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author | chriseth <c@ethdev.com> | 2016-12-12 00:51:17 +0800 |
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committer | chriseth <c@ethdev.com> | 2016-12-12 00:57:15 +0800 |
commit | bfa4f451160bff14d79bf6e25d969b1f586a8b00 (patch) | |
tree | dd16eb515fd3c1594a044d1ec7235782ef6ffa36 /libsolidity/codegen/CompilerUtils.cpp | |
parent | 4184525d4ad7aff3acb2d521c3cdc21054e36eff (diff) | |
download | dexon-solidity-bfa4f451160bff14d79bf6e25d969b1f586a8b00.tar.gz dexon-solidity-bfa4f451160bff14d79bf6e25d969b1f586a8b00.tar.zst dexon-solidity-bfa4f451160bff14d79bf6e25d969b1f586a8b00.zip |
Split memcopy into three functions.
Diffstat (limited to 'libsolidity/codegen/CompilerUtils.cpp')
-rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 114 |
1 files changed, 63 insertions, 51 deletions
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 8b94bd0d..da2e78e8 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -298,61 +298,73 @@ void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type) m_context << Instruction::SWAP1 << Instruction::POP; } -void CompilerUtils::memoryCopy(bool _useIdentityPrecompile) +void CompilerUtils::memoryCopyPrecompile() { - //@TODO do not use ::CALL if less than 32 bytes? + // Stack here: size target source + m_context.appendInlineAssembly(R"( + { + let words := div(add(len, 31), 32) + let cost := add(15, mul(3, words)) + jumpi(invalidJumpLabel, iszero(call(cost, $identityContractAddress, 0, src, len, dst, len))) + } + )", + { "len", "dst", "src" }, + map<string, string> { + { "$identityContractAddress", toString(identityContractAddress) } + } + ); + m_context << Instruction::POP << Instruction::POP << Instruction::POP; +} + +void CompilerUtils::memoryCopy32() +{ // Stack here: size target source - if (!_useIdentityPrecompile) - { - m_context.appendInlineAssembly(R"( - { - // expects three locals: src, dst, len - - // copy 32 bytes at once - start32: - jumpi(end32, lt(len, 32)) - mstore(dst, mload(src)) - dst := add(dst, 32) - src := add(src, 32) - len := sub(len, 32) - jump(start32) - end32: - - // copy the remainder (0 < len < 32) - let mask := sub(exp(256, sub(32, len)), 1) - let srcpart := and(mload(src), not(mask)) - let dstpart := and(mload(dst), mask) - mstore(dst, or(srcpart, dstpart)) - } - )", - { "len", "dst", "src" } - ); - m_context << Instruction::POP; - m_context << Instruction::POP; - m_context << Instruction::POP; - return; - } - else - { - m_context.appendInlineAssembly(R"( - { - let words := div(add(len, 31), 32) - let cost := add(15, mul(3, words)) - jump(invalidJumpLabel, iszero(call(cost, $identityContractAddress, 0, src, len, dst, len))) - } - )", - { "len", "dst", "src" }, - map<string, string> { - { "$identityContractAddress", toString(identityContractAddress) } - } - ); - m_context << Instruction::POP; - m_context << Instruction::POP; - m_context << Instruction::POP; - return; - } + m_context.appendInlineAssembly(R"( + { + jumpi(end, eq(len, 0)) + start: + mstore(dst, mload(src)) + jumpi(end, iszero(gt(len, 32))) + dst := add(dst, 32) + src := add(src, 32) + len := sub(len, 32) + jump(start) + end: + } + )", + { "len", "dst", "src" } + ); + m_context << Instruction::POP << Instruction::POP << Instruction::POP; +} + +void CompilerUtils::memoryCopy() +{ + // Stack here: size target source + + m_context.appendInlineAssembly(R"( + { + // copy 32 bytes at once + start32: + jumpi(end32, lt(len, 32)) + mstore(dst, mload(src)) + dst := add(dst, 32) + src := add(src, 32) + len := sub(len, 32) + jump(start32) + end32: + + // copy the remainder (0 < len < 32) + let mask := sub(exp(256, sub(32, len)), 1) + let srcpart := and(mload(src), not(mask)) + let dstpart := and(mload(dst), mask) + mstore(dst, or(srcpart, dstpart)) + } + )", + { "len", "dst", "src" } + ); + m_context << Instruction::POP << Instruction::POP << Instruction::POP; } void CompilerUtils::splitExternalFunctionType(bool _leftAligned) |