cerc-io/solidity
16
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

Use builtin iszero for for loop condition rewriting.

Browse Source
This commit is contained in:
chriseth 2019-09-11 16:30:47 +02:00 committed by Daniel Kirchner
parent 324cc71b13
commit 4f80117eef
12 changed files with 111 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
libyul/Dialect.h
View File

@ -61,6 +61,7 @@ struct Dialect: boost::noncopyable
virtual BuiltinFunction const* discardFunction() const { return nullptr; }
virtual BuiltinFunction const* equalityFunction() const { return nullptr; }
virtual BuiltinFunction const* booleanNegationFunction() const { return nullptr; }
virtual std::set<YulString> fixedFunctionNames() const { return {}; }

1
libyul/backends/evm/EVMDialect.h
View File

@ -70,6 +70,7 @@ struct EVMDialect: public Dialect
BuiltinFunctionForEVM const* discardFunction() const override { return builtin("pop"_yulstring); }
BuiltinFunctionForEVM const* equalityFunction() const override { return builtin("eq"_yulstring); }
BuiltinFunctionForEVM const* booleanNegationFunction() const override { return builtin("iszero"_yulstring); }
static EVMDialect const& looseAssemblyForEVM(langutil::EVMVersion _version);
static EVMDialect const& strictAssemblyForEVM(langutil::EVMVersion _version);

1
libyul/backends/wasm/WasmDialect.h
View File

@ -47,6 +47,7 @@ struct WasmDialect: public Dialect
BuiltinFunction const* builtin(YulString _name) const override;
BuiltinFunction const* discardFunction() const override { return builtin("drop"_yulstring); }
BuiltinFunction const* equalityFunction() const override { return builtin("i64.eq"_yulstring); }
BuiltinFunction const* booleanNegationFunction() const override { return builtin("i64.eqz"_yulstring); }
std::set<YulString> fixedFunctionNames() const override { return {"main"_yulstring}; }

6
libyul/optimiser/ForLoopConditionIntoBody.cpp
View File

@ -25,7 +25,7 @@ using namespace yul;
void ForLoopConditionIntoBody::operator()(ForLoop& _forLoop)
{
if (_forLoop.condition->type() != typeid(Literal))
if (m_dialect.booleanNegationFunction() && _forLoop.condition->type() != typeid(Literal))
{
langutil::SourceLocation loc = locationOf(*_forLoop.condition);
_forLoop.body.statements.insert(
@ -33,9 +33,9 @@ void ForLoopConditionIntoBody::operator()(ForLoop& _forLoop)
If {
loc,
make_unique<Expression>(
FunctionalInstruction {
FunctionCall {
loc,
eth::Instruction::ISZERO,
{loc, m_dialect.booleanNegationFunction()->name},
make_vector<Expression>(std::move(*_forLoop.condition))
}
),

8
libyul/optimiser/ForLoopConditionIntoBody.h
View File

@ -17,6 +17,7 @@
#pragma once
#include <libyul/optimiser/ASTWalker.h>
#include <libyul/Dialect.h>
namespace yul
{
@ -29,17 +30,22 @@ namespace yul
* By moving the iteration check part into the ForLoop body, we can apply expression splitter
* to the condition expression.
*
* This rewritter will skip loops that already have literal constant as iteration condition.
* This rewriter will skip loops that already have literal constant as iteration condition.
*
* Requirements:
* - The Disambiguator must be run upfront.
* - To avoid unnecessary rewrite, it is recommended to run this rewriter after StructuralSimplifier.
* - Only works for dialects with a builtin boolean negation function.
*/
class ForLoopConditionIntoBody: public ASTModifier
{
public:
ForLoopConditionIntoBody(Dialect const& _dialect): m_dialect(_dialect) {}
using ASTModifier::operator();
void operator()(ForLoop& _forLoop) override;
private:
Dialect const& m_dialect;
};
}

