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| author | Sanjay Patel <spatel@rotateright.com> | 2021-05-18 13:28:31 -0400 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2021-05-18 13:32:07 -0400 |
| commit | 6d949a9c8fa440b0b91c9a96a30a9b7c1b7cf1e1 (patch) | |
| tree | fa5b77af889149e8c1bee6f0a15b2a9beeda9f11 /llvm/lib/Bitcode/Reader/BitcodeReader.cpp | |
| parent | 0b031eeefa8f510f78a4b63d52ce12bab28bf54c (diff) | |
[InstCombine] restrict funnel shift match to avoid miscompile
As noted in the post-commit discussion for:
https://reviews.llvm.org/rGabd7529625a73f405e40a63dcc446c41d51a219e
...that change exposed a logic hole that allows a miscompile
if the shift amount could exceed the narrow width:
https://alive2.llvm.org/ce/z/-i_CiM
https://alive2.llvm.org/ce/z/NaYz28
The restriction isn't necessary for a rotate (same operand for
both shifts), so we should adjust the matching for the shift
value as a follow-up enhancement:
https://alive2.llvm.org/ce/z/ahuuQb
Diffstat (limited to 'llvm/lib/Bitcode/Reader/BitcodeReader.cpp')
0 files changed, 0 insertions, 0 deletions