+    if (Type == ELF::R_MIPS_GOT_PAGE)
+      Value = (Value + 0x8000) & ~0xffff;
+
+    if (GOTEntry)
+      assert(GOTEntry == Value &&
+                   "GOT entry has two different addresses.");
+    else
+      writeBytesUnaligned(Value, LocalGOTAddr, getGOTEntrySize());
+
+    return (SymOffset - 0x7ff0) & 0xffff;
+  }
+  case ELF::R_MIPS_GOT_OFST: {
+    int64_t page = (Value + Addend + 0x8000) & ~0xffff;
+    return (Value + Addend - page) & 0xffff;
+  }
+  case ELF::R_MIPS_GPREL32: {
+    uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
+    return Value + Addend - (GOTAddr + 0x7ff0);
+  }
+  case ELF::R_MIPS_PC16: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - FinalAddress) >> 2) & 0xffff;
+  }
+  case ELF::R_MIPS_PC32: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return Value + Addend - FinalAddress;
+  }
+  case ELF::R_MIPS_PC18_S3: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - (FinalAddress & ~0x7)) >> 3) & 0x3ffff;
+  }
+  case ELF::R_MIPS_PC19_S2: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - (FinalAddress & ~0x3)) >> 2) & 0x7ffff;
+  }
+  case ELF::R_MIPS_PC21_S2: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
+  }
+  case ELF::R_MIPS_PC26_S2: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
+  }
+  case ELF::R_MIPS_PCHI16: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
+  }
+  case ELF::R_MIPS_PCLO16: {
+    uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
+    return (Value + Addend - FinalAddress) & 0xffff;
+  }
+  }
+  return 0;
+}
+
+void RuntimeDyldELFMips::applyMIPSRelocation(uint8_t *TargetPtr, int64_t Value,
+                                             uint32_t Type) {
+  uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
+
+  switch (Type) {
+  default:
+    llvm_unreachable("Unknown relocation type!");
+    break;
+  case ELF::R_MIPS_GPREL16:
+  case ELF::R_MIPS_HI16:
+  case ELF::R_MIPS_LO16:
+  case ELF::R_MIPS_PC16:
+  case ELF::R_MIPS_PCHI16:
+  case ELF::R_MIPS_PCLO16:
+  case ELF::R_MIPS_CALL16:
+  case ELF::R_MIPS_GOT_DISP:
+  case ELF::R_MIPS_GOT_PAGE:
+  case ELF::R_MIPS_GOT_OFST:
+    Insn = (Insn & 0xffff0000) | (Value & 0x0000ffff);
+    writeBytesUnaligned(Insn, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_PC18_S3:
+    Insn = (Insn & 0xfffc0000) | (Value & 0x0003ffff);
+    writeBytesUnaligned(Insn, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_PC19_S2:
+    Insn = (Insn & 0xfff80000) | (Value & 0x0007ffff);
+    writeBytesUnaligned(Insn, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_PC21_S2:
+    Insn = (Insn & 0xffe00000) | (Value & 0x001fffff);
+    writeBytesUnaligned(Insn, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_26:
+  case ELF::R_MIPS_PC26_S2:
+    Insn = (Insn & 0xfc000000) | (Value & 0x03ffffff);
+    writeBytesUnaligned(Insn, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_32:
+  case ELF::R_MIPS_GPREL32:
+  case ELF::R_MIPS_PC32:
+    writeBytesUnaligned(Value & 0xffffffff, TargetPtr, 4);
+    break;
+  case ELF::R_MIPS_64:
+  case ELF::R_MIPS_SUB:
+    writeBytesUnaligned(Value, TargetPtr, 8);
+    break;
+  }
+}
+
+void RuntimeDyldELFMips::resolveMIPSN32Relocation(
+    const SectionEntry &Section, uint64_t Offset, uint64_t Value, uint32_t Type,
+    int64_t Addend, uint64_t SymOffset, SID SectionID) {
+  int64_t CalculatedValue = evaluateMIPS64Relocation(
+      Section, Offset, Value, Type, Addend, SymOffset, SectionID);
+  applyMIPSRelocation(Section.getAddressWithOffset(Offset), CalculatedValue,
+                      Type);
+}
+
+void RuntimeDyldELFMips::resolveMIPSN64Relocation(
+    const SectionEntry &Section, uint64_t Offset, uint64_t Value, uint32_t Type,
+    int64_t Addend, uint64_t SymOffset, SID SectionID) {
+  uint32_t r_type = Type & 0xff;
+  uint32_t r_type2 = (Type >> 8) & 0xff;
+  uint32_t r_type3 = (Type >> 16) & 0xff;
+
+  // RelType is used to keep information for which relocation type we are
+  // applying relocation.
