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