X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FEndian.h;h=bc93c9a66eef9a221a13ae534782c409ae06554e;hb=40288f72380d2951cd2d4034922c2c515acb6cfd;hp=81690605e87d391143d8d0f658065e77b5b74f91;hpb=2563e201c14bfd45605e151a68e0ce11e1fc0ee9;p=oota-llvm.git

diff --git a/include/llvm/Support/Endian.h b/include/llvm/Support/Endian.h
index 81690605e87..bc93c9a66ee 100644
--- a/include/llvm/Support/Endian.h
+++ b/include/llvm/Support/Endian.h
@@ -38,7 +38,7 @@ namespace endian {
 template<typename value_type, endianness endian>
 inline value_type byte_swap(value_type value) {
   if (endian != native && sys::IsBigEndianHost != (endian == big))
-    return sys::SwapByteOrder(value);
+    sys::swapByteOrder(value);
   return value;
 }
 
@@ -56,6 +56,16 @@ inline value_type read(const void *memory) {
   return byte_swap<value_type, endian>(ret);
 }
 
+/// Read a value of a particular endianness from a buffer, and increment the
+/// buffer past that value.
+template<typename value_type, endianness endian, std::size_t alignment,
+         typename CharT>
+inline value_type readNext(const CharT *&memory) {
+  value_type ret = read<value_type, endian, alignment>(memory);
+  memory += sizeof(value_type);
+  return ret;
+}
+
 /// Write a value to memory with a particular endianness.
 template<typename value_type,
          endianness endian,
@@ -67,6 +77,95 @@ inline void write(void *memory, value_type value) {
          &value,
          sizeof(value_type));
 }
+
+template <typename value_type>
+using make_unsigned_t = typename std::make_unsigned<value_type>::type;
+
+/// Read a value of a particular endianness from memory, for a location
+/// that starts at the given bit offset within the first byte.
+template <typename value_type, endianness endian, std::size_t alignment>
+inline value_type readAtBitAlignment(const void *memory, uint64_t startBit) {
+  assert(startBit < 8);
+  if (startBit == 0)
+    return read<value_type, endian, alignment>(memory);
+  else {
+    // Read two values and compose the result from them.
+    value_type val[2];
+    memcpy(&val[0],
+           LLVM_ASSUME_ALIGNED(
+               memory, (detail::PickAlignment<value_type, alignment>::value)),
+           sizeof(value_type) * 2);
+    val[0] = byte_swap<value_type, endian>(val[0]);
+    val[1] = byte_swap<value_type, endian>(val[1]);
+
+    // Shift bits from the lower value into place.
+    make_unsigned_t<value_type> lowerVal = val[0] >> startBit;
+    // Mask off upper bits after right shift in case of signed type.
+    make_unsigned_t<value_type> numBitsFirstVal =
+        (sizeof(value_type) * 8) - startBit;
+    lowerVal &= ((make_unsigned_t<value_type>)1 << numBitsFirstVal) - 1;
+
+    // Get the bits from the upper value.
+    make_unsigned_t<value_type> upperVal =
+        val[1] & (((make_unsigned_t<value_type>)1 << startBit) - 1);
+    // Shift them in to place.
+    upperVal <<= numBitsFirstVal;
+
+    return lowerVal | upperVal;
+  }
+}
+
+/// Write a value to memory with a particular endianness, for a location
+/// that starts at the given bit offset within the first byte.
+template <typename value_type, endianness endian, std::size_t alignment>
+inline void writeAtBitAlignment(void *memory, value_type value,
+                                uint64_t startBit) {
+  assert(startBit < 8);
+  if (startBit == 0)
+    write<value_type, endian, alignment>(memory, value);
+  else {
+    // Read two values and shift the result into them.
+    value_type val[2];
+    memcpy(&val[0],
+           LLVM_ASSUME_ALIGNED(
+               memory, (detail::PickAlignment<value_type, alignment>::value)),
+           sizeof(value_type) * 2);
+    val[0] = byte_swap<value_type, endian>(val[0]);
+    val[1] = byte_swap<value_type, endian>(val[1]);
+
+    // Mask off any existing bits in the upper part of the lower value that
+    // we want to replace.
+    val[0] &= ((make_unsigned_t<value_type>)1 << startBit) - 1;
+    make_unsigned_t<value_type> numBitsFirstVal =
+        (sizeof(value_type) * 8) - startBit;
+    make_unsigned_t<value_type> lowerVal = value;
+    if (startBit > 0) {
+      // Mask off the upper bits in the new value that are not going to go into
+      // the lower value. This avoids a left shift of a negative value, which
+      // is undefined behavior.
+      lowerVal &= (((make_unsigned_t<value_type>)1 << numBitsFirstVal) - 1);
+      // Now shift the new bits into place
+      lowerVal <<= startBit;
+    }
+    val[0] |= lowerVal;
+
+    // Mask off any existing bits in the lower part of the upper value that
+    // we want to replace.
+    val[1] &= ~(((make_unsigned_t<value_type>)1 << startBit) - 1);
+    // Next shift the bits that go into the upper value into position.
+    make_unsigned_t<value_type> upperVal = value >> numBitsFirstVal;
+    // Mask off upper bits after right shift in case of signed type.
+    upperVal &= ((make_unsigned_t<value_type>)1 << startBit) - 1;
+    val[1] |= upperVal;
+
+    // Finally, rewrite values.
+    val[0] = byte_swap<value_type, endian>(val[0]);
+    val[1] = byte_swap<value_type, endian>(val[1]);
+    memcpy(LLVM_ASSUME_ALIGNED(
+               memory, (detail::PickAlignment<value_type, alignment>::value)),
+           &val[0], sizeof(value_type) * 2);
+  }
+}
 } // end namespace endian
 
