PKGBUILDs/extra/gn/0001-Add-ARM-headers-back.patch

From 65fd24e06b2f1b559a7c788d5b90afacf9dba9a4 Mon Sep 17 00:00:00 2001
From: Kevin Mihelich <kevin@archlinuxarm.org>
Date: Sun, 12 Aug 2018 18:11:42 -0600
Subject: [PATCH] Add ARM headers back

---
 base/numerics/safe_conversions_arm_impl.h |  51 +++++++++
 base/numerics/safe_math_arm_impl.h        | 122 ++++++++++++++++++++++
 2 files changed, 173 insertions(+)
 create mode 100644 base/numerics/safe_conversions_arm_impl.h
 create mode 100644 base/numerics/safe_math_arm_impl.h

diff --git a/base/numerics/safe_conversions_arm_impl.h b/base/numerics/safe_conversions_arm_impl.h
new file mode 100644
index 00000000..da5813f6
--- /dev/null
+++ b/base/numerics/safe_conversions_arm_impl.h
@@ -0,0 +1,51 @@
+// 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_CONVERSIONS_ARM_IMPL_H_
+#define BASE_NUMERICS_SAFE_CONVERSIONS_ARM_IMPL_H_
+
+#include <cassert>
+#include <limits>
+#include <type_traits>
+
+#include "base/numerics/safe_conversions_impl.h"
+
+namespace base {
+namespace internal {
+
+// Fast saturation to a destination type.
+template <typename Dst, typename Src>
+struct SaturateFastAsmOp {
+  static const bool is_supported =
+      std::is_signed<Src>::value && std::is_integral<Dst>::value &&
+      std::is_integral<Src>::value &&
+      IntegerBitsPlusSign<Src>::value <= IntegerBitsPlusSign<int32_t>::value &&
+      IntegerBitsPlusSign<Dst>::value <= IntegerBitsPlusSign<int32_t>::value &&
+      !IsTypeInRangeForNumericType<Dst, Src>::value;
+
+  __attribute__((always_inline)) static Dst Do(Src value) {
+    int32_t src = value;
+    typename std::conditional<std::is_signed<Dst>::value, int32_t,
+                              uint32_t>::type result;
+    if (std::is_signed<Dst>::value) {
+      asm("ssat %[dst], %[shift], %[src]"
+          : [dst] "=r"(result)
+          : [src] "r"(src), [shift] "n"(IntegerBitsPlusSign<Dst>::value <= 32
+                                            ? IntegerBitsPlusSign<Dst>::value
+                                            : 32));
+    } else {
+      asm("usat %[dst], %[shift], %[src]"
+          : [dst] "=r"(result)
+          : [src] "r"(src), [shift] "n"(IntegerBitsPlusSign<Dst>::value < 32
+                                            ? IntegerBitsPlusSign<Dst>::value
+                                            : 31));
+    }
+    return static_cast<Dst>(result);
+  }
+};
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // BASE_NUMERICS_SAFE_CONVERSIONS_ARM_IMPL_H_
diff --git a/base/numerics/safe_math_arm_impl.h b/base/numerics/safe_math_arm_impl.h
new file mode 100644
index 00000000..a7cda1bb
--- /dev/null
+++ b/base/numerics/safe_math_arm_impl.h
@@ -0,0 +1,122 @@
+// 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_ARM_IMPL_H_
+#define BASE_NUMERICS_SAFE_MATH_ARM_IMPL_H_
+
+#include <cassert>
+#include <limits>
+#include <type_traits>
+
+#include "base/numerics/safe_conversions.h"
+
+namespace base {
+namespace internal {
+
+template <typename T, typename U>
+struct CheckedMulFastAsmOp {
+  static const bool is_supported =
+      FastIntegerArithmeticPromotion<T, U>::is_contained;
+
+  // The following is much more efficient than the Clang and GCC builtins for
+  // performing overflow-checked multiplication when a twice wider type is
+  // available. The below compiles down to 2-3 instructions, depending on the
