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| author | Vedant Kumar <vsk@apple.com> | 2017-04-26 02:17:21 +0000 |
|---|---|---|
| committer | Vedant Kumar <vsk@apple.com> | 2017-04-26 02:17:21 +0000 |
| commit | e859ebbd0619c901f2f845c54ce484f5afdd8ab6 (patch) | |
| tree | 3b553163aacada92afca4d47b3c9666bfc65c26d /llvm/tools/llvm-xray/xray-graph-diff.cc | |
| parent | 0827b7ff3ecbe9d826ecc8fadb52717e373200e5 (diff) | |
| download | bcm5719-llvm-e859ebbd0619c901f2f845c54ce484f5afdd8ab6.tar.gz bcm5719-llvm-e859ebbd0619c901f2f845c54ce484f5afdd8ab6.zip | |
[ubsan] Skip alignment checks on allocas with known alignment
It's possible to determine the alignment of an alloca at compile-time.
Use this information to skip emitting some runtime alignment checks.
Testing: check-clang, check-ubsan.
This significantly reduces the amount of alignment checks we emit when
compiling X86ISelLowering.cpp. Here are the numbers from patched/unpatched
clangs based on r301361.
------------------------------------------
| Setup | # of alignment checks |
------------------------------------------
| unpatched, -O0 | 47195 |
| patched, -O0 | 30876 | (-34.6%)
------------------------------------------
llvm-svn: 301377
Diffstat (limited to 'llvm/tools/llvm-xray/xray-graph-diff.cc')
0 files changed, 0 insertions, 0 deletions
