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| author | Roman Lebedev <lebedev.ri@gmail.com> | 2018-09-12 18:19:43 +0000 |
|---|---|---|
| committer | Roman Lebedev <lebedev.ri@gmail.com> | 2018-09-12 18:19:43 +0000 |
| commit | 75404fb9f8a83cef60720cf504cb10a7b01b4271 (patch) | |
| tree | 6785403bddf925e0e8ab10c552f8a9aff6b33f3e /llvm/lib/Target/ARC/ARCMachineFunctionInfo.cpp | |
| parent | aad4027dc3b6e96fb949242a0635ef69151d6d70 (diff) | |
| download | bcm5719-llvm-75404fb9f8a83cef60720cf504cb10a7b01b4271.tar.gz bcm5719-llvm-75404fb9f8a83cef60720cf504cb10a7b01b4271.zip | |
[InstCombine] Inefficient pattern for high-bits checking (PR38708)
Summary:
It is sometimes important to check that some newly-computed value
is non-negative and only `n` bits wide (where `n` is a variable.)
There are **many** ways to check that:
https://godbolt.org/z/o4RB8D
The last variant seems best?
(I'm sure there are some other variations i haven't thought of..)
Let's handle the second variant first, since it is much simpler.
https://rise4fun.com/Alive/LYjY
https://bugs.llvm.org/show_bug.cgi?id=38708
Reviewers: spatel, craig.topper, RKSimon
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51985
llvm-svn: 342067
Diffstat (limited to 'llvm/lib/Target/ARC/ARCMachineFunctionInfo.cpp')
0 files changed, 0 insertions, 0 deletions
