#ifndef LLVM_SUPPORT_ENDIAN_H
#define LLVM_SUPPORT_ENDIAN_H
-#include "llvm/Config/config.h"
-#include "llvm/System/SwapByteOrder.h"
-#include "llvm/Support/type_traits.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/SwapByteOrder.h"
namespace llvm {
namespace support {
+enum endianness {big, little, native};
-enum endianness {big, little};
-enum alignment {unaligned, aligned};
+// These are named values for common alignments.
+enum {aligned = 0, unaligned = 1};
-template<typename value_type, int host, int target>
-static typename enable_if_c<host == target, value_type>::type
-SwapByteOrderIfDifferent(value_type value) {
- // Target endianess is the same as the host. Just pass the value through.
+namespace detail {
+ /// \brief ::value is either alignment, or alignof(T) if alignment is 0.
+ template<class T, int alignment>
+ struct PickAlignment {
+ enum {value = alignment == 0 ? AlignOf<T>::Alignment : alignment};
+ };
+} // end namespace detail
+
+namespace endian {
+/// Swap the bytes of value to match the given endianness.
+template<typename value_type, endianness endian>
+inline value_type byte_swap(value_type value) {
+ if (endian != native && sys::IsBigEndianHost != (endian == big))
+ sys::swapByteOrder(value);
return value;
}
-template<typename value_type, int host, int target>
-static typename enable_if_c<host != target, value_type>::type
-SwapByteOrderIfDifferent(value_type value) {
- return sys::SwapByteOrder<value_type>(value);
+/// Read a value of a particular endianness from memory.
+template<typename value_type,
+ endianness endian,
+ std::size_t alignment>
+inline value_type read(const void *memory) {
+ value_type ret;
+
+ memcpy(&ret,
+ LLVM_ASSUME_ALIGNED(memory,
+ (detail::PickAlignment<value_type, alignment>::value)),
+ sizeof(value_type));
+ return byte_swap<value_type, endian>(ret);
}
-namespace detail {
-
-template<typename value_type, alignment align>
-struct alignment_access_helper;
-
-template<typename value_type>
-struct alignment_access_helper<value_type, aligned>
-{
- value_type val;
-};
-
-// Provides unaligned loads and stores.
-#pragma pack(push)
-#pragma pack(1)
-template<typename value_type>
-struct alignment_access_helper<value_type, unaligned>
-{
- value_type val;
-};
-#pragma pack(pop)
-
-} // end namespace detail
+/// 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;
+}
-#if defined(LLVM_IS_HOST_BIG_ENDIAN) \
- || defined(_BIG_ENDIAN) || defined(__BIG_ENDIAN__)
-static const endianness host_endianness = big;
-#else
-static const endianness host_endianness = little;
-#endif
+/// Write a value to memory with a particular endianness.
+template<typename value_type,
+ endianness endian,
+ std::size_t alignment>
+inline void write(void *memory, value_type value) {
+ value = byte_swap<value_type, endian>(value);
+ memcpy(LLVM_ASSUME_ALIGNED(memory,
+ (detail::PickAlignment<value_type, alignment>::value)),
+ &value,
+ sizeof(value_type));
+}
-struct endian {
- template<typename value_type, alignment align>
- static value_type read_le(const void *memory) {
- return SwapByteOrderIfDifferent<value_type, host_endianness, little>(
- reinterpret_cast<const detail::alignment_access_helper
- <value_type, align> *>(memory)->val);
+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;
}
+}
- template<typename value_type, alignment align>
- static void write_le(void *memory, value_type value) {
- reinterpret_cast<detail::alignment_access_helper<value_type, align> *>
- (memory)->val =
- SwapByteOrderIfDifferent< value_type
- , host_endianness
- , little>(value);
+/// 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
- template<typename value_type, alignment align>
- static value_type read_be(const void *memory) {
- return SwapByteOrderIfDifferent<value_type, host_endianness, big>(
- reinterpret_cast<const detail::alignment_access_helper
- <value_type, align> *>(memory)->val);
+namespace detail {
+template<typename value_type,
+ endianness endian,
+ std::size_t alignment>
+struct packed_endian_specific_integral {
+ operator value_type() const {
+ return endian::read<value_type, endian, alignment>(
+ (const void*)Value.buffer);
}
- template<typename value_type, alignment align>
- static void write_be(void *memory, value_type value) {
- reinterpret_cast<detail::alignment_access_helper
- <value_type, align> *>(memory)->val =
- SwapByteOrderIfDifferent< value_type
- , host_endianness
- , big>(value);
+ void operator=(value_type newValue) {
+ endian::write<value_type, endian, alignment>(
+ (void*)Value.buffer, newValue);
}
-};
-
-namespace detail {
-template<typename value_type,
- endianness target_endianness,
- alignment target_alignment>
-class packed_endian_specific_integral;
+ packed_endian_specific_integral &operator+=(value_type newValue) {
+ *this = *this + newValue;
+ return *this;
+ }
-template<typename value_type>
-class packed_endian_specific_integral<value_type, little, unaligned> {
-public:
- operator value_type() const {
- return endian::read_le<value_type, unaligned>(Value);
+ packed_endian_specific_integral &operator-=(value_type newValue) {
+ *this = *this - newValue;
+ return *this;
}
-private:
- uint8_t Value[sizeof(value_type)];
-};
-template<typename value_type>
-class packed_endian_specific_integral<value_type, big, unaligned> {
-public:
- operator value_type() const {
- return endian::read_be<value_type, unaligned>(Value);
+ packed_endian_specific_integral &operator|=(value_type newValue) {
+ *this = *this | newValue;
+ return *this;
}
-private:
- uint8_t Value[sizeof(value_type)];
-};
-template<typename value_type>
-class packed_endian_specific_integral<value_type, little, aligned> {
-public:
- operator value_type() const {
- return endian::read_le<value_type, aligned>(&Value);
+ packed_endian_specific_integral &operator&=(value_type newValue) {
+ *this = *this & newValue;
+ return *this;
}
+
private:
- value_type Value;
-};
+ AlignedCharArray<PickAlignment<value_type, alignment>::value,
+ sizeof(value_type)> Value;
-template<typename value_type>
-class packed_endian_specific_integral<value_type, big, aligned> {
public:
- operator value_type() const {
- return endian::read_be<value_type, aligned>(&Value);
- }
-private:
- value_type Value;
+ 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
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
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
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
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
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
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
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
typedef detail::packed_endian_specific_integral
<int64_t, big, aligned> aligned_big64_t;
-} // end namespace llvm
+typedef detail::packed_endian_specific_integral
+ <uint16_t, native, unaligned> unaligned_uint16_t;
+typedef detail::packed_endian_specific_integral
+ <uint32_t, native, unaligned> unaligned_uint32_t;
+typedef detail::packed_endian_specific_integral
+ <uint64_t, native, unaligned> unaligned_uint64_t;
+
+typedef detail::packed_endian_specific_integral
+ <int16_t, native, unaligned> unaligned_int16_t;
+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;
+
+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
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