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| author | Craig Topper <craig.topper@intel.com> | 2017-06-14 17:04:59 +0000 |
|---|---|---|
| committer | Craig Topper <craig.topper@intel.com> | 2017-06-14 17:04:59 +0000 |
| commit | f93b7b1c1f0e535b59171e4145cd587e498370f6 (patch) | |
| tree | 125193efd6cedcc409ee08a718d3b13f7903acd7 /llvm/lib/Support/DebugCounter.cpp | |
| parent | 02b0e9d97a8d0a519dcb386e7162f3bcbaef3f48 (diff) | |
| download | llvm-f93b7b1c1f0e535b59171e4145cd587e498370f6.zip llvm-f93b7b1c1f0e535b59171e4145cd587e498370f6.tar.gz llvm-f93b7b1c1f0e535b59171e4145cd587e498370f6.tar.bz2 | |
[ValueTracking] Correct early out in computeKnownBitsFromOperator to work with non power of 2 bit widths
There's an early out that's trying to detect when we don't know any bits that make up the legal range of a shift. The code subtracts one from BitWidth which creates a mask in the lower bits for power of 2 bit widths. This is then ANDed with the known bits to see if any of those bits are known. If the bit width isn't a power of 2 this creates a non-sensical mask.
This patch corrects this by rounding up to a power of 2 before doing the subtract and mask.
Differential Revision: https://reviews.llvm.org/D34165
llvm-svn: 305400
Diffstat (limited to 'llvm/lib/Support/DebugCounter.cpp')
0 files changed, 0 insertions, 0 deletions