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Tidy EightBit library header usage (avoids compilation error with latest VS2019, "Memory.h")

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Signed-off-by: Adrian Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon
2021-05-29 10:31:32 +01:00
parent b1ca06447f
commit d199adb027
18 changed files with 45 additions and 58 deletions
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inc/EightBitCompilerDefinitions.h
+20 -25
View File
@@ -1,14 +1,15 @@
#pragma once
#include <cassert>
#ifdef _MSC_VER
# include <intrin.h>
#endif
#ifdef __GNUG__
# include <x86intrin.h>
#else
#endif
#if !(defined(_MSC_VER) || defined(__GNUG__))
# include <cassert>
# include <bitset>
#endif
@@ -16,12 +17,13 @@ namespace EightBit {
[[nodiscard]] int countBits(uint8_t value) noexcept;
[[nodiscard]] bool oddParity(uint8_t value) noexcept;
[[nodiscard]] int findFirstSet(unsigned long value) noexcept;
constexpr void assume(int expression);
}
inline int EightBit::countBits(uint8_t value) noexcept {
#ifdef _MSC_VER
#if defined(_MSC_VER)
return __popcnt(value);
#elif defined(__GNUG__)
return __builtin_popcount(value);
#else
/*
Published in 1988, the C Programming Language 2nd Ed.
@@ -40,12 +42,16 @@ inline int EightBit::countBits(uint8_t value) noexcept {
}
inline bool EightBit::oddParity(const uint8_t value) noexcept {
#ifdef __GNUG__
return __builtin_parity(value)
#else
return countBits(value) % 2;
#endif
}
inline int EightBit::findFirstSet(const unsigned long value) noexcept {
#ifdef _MSC_VER
unsigned long index;
#if defined(_MSC_VER)
unsigned long index = 0;
if (_BitScanForward(&index, value))
return index + 1;
return 0;
@@ -60,44 +66,33 @@ inline int EightBit::findFirstSet(const unsigned long value) noexcept {
#endif
}
inline constexpr void EightBit::assume(const int expression) {
#ifdef _MSC_VER
__assume(expression);
#elif defined(__GNUG__)
if (!expression)
__builtin_unreachable();
#else
assert(expression);
#endif
}
#define ASSUME(x) EightBit::assume(x)
#define PARITY(x) EightBit::oddParity(x)
#ifdef _MSC_VER
# define ASSUME(x) __assume(x);
# define LIKELY(x) (x)
# define UNLIKELY(x) (x)
# define PARITY(x) EightBit::oddParity(x)
# define UNREACHABLE { ASSUME(0); throw std::exception("unreachable"); }
#elif defined(__GNUG__)
# define ASSUME(x) { if (!x) __builtin_unreachable(); }
# define LIKELY(x) __builtin_expect(!!(x), 1)
# define UNLIKELY(x) __builtin_expect(!!(x), 0)
# define PARITY(x) __builtin_parity(x)
# define UNREACHABLE __builtin_unreachable();
#else
# define ASSUME(x) assert(x);
# define LIKELY(x) (x)
# define UNLIKELY(x) (x)
# define PARITY(x) EightBit::oddParity(x)
# define UNREACHABLE ASSUME(0)
#endif
inc/Processor.h
+7 -1
View File
@@ -11,9 +11,15 @@
namespace EightBit {
class Processor : public ClockedChip {
public:
// http://graphics.stanford.edu/~seander/bithacks.html#FixedSignExtend
// b: number of bits representing the number in x
// x: sign extend this b-bit number to r
[[nodiscard]] static int8_t signExtend(int b, uint8_t x) noexcept;
[[nodiscard]] static constexpr int8_t signExtend(int b, uint8_t x) noexcept {
const uint8_t m = bit(b - 1); // mask can be pre-computed if b is fixed
x = x & (bit(b) - 1); // (Skip this if bits in x above position b are already zero.)
const auto result = (x ^ m) - m;
return result;
}
~Processor() = default;