diff options
Diffstat (limited to 'libsolidity/codegen/CompilerUtils.cpp')
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 676d5d4e..deaef017 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -495,14 +495,34 @@ void CompilerUtils::abiDecodeV2(TypePointers const& _parameterTypes, bool _fromM void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type) { - auto repeat = m_context.newTag(); - m_context << repeat; - pushZeroValue(*_type.baseType()); - storeInMemoryDynamic(*_type.baseType()); - m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1; - m_context << Instruction::SUB << Instruction::SWAP1; - m_context << Instruction::DUP2; - m_context.appendConditionalJumpTo(repeat); + if (_type.baseType()->hasSimpleZeroValueInMemory()) + { + solAssert(_type.baseType()->isValueType(), ""); + Whiskers templ(R"({ + let size := mul(length, <element_size>) + // cheap way of zero-initializing a memory range + codecopy(memptr, codesize(), size) + memptr := add(memptr, size) + })"); + templ("element_size", to_string(_type.baseType()->memoryHeadSize())); + m_context.appendInlineAssembly(templ.render(), {"length", "memptr"}); + } + else + { + // TODO: Potential optimization: + // When we create a new multi-dimensional dynamic array, each element + // is initialized to an empty array. It actually does not hurt + // to re-use exactly the same empty array for all elements. Currently, + // a new one is created each time. + auto repeat = m_context.newTag(); + m_context << repeat; + pushZeroValue(*_type.baseType()); + storeInMemoryDynamic(*_type.baseType()); + m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1; + m_context << Instruction::SUB << Instruction::SWAP1; + m_context << Instruction::DUP2; + m_context.appendConditionalJumpTo(repeat); + } m_context << Instruction::SWAP1 << Instruction::POP; } |