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| author | Roman Lebedev <lebedev.ri@gmail.com> | 2019-09-18 20:10:07 +0000 |
|---|---|---|
| committer | Roman Lebedev <lebedev.ri@gmail.com> | 2019-09-18 20:10:07 +0000 |
| commit | b646dd92c2385d31104057e8ff6f651b28c931b6 (patch) | |
| tree | 18ff0f8da03c25350b990099be6419ebac30f90b /llvm/lib/Support/Errno.cpp | |
| parent | 366ab0d086a457b085e3c9ba1c987d5499079cd6 (diff) | |
| download | bcm5719-llvm-b646dd92c2385d31104057e8ff6f651b28c931b6.tar.gz bcm5719-llvm-b646dd92c2385d31104057e8ff6f651b28c931b6.zip | |
[InstCombine] foldUnsignedUnderflowCheck(): handle last few cases (PR43251)
Summary:
I don't have a direct motivational case for this,
but it would be good to have this for completeness/symmetry.
This pattern is basically the motivational pattern from
https://bugs.llvm.org/show_bug.cgi?id=43251
but with different predicate that requires that the offset is non-zero.
The completeness bit comes from the fact that a similar pattern (offset != zero)
will be needed for https://bugs.llvm.org/show_bug.cgi?id=43259,
so it'd seem to be good to not overlook very similar patterns..
Proofs: https://rise4fun.com/Alive/21b
Also, there is something odd with `isKnownNonZero()`, if the non-zero
knowledge was specified as an assumption, it didn't pick it up (PR43267)
With this, i see no other missing folds for
https://bugs.llvm.org/show_bug.cgi?id=43251
Reviewers: spatel, nikic, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67412
llvm-svn: 372257
Diffstat (limited to 'llvm/lib/Support/Errno.cpp')
0 files changed, 0 insertions, 0 deletions