 namespace detail {
@@ -84,14 +183,49 @@ struct packed_endian_specific_integral {
       (void*)Value.buffer, newValue);
   }
 
+  packed_endian_specific_integral &operator+=(value_type newValue) {
+    *this = *this + newValue;
+    return *this;
+  }
+
+  packed_endian_specific_integral &operator-=(value_type newValue) {
+    *this = *this - newValue;
+    return *this;
+  }
+
+  packed_endian_specific_integral &operator|=(value_type newValue) {
+    *this = *this | newValue;
+    return *this;
+  }
+
+  packed_endian_specific_integral &operator&=(value_type newValue) {
+    *this = *this & newValue;
+    return *this;
+  }
+
 private:
   AlignedCharArray<PickAlignment<value_type, alignment>::value,
                    sizeof(value_type)> Value;
+
+public:
+  struct ref {
+    explicit ref(void *Ptr) : Ptr(Ptr) {}
+
+    operator value_type() const {
+      return endian::read<value_type, endian, alignment>(Ptr);
+    }
+
+    void operator=(value_type NewValue) {
+      endian::write<value_type, endian, alignment>(Ptr, NewValue);
+    }
+
+  private:
+    void *Ptr;
+  };
 };
+
 } // end namespace detail
 
-typedef detail::packed_endian_specific_integral
-                  <uint8_t, little, unaligned>  ulittle8_t;
 typedef detail::packed_endian_specific_integral
                   <uint16_t, little, unaligned> ulittle16_t;
 typedef detail::packed_endian_specific_integral
@@ -99,8 +233,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                   <uint64_t, little, unaligned> ulittle64_t;
 
-typedef detail::packed_endian_specific_integral
-                   <int8_t, little, unaligned>  little8_t;
 typedef detail::packed_endian_specific_integral
                    <int16_t, little, unaligned> little16_t;
 typedef detail::packed_endian_specific_integral
@@ -108,8 +240,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                    <int64_t, little, unaligned> little64_t;
 
-typedef detail::packed_endian_specific_integral
-                    <uint8_t, little, aligned>  aligned_ulittle8_t;
 typedef detail::packed_endian_specific_integral
                     <uint16_t, little, aligned> aligned_ulittle16_t;
 typedef detail::packed_endian_specific_integral
@@ -117,8 +247,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                     <uint64_t, little, aligned> aligned_ulittle64_t;
 
