diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
index f3139739cd1..dc5e095155f 100644
--- a/include/llvm/Bitcode/BitstreamReader.h
+++ b/include/llvm/Bitcode/BitstreamReader.h
@@ -244,7 +244,7 @@ public:
 
   uint32_t getWord(size_t pos) {
     uint8_t buf[4] = { 0xFF, 0xFF, 0xFF, 0xFF };
-    BitStream->getBitcodeBytes().readBytes(pos, sizeof(buf), buf, NULL);
+    BitStream->getBitcodeBytes().readBytes(pos, sizeof(buf), buf);
     return *reinterpret_cast<support::ulittle32_t *>(buf);
   }
 
@@ -366,8 +366,7 @@ public:
     // Read the next word from the stream.
     uint8_t Array[sizeof(word_t)] = {0};
 
-    BitStream->getBitcodeBytes().readBytes(NextChar, sizeof(Array),
-                                           Array, NULL);
+    BitStream->getBitcodeBytes().readBytes(NextChar, sizeof(Array), Array);
 
     // Handle big-endian byte-swapping if necessary.
     support::detail::packed_endian_specific_integral
diff --git a/include/llvm/Support/MemoryObject.h b/include/llvm/Support/MemoryObject.h
index 732b0f07746..17aa9d2f675 100644
--- a/include/llvm/Support/MemoryObject.h
+++ b/include/llvm/Support/MemoryObject.h
@@ -42,7 +42,7 @@ public:
   /// @param ptr      - A pointer to a byte to be filled in.  Must be non-NULL.
   /// @result         - 0 if successful; -1 if not.  Failure may be due to a
   ///                   bounds violation or an implementation-specific error.
-  virtual int readByte(uint64_t address, uint8_t* ptr) const = 0;
+  virtual int readByte(uint64_t address, uint8_t *ptr) const = 0;
 
   /// readBytes       - Tries to read a contiguous range of bytes from the
   ///                   region, up to the end of the region.
@@ -51,17 +51,12 @@ public:
   ///
   /// @param address  - The address of the first byte, in the same space as 
   ///                   getBase().
-  /// @param size     - The maximum number of bytes to copy.
+  /// @param size     - The number of bytes to copy.
   /// @param buf      - A pointer to a buffer to be filled in.  Must be non-NULL
   ///                   and large enough to hold size bytes.
-  /// @param copied   - A pointer to a nunber that is filled in with the number
-  ///                   of bytes actually read.  May be NULL.
   /// @result         - 0 if successful; -1 if not.  Failure may be due to a
   ///                   bounds violation or an implementation-specific error.
-  virtual int readBytes(uint64_t address,
-                        uint64_t size,
-                        uint8_t* buf,
-                        uint64_t* copied) const;
+  virtual int readBytes(uint64_t address, uint64_t size, uint8_t *buf) const;
 };
 
 }
diff --git a/include/llvm/Support/StreamableMemoryObject.h b/include/llvm/Support/StreamableMemoryObject.h
index 385548579b1..e823d489d3a 100644
--- a/include/llvm/Support/StreamableMemoryObject.h
+++ b/include/llvm/Support/StreamableMemoryObject.h
@@ -38,7 +38,7 @@ class StreamableMemoryObject : public MemoryObject {
   /// getBase         - Returns the lowest valid address in the region.
   ///
   /// @result         - The lowest valid address.
-  virtual uint64_t getBase() const = 0;
+  virtual uint64_t getBase() const LLVM_OVERRIDE = 0;
 
   /// getExtent       - Returns the size of the region in bytes.  (The region is
   ///                   contiguous, so the highest valid address of the region
@@ -46,7 +46,7 @@ class StreamableMemoryObject : public MemoryObject {
   ///                   May block until all bytes in the stream have been read
   ///
   /// @result         - The size of the region.
-  virtual uint64_t getExtent() const = 0;
+  virtual uint64_t getExtent() const LLVM_OVERRIDE = 0;
 
   /// readByte        - Tries to read a single byte from the region.
   ///                   May block until (address - base) bytes have been read
@@ -54,7 +54,7 @@ class StreamableMemoryObject : public MemoryObject {
   /// @param ptr      - A pointer to a byte to be filled in.  Must be non-NULL.
   /// @result         - 0 if successful; -1 if not.  Failure may be due to a
   ///                   bounds violation or an implementation-specific error.
-  virtual int readByte(uint64_t address, uint8_t* ptr) const = 0;
+  virtual int readByte(uint64_t address, uint8_t *ptr) const LLVM_OVERRIDE = 0;
 