+  // width of the types in use.
+  // As an example, an int32_t multiply compiles to:
+  //    smull   r0, r1, r0, r1
+  //    cmp     r1, r1, asr #31
+  // And an int16_t multiply compiles to:
+  //    smulbb  r1, r1, r0
+  //    asr     r2, r1, #16
+  //    cmp     r2, r1, asr #15
+  template <typename V>
+  __attribute__((always_inline)) static bool Do(T x, U y, V* result) {
+    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
+    Promotion presult;
+
+    presult = static_cast<Promotion>(x) * static_cast<Promotion>(y);
+    *result = static_cast<V>(presult);
+    return IsValueInRangeForNumericType<V>(presult);
+  }
+};
+
+template <typename T, typename U>
+struct ClampedAddFastAsmOp {
+  static const bool is_supported =
+      BigEnoughPromotion<T, U>::is_contained &&
+      IsTypeInRangeForNumericType<
+          int32_t,
+          typename BigEnoughPromotion<T, U>::type>::value;
+
+  template <typename V>
+  __attribute__((always_inline)) static V Do(T x, U y) {
+    // This will get promoted to an int, so let the compiler do whatever is
+    // clever and rely on the saturated cast to bounds check.
+    if (IsIntegerArithmeticSafe<int, T, U>::value)
+      return saturated_cast<V>(x + y);
+
+    int32_t result;
+    int32_t x_i32 = x;
+    int32_t y_i32 = y;
+
+    asm("qadd %[result], %[first], %[second]"
+        : [result] "=r"(result)
+        : [first] "r"(x_i32), [second] "r"(y_i32));
+    return saturated_cast<V>(result);
+  }
+};
+
+template <typename T, typename U>
+struct ClampedSubFastAsmOp {
+  static const bool is_supported =
+      BigEnoughPromotion<T, U>::is_contained &&
+      IsTypeInRangeForNumericType<
+          int32_t,
+          typename BigEnoughPromotion<T, U>::type>::value;
+
+  template <typename V>
+  __attribute__((always_inline)) static V Do(T x, U y) {
+    // This will get promoted to an int, so let the compiler do whatever is
+    // clever and rely on the saturated cast to bounds check.
+    if (IsIntegerArithmeticSafe<int, T, U>::value)
+      return saturated_cast<V>(x - y);
+
+    int32_t result;
+    int32_t x_i32 = x;
+    int32_t y_i32 = y;
+
+    asm("qsub %[result], %[first], %[second]"
+        : [result] "=r"(result)
+        : [first] "r"(x_i32), [second] "r"(y_i32));
+    return saturated_cast<V>(result);
+  }
+};
+
+template <typename T, typename U>
+struct ClampedMulFastAsmOp {
+  static const bool is_supported = CheckedMulFastAsmOp<T, U>::is_supported;
+
+  template <typename V>
+  __attribute__((always_inline)) static V Do(T x, U y) {
+    // Use the CheckedMulFastAsmOp for full-width 32-bit values, because
+    // it's fewer instructions than promoting and then saturating.
+    if (!IsIntegerArithmeticSafe<int32_t, T, U>::value &&
+        !IsIntegerArithmeticSafe<uint32_t, T, U>::value) {
+      V result;
+      if (CheckedMulFastAsmOp<T, U>::Do(x, y, &result))
+        return result;
+      return CommonMaxOrMin<V>(IsValueNegative(x) ^ IsValueNegative(y));
+    }
+
+    assert((FastIntegerArithmeticPromotion<T, U>::is_contained));
+    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
+    return saturated_cast<V>(static_cast<Promotion>(x) *
+                             static_cast<Promotion>(y));
+  }
+};
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // BASE_NUMERICS_SAFE_MATH_ARM_IMPL_H_
-- 
2.18.0