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| author | Duncan Sands <baldrick@free.fr> | 2011-01-18 09:24:58 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2011-01-18 09:24:58 +0000 |
| commit | 9b8e2bd8ef852dd43d1f2c9778e76d17eca5a61f (patch) | |
| tree | 1fe81e43fa1029973d2d67f60eae39902e42ec10 /clang/lib/CodeGen/CodeGenModule.h | |
| parent | 065494626880e3fab0e867f9131aa0545eedc8ce (diff) | |
| download | llvm-9b8e2bd8ef852dd43d1f2c9778e76d17eca5a61f.zip llvm-9b8e2bd8ef852dd43d1f2c9778e76d17eca5a61f.tar.gz llvm-9b8e2bd8ef852dd43d1f2c9778e76d17eca5a61f.tar.bz2 | |
Simplify (X<<1)-X into X. According to my auto-simplier this is the most common missed
simplification in fully optimized code. It occurs sporadically in the testsuite, and
many times in 403.gcc: the final bitcode has 131 fewer subtractions after this change.
The reason that the multiplies are not eliminated is the same reason that instcombine
did not catch this: they are used by other instructions (instcombine catches this with
a more general transform which in general is only profitable if the operands have only
one use).
llvm-svn: 123754
Diffstat (limited to 'clang/lib/CodeGen/CodeGenModule.h')
0 files changed, 0 insertions, 0 deletions