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Merged
merged 4 commits into from
Jul 19, 2021
Merged

Patch 2 #2

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d89adac
Update cxa_thread_atexit.cpp
AZero13 Jul 19, 2021
11fc84d
Make more MathExtras constexpr
AZero13 Jul 19, 2021
1aa2699
Update MathExtras.h
AZero13 Jul 19, 2021
c9f119f
Update cxa_thread_atexit.cpp
AZero13 Jul 19, 2021
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96 changes: 59 additions & 37 deletions llvm/include/llvm/Support/MathExtras.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,15 +27,7 @@
#endif

#ifdef _MSC_VER
// Declare these intrinsics manually rather including intrin.h. It's very
// expensive, and MathExtras.h is popular.
// #include <intrin.h>
extern "C" {
unsigned char _BitScanForward(unsigned long *_Index, unsigned long _Mask);
unsigned char _BitScanForward64(unsigned long *_Index, unsigned __int64 _Mask);
unsigned char _BitScanReverse(unsigned long *_Index, unsigned long _Mask);
unsigned char _BitScanReverse64(unsigned long *_Index, unsigned __int64 _Mask);
}
#include <intrin.h>
#endif

namespace llvm {
Expand Down Expand Up @@ -88,9 +80,9 @@ constexpr float ef = 2.71828183F, // (0x1.5bf0a8P+1) https://oeis.org/A

namespace detail {
template <typename T, std::size_t SizeOfT> struct TrailingZerosCounter {
static unsigned count(T Val, ZeroBehavior) {
constexpr static unsigned count(T Val, ZeroBehavior) {
if (!Val)
return std::numeric_limits<T>::digits;
return std::numeric_limits<T>::digits;
if (Val & 0x1)
return 0;

Expand All @@ -112,32 +104,46 @@ template <typename T, std::size_t SizeOfT> struct TrailingZerosCounter {

#if defined(__GNUC__) || defined(_MSC_VER)
template <typename T> struct TrailingZerosCounter<T, 4> {
static unsigned count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 32;
constexpr static unsigned count(T Val, ZeroBehavior ZB) {

#if __has_builtin(__builtin_ctz) || defined(__GNUC__)
return __builtin_ctz(Val);
#elif defined(_MSC_VER)
unsigned long Index;
#if defined(_M_AMD64)
return __tzcnt(Val);
#elif defined(_M_ARM) || defined(_M_ARM64)
return _CountTrailingZeros(Val);
#else
constexpr unsigned long Index = 0;
_BitScanForward(&Index, Val);
return Index;
#endif
#else
#error unsupported architecture
#endif
}
};

#if !defined(_MSC_VER) || defined(_M_X64)
template <typename T> struct TrailingZerosCounter<T, 8> {
static unsigned count(T Val, ZeroBehavior ZB) {
constexpr static unsigned count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 64;

#if __has_builtin(__builtin_ctzll) || defined(__GNUC__)
return __builtin_ctzll(Val);
#elif defined(_MSC_VER)
unsigned long Index;
#if defined(_M_AMD64)
return __tzcnt(Val);
#elif defined(_M_ARM) || defined(_M_ARM64)
return _CountTrailingZeros64(Val);
#else
constexpr unsigned long Index = 0;
_BitScanForward64(&Index, Val);
return Index;
#endif
#else
#error unsupported architecture
#endif
}
};
Expand All @@ -153,7 +159,7 @@ template <typename T> struct TrailingZerosCounter<T, 8> {
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
/// valid arguments.
template <typename T>
unsigned countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
constexpr unsigned countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
Expand All @@ -162,9 +168,9 @@ unsigned countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {

namespace detail {
template <typename T, std::size_t SizeOfT> struct LeadingZerosCounter {
static unsigned count(T Val, ZeroBehavior) {
constexpr static unsigned count(T Val, ZeroBehavior) {
if (!Val)
return std::numeric_limits<T>::digits;
return std::numeric_limits<T>::digits;

// Bisection method.
unsigned ZeroBits = 0;
Expand All @@ -181,32 +187,48 @@ template <typename T, std::size_t SizeOfT> struct LeadingZerosCounter {

#if defined(__GNUC__) || defined(_MSC_VER)
template <typename T> struct LeadingZerosCounter<T, 4> {
static unsigned count(T Val, ZeroBehavior ZB) {
constexpr static unsigned count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 32;

#if __has_builtin(__builtin_clz) || defined(__GNUC__)
return __builtin_clz(Val);
#elif defined(_MSC_VER)
unsigned long Index;
#if defined(_M_AMD64)
return __lzcnt(Val);
#elif defined(_M_ARM) || defined(_M_ARM64)
return _CountLeadingZeros(Val);
#else
constexpr unsigned long Index = 0;
_BitScanReverse(&Index, Val);
return Index ^ 31;
#endif
#else
#error unsupported architecture
#endif
}
};