   /// readBytes       - Tries to read a contiguous range of bytes from the
   ///                   region, up to the end of the region.
@@ -65,17 +65,14 @@ class StreamableMemoryObject : public MemoryObject {
   ///
   /// @param address  - The address of the first byte, in the same space as
   ///                   getBase().
-  /// @param size     - The maximum number of bytes to copy.
+  /// @param size     - The number of bytes to copy.
   /// @param buf      - A pointer to a buffer to be filled in.  Must be non-NULL
   ///                   and large enough to hold size bytes.
-  /// @param copied   - A pointer to a nunber that is filled in with the number
-  ///                   of bytes actually read.  May be NULL.
   /// @result         - 0 if successful; -1 if not.  Failure may be due to a
   ///                   bounds violation or an implementation-specific error.
   virtual int readBytes(uint64_t address,
                         uint64_t size,
-                        uint8_t* buf,
-                        uint64_t* copied) const = 0;
+                        uint8_t *buf) const LLVM_OVERRIDE = 0;
 
   /// getPointer  - Ensures that the requested data is in memory, and returns
   ///               A pointer to it. More efficient than using readBytes if the
@@ -110,11 +107,10 @@ public:
   StreamingMemoryObject(DataStreamer *streamer);
   virtual uint64_t getBase() const LLVM_OVERRIDE { return 0; }
   virtual uint64_t getExtent() const LLVM_OVERRIDE;
-  virtual int readByte(uint64_t address, uint8_t* ptr) const LLVM_OVERRIDE;
+  virtual int readByte(uint64_t address, uint8_t *ptr) const LLVM_OVERRIDE;
   virtual int readBytes(uint64_t address,
                         uint64_t size,
-                        uint8_t* buf,
-                        uint64_t* copied) const LLVM_OVERRIDE;
+                        uint8_t *buf) const LLVM_OVERRIDE;
   virtual const uint8_t *getPointer(uint64_t address,
                                     uint64_t size) const LLVM_OVERRIDE {
     // This could be fixed by ensuring the bytes are fetched and making a copy,
diff --git a/include/llvm/Support/StringRefMemoryObject.h b/include/llvm/Support/StringRefMemoryObject.h
index a0ef35a9e1d..994fa34b74b 100644
--- a/include/llvm/Support/StringRefMemoryObject.h
+++ b/include/llvm/Support/StringRefMemoryObject.h
@@ -16,6 +16,7 @@
 #define LLVM_SUPPORT_STRINGREFMEMORYOBJECT_H
 
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/MemoryObject.h"
 
 namespace llvm {
@@ -28,13 +29,11 @@ public:
   StringRefMemoryObject(StringRef Bytes, uint64_t Base = 0)
     : Bytes(Bytes), Base(Base) {}
 
-  uint64_t getBase() const { return Base; }
-  uint64_t getExtent() const { return Bytes.size(); }
-
-  int readByte(uint64_t Addr, uint8_t *Byte) const;
-  int readBytes(uint64_t Addr, uint64_t Size,
-                uint8_t *Buf, uint64_t *Copied) const;
+  uint64_t getBase() const LLVM_OVERRIDE { return Base; }
+  uint64_t getExtent() const LLVM_OVERRIDE { return Bytes.size(); }
 
+  int readByte(uint64_t Addr, uint8_t *Byte) const LLVM_OVERRIDE;
+  int readBytes(uint64_t Addr, uint64_t Size, uint8_t *Buf) const LLVM_OVERRIDE;
 };
 
 }
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index e6ff4b43b13..cf827c5d4b0 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3010,7 +3010,7 @@ bool BitcodeReader::InitLazyStream() {
   Stream.init(*StreamFile);
 
   unsigned char buf[16];
-  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
+  if (Bytes->readBytes(0, 16, buf) == -1)
     return Error("Bitcode stream must be at least 16 bytes in length");
 
   if (!isBitcode(buf, buf + 16))
diff --git a/lib/Support/MemoryObject.cpp b/lib/Support/MemoryObject.cpp
index b20ab892381..02b5b5034fb 100644
--- a/lib/Support/MemoryObject.cpp
+++ b/lib/Support/MemoryObject.cpp
@@ -15,8 +15,7 @@ MemoryObject::~MemoryObject() {
 
 int MemoryObject::readBytes(uint64_t address,
                             uint64_t size,
-                            uint8_t* buf,
-                            uint64_t* copied) const {
+                            uint8_t* buf) const {
   uint64_t current = address;
   uint64_t limit = getBase() + getExtent();
 
