--- /dev/null
+// Copyright 2015, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+// * Neither the name of ARM Limited nor the names of its contributors may be
+// used to endorse or promote products derived from this software without
+// specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_UTILS_H
+#define VIXL_UTILS_H
+
+#include <string.h>
+#include <cmath>
+#include "vixl/globals.h"
+#include "vixl/compiler-intrinsics.h"
+
+namespace vixl {
+
+// Macros for compile-time format checking.
+#if GCC_VERSION_OR_NEWER(4, 4, 0)
+#define PRINTF_CHECK(format_index, varargs_index) \
+ __attribute__((format(gnu_printf, format_index, varargs_index)))
+#else
+#define PRINTF_CHECK(format_index, varargs_index)
+#endif
+
+// Check number width.
+inline bool is_intn(unsigned n, int64_t x) {
+ VIXL_ASSERT((0 < n) && (n < 64));
+ int64_t limit = INT64_C(1) << (n - 1);
+ return (-limit <= x) && (x < limit);
+}
+
+inline bool is_uintn(unsigned n, int64_t x) {
+ VIXL_ASSERT((0 < n) && (n < 64));
+ return !(x >> n);
+}
+
+inline uint32_t truncate_to_intn(unsigned n, int64_t x) {
+ VIXL_ASSERT((0 < n) && (n < 64));
+ return static_cast<uint32_t>(x & ((INT64_C(1) << n) - 1));
+}
+
+#define INT_1_TO_63_LIST(V) \
+V(1) V(2) V(3) V(4) V(5) V(6) V(7) V(8) \
+V(9) V(10) V(11) V(12) V(13) V(14) V(15) V(16) \
+V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24) \
+V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32) \
+V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40) \
+V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48) \
+V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56) \
+V(57) V(58) V(59) V(60) V(61) V(62) V(63)
+
+#define DECLARE_IS_INT_N(N) \
+inline bool is_int##N(int64_t x) { return is_intn(N, x); }
+#define DECLARE_IS_UINT_N(N) \
+inline bool is_uint##N(int64_t x) { return is_uintn(N, x); }
+#define DECLARE_TRUNCATE_TO_INT_N(N) \
+inline uint32_t truncate_to_int##N(int x) { return truncate_to_intn(N, x); }
+INT_1_TO_63_LIST(DECLARE_IS_INT_N)
+INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
+INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
+#undef DECLARE_IS_INT_N
+#undef DECLARE_IS_UINT_N
+#undef DECLARE_TRUNCATE_TO_INT_N
+
+// Bit field extraction.
+inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
+ return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
+}
+
+inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
+ return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
+}
+
+inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
+ return (x << (31 - msb)) >> (lsb + 31 - msb);
+}
+
+inline int64_t signed_bitextract_64(int msb, int lsb, int64_t x) {
+ return (x << (63 - msb)) >> (lsb + 63 - msb);
+}
+
+// Floating point representation.
+uint32_t float_to_rawbits(float value);
+uint64_t double_to_rawbits(double value);
+float rawbits_to_float(uint32_t bits);
+double rawbits_to_double(uint64_t bits);
+
+uint32_t float_sign(float val);
+uint32_t float_exp(float val);
+uint32_t float_mantissa(float val);
+uint32_t double_sign(double val);
+uint32_t double_exp(double val);
+uint64_t double_mantissa(double val);
+
+float float_pack(uint32_t sign, uint32_t exp, uint32_t mantissa);
+double double_pack(uint64_t sign, uint64_t exp, uint64_t mantissa);
+
+// An fpclassify() function for 16-bit half-precision floats.
+int float16classify(float16 value);
+
+// NaN tests.
+inline bool IsSignallingNaN(double num) {
+ const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
+ uint64_t raw = double_to_rawbits(num);
+ if (std::isnan(num) && ((raw & kFP64QuietNaNMask) == 0)) {
+ return true;
+ }
+ return false;
+}
+
+
+inline bool IsSignallingNaN(float num) {
+ const uint32_t kFP32QuietNaNMask = 0x00400000;
+ uint32_t raw = float_to_rawbits(num);
+ if (std::isnan(num) && ((raw & kFP32QuietNaNMask) == 0)) {
+ return true;
+ }
+ return false;
+}
+
+
+inline bool IsSignallingNaN(float16 num) {
+ const uint16_t kFP16QuietNaNMask = 0x0200;
+ return (float16classify(num) == FP_NAN) &&
+ ((num & kFP16QuietNaNMask) == 0);
+}
+
+
+template <typename T>
+inline bool IsQuietNaN(T num) {
+ return std::isnan(num) && !IsSignallingNaN(num);
+}
+
+
+// Convert the NaN in 'num' to a quiet NaN.
