Connect successors before creating the DAG node for the branch. This has

no visible functionality change, but enables a future patch where node creation
will update the CFG if it decides to create an unconditional rather than a conditional branch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52067 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2008-06-07 00:00:23 +00:00
parent 76aca6f38f
commit 2d389e8ad7

View File

@ -1381,13 +1381,13 @@ void SelectionDAGLowering::visitBr(BranchInst &I) {
NextBlock = BBI;
if (I.isUnconditional()) {
// Update machine-CFG edges.
CurMBB->addSuccessor(Succ0MBB);
// If this is not a fall-through branch, emit the branch.
if (Succ0MBB != NextBlock)
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(),
DAG.getBasicBlock(Succ0MBB)));
// Update machine-CFG edges.
CurMBB->addSuccessor(Succ0MBB);
return;
}
@ -1484,9 +1484,12 @@ void SelectionDAGLowering::visitSwitchCase(SelectionDAGISel::CaseBlock &CB) {
Cond = DAG.getSetCC(MVT::i1, SUB,
DAG.getConstant(High-Low, VT), ISD::SETULE);
}
}
// Update successor info
CurMBB->addSuccessor(CB.TrueBB);
CurMBB->addSuccessor(CB.FalseBB);
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
@ -1508,9 +1511,6 @@ void SelectionDAGLowering::visitSwitchCase(SelectionDAGISel::CaseBlock &CB) {
else
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, BrCond,
DAG.getBasicBlock(CB.FalseBB)));
// Update successor info
CurMBB->addSuccessor(CB.TrueBB);
CurMBB->addSuccessor(CB.FalseBB);
}
/// visitJumpTable - Emit JumpTable node in the current MBB
@ -1606,9 +1606,6 @@ void SelectionDAGLowering::visitBitTestHeader(SelectionDAGISel::BitTestBlock &B)
SDOperand CopyTo = DAG.getCopyToReg(getControlRoot(), SwitchReg, SwitchVal);
B.Reg = SwitchReg;
SDOperand BrRange = DAG.getNode(ISD::BRCOND, MVT::Other, CopyTo, RangeCmp,
DAG.getBasicBlock(B.Default));
// Set NextBlock to be the MBB immediately after the current one, if any.
// This is used to avoid emitting unnecessary branches to the next block.
MachineBasicBlock *NextBlock = 0;
@ -1617,15 +1614,19 @@ void SelectionDAGLowering::visitBitTestHeader(SelectionDAGISel::BitTestBlock &B)
NextBlock = BBI;
MachineBasicBlock* MBB = B.Cases[0].ThisBB;
CurMBB->addSuccessor(B.Default);
CurMBB->addSuccessor(MBB);
SDOperand BrRange = DAG.getNode(ISD::BRCOND, MVT::Other, CopyTo, RangeCmp,
DAG.getBasicBlock(B.Default));
if (MBB == NextBlock)
DAG.setRoot(BrRange);
else
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, CopyTo,
DAG.getBasicBlock(MBB)));
CurMBB->addSuccessor(B.Default);
CurMBB->addSuccessor(MBB);
return;
}
@ -1643,6 +1644,10 @@ void SelectionDAGLowering::visitBitTestCase(MachineBasicBlock* NextMBB,
SDOperand AndCmp = DAG.getSetCC(TLI.getSetCCResultType(AndOp), AndOp,
DAG.getConstant(0, TLI.getPointerTy()),
ISD::SETNE);
CurMBB->addSuