1 files changed, 182 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/safe_math_clang_gcc_impl.h b/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/safe_math_clang_gcc_impl.h
new file mode 100644
index 0000000000..0f6a1e14d6
--- /dev/null
+++ b/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/safe_math_clang_gcc_impl.h
@@ -0,0 +1,182 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_
+#define BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_
+
+#include <cassert>
+#include <limits>
+#include <type_traits>
+
+#include "anglebase/numerics/safe_conversions.h"
+
+#if !defined(__native_client__) && (defined(__ARMEL__) || defined(__arch64__))
+#    include "anglebase/numerics/safe_math_arm_impl.h"
+#    define BASE_HAS_ASSEMBLER_SAFE_MATH (1)
+#else
+#    define BASE_HAS_ASSEMBLER_SAFE_MATH (0)
+#endif
+
+namespace angle
+{
+namespace base
+{
+namespace internal
+{
+
+// These are the non-functioning boilerplate implementations of the optimized
+// safe math routines.
+#if !BASE_HAS_ASSEMBLER_SAFE_MATH
+template <typename T, typename U>
+struct CheckedMulFastAsmOp
+{
+    static const bool is_supported = false;
+    template <typename V>
+    static constexpr bool Do(T, U, V *)
+    {
+        // Force a compile failure if instantiated.
+        return CheckOnFailure::template HandleFailure<bool>();
+    }
+};
+
+template <typename T, typename U>
+struct ClampedAddFastAsmOp
+{
+    static const bool is_supported = false;
+    template <typename V>
+    static constexpr V Do(T, U)
+    {
+        // Force a compile failure if instantiated.
+        return CheckOnFailure::template HandleFailure<V>();
+    }
+};
+
+template <typename T, typename U>
+struct ClampedSubFastAsmOp
+{
+    static const bool is_supported = false;
+    template <typename V>
+    static constexpr V Do(T, U)
+    {
+        // Force a compile failure if instantiated.
+        return CheckOnFailure::template HandleFailure<V>();
+    }
+};
+
+template <typename T, typename U>
+struct ClampedMulFastAsmOp
+{
+    static const bool is_supported = false;
+    template <typename V>
+    static constexpr V Do(T, U)
+    {
+        // Force a compile failure if instantiated.
+        return CheckOnFailure::template HandleFailure<V>();
+    }
+};
+#endif  // BASE_HAS_ASSEMBLER_SAFE_MATH
+#undef BASE_HAS_ASSEMBLER_SAFE_MATH
+
+template <typename T, typename U>
+struct CheckedAddFastOp
+{
+    static const bool is_supported = true;
+    template <typename V>
+    __attribute__((always_inline)) static constexpr bool Do(T x, U y, V *result)
+    {
+        return !__builtin_add_overflow(x, y, result);
+    }
+};
+
+template <typename T, typename U>
+struct CheckedSubFastOp
+{
+    static const bool is_supported = true;
+    template <typename V>
+    __attribute__((always_inline)) static constexpr bool Do(T x, U y, V *result)
+    {
+        return !__builtin_sub_overflow(x, y, result);
+    }
+};
+
+template <typename T, typename U>
+struct CheckedMulFastOp
+{
+#if defined(__clang__)
+    // TODO(jschuh): Get the Clang runtime library issues sorted out so we can
+    // support full-width, mixed-sign multiply builtins.
+    // https://crbug.com/613003
+    // We can support intptr_t, uintptr_t, or a smaller common type.
+    static const bool is_supported = (IsTypeInRangeForNumericType<intptr_t, T>::value &&
+                                      IsTypeInRangeForNumericType<intptr_t, U>::value) ||
+                                     (IsTypeInRangeForNumericType<uintptr_t, T>::value &&
+                                      IsTypeInRangeForNumericType<uintptr_t, U>::value);
+#else
+    static const bool is_supported = true;
+#endif
+    template <typename V>
+    __attribute__((always_inline)) static constexpr bool Do(T x, U y, V *result)
+    {
+        return CheckedMulFastAsmOp<T, U>::is_supported ? CheckedMulFastAsmOp<T, U>::Do(x, y, result)
+                                                       : !__builtin_mul_overflow(x, y, result);
+    }
+};
+
+template <typename T, typename U>
+struct ClampedAddFastOp
+{
+    static const bool is_supported = ClampedAddFastAsmOp<T, U>::is_supported;
+    template <typename V>
+    __attribute__((always_inline)) static V Do(T x, U y)
+    {
+        return ClampedAddFastAsmOp<T, U>::template Do<V>(x, y);
+    }
+};
+
+template <typename T, typename U>
+struct ClampedSubFastOp
+{
+    static const bool is_supported = ClampedSubFastAsmOp<T, U>::is_supported;
+    template <typename V>
+    __attribute__((always_inline)) static V Do(T x, U y)
+    {
+        return ClampedSubFastAsmOp<T, U>::template Do<V>(x, y);
+    }
+};
+
+template <typename T, typename U>
+struct ClampedMulFastOp
+{
+    static const bool is_supported = ClampedMulFastAsmOp<T, U>::is_supported;
+    template <typename V>
+    __attribute__((always_inline)) static V Do(T x, U y)
+    {
+        return ClampedMulFastAsmOp<T, U>::template Do<V>(x, y);
+    }
+};
+
+template <typename T>
+struct ClampedNegFastOp
+{
+    static const bool is_supported = std::is_signed<T>::value;
+    __attribute__((always_inline)) static T Do(T value)
+    {
+        // Use this when there is no assembler path available.
+        if (!ClampedSubFastAsmOp<T, T>::is_supported)
+        {
+            T result;
+            return !__builtin_sub_overflow(T(0), value, &result) ? result
+                                                                 : std::numeric_limits<T>::max();
+        }
+
+        // Fallback to the normal subtraction path.
+        return ClampedSubFastOp<T, T>::template Do<T>(T(0), value);
+    }
+};
+
+}  // namespace internal
+}  // namespace base
+}  // namespace angle
+
+#endif  // BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_