[MCJIT] Simplify immediate decoding code in the RuntimeDyldMachO hierarchy.

Cleanup only: no functional change.

This patch makes RuntimeDyldMachO targets directly responsible for decoding
immediates, rather than letting them implement catch a callback from generic
code. Since this is a very target specific operation, it makes sense to let the
target-specific code drive it.

llvm-svn: 215255

6 files changed, 49 insertions, 44 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index bae2471054d..986daef8a90 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -27,8 +27,10 @@ using namespace llvm::object;
 
 namespace llvm {
 
-int64_t RuntimeDyldMachO::decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
-                                       MachO::RelocationInfoType) const {
+int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {
+  const SectionEntry &Section = Sections[RE.SectionID];
+  uint8_t *LocalAddress = Section.Address + RE.Offset;
+  unsigned NumBytes = 1 << RE.Size;
   int64_t Addend = 0;
   memcpy(&Addend, LocalAddress, NumBytes);
   return Addend;
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
index 30f61e98e32..b18d167fab4 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
@@ -52,9 +52,31 @@ protected:
 
   RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
 
-  /// Extract the addend encoded in the instruction.
-  int64_t decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
-                       MachO::RelocationInfoType RelType) const;
+  /// This convenience method uses memcpy to extract a contiguous addend (the
+  /// addend size and offset are taken from the corresponding fields of the RE).
+  int64_t memcpyAddend(const RelocationEntry &RE) const;
+
+  /// Given a relocation_iterator for a non-scattered relocation, construct a
+  /// RelocationEntry and fill in the common fields. The 'Addend' field is *not*
+  /// filled in, since immediate encodings are highly target/opcode specific.
+  /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the
+  /// memcpyAddend method can be used to read the immediate.
+  RelocationEntry getRelocationEntry(unsigned SectionID, ObjectImage &ObjImg,
+                                     const relocation_iterator &RI) const {
+    const MachOObjectFile &Obj =
+      static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
+    MachO::any_relocation_info RelInfo =
+      Obj.getRelocation(RI->getRawDataRefImpl());
+
+    bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
+    unsigned Size = Obj.getAnyRelocationLength(RelInfo);
+    uint64_t Offset;
+    RI->getOffset(Offset);
+    MachO::RelocationInfoType RelType =
+      static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo));
+
+    return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size);
+  }
 
   /// Construct a RelocationValueRef representing the relocation target.
   /// For Symbols in known sections, this will return a RelocationValueRef
@@ -119,33 +141,6 @@ private:
   Impl &impl() { return static_cast<Impl &>(*this); }
   const Impl &impl() const { return static_cast<const Impl &>(*this); }
 
-protected:
-
-  /// Parse the given relocation, which must be a non-scattered, and
-  /// return a RelocationEntry representing the information. The 'Addend' field
-  /// will contain the unmodified instruction immediate.
-  RelocationEntry getBasicRelocationEntry(unsigned SectionID,
-                                          ObjectImage &ObjImg,
-                                          const relocation_iterator &RI) const {
-    const MachOObjectFile &Obj =
-      static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
-    MachO::any_relocation_info RelInfo =
-      Obj.getRelocation(RI->getRawDataRefImpl());
-
-    const SectionEntry &Section = Sections[SectionID];
-    bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
-    unsigned Size = Obj.getAnyRelocationLength(RelInfo);
-    uint64_t Offset;
-    RI->getOffset(Offset);
-    uint8_t *LocalAddress = Section.Address + Offset;
-    unsigned NumBytes = 1 << Size;
-    MachO::RelocationInfoType RelType =
-      static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo));
-    int64_t Addend = impl().decodeAddend(LocalAddress, NumBytes, RelType);
-
-    return RelocationEntry(SectionID, Offset, RelType, Addend, IsPCRel, Size);
-  }
-
 public:
   RuntimeDyldMachOCRTPBase(RTDyldMemoryManager *mm) : RuntimeDyldMachO(mm) {}
 
