| commit | 3808e8c85d0923c8adfb0645eed4fb0e595baaa8 | |
| author | James Molloy <james.molloy@arm.com> | |
| Fri, 13 Nov 2015 10:02:36 +0000 (13 10:02 +0000) | ||
| committer | James Molloy <james.molloy@arm.com> | |
| Fri, 13 Nov 2015 10:02:36 +0000 (13 10:02 +0000) | ||
| tree | bc473db00e01185a6ce9a39636f2a756ce87a579 | treesnapshot (tar.gz zip) |
| parent | 63f8155d9d57520dcb065c3f8cf4295911a877f9 | commitdiff |
[SDAG] Fix expansion of BITREVERSE
Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash.
What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size.
Use an APInt for the shift and VT.getScalarSizeInBits().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253023 91177308-0d34-0410-b5e6-96231b3b80d8
Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash.
What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size.
Use an APInt for the shift and VT.getScalarSizeInBits().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253023 91177308-0d34-0410-b5e6-96231b3b80d8
| lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | diffblobblamehistory | |
| test/CodeGen/AArch64/bitreverse.ll | diffblobblamehistory |