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| author | Chris Lattner <sabre@nondot.org> | 2009-12-09 17:27:45 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2009-12-09 17:27:45 +0000 |
| commit | 4d3a16f81b2a0f0211b58f2c1e5a28e2bbd432c7 (patch) | |
| tree | 3ca580ee7ed42fff4cc9bc1d98c37ec893e38d07 /lib/Analysis/PHITransAddr.cpp | |
| parent | 16f1692dca19431768e6f113af4acac470f8adf8 (diff) | |
| download | llvm-4d3a16f81b2a0f0211b58f2c1e5a28e2bbd432c7.tar.gz llvm-4d3a16f81b2a0f0211b58f2c1e5a28e2bbd432c7.tar.bz2 llvm-4d3a16f81b2a0f0211b58f2c1e5a28e2bbd432c7.tar.xz | |
Add a minor optimization: if we haven't changed the operands of an
add, there is no need to scan the world to find the same add again.
This invalidates the previous testcase, which wasn't wonderful anyway,
because it needed a run of instcombine to permute the use-lists in
just the right way to before GVN was run (so it was really fragile).
Not a big loss.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90973 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/PHITransAddr.cpp')
| -rw-r--r-- | lib/Analysis/PHITransAddr.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/Analysis/PHITransAddr.cpp b/lib/Analysis/PHITransAddr.cpp index a1b2afbaf7..07e291971a 100644 --- a/lib/Analysis/PHITransAddr.cpp +++ b/lib/Analysis/PHITransAddr.cpp @@ -275,6 +275,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB, RemoveInstInputs(LHS, InstInputs); return AddAsInput(Res); } + + // If we didn't modify the add, just return it. + if (LHS == Inst->getOperand(0) && RHS == Inst->getOperand(1)) + return Inst; // Otherwise, see if we have this add available somewhere. for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end(); |