-typedef detail::packed_endian_specific_integral
-                     <int8_t, little, aligned>  aligned_little8_t;
 typedef detail::packed_endian_specific_integral
                      <int16_t, little, aligned> aligned_little16_t;
 typedef detail::packed_endian_specific_integral
@@ -126,8 +254,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                      <int64_t, little, aligned> aligned_little64_t;
 
-typedef detail::packed_endian_specific_integral
-                  <uint8_t, big, unaligned>     ubig8_t;
 typedef detail::packed_endian_specific_integral
                   <uint16_t, big, unaligned>    ubig16_t;
 typedef detail::packed_endian_specific_integral
@@ -135,8 +261,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                   <uint64_t, big, unaligned>    ubig64_t;
 
-typedef detail::packed_endian_specific_integral
-                   <int8_t, big, unaligned>     big8_t;
 typedef detail::packed_endian_specific_integral
                    <int16_t, big, unaligned>    big16_t;
 typedef detail::packed_endian_specific_integral
@@ -144,8 +268,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                    <int64_t, big, unaligned>    big64_t;
 
-typedef detail::packed_endian_specific_integral
-                    <uint8_t, big, aligned>     aligned_ubig8_t;
 typedef detail::packed_endian_specific_integral
                     <uint16_t, big, aligned>    aligned_ubig16_t;
 typedef detail::packed_endian_specific_integral
@@ -153,8 +275,6 @@ typedef detail::packed_endian_specific_integral
 typedef detail::packed_endian_specific_integral
                     <uint64_t, big, aligned>    aligned_ubig64_t;
 
-typedef detail::packed_endian_specific_integral
-                     <int8_t, big, aligned>     aligned_big8_t;
 typedef detail::packed_endian_specific_integral
                      <int16_t, big, aligned>    aligned_big16_t;
 typedef detail::packed_endian_specific_integral
@@ -175,7 +295,51 @@ typedef detail::packed_endian_specific_integral
                    <int32_t, native, unaligned> unaligned_int32_t;
 typedef detail::packed_endian_specific_integral
                    <int64_t, native, unaligned> unaligned_int64_t;
-} // end namespace llvm
+
+namespace endian {
+template <typename T, endianness E> inline T read(const void *P) {
+  return *(const detail::packed_endian_specific_integral<T, E, unaligned> *)P;
+}
+
+template <endianness E> inline uint16_t read16(const void *P) {
+  return read<uint16_t, E>(P);
+}
+template <endianness E> inline uint32_t read32(const void *P) {
+  return read<uint32_t, E>(P);
+}
+template <endianness E> inline uint64_t read64(const void *P) {
+  return read<uint64_t, E>(P);
+}
+
+inline uint16_t read16le(const void *P) { return read16<little>(P); }
+inline uint32_t read32le(const void *P) { return read32<little>(P); }
+inline uint64_t read64le(const void *P) { return read64<little>(P); }
+inline uint16_t read16be(const void *P) { return read16<big>(P); }
+inline uint32_t read32be(const void *P) { return read32<big>(P); }
+inline uint64_t read64be(const void *P) { return read64<big>(P); }
+
+template <typename T, endianness E> inline void write(void *P, T V) {
+  *(detail::packed_endian_specific_integral<T, E, unaligned> *)P = V;
+}
+
+template <endianness E> inline void write16(void *P, uint16_t V) {
+  write<uint16_t, E>(P, V);
+}
+template <endianness E> inline void write32(void *P, uint32_t V) {
+  write<uint32_t, E>(P, V);
+}
+template <endianness E> inline void write64(void *P, uint64_t V) {
+  write<uint64_t, E>(P, V);
+}
+
+inline void write16le(void *P, uint16_t V) { write16<little>(P, V); }
+inline void write32le(void *P, uint32_t V) { write32<little>(P, V); }
+inline void write64le(void *P, uint64_t V) { write64<little>(P, V); }
+inline void write16be(void *P, uint16_t V) { write16<big>(P, V); }
+inline void write32be(void *P, uint32_t V) { write32<big>(P, V); }
+inline void write64be(void *P, uint64_t V) { write64<big>(P, V); }
+} // end namespace endian
 } // end namespace support
+} // end namespace llvm
 
 #endif