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AK+Everywhere: Replace __builtin bit functions

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In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
This commit is contained in:
Nick Johnson 2021-12-19 15:46:55 -06:00 • committed by Andreas Kling
parent 26bb3e1acf
commit 08e4a1a4dc
20 changed files with 108 additions and 115 deletions
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15
AK/UFixedBigInt.h
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@ -6,6 +6,7 @@
#pragma once
#include <AK/BuiltinWrappers.h>
#include <AK/Checked.h>
#include <AK/Concepts.h>
#include <AK/Format.h>
@ -90,9 +91,9 @@ public:
constexpr size_t clz() const requires(IsSame<T, u64>)
{
if (m_high)
return __builtin_clzll(m_high);
return count_leading_zeroes(m_high);
else
return sizeof(T) * 8 + __builtin_clzll(m_low);
return sizeof(T) * 8 + count_leading_zeroes(m_low);
}
constexpr size_t clz() const requires(!IsSame<T, u64>)
{
@ -104,9 +105,9 @@ public:
constexpr size_t ctz() const requires(IsSame<T, u64>)
{
if (m_low)
return __builtin_ctzll(m_low);
return count_trailing_zeroes(m_low);
else
return sizeof(T) * 8 + __builtin_ctzll(m_high);
return sizeof(T) * 8 + count_trailing_zeroes(m_high);
}
constexpr size_t ctz() const requires(!IsSame<T, u64>)
{
@ -598,7 +599,7 @@ public:
R x1 = *this;
R x2 = *this * *this;
u64 exp_copy = exp;
for (ssize_t i = sizeof(u64) * 8 - __builtin_clzll(exp) - 2; i >= 0; --i) {
for (ssize_t i = sizeof(u64) * 8 - count_leading_zeroes(exp) - 2; i >= 0; --i) {
if (exp_copy & 1u) {
x2 *= x1;
x1 *= x1;
@ -642,7 +643,7 @@ public:
U res = 1;
u64 exp_copy = exp;
for (size_t i = sizeof(u64) - __builtin_clzll(exp) - 1u; i < exp; ++i) {
for (size_t i = sizeof(u64) - count_leading_zeroes(exp) - 1u; i < exp; ++i) {
res *= res;
res %= mod;
if (exp_copy & 1u) {
@ -682,7 +683,7 @@ public:
constexpr size_t logn(u64 base)
{
// FIXME: proper rounding
return log2() / (sizeof(u64) - __builtin_clzll(base));
return log2() / (sizeof(u64) - count_leading_zeroes(base));
}
template<Unsigned U>
requires(sizeof(U) > sizeof(u64)) constexpr size_t logn(U base)