1 files changed, 81 insertions, 0 deletions
diff --git a/thirdparty/glslang/SPIRV/bitutils.h b/thirdparty/glslang/SPIRV/bitutils.h
new file mode 100644
index 0000000000..22e44cec26
--- /dev/null
+++ b/thirdparty/glslang/SPIRV/bitutils.h
@@ -0,0 +1,81 @@
+// Copyright (c) 2015-2016 The Khronos Group Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef LIBSPIRV_UTIL_BITUTILS_H_
+#define LIBSPIRV_UTIL_BITUTILS_H_
+
+#include <cstdint>
+#include <cstring>
+
+namespace spvutils {
+
+// Performs a bitwise copy of source to the destination type Dest.
+template <typename Dest, typename Src>
+Dest BitwiseCast(Src source) {
+  Dest dest;
+  static_assert(sizeof(source) == sizeof(dest),
+                "BitwiseCast: Source and destination must have the same size");
+  std::memcpy(static_cast<void*>(&dest), &source, sizeof(dest));
+  return dest;
+}
+
+// SetBits<T, First, Num> returns an integer of type <T> with bits set
+// for position <First> through <First + Num - 1>, counting from the least
+// significant bit. In particular when Num == 0, no positions are set to 1.
+// A static assert will be triggered if First + Num > sizeof(T) * 8, that is,
+// a bit that will not fit in the underlying type is set.
+template <typename T, size_t First = 0, size_t Num = 0>
+struct SetBits {
+  static_assert(First < sizeof(T) * 8,
+                "Tried to set a bit that is shifted too far.");
+  const static T get = (T(1) << First) | SetBits<T, First + 1, Num - 1>::get;
+};
+
+template <typename T, size_t Last>
+struct SetBits<T, Last, 0> {
+  const static T get = T(0);
+};
+
+// This is all compile-time so we can put our tests right here.
+static_assert(SetBits<uint32_t, 0, 0>::get == uint32_t(0x00000000),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 0, 1>::get == uint32_t(0x00000001),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 31, 1>::get == uint32_t(0x80000000),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 1, 2>::get == uint32_t(0x00000006),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 30, 2>::get == uint32_t(0xc0000000),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 0, 31>::get == uint32_t(0x7FFFFFFF),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 0, 32>::get == uint32_t(0xFFFFFFFF),
+              "SetBits failed");
+static_assert(SetBits<uint32_t, 16, 16>::get == uint32_t(0xFFFF0000),
+              "SetBits failed");
+
+static_assert(SetBits<uint64_t, 0, 1>::get == uint64_t(0x0000000000000001LL),
+              "SetBits failed");
+static_assert(SetBits<uint64_t, 63, 1>::get == uint64_t(0x8000000000000000LL),
+              "SetBits failed");
+static_assert(SetBits<uint64_t, 62, 2>::get == uint64_t(0xc000000000000000LL),
+              "SetBits failed");
+static_assert(SetBits<uint64_t, 31, 1>::get == uint64_t(0x0000000080000000LL),
+              "SetBits failed");
+static_assert(SetBits<uint64_t, 16, 16>::get == uint64_t(0x00000000FFFF0000LL),
+              "SetBits failed");
+
+}  // namespace spvutils
+
+#endif  // LIBSPIRV_UTIL_BITUTILS_H_