2
libyul/optimiser/Suite.cpp
View File

@ -33,6 +33,7 @@
#include <libyul/optimiser/ExpressionJoiner.h>
#include <libyul/optimiser/ExpressionInliner.h>
#include <libyul/optimiser/FullInliner.h>
#include <libyul/optimiser/ForLoopConditionIntoBody.h>
#include <libyul/optimiser/ForLoopInitRewriter.h>
#include <libyul/optimiser/Rematerialiser.h>
#include <libyul/optimiser/UnusedPruner.h>
@ -94,6 +95,7 @@ void OptimiserSuite::run(
LiteralRematerialiser{_dialect}(ast);
StructuralSimplifier{}(ast);
ControlFlowSimplifier{_dialect}(ast);
ForLoopConditionIntoBody{_dialect}(ast);
BlockFlattener{}(ast);
// None of the above can make stack problems worse.

6
test/libsolidity/gasTests/abiv2_optimised.sol
View File

@ -17,9 +17,9 @@ contract C {
// optimize-yul: true
// ----
// creation:
// codeDepositCost: 610600
// executionCost: 645
// totalCost: 611245
// codeDepositCost: 624200
// executionCost: 657
// totalCost: 624857
// external:
// a(): 429
// b(uint256): 884

2
test/libyul/YulOptimizerTest.cpp
View File

@ -141,7 +141,7 @@ TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _line
else if (m_optimizerStep == "forLoopConditionIntoBody")
{
disambiguate();
ForLoopConditionIntoBody{}(*m_ast);
ForLoopConditionIntoBody{*m_dialect}(*m_ast);
}
else if (m_optimizerStep == "forLoopInitRewriter")
{

77
test/libyul/yulOptimizerTests/commonSubexpressionEliminator/loop.yul Normal file
View File

@ -0,0 +1,77 @@
{
let _1 := 0
let _33 := calldataload(_1)
let sum_50_141 := _1
let sum_50_146 := _1
let sum_50 := _1
let length_51 := calldataload(_33)
let i_53_142 := _1
let i_53_147 := _1
let i_53 := _1
for { }
1
{
let _108 := 1
let i_53_121 := add(i_53, _108)
let i_53_144 := i_53_121
let i_53_149 := i_53_121
i_53 := i_53_121
}
{
let _109 := lt(i_53, length_51)
let _110 := iszero(_109)
if _110 { break }
let _114_128 := iszero(_109)
if _114_128 { revert(_1, _1) }
let _13_129 := 0x20
let _115_130 := mul(i_53, _13_129)
let _116_131 := add(_33, _115_130)
let _117_132 := add(_116_131, _13_129)
let v_122_133 := calldataload(_117_132)
let sum_50_120 := add(sum_50, v_122_133)
let sum_50_143 := sum_50_120
let sum_50_148 := sum_50_120
sum_50 := sum_50_120
}
sstore(_1, sum_50)
}
// ====
// step: commonSubexpressionEliminator
// ----
// {
// let _1 := 0
// let _33 := calldataload(_1)
// let sum_50_141 := _1
// let sum_50_146 := _1
// let sum_50 := _1
// let length_51 := calldataload(_33)
// let i_53_142 := _1
// let i_53_147 := _1
// let i_53 := _1
// for { }
// 1
// {
// let _108 := 1
// let i_53_121 := add(i_53, _108)
// let i_53_144 := i_53_121
// let i_53_149 := i_53_121
// i_53 := i_53_121
// }
// {
// let _109 := lt(i_53, length_51)
// let _110 := iszero(_109)
// if _110 { break }
// let _114_128 := _110
// if _110 { revert(_1, _1) }
// let _13_129 := 0x20
// let _115_130 := mul(i_53, _13_129)
// let _116_131 := add(_33, _115_130)
// let _117_132 := add(_116_131, _13_129)
// let v_122_133 := calldataload(_117_132)
// let sum_50_120 := add(sum_50, v_122_133)
// let sum_50_143 := sum_50_120
// let sum_50_148 := sum_50_120
// sum_50 := sum_50_120
// }
// sstore(_1, sum_50)
// }

