diff options
| -rw-r--r-- | libsolidity/codegen/ExpressionCompiler.cpp | 17 | ||||
| -rw-r--r-- | test/libsolidity/SolidityEndToEndTest.cpp | 2 |
2 files changed, 14 insertions, 5 deletions
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index 96ca4296..26acd8a4 100644 --- a/libsolidity/codegen/ExpressionCompiler.cpp +++ b/libsolidity/codegen/ExpressionCompiler.cpp @@ -1476,6 +1476,18 @@ void ExpressionCompiler::appendExternalFunctionCall( utils().storeFreeMemoryPointer(); } + // Touch the end of the output area so that we do not pay for memory resize during the call + // (which we would have to subtract from the gas left) + // We could also just use MLOAD; POP right before the gas calculation, but the optimizer + // would remove that, so we use MSTORE here. + if (!_functionType.gasSet() && retSize > 0) + { + m_context << u256(0); + utils().fetchFreeMemoryPointer(); + // This touches too much, but that way we save some rounding arithmetics + m_context << u256(retSize) << Instruction::ADD << Instruction::MSTORE; + } + // Copy function identifier to memory. utils().fetchFreeMemoryPointer(); if (!_functionType.isBareCall() || manualFunctionId) @@ -1551,10 +1563,7 @@ void ExpressionCompiler::appendExternalFunctionCall( gasNeededByCaller += eth::GasCosts::callValueTransferGas; if (!isCallCode && !isDelegateCall && !existenceChecked) gasNeededByCaller += eth::GasCosts::callNewAccountGas; // we never know - m_context << - gasNeededByCaller << - Instruction::GAS << - Instruction::SUB; + m_context << gasNeededByCaller << Instruction::GAS << Instruction::SUB; } if (isDelegateCall) m_context << Instruction::DELEGATECALL; diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index c8bc7ff9..0ce2851b 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -7191,7 +7191,7 @@ BOOST_AUTO_TEST_CASE(mem_resize_is_not_paid_at_call) // This tests that memory resize for return values is not paid during the call, which would // make the gas calculation overly complex. We access the end of the output area before // the call is made. - // Tests that this also survivecs the optimizer. + // Tests that this also survives the optimizer. char const* sourceCode = R"( contract C { function f() returns (uint[200]) {} |