diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-01-01 22:29:12 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-01-01 22:29:12 +0000 |
| commit | f2ebc682d1ee008782d44261f28e92bf982790c2 (patch) | |
| tree | b2626bebd963858de49c9c0017afac91d0d102f7 /lib/Transforms/Scalar/InstructionCombining.cpp | |
| parent | 33767185055399d729e2a1b2c24d4d36efab125c (diff) | |
teach instcombine to optimize pointer difference idioms involving constant
expressions. This is a step towards comment #4 in PR3351.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92401 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar/InstructionCombining.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index ee0b9374cb..6c5a16c361 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -2950,20 +2950,16 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) { // &A[10] - &A[0]: we should compile this to "10". if (TD) { Value *LHSOp, *RHSOp; - if (match(Op0, m_Cast<PtrToIntInst>(m_Value(LHSOp))) && - match(Op1, m_Cast<PtrToIntInst>(m_Value(RHSOp)))) + if (match(Op0, m_PtrToInt(m_Value(LHSOp))) && + match(Op1, m_PtrToInt(m_Value(RHSOp)))) if (Value *Res = OptimizePointerDifference(LHSOp, RHSOp, I.getType())) return ReplaceInstUsesWith(I, Res); // trunc(p)-trunc(q) -> trunc(p-q) - if (TruncInst *LHST = dyn_cast<TruncInst>(Op0)) - if (TruncInst *RHST = dyn_cast<TruncInst>(Op1)) - if (PtrToIntInst *LHS = dyn_cast<PtrToIntInst>(LHST->getOperand(0))) - if (PtrToIntInst *RHS = dyn_cast<PtrToIntInst>(RHST->getOperand(0))) - if (Value *Res = OptimizePointerDifference(LHS->getOperand(0), - RHS->getOperand(0), - I.getType())) - return ReplaceInstUsesWith(I, Res); + if (match(Op0, m_Trunc(m_PtrToInt(m_Value(LHSOp)))) && + match(Op1, m_Trunc(m_PtrToInt(m_Value(RHSOp))))) + if (Value *Res = OptimizePointerDifference(LHSOp, RHSOp, I.getType())) + return ReplaceInstUsesWith(I, Res); } return 0; |