diff options
Diffstat (limited to 'lib/Target/X86/X86ISelLowering.cpp')
-rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 40 |
1 files changed, 0 insertions, 40 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 9ff05a2d11..1580935fb2 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -14415,7 +14415,6 @@ static SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG, if (TrueC->getAPIntValue().ult(FalseC->getAPIntValue())) { CC = X86::GetOppositeBranchCondition(CC); std::swap(TrueC, FalseC); - std::swap(TrueOp, FalseOp); } // Optimize C ? 8 : 0 -> zext(setcc(C)) << 3. Likewise for any pow2/0. @@ -14498,45 +14497,6 @@ static SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG, } } } - - // Handle these cases: - // (select (x != c), e, c) -> select (x != c), e, x), - // (select (x == c), c, e) -> select (x == c), x, e) - // where the c is an integer constant, and the "select" is the combination - // of CMOV and CMP. - // - // The rationale for this change is that the conditional-move from a constant - // needs two instructions, however, conditional-move from a register needs - // only one instruction. - // - // CAVEAT: By replacing a constant with a symbolic value, it may obscure - // some instruction-combining opportunities. This opt needs to be - // postponed as late as possible. - // - if (!DCI.isBeforeLegalize() && !DCI.isBeforeLegalizeOps()) { - // the DCI.xxxx conditions are provided to postpone the optimization as - // late as possible. - - ConstantSDNode *CmpAgainst = 0; - if ((Cond.getOpcode() == X86ISD::CMP || Cond.getOpcode() == X86ISD::SUB) && - (CmpAgainst = dyn_cast<ConstantSDNode>(Cond.getOperand(1))) && - dyn_cast<ConstantSDNode>(Cond.getOperand(0)) == 0) { - - if (CC == X86::COND_NE && - CmpAgainst == dyn_cast<ConstantSDNode>(FalseOp)) { - CC = X86::GetOppositeBranchCondition(CC); - std::swap(TrueOp, FalseOp); - } - - if (CC == X86::COND_E && - CmpAgainst == dyn_cast<ConstantSDNode>(TrueOp)) { - SDValue Ops[] = { FalseOp, Cond.getOperand(0), N->getOperand(2), Cond }; - return DAG.getNode(X86ISD::CMOV, DL, N->getVTList (), Ops, - array_lengthof(Ops)); - } - } - } - return SDValue(); } |