Make x86's BT instruction matching more thorough, and add some

dagcombines that help it match in several more cases. Add
several more cases to test/CodeGen/X86/bt.ll. This doesn't
yet include matching for BT with an immediate operand, it
just covers more register+register cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63266 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman
2009-01-29 01:59:02 +00:00
parent 63e3e6350b
commit e5af2d3a22
6 changed files with 562 additions and 40 deletions
+31 -19
View File
@@ -102,6 +102,8 @@ namespace {
SDValue To[] = { Res0, Res1 };
return CombineTo(N, To, 2, AddTo);
}
void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
private:
@@ -298,6 +300,10 @@ CombineTo(SDNode *N, SDValue Res0, SDValue Res1) {
return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
}
void TargetLowering::DAGCombinerInfo::
CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
}
//===----------------------------------------------------------------------===//
// Helper Functions
@@ -539,29 +545,14 @@ SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
return SDValue(N, 0);
}
/// SimplifyDemandedBits - Check the specified integer node value to see if
/// it can be simplified or if things it uses can be simplified by bit
/// propagation. If so, return true.
bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
TargetLowering::TargetLoweringOpt TLO(DAG);
APInt KnownZero, KnownOne;
if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
return false;
// Revisit the node.
AddToWorkList(Op.getNode());
// Replace the old value with the new one.
++NodesCombined;
DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.getNode()->dump(&DAG));
DOUT << "\nWith: "; DEBUG(TLO.New.getNode()->dump(&DAG));
DOUT << '\n';
void
DAGCombiner::CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &
TLO) {
// Replace all uses. If any nodes become isomorphic to other nodes and
// are deleted, make sure to remove them from our worklist.
WorkListRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
// Push the new node and any (possibly new) users onto the worklist.
AddToWorkList(TLO.New.getNode());
AddUsersToWorkList(TLO.New.getNode());
@@ -580,6 +571,27 @@ bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
DAG.DeleteNode(TLO.Old.getNode());
}
}
/// SimplifyDemandedBits - Check the specified integer node value to see if
/// it can be simplified or if things it uses can be simplified by bit
/// propagation. If so, return true.
bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
TargetLowering::TargetLoweringOpt TLO(DAG);
APInt KnownZero, KnownOne;
if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
return false;
// Revisit the node.
AddToWorkList(Op.getNode());
// Replace the old value with the new one.
++NodesCombined;
DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.getNode()->dump(&DAG));
DOUT << "\nWith: "; DEBUG(TLO.New.getNode()->dump(&DAG));
DOUT << '\n';
CommitTargetLoweringOpt(TLO);
return true;
}