cerc-io/solidity
10
0
Fork 0
mirror of https://github.com/ethereum/solidity synced 2023-10-03 13:03:40 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Slightly changed shuffling.

Browse Source
This commit is contained in:
Daniel Kirchner 2021-03-09 18:09:09 +01:00
parent a5a99620dc
commit 0122f4db02
1 changed files with 16 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
libyul/backends/evm/EVMCodeTransform.cpp
View File

@ -33,6 +33,7 @@
#include <range/v3/algorithm/none_of.hpp>
#include <range/v3/view/drop.hpp>
#include <range/v3/view/enumerate.hpp>
#include <range/v3/view/iota.hpp>
#include <range/v3/view/reverse.hpp>
#include <range/v3/view/take.hpp>
#include <range/v3/view/transform.hpp>
@ -408,33 +409,29 @@ void CodeTransform::operator()(Switch const& _switch)
namespace
{
/// Shuffles @a _container by swapping and popping its elements using the
/// @a _swap and @a _pop functions in order to remove the elements for which
/// Shuffles @a _n elements by swapping and popping using the @a _swap
/// and @a _pop functions in order to remove the elements for which
/// @a _keep returns false.
template<typename C, typename KeepFn, typename SwapFn, typename PopFn>
void shuffle(C& _container, KeepFn&& _keep, SwapFn&& _swap, PopFn&& _pop)
template<typename KeepFn, typename SwapFn, typename PopFn>
void shuffle(int _n, KeepFn&& _keep, SwapFn&& _swap, PopFn&& _pop)
{
set<int> slotsToBeRemoved;
for (auto&& [n, elem]: ranges::views::enumerate(_container))
if (!_keep(elem))
slotsToBeRemoved.emplace(static_cast<int>(n));
for (int slot: ranges::views::iota(0, _n))
if (!_keep(slot))
slotsToBeRemoved.emplace_hint(slotsToBeRemoved.end(), slot);
while (!slotsToBeRemoved.empty())
{
if (_keep(_container.back()))
if (_keep(--_n))
{
yulAssert(!slotsToBeRemoved.empty(), "");
int slot = *slotsToBeRemoved.begin();
slotsToBeRemoved.erase(slotsToBeRemoved.begin());
_swap(slot);
_pop();
}
else
{
slotsToBeRemoved.erase(std::prev(slotsToBeRemoved.end()));
_pop();
}
_pop();
}
}
@ -541,7 +538,7 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
// Shuffle leftover arguments up and pop them.
int stackDeficit = 0;
auto keepSlot = [](bool _v) { return _v; };
auto keepSlot = [&](int _slot) { return keep.at(static_cast<size_t>(_slot)); };
auto swapSlot = [&](int _slot) {
if (m_assembly.stackHeight() - _slot > 17)
stackDeficit = std::max(stackDeficit, m_assembly.stackHeight() - _slot - 17);
@ -555,7 +552,7 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
keep.pop_back();
m_assembly.appendInstruction(evmasm::Instruction::POP);
};
shuffle(keep, keepSlot, swapSlot, popSlot);
shuffle(m_assembly.stackHeight(), keepSlot, swapSlot, popSlot);
if (stackDeficit)
{
@ -788,12 +785,12 @@ void CodeTransform::setupReturnVariablesAndFunctionExit()
layout.at(static_cast<size_t>(slot)) = static_cast<int>(n + 1);
layout[0] = 0;
auto keepSlot = [](auto const& _v) { return _v != -1; };
auto swapSlot = [&](int slot) {
swap(layout.at(static_cast<size_t>(slot)), layout.back());
auto keepSlot = [&](int _slot) { return layout.at(static_cast<size_t>(_slot)) != -1; };
auto swapSlot = [&](int _slot) {
swap(layout.at(static_cast<size_t>(_slot)), layout.back());
};
auto popSlot = [&]() { layout.pop_back(); };
shuffle(layout, keepSlot, swapSlot, popSlot);
shuffle(maxHeight, keepSlot, swapSlot, popSlot);
yulAssert(layout.size() == m_delayedReturnVariables.size() + 1, "");