Implement r160312 as target indepedenet dag combine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160354 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index d439a6f..14f0ef5 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2342,6 +2342,33 @@
return DAG.getSetCC(dl, VT, Shift, CmpRHS, Cond);
}
}
+ } else if (Cond == ISD::SETULT || Cond == ISD::SETUGE ||
+ Cond == ISD::SETULE || Cond == ISD::SETUGT) {
+ bool AdjOne = (Cond == ISD::SETULE || Cond == ISD::SETUGT);
+ // X < 0x100000000 -> (X >> 32) < 1
+ // X >= 0x100000000 -> (X >> 32) >= 1
+ // X <= 0x0ffffffff -> (X >> 32) < 1
+ // X > 0x0ffffffff -> (X >> 32) >= 1
+ unsigned ShiftBits;
+ APInt NewC = C1;
+ ISD::CondCode NewCond = Cond;
+ if (AdjOne) {
+ ShiftBits = C1.countTrailingOnes();
+ NewC = NewC + 1;
+ NewCond = (Cond == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
+ } else {
+ ShiftBits = C1.countTrailingZeros();
+ }
+ NewC = NewC.lshr(ShiftBits);
+ if (ShiftBits && isLegalICmpImmediate(NewC.getSExtValue())) {
+ EVT ShiftTy = DCI.isBeforeLegalize() ?
+ getPointerTy() : getShiftAmountTy(N0.getValueType());
+ EVT CmpTy = N0.getValueType();
+ SDValue Shift = DAG.getNode(ISD::SRL, dl, CmpTy, N0,
+ DAG.getConstant(ShiftBits, ShiftTy));
+ SDValue CmpRHS = DAG.getConstant(NewC, CmpTy);
+ return DAG.getSetCC(dl, VT, Shift, CmpRHS, NewCond);
+ }
}
}
}