+  uint32_t RelType = r_type;
+  int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
+                                                     RelType, Addend,
+                                                     SymOffset, SectionID);
+  if (r_type2 != ELF::R_MIPS_NONE) {
+    RelType = r_type2;
+    CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
+                                               CalculatedValue, SymOffset,
+                                               SectionID);
+  }
+  if (r_type3 != ELF::R_MIPS_NONE) {
+    RelType = r_type3;
+    CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
+                                               CalculatedValue, SymOffset,
+                                               SectionID);
+  }
+  applyMIPSRelocation(Section.getAddressWithOffset(Offset), CalculatedValue,
+                      RelType);
+}
+
+void RuntimeDyldELFMips::resolveMIPSO32Relocation(const SectionEntry &Section,
+                                                  uint64_t Offset,
+                                                  uint32_t Value, uint32_t Type,
+                                                  int32_t Addend) {
+  uint8_t *TargetPtr = Section.getAddressWithOffset(Offset);
+  Value += Addend;
+
+  DEBUG(dbgs() << "resolveMIPSO32Relocation, LocalAddress: "
+               << Section.getAddressWithOffset(Offset) << " FinalAddress: "
+               << format("%p", Section.getLoadAddressWithOffset(Offset))
+               << " Value: " << format("%x", Value)
+               << " Type: " << format("%x", Type)
+               << " Addend: " << format("%x", Addend) << "\n");
+
+  Value = evaluateMIPS32Relocation(Section, Offset, Value, Type);
+
+  applyMIPSRelocation(TargetPtr, Value, Type);
+}

lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldELFMips.h

@@ -0,0 +1,68 @@
+//===-- RuntimeDyldELFMips.h ---- ELF/Mips specific code. -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDELFMIPS_H
+#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDELFMIPS_H
+
+#include "../RuntimeDyldELF.h"
+#include <string>
+
+#define DEBUG_TYPE "dyld"
+
+namespace llvm {
+
+class RuntimeDyldELFMips : public RuntimeDyldELF {
+public:
+
+  typedef uint64_t TargetPtrT;
+
+  RuntimeDyldELFMips(RuntimeDyld::MemoryManager &MM,
+                     JITSymbolResolver &Resolver)
+      : RuntimeDyldELF(MM, Resolver) {}
+
+  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
+
+protected:
+  void resolveMIPSO32Relocation(const SectionEntry &Section, uint64_t Offset,
+                                uint32_t Value, uint32_t Type, int32_t Addend);
+  void resolveMIPSN32Relocation(const SectionEntry &Section, uint64_t Offset,
+                                uint64_t Value, uint32_t Type, int64_t Addend,
+                                uint64_t SymOffset, SID SectionID);
+  void resolveMIPSN64Relocation(const SectionEntry &Section, uint64_t Offset,
+                                uint64_t Value, uint32_t Type, int64_t Addend,
+                                uint64_t SymOffset, SID SectionID);
+
+private:
+  /// \brief A object file specific relocation resolver
+  /// \param RE The relocation to be resolved
+  /// \param Value Target symbol address to apply the relocation action
+  uint64_t evaluateRelocation(const RelocationEntry &RE, uint64_t Value,
+                              uint64_t Addend);
+
+  /// \brief A object file specific relocation resolver
+  /// \param RE The relocation to be resolved
+  /// \param Value Target symbol address to apply the relocation action
+  void applyRelocation(const RelocationEntry &RE, uint64_t Value);
+
+  int64_t evaluateMIPS32Relocation(const SectionEntry &Section, uint64_t Offset,
+                                   uint64_t Value, uint32_t Type);
+  int64_t evaluateMIPS64Relocation(const SectionEntry &Section,
+                                   uint64_t Offset, uint64_t Value,
+                                   uint32_t Type,  int64_t Addend,
+                                   uint64_t SymOffset, SID SectionID);
+
+  void applyMIPSRelocation(uint8_t *TargetPtr, int64_t CalculatedValue,
+                           uint32_t Type);
+
+};
+}
+
+#undef DEBUG_TYPE
+
+#endif