@@ -30,8 +29,5 @@ int MemoryObject::readBytes(uint64_t address,
     current++;
   }
   
-  if (copied)
-    *copied = current - address;
-  
   return 0;
 }
diff --git a/lib/Support/StreamableMemoryObject.cpp b/lib/Support/StreamableMemoryObject.cpp
index 59e27a263e0..2ed7c5c100a 100644
--- a/lib/Support/StreamableMemoryObject.cpp
+++ b/lib/Support/StreamableMemoryObject.cpp
@@ -31,8 +31,7 @@ public:
   virtual int readByte(uint64_t address, uint8_t* ptr) const LLVM_OVERRIDE;
   virtual int readBytes(uint64_t address,
                         uint64_t size,
-                        uint8_t* buf,
-                        uint64_t* copied) const LLVM_OVERRIDE;
+                        uint8_t *buf) const LLVM_OVERRIDE;
   virtual const uint8_t *getPointer(uint64_t address,
                                     uint64_t size) const LLVM_OVERRIDE;
   virtual bool isValidAddress(uint64_t address) const LLVM_OVERRIDE {
@@ -67,11 +66,9 @@ int RawMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
 
 int RawMemoryObject::readBytes(uint64_t address,
                                uint64_t size,
-                               uint8_t* buf,
-                               uint64_t* copied) const {
+                               uint8_t *buf) const {
   if (!validAddress(address) || !validAddress(address + size - 1)) return -1;
   memcpy(buf, (uint8_t *)(uintptr_t)(address + FirstChar), size);
-  if (copied) *copied = size;
   return size;
 }
 
@@ -111,11 +108,9 @@ int StreamingMemoryObject::readByte(uint64_t address, uint8_t* ptr) const {
 
 int StreamingMemoryObject::readBytes(uint64_t address,
                                      uint64_t size,
-                                     uint8_t* buf,
-                                     uint64_t* copied) const {
+                                     uint8_t *buf) const {
   if (!fetchToPos(address + size - 1)) return -1;
   memcpy(buf, &Bytes[address + BytesSkipped], size);
-  if (copied) *copied = size;
   return 0;
 }
 
diff --git a/lib/Support/StringRefMemoryObject.cpp b/lib/Support/StringRefMemoryObject.cpp
index 5db11e918cd..e035ed1d2ef 100644
--- a/lib/Support/StringRefMemoryObject.cpp
+++ b/lib/Support/StringRefMemoryObject.cpp
@@ -20,15 +20,10 @@ int StringRefMemoryObject::readByte(uint64_t Addr, uint8_t *Byte) const {
 
 int StringRefMemoryObject::readBytes(uint64_t Addr,
                                      uint64_t Size,
-                                     uint8_t *Buf,
-                                     uint64_t *Copied) const {
-  if (Addr >= Base + getExtent() || Addr < Base)
-    return -1;
+                                     uint8_t *Buf) const {
   uint64_t Offset = Addr - Base;
-  if (Size > getExtent() - Offset)
-    Size = getExtent() - Offset;
+  if (Addr >= Base + getExtent() || Offset + Size > getExtent() || Addr < Base)
+    return -1;
   memcpy(Buf, Bytes.data() + Offset, Size);
-  if (Copied)
-    *Copied = Size;
   return 0;
 }
diff --git a/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
index 12c1b8f4c81..1c397b5fa96 100644
--- a/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
+++ b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
@@ -208,7 +208,7 @@ DecodeStatus AArch64Disassembler::getInstruction(MCInst &MI, uint64_t &Size,
   uint8_t bytes[4];
 
   // We want to read exactly 4 bytes of data.
-  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
+  if (Region.readBytes(Address, 4, bytes) == -1) {
     Size = 0;
     return MCDisassembler::Fail;
   }
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 284761cf295..0a7d5eeb870 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -413,7 +413,7 @@ DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
          "Asked to disassemble an ARM instruction but Subtarget is in Thumb mode!");
 