15
test/libyul/yulOptimizerTests/fullSuite/abi_example1.yul
View File

@ -471,8 +471,9 @@
// pos := 64
// let srcPtr := add(_2, pos_1)
// let i := _1
// for { } lt(i, length) { i := add(i, 1) }
// for { } 1 { i := add(i, 1) }
// {
// if iszero(lt(i, length)) { break }
// abi_encode_t_array$_t_contract$_C_$55_$3_memory_to_t_array$_t_address_$3_memory_ptr(mload(srcPtr), pos)
// srcPtr := add(srcPtr, pos_1)
// pos := add(pos, 0x60)
@ -503,8 +504,9 @@
// let src := add(offset, _1)
// if gt(add(add(offset, mul(length, 0x40)), _1), end) { revert(0, 0) }
// let i := 0
// for { } lt(i, length) { i := add(i, 1) }
// for { } 1 { i := add(i, 1) }
// {
// if iszero(lt(i, length)) { break }
// if iszero(slt(add(src, 0x1f), end)) { revert(0, 0) }
// let dst_1 := allocateMemory(array_allocation_size_t_array$_t_uint256_$2_memory(0x2))
// let dst_2 := dst_1
@ -512,8 +514,9 @@
// let _2 := add(src, 0x40)
// if gt(_2, end) { revert(0, 0) }
// let i_1 := 0
// for { } lt(i_1, 0x2) { i_1 := add(i_1, 1) }
// for { } 1 { i_1 := add(i_1, 1) }
// {
// if iszero(lt(i_1, 0x2)) { break }
// mstore(dst_1, calldataload(src_1))
// dst_1 := add(dst_1, _1)
// src_1 := add(src_1, _1)
@ -535,8 +538,9 @@
// let src := add(offset, _1)
// if gt(add(add(offset, mul(length, _1)), _1), end) { revert(0, 0) }
// let i := 0
// for { } lt(i, length) { i := add(i, 1) }
// for { } 1 { i := add(i, 1) }
// {
// if iszero(lt(i, length)) { break }
// mstore(dst, calldataload(src))
// dst := add(dst, _1)
// src := add(src, _1)
@ -546,8 +550,9 @@
// {
// let srcPtr := value
// let i := 0
// for { } lt(i, 0x3) { i := add(i, 1) }
// for { } 1 { i := add(i, 1) }
// {
// if iszero(lt(i, 0x3)) { break }
// mstore(pos, and(mload(srcPtr), sub(shl(160, 1), 1)))
// srcPtr := add(srcPtr, 0x20)
// pos := add(pos, 0x20)

6
test/libyul/yulOptimizerTests/fullSuite/aztec.yul
View File

@ -254,8 +254,9 @@
// let b := add(0x300, mul(n, 0x80))
// let i := 0
// let i_1 := i
// for { } lt(i, n) { i := add(i, 0x01) }
// for { } 1 { i := add(i, 0x01) }
// {
// if iszero(lt(i, n)) { break }
// let _2 := add(calldataload(0x04), mul(i, 0xc0))
// let noteIndex := add(_2, 0x24)
// let k := i_1
@ -373,8 +374,9 @@
// function hashCommitments(notes, n)
// {
// let i := 0
// for { } lt(i, n) { i := add(i, 0x01) }
// for { } 1 { i := add(i, 0x01) }
// {
// if iszero(lt(i, n)) { break }
// calldatacopy(add(0x300, mul(i, 0x80)), add(add(notes, mul(i, 0xc0)), 0x60), 0x80)
// }
// mstore(0, keccak256(0x300, mul(n, 0x80)))

2
test/tools/yulopti.cpp
View File

@ -151,7 +151,7 @@ public:
ForLoopInitRewriter{}(*m_ast);
break;
case 'O':
ForLoopConditionIntoBody{}(*m_ast);
ForLoopConditionIntoBody{m_dialect}(*m_ast);
break;
case 'c':
CommonSubexpressionEliminator::run(m_dialect, *m_ast);