dep: Add vixl (AArch32/64 assembler)

dep/vixl/include/vixl/compiler-intrinsics-vixl.h

@@ -0,0 +1,160 @@
+// Copyright 2015, VIXL authors
+// 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_COMPILER_INTRINSICS_H
+#define VIXL_COMPILER_INTRINSICS_H
+
+#include "globals-vixl.h"
+
+namespace vixl {
+
+// Helper to check whether the version of GCC used is greater than the specified
+// requirement.
+#define MAJOR 1000000
+#define MINOR 1000
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+#define GCC_VERSION_OR_NEWER(major, minor, patchlevel)                      \
+  ((__GNUC__ * (MAJOR) + __GNUC_MINOR__ * (MINOR) + __GNUC_PATCHLEVEL__) >= \
+   ((major) * (MAJOR) + ((minor)) * (MINOR) + (patchlevel)))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+#define GCC_VERSION_OR_NEWER(major, minor, patchlevel) \
+  ((__GNUC__ * (MAJOR) + __GNUC_MINOR__ * (MINOR)) >=  \
+   ((major) * (MAJOR) + ((minor)) * (MINOR) + (patchlevel)))
+#else
+#define GCC_VERSION_OR_NEWER(major, minor, patchlevel) 0
+#endif
+
+
+#if defined(__clang__) && !defined(VIXL_NO_COMPILER_BUILTINS)
+
+// clang-format off
+#define COMPILER_HAS_BUILTIN_CLRSB    (__has_builtin(__builtin_clrsb))
+#define COMPILER_HAS_BUILTIN_CLZ      (__has_builtin(__builtin_clz))
+#define COMPILER_HAS_BUILTIN_CTZ      (__has_builtin(__builtin_ctz))
+#define COMPILER_HAS_BUILTIN_FFS      (__has_builtin(__builtin_ffs))
+#define COMPILER_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
+// clang-format on
+
+#elif defined(__GNUC__) && !defined(VIXL_NO_COMPILER_BUILTINS)
+// The documentation for these builtins is available at:
+// https://gcc.gnu.org/onlinedocs/gcc-$MAJOR.$MINOR.$PATCHLEVEL/gcc//Other-Builtins.html
+
+// clang-format off
+# define COMPILER_HAS_BUILTIN_CLRSB    (GCC_VERSION_OR_NEWER(4, 7, 0))
+# define COMPILER_HAS_BUILTIN_CLZ      (GCC_VERSION_OR_NEWER(3, 4, 0))
+# define COMPILER_HAS_BUILTIN_CTZ      (GCC_VERSION_OR_NEWER(3, 4, 0))
+# define COMPILER_HAS_BUILTIN_FFS      (GCC_VERSION_OR_NEWER(3, 4, 0))
+# define COMPILER_HAS_BUILTIN_POPCOUNT (GCC_VERSION_OR_NEWER(3, 4, 0))
+// clang-format on
+
+#else
+// One can define VIXL_NO_COMPILER_BUILTINS to force using the manually
+// implemented C++ methods.
+
+// clang-format off
+#define COMPILER_HAS_BUILTIN_BSWAP    false
+#define COMPILER_HAS_BUILTIN_CLRSB    false
+#define COMPILER_HAS_BUILTIN_CLZ      false
+#define COMPILER_HAS_BUILTIN_CTZ      false
+#define COMPILER_HAS_BUILTIN_FFS      false
+#define COMPILER_HAS_BUILTIN_POPCOUNT false
+// clang-format on
+
+#endif
+
+
+template <typename V>
+inline bool IsPowerOf2(V value) {
+  return (value != 0) && ((value & (value - 1)) == 0);
+}
+
+
+// Declaration of fallback functions.
+int CountLeadingSignBitsFallBack(int64_t value, int width);
+int CountLeadingZerosFallBack(uint64_t value, int width);
+int CountSetBitsFallBack(uint64_t value, int width);
+int CountTrailingZerosFallBack(uint64_t value, int width);
+
+
+// Implementation of intrinsics functions.
+// TODO: The implementations could be improved for sizes different from 32bit
+// and 64bit: we could mask the values and call the appropriate builtin.
+
+template <typename V>
+inline int CountLeadingSignBits(V value, int width = (sizeof(V) * 8)) {
+#if COMPILER_HAS_BUILTIN_CLRSB
+  if (width == 32) {
+    return __builtin_clrsb(value);
+  } else if (width == 64) {
+    return __builtin_clrsbll(value);
+  }
+#endif
+  return CountLeadingSignBitsFallBack(value, width);
+}
+
+
+template <typename V>
+inline int CountLeadingZeros(V value, int width = (sizeof(V) * 8)) {
+#if COMPILER_HAS_BUILTIN_CLZ
+  if (width == 32) {
+    return (value == 0) ? 32 : __builtin_clz(static_cast<unsigned>(value));
+  } else if (width == 64) {
+    return (value == 0) ? 64 : __builtin_clzll(value);
+  }
+#endif
+  return CountLeadingZerosFallBack(value, width);
+}
+
+
+template <typename V>
+inline int CountSetBits(V value, int width = (sizeof(V) * 8)) {
+#if COMPILER_HAS_BUILTIN_POPCOUNT
+  if (width == 32) {
+    return __builtin_popcount(static_cast<unsigned>(value));
+  } else if (width == 64) {
+    return __builtin_popcountll(value);
+  }
+#endif
+  return CountSetBitsFallBack(value, width);
+}
+
+
+template <typename V>
+inline int CountTrailingZeros(V value, int width = (sizeof(V) * 8)) {
+#if COMPILER_HAS_BUILTIN_CTZ
+  if (width == 32) {
+    return (value == 0) ? 32 : __builtin_ctz(static_cast<unsigned>(value));
+  } else if (width == 64) {
+    return (value == 0) ? 64 : __builtin_ctzll(value);
+  }
+#endif
+  return CountTrailingZerosFallBack(value, width);
+}
+
+}  // namespace vixl
+
+#endif  // VIXL_COMPILER_INTRINSICS_H