* Introduce a new SelectionDAG::getIntPtrConstant method
and switch various codegen pieces and the X86 backend over
to using it.
* Add some comments to SelectionDAGNodes.h
* Introduce a second argument to FP_ROUND, which indicates
whether the FP_ROUND changes the value of its input. If
not it is safe to xform things like fp_extend(fp_round(x)) -> x.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46125 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 80ba27f..ad176d4 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -135,6 +135,7 @@
SDOperand To[] = { Res0, Res1 };
return CombineTo(N, To, 2, AddTo);
}
+
private:
/// SimplifyDemandedBits - Check the specified integer node value to see if
@@ -460,10 +461,13 @@
GetNegatedExpression(Op.getOperand(1), DAG, Depth+1));
case ISD::FP_EXTEND:
- case ISD::FP_ROUND:
case ISD::FSIN:
return DAG.getNode(Op.getOpcode(), Op.getValueType(),
GetNegatedExpression(Op.getOperand(0), DAG, Depth+1));
+ case ISD::FP_ROUND:
+ return DAG.getNode(ISD::FP_ROUND, Op.getValueType(),
+ GetNegatedExpression(Op.getOperand(0), DAG, Depth+1),
+ Op.getOperand(1));
}
}
@@ -3632,12 +3636,13 @@
SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) {
SDOperand N0 = N->getOperand(0);
+ SDOperand N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
MVT::ValueType VT = N->getValueType(0);
// fold (fp_round c1fp) -> c1fp
if (N0CFP && N0.getValueType() != MVT::ppcf128)
- return DAG.getNode(ISD::FP_ROUND, VT, N0);
+ return DAG.getNode(ISD::FP_ROUND, VT, N0, N1);
// fold (fp_round (fp_extend x)) -> x
if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
@@ -3645,7 +3650,7 @@
// fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) {
- SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0));
+ SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0), N1);
AddToWorkList(Tmp.Val);
return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1));
}
@@ -3675,12 +3680,22 @@
// If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
if (N->hasOneUse() && (*N->use_begin())->getOpcode() == ISD::FP_ROUND)
return SDOperand();
-
+
// fold (fp_extend c1fp) -> c1fp
if (N0CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FP_EXTEND, VT, N0);
-
- // fold (fpext (load x)) -> (fpext (fpround (extload x)))
+
+ // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
+ // value of X.
+ if (N0.getOpcode() == ISD::FP_ROUND && N0.Val->getConstantOperandVal(1) == 1){
+ SDOperand In = N0.getOperand(0);
+ if (In.getValueType() == VT) return In;
+ if (VT < In.getValueType())
+ return DAG.getNode(ISD::FP_ROUND, VT, In, N0.getOperand(1));
+ return DAG.getNode(ISD::FP_EXTEND, VT, In);
+ }
+
+ // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
(!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
@@ -3691,7 +3706,8 @@
LN0->isVolatile(),
LN0->getAlignment());
CombineTo(N, ExtLoad);
- CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad),
+ CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad,
+ DAG.getIntPtrConstant(1)),
ExtLoad.getValue(1));
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
}
@@ -4435,13 +4451,11 @@
// Otherwise, use InIdx + VecSize
unsigned Idx = cast<ConstantSDNode>(Extract.getOperand(1))->getValue();
- BuildVecIndices.push_back(DAG.getConstant(Idx+NumInScalars,
- TLI.getPointerTy()));
+ BuildVecIndices.push_back(DAG.getIntPtrConstant(Idx+NumInScalars));
}
// Add count and size info.
- MVT::ValueType BuildVecVT =
- MVT::getVectorType(TLI.getPointerTy(), NumElts);
+ MVT::ValueType BuildVecVT = MVT::getVectorType(TLI.getPointerTy(), NumElts);
// Return the new VECTOR_SHUFFLE node.
SDOperand Ops[5];