Squashed 'external/parallel-rdp/parallel-rdp-standalone/' content from commit 3f59f61f2c

git-subtree-dir: external/parallel-rdp/parallel-rdp-standalone
git-subtree-split: 3f59f61f2c1c56424356003041df5e4a10612049

util/bitops.hpp

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+/* Copyright (c) 2017-2023 Hans-Kristian Arntzen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
+
+namespace Util
+{
+#ifdef __GNUC__
+#define leading_zeroes_(x) ((x) == 0 ? 32 : __builtin_clz(x))
+#define trailing_zeroes_(x) ((x) == 0 ? 32 : __builtin_ctz(x))
+#define trailing_ones_(x) __builtin_ctz(~uint32_t(x))
+#define leading_zeroes64_(x) ((x) == 0 ? 64 : __builtin_clzll(x))
+#define trailing_zeroes64_(x) ((x) == 0 ? 64 : __builtin_ctzll(x))
+#define trailing_ones64_(x) __builtin_ctzll(~uint64_t(x))
+#define popcount32_(x) __builtin_popcount(x)
+
+static inline uint32_t leading_zeroes(uint32_t x) { return leading_zeroes_(x); }
+static inline uint32_t trailing_zeroes(uint32_t x) { return trailing_zeroes_(x); }
+static inline uint32_t trailing_ones(uint32_t x) { return trailing_ones_(x); }
+static inline uint32_t leading_zeroes64(uint64_t x) { return leading_zeroes64_(x); }
+static inline uint32_t trailing_zeroes64(uint64_t x) { return trailing_zeroes64_(x); }
+static inline uint32_t trailing_ones64(uint64_t x) { return trailing_ones64_(x); }
+static inline uint32_t popcount32(uint32_t x) { return popcount32_(x); }
+
+#elif defined(_MSC_VER)
+namespace Internal
+{
+static inline uint32_t popcount32(uint32_t x)
+{
+	return __popcnt(x);
+}
+
+static inline uint32_t clz(uint32_t x)
+{
+	unsigned long result;
+	if (_BitScanReverse(&result, x))
+		return 31 - result;
+	else
+		return 32;
+}
+
+static inline uint32_t ctz(uint32_t x)
+{
+	unsigned long result;
+	if (_BitScanForward(&result, x))
+		return result;
+	else
+		return 32;
+}
+
+static inline uint32_t clz64(uint64_t x)
+{
+	unsigned long result;
+	if (_BitScanReverse64(&result, x))
+		return 63 - result;
+	else
+		return 64;
+}
+
+static inline uint32_t ctz64(uint64_t x)
+{
+	unsigned long result;
+	if (_BitScanForward64(&result, x))
+		return result;
+	else
+		return 64;
+}
+}
+
+static inline uint32_t leading_zeroes(uint32_t x) { return Internal::clz(x); }
+static inline uint32_t trailing_zeroes(uint32_t x) { return Internal::ctz(x); }
+static inline uint32_t trailing_ones(uint32_t x) { return Internal::ctz(~x); }
+static inline uint32_t leading_zeroes64(uint64_t x) { return Internal::clz64(x); }
+static inline uint32_t trailing_zeroes64(uint64_t x) { return Internal::ctz64(x); }
+static inline uint32_t trailing_ones64(uint64_t x) { return Internal::ctz64(~x); }
+static inline uint32_t popcount32(uint32_t x) { return Internal::popcount32(x); }
+#else
+#error "Implement me."
+#endif
+
+template <typename T>
+inline void for_each_bit64(uint64_t value, const T &func)
+{
+	while (value)
+	{
+		uint32_t bit = trailing_zeroes64(value);
+		func(bit);
+		value &= ~(1ull << bit);
+	}
+}
+
+template <typename T>
+inline void for_each_bit(uint32_t value, const T &func)
+{
+	while (value)
+	{
+		uint32_t bit = trailing_zeroes(value);
+		func(bit);
+		value &= ~(1u << bit);
+	}
+}
+
+template <typename T>
+inline void for_each_bit_range(uint32_t value, const T &func)
+{
+	if (value == ~0u)
+	{
+		func(0, 32);
+		return;
+	}
+
+	uint32_t bit_offset = 0;
+	while (value)
+	{
+		uint32_t bit = trailing_zeroes(value);
+		bit_offset += bit;
+		value >>= bit;
+		uint32_t range = trailing_ones(value);
+		func(bit_offset, range);
+		value &= ~((1u << range) - 1);
+	}
+}
+
+template <typename T>
+inline bool is_pow2(T value)
+{
+	return (value & (value - T(1))) == T(0);
+}
+
+inline uint32_t next_pow2(uint32_t v)
+{
+	v--;
+	v |= v >> 16;
+	v |= v >> 8;
+	v |= v >> 4;
+	v |= v >> 2;
+	v |= v >> 1;
+	return v + 1;
+}
+
+inline uint32_t prev_pow2(uint32_t v)
+{
+	return next_pow2(v + 1) >> 1;
+}
+
+inline uint32_t floor_log2(uint32_t v)
+{
+	return 31 - leading_zeroes(v);
+}
+}