+inline double ToQuietNaN(double num) {
+ const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
+ VIXL_ASSERT(std::isnan(num));
+ return rawbits_to_double(double_to_rawbits(num) | kFP64QuietNaNMask);
+}
+
+
+inline float ToQuietNaN(float num) {
+ const uint32_t kFP32QuietNaNMask = 0x00400000;
+ VIXL_ASSERT(std::isnan(num));
+ return rawbits_to_float(float_to_rawbits(num) | kFP32QuietNaNMask);
+}
+
+
+// Fused multiply-add.
+inline double FusedMultiplyAdd(double op1, double op2, double a) {
+ return fma(op1, op2, a);
+}
+
+
+inline float FusedMultiplyAdd(float op1, float op2, float a) {
+ return fmaf(op1, op2, a);
+}
+
+
+inline uint64_t LowestSetBit(uint64_t value) {
+ return value & -value;
+}
+
+
+template<typename T>
+inline int HighestSetBitPosition(T value) {
+ VIXL_ASSERT(value != 0);
+ return (sizeof(value) * 8 - 1) - CountLeadingZeros(value);
+}
+
+
+template<typename V>
+inline int WhichPowerOf2(V value) {
+ VIXL_ASSERT(IsPowerOf2(value));
+ return CountTrailingZeros(value);
+}
+
+
+unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size);
+
+
+template <typename T>
+T ReverseBits(T value) {
+ VIXL_ASSERT((sizeof(value) == 1) || (sizeof(value) == 2) ||
+ (sizeof(value) == 4) || (sizeof(value) == 8));
+ T result = 0;
+ for (unsigned i = 0; i < (sizeof(value) * 8); i++) {
+ result = (result << 1) | (value & 1);
+ value >>= 1;
+ }
+ return result;
+}
+
+
+template <typename T>
+T ReverseBytes(T value, int block_bytes_log2) {
+ VIXL_ASSERT((sizeof(value) == 4) || (sizeof(value) == 8));
+ VIXL_ASSERT((1U << block_bytes_log2) <= sizeof(value));
+ // Split the 64-bit value into an 8-bit array, where b[0] is the least
+ // significant byte, and b[7] is the most significant.
+ uint8_t bytes[8];
+ uint64_t mask = UINT64_C(0xff00000000000000);
+ for (int i = 7; i >= 0; i--) {
+ bytes[i] = (static_cast<uint64_t>(value) & mask) >> (i * 8);
+ mask >>= 8;
+ }
+
+ // Permutation tables for REV instructions.
+ // permute_table[0] is used by REV16_x, REV16_w
+ // permute_table[1] is used by REV32_x, REV_w
+ // permute_table[2] is used by REV_x
+ VIXL_ASSERT((0 < block_bytes_log2) && (block_bytes_log2 < 4));
+ static const uint8_t permute_table[3][8] = { {6, 7, 4, 5, 2, 3, 0, 1},
+ {4, 5, 6, 7, 0, 1, 2, 3},
+ {0, 1, 2, 3, 4, 5, 6, 7} };
+ T result = 0;
+ for (int i = 0; i < 8; i++) {
+ result <<= 8;
+ result |= bytes[permute_table[block_bytes_log2 - 1][i]];
+ }
+ return result;
+}
+
+
+// Pointer alignment
+// TODO: rename/refactor to make it specific to instructions.
+template<typename T>
+bool IsWordAligned(T pointer) {
+ VIXL_ASSERT(sizeof(pointer) == sizeof(intptr_t)); // NOLINT(runtime/sizeof)
+ return ((intptr_t)(pointer) & 3) == 0;
+}
+
+// Increment a pointer (up to 64 bits) until it has the specified alignment.
+template<class T>
+T AlignUp(T pointer, size_t alignment) {
+ // Use C-style casts to get static_cast behaviour for integral types (T), and
+ // reinterpret_cast behaviour for other types.
+
+ uint64_t pointer_raw = (uint64_t)pointer;
+ VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
+
+ size_t align_step = (alignment - pointer_raw) % alignment;
+ VIXL_ASSERT((pointer_raw + align_step) % alignment == 0);
+
+ return (T)(pointer_raw + align_step);
+}
+
+// Decrement a pointer (up to 64 bits) until it has the specified alignment.
+template<class T>
+T AlignDown(T pointer, size_t alignment) {
+ // Use C-style casts to get static_cast behaviour for integral types (T), and
+ // reinterpret_cast behaviour for other types.
+
+ uint64_t pointer_raw = (uint64_t)pointer;
+ VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
+
+ size_t align_step = pointer_raw % alignment;
+ VIXL_ASSERT((pointer_raw - align_step) % alignment == 0);
+
+ return (T)(pointer_raw - align_step);
+}
+
+} // namespace vixl
+
+#endif // VIXL_UTILS_H
Code Review / kvmfornfv.git / blobdiff