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| author | Chris Lattner <sabre@nondot.org> | 2010-08-27 22:53:44 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-08-27 22:53:44 +0000 |
| commit | 6c1395f62ae1319143b77cf4fc15fe8b744aaf35 (patch) | |
| tree | ba2d5d91647e469620121ae1a0c8abb07e996957 /llvm/lib/Target/CppBackend/CPPBackend.cpp | |
| parent | 71cc9d886ada122bd82ed7d20325a98fa19390a3 (diff) | |
| download | bcm5719-llvm-6c1395f62ae1319143b77cf4fc15fe8b744aaf35.tar.gz bcm5719-llvm-6c1395f62ae1319143b77cf4fc15fe8b744aaf35.zip | |
Enhance the shift propagator to handle the case when you have:
A = shl x, 42
...
B = lshr ..., 38
which can be transformed into:
A = shl x, 4
...
iff we can prove that the would-be-shifted-in bits
are already zero. This eliminates two shifts in the testcase
and allows eliminate of the whole i128 chain in the real example.
llvm-svn: 112314
Diffstat (limited to 'llvm/lib/Target/CppBackend/CPPBackend.cpp')
0 files changed, 0 insertions, 0 deletions
