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| author | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | 2014-01-09 10:56:42 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | 2014-01-09 10:56:42 +0000 |
| commit | 15cfc1c33c57aefbfaf9c01a1979f3d7d1a2c806 (patch) | |
| tree | b67f047be4e6af4c05314bf5e08ef08fe394cdc3 /clang/lib/CodeGen/CodeGenFunction.cpp | |
| parent | 0f264db3c6928642301fbb4cd2d465d0b8716c6f (diff) | |
| download | llvm-15cfc1c33c57aefbfaf9c01a1979f3d7d1a2c806.zip llvm-15cfc1c33c57aefbfaf9c01a1979f3d7d1a2c806.tar.gz llvm-15cfc1c33c57aefbfaf9c01a1979f3d7d1a2c806.tar.bz2 | |
Handle masked rotate amounts
At the moment we expect rotates to have the form:
(or (shl X, Y), (shr X, Z))
where Y == bitsize(X) - Z or Z == bitsize(X) - Y. This form means that
the (or ...) is undefined for Y == 0 or Z == 0. This undefinedness can
be avoided by using Y == (C * bitsize(X) - Z) & (bitsize(X) - 1) or
Z == (C * bitsize(X) - Y) & (bitsize(X) - 1) for any integer C
(including 0, the most natural choice).
llvm-svn: 198861
Diffstat (limited to 'clang/lib/CodeGen/CodeGenFunction.cpp')
0 files changed, 0 insertions, 0 deletions