   // We want to read exactly 4 bytes of data.
-  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
+  if (Region.readBytes(Address, 4, bytes) == -1) {
     Size = 0;
     return MCDisassembler::Fail;
   }
@@ -659,7 +659,7 @@ DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
 
   // We want to read exactly 2 bytes of data.
-  if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1) {
+  if (Region.readBytes(Address, 2, bytes) == -1) {
     Size = 0;
     return MCDisassembler::Fail;
   }
@@ -711,7 +711,7 @@ DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   }
 
   // We want to read exactly 4 bytes of data.
-  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
+  if (Region.readBytes(Address, 4, bytes) == -1) {
     Size = 0;
     return MCDisassembler::Fail;
   }
diff --git a/lib/Target/MBlaze/Disassembler/MBlazeDisassembler.cpp b/lib/Target/MBlaze/Disassembler/MBlazeDisassembler.cpp
index c03ab3803b6..0acfb3ec2a0 100644
--- a/lib/Target/MBlaze/Disassembler/MBlazeDisassembler.cpp
+++ b/lib/Target/MBlaze/Disassembler/MBlazeDisassembler.cpp
@@ -501,14 +501,13 @@ MCDisassembler::DecodeStatus MBlazeDisassembler::getInstruction(MCInst &instr,
                                         raw_ostream &cStream) const {
   // The machine instruction.
   uint32_t insn;
-  uint64_t read;
   uint8_t bytes[4];
 
   // By default we consume 1 byte on failure
   size = 1;
 
   // We want to read exactly 4 bytes of data.
-  if (region.readBytes(address, 4, (uint8_t*)bytes, &read) == -1 || read < 4)
+  if (region.readBytes(address, 4, bytes) == -1)
     return Fail;
 
   // Encoded as a big-endian 32-bit word in the stream.
diff --git a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
index 0dba33a2767..4af67037e97 100644
--- a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
+++ b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
@@ -252,7 +252,7 @@ static DecodeStatus readInstruction32(const MemoryObject &region,
   uint8_t Bytes[4];
 
   // We want to read exactly 4 Bytes of data.
-  if (region.readBytes(address, 4, (uint8_t*)Bytes, NULL) == -1) {
+  if (region.readBytes(address, 4, Bytes) == -1) {
     size = 0;
     return MCDisassembler::Fail;
   }
diff --git a/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp b/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
index 9a9de782240..4e4816badab 100644
--- a/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
+++ b/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
@@ -272,7 +272,7 @@ DecodeStatus SystemZDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   // Get the first two bytes of the instruction.
   uint8_t Bytes[6];
   Size = 0;
-  if (Region.readBytes(Address, 2, Bytes, 0) == -1)
+  if (Region.readBytes(Address, 2, Bytes) == -1)
     return MCDisassembler::Fail;
 
   // The top 2 bits of the first byte specify the size.
@@ -289,7 +289,7 @@ DecodeStatus SystemZDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   }
 
   // Read any remaining bytes.
-  if (Size > 2 && Region.readBytes(Address + 2, Size - 2, Bytes + 2, 0) == -1)
+  if (Size > 2 && Region.readBytes(Address + 2, Size - 2, Bytes + 2) == -1)
     return MCDisassembler::Fail;
 
   // Construct the instruction.
diff --git a/lib/Target/XCore/Disassembler/XCoreDisassembler.cpp b/lib/Target/XCore/Disassembler/XCoreDisassembler.cpp
index a2ae40c58a6..dcc0955028b 100644
--- a/lib/Target/XCore/Disassembler/XCoreDisassembler.cpp
+++ b/lib/Target/XCore/Disassembler/XCoreDisassembler.cpp
@@ -53,7 +53,7 @@ static bool readInstruction16(const MemoryObject &region,
   uint8_t Bytes[4];
 
   // We want to read exactly 2 Bytes of data.
-  if (region.readBytes(address, 2, Bytes, NULL) == -1) {
+  if (region.readBytes(address, 2, Bytes) == -1) {
     size = 0;
     return false;
   }
@@ -69,7 +69,7 @@ static bool readInstruction32(const MemoryObject &region,
   uint8_t Bytes[4];
 
   // We want to read exactly 4 Bytes of data.
-  if (region.readBytes(address, 4, Bytes, NULL) == -1) {
+  if (region.readBytes(address, 4, Bytes) == -1) {
     size = 0;
     return false;
   }