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
index ffdb53a6b18..e7e8fa580ff 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
@@ -28,11 +28,13 @@ public:
   unsigned getStubAlignment() override { return 8; }
 
   /// Extract the addend encoded in the instruction / memory location.
-  int64_t decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
-                       MachO::RelocationInfoType RelType) const {
+  int64_t decodeAddend(const RelocationEntry &RE) const {
+    const SectionEntry &Section = Sections[RE.SectionID];
+    uint8_t *LocalAddress = Section.Address + RE.Offset;
+    unsigned NumBytes = 1 << RE.Size;
     int64_t Addend = 0;
     // Verify that the relocation has the correct size and alignment.
-    switch (RelType) {
+    switch (RE.RelType) {
     default:
       llvm_unreachable("Unsupported relocation type!");
     case MachO::ARM64_RELOC_UNSIGNED:
@@ -49,7 +51,7 @@ public:
       break;
     }
 
-    switch (RelType) {
+    switch (RE.RelType) {
     default:
       llvm_unreachable("Unsupported relocation type!");
     case MachO::ARM64_RELOC_UNSIGNED:
@@ -263,7 +265,8 @@ public:
       RelInfo = Obj.getRelocation(RelI->getRawDataRefImpl());
     }
 
-    RelocationEntry RE(getBasicRelocationEntry(SectionID, ObjImg, RelI));
+    RelocationEntry RE(getRelocationEntry(SectionID, ObjImg, RelI));
+    RE.Addend = decodeAddend(RE);
     RelocationValueRef Value(
         getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));
 
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
index b7bd0b9d04f..f784fa6b672 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
@@ -28,11 +28,13 @@ public:
 
   unsigned getStubAlignment() override { return 4; }
 
-  int64_t decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
-                       MachO::RelocationInfoType RelType) const {
-    switch (RelType) {
+  int64_t decodeAddend(const RelocationEntry &RE) const {
+    const SectionEntry &Section = Sections[RE.SectionID];
+    uint8_t *LocalAddress = Section.Address + RE.Offset;
+
+    switch (RE.RelType) {
       default:
-        return ParentT::decodeAddend(LocalAddress, NumBytes, RelType);
+        return memcpyAddend(RE);
       case MachO::ARM_RELOC_BR24: {
         uint32_t Temp;
         memcpy(&Temp, LocalAddress, 4);
@@ -55,7 +57,8 @@ public:
     if (Obj.isRelocationScattered(RelInfo))
       return ++++RelI;
 
-    RelocationEntry RE(getBasicRelocationEntry(SectionID, ObjImg, RelI));
+    RelocationEntry RE(getRelocationEntry(SectionID, ObjImg, RelI));
+    RE.Addend = decodeAddend(RE);
     RelocationValueRef Value(
         getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));
 
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
index 156287b3af1..e7389776e25 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
@@ -47,7 +47,8 @@ public:
       llvm_unreachable("Unhandled scattered relocation.");
     }
 
-    RelocationEntry RE(getBasicRelocationEntry(SectionID, ObjImg, RelI));
+    RelocationEntry RE(getRelocationEntry(SectionID, ObjImg, RelI));
+    RE.Addend = memcpyAddend(RE);
     RelocationValueRef Value(
         getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));
 
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOX86_64.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOX86_64.h
index 9106f415422..4a6e76b5d15 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOX86_64.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOX86_64.h
@@ -38,7 +38,8 @@ public:
     assert(!Obj.isRelocationScattered(RelInfo) &&
            "Scattered relocations not supported on X86_64");
 
-    RelocationEntry RE(getBasicRelocationEntry(SectionID, ObjImg, RelI));
+    RelocationEntry RE(getRelocationEntry(SectionID, ObjImg, RelI));
+    RE.Addend = memcpyAddend(RE);
     RelocationValueRef Value(
         getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));