#if !defined(_MSC_VER) || defined(_M_X64)
template <typename T> struct LeadingZerosCounter<T, 8> {
static unsigned count(T Val, ZeroBehavior ZB) {
constexpr static unsigned count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 64;

#if __has_builtin(__builtin_clzll) || defined(__GNUC__)
return __builtin_clzll(Val);
#elif defined(_MSC_VER)
unsigned long Index;
_BitScanReverse64(&Index, Val);
return Index ^ 63;
#if defined(_M_AMD64)
return __lzcnt(Val);
#elif defined(_M_ARM) || defined(_M_ARM64)
return _CountLeadingZeros64(Val);
#else
constexpr unsigned long Index = 0
_BitScanReverse(&Index, Val);
return Index ^ 31;
#endif
#else
#error unsupported architecture
#endif
}
};
Expand All @@ -222,7 +244,7 @@ template <typename T> struct LeadingZerosCounter<T, 8> {
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
/// valid arguments.
template <typename T>
unsigned countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
constexpr unsigned countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
Expand All @@ -236,7 +258,7 @@ unsigned countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
/// valid arguments.
template <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
constexpr template <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
if (ZB == ZB_Max && Val == 0)
return std::numeric_limits<T>::max();

Expand All @@ -245,7 +267,7 @@ template <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {

/// Create a bitmask with the N right-most bits set to 1, and all other
/// bits set to 0. Only unsigned types are allowed.
template <typename T> T maskTrailingOnes(unsigned N) {
constexpr template <typename T> T maskTrailingOnes(unsigned N) {
static_assert(std::is_unsigned<T>::value, "Invalid type!");
const unsigned Bits = CHAR_BIT * sizeof(T);
assert(N <= Bits && "Invalid bit index");
Expand All @@ -254,19 +276,19 @@ template <typename T> T maskTrailingOnes(unsigned N) {

/// Create a bitmask with the N left-most bits set to 1, and all other
/// bits set to 0. Only unsigned types are allowed.
template <typename T> T maskLeadingOnes(unsigned N) {
constexpr template <typename T> T maskLeadingOnes(unsigned N) {
return ~maskTrailingOnes<T>(CHAR_BIT * sizeof(T) - N);
}

/// Create a bitmask with the N right-most bits set to 0, and all other
/// bits set to 1. Only unsigned types are allowed.
template <typename T> T maskTrailingZeros(unsigned N) {
constexpr template <typename T> T maskTrailingZeros(unsigned N) {
return maskLeadingOnes<T>(CHAR_BIT * sizeof(T) - N);
}

/// Create a bitmask with the N left-most bits set to 0, and all other
/// bits set to 1. Only unsigned types are allowed.
template <typename T> T maskLeadingZeros(unsigned N) {
constexpr template <typename T> T maskLeadingZeros(unsigned N) {
return maskTrailingOnes<T>(CHAR_BIT * sizeof(T) - N);
}

Expand All @@ -277,7 +299,7 @@ template <typename T> T maskLeadingZeros(unsigned N) {
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
/// valid arguments.
template <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) {
constexpr template <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) {
if (ZB == ZB_Max && Val == 0)
return std::numeric_limits<T>::max();

Expand Down Expand Up @@ -314,28 +336,28 @@ T reverseBits(T Val) {

#if __has_builtin(__builtin_bitreverse8)
template<>
inline uint8_t reverseBits<uint8_t>(uint8_t Val) {
constexpr inline uint8_t reverseBits<uint8_t>(uint8_t Val) {
return __builtin_bitreverse8(Val);
}
#endif

#if __has_builtin(__builtin_bitreverse16)
template<>
inline uint16_t reverseBits<uint16_t>(uint16_t Val) {
constexpr inline uint16_t reverseBits<uint16_t>(uint16_t Val) {
return __builtin_bitreverse16(Val);
}
#endif

#if __has_builtin(__builtin_bitreverse32)
template<>
inline uint32_t reverseBits<uint32_t>(uint32_t Val) {
constexpr inline uint32_t reverseBits<uint32_t>(uint32_t Val) {
return __builtin_bitreverse32(Val);
}
#endif

#if __has_builtin(__builtin_bitreverse64)
template<>
inline uint64_t reverseBits<uint64_t>(uint64_t Val) {
constexpr inline uint64_t reverseBits<uint64_t>(uint64_t Val) {
return __builtin_bitreverse64(Val);
}
#endif
Expand Down