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 for loop for assembly memcopy.

Browse Source
This commit is contained in:
chriseth 2017-06-22 18:25:22 +02:00
parent f879489291
commit 0aaa6d876d
1 changed files with 15 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
libsolidity/codegen/CompilerUtils.cpp
View File

@ -305,15 +305,9 @@ void CompilerUtils::memoryCopy32()
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:
for { let i := 0 } lt(i, len) { i := add(i, 32) } {
mstore(add(dst, i), mload(add(src, i)))
}
}
)",
{ "len", "dst", "src" }
@ -327,21 +321,19 @@ void CompilerUtils::memoryCopy()
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 32 bytes at once
for {} iszero(lt(len, 32)) {
dst := add(dst, 32)
src := add(src, 32)
len := sub(len, 32)
}
{ mstore(dst, mload(src)) }
// 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))
// 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" }