diff options
| author | Justin Bogner <mail@justinbogner.com> | 2016-12-02 00:11:01 +0000 |
|---|---|---|
| committer | Justin Bogner <mail@justinbogner.com> | 2016-12-02 00:11:01 +0000 |
| commit | 35c5e58f8ce802e49dbadf52942779ec9078f0f2 (patch) | |
| tree | fa5a6e721046da72b96a009b3bbb44f8f36dc593 /llvm/lib/Object/MachOObjectFile.cpp | |
| parent | 8986361fa15a4560d8a241bae726bb237b5c27e5 (diff) | |
| download | bcm5719-llvm-35c5e58f8ce802e49dbadf52942779ec9078f0f2.tar.gz bcm5719-llvm-35c5e58f8ce802e49dbadf52942779ec9078f0f2.zip | |
SDAG: Avoid a large, usually empty SmallVector in a recursive function
This SmallVector is using up 128 bytes on the stack every time despite
almost always being empty[1], and since this function can recurse quite
deeply that adds up to a lot of overhead. We've seen this run afoul of
ulimits in some cases with ASAN on.
Replacing the SmallVector with a std::vector trades an occasional heap
allocation for vastly less stack usage.
[1]: I gathered some stats on an internal test suite and the vector
was non-empty in only 45,000 of 10,000,000 calls to this function.
llvm-svn: 288441
Diffstat (limited to 'llvm/lib/Object/MachOObjectFile.cpp')
0 files changed, 0 insertions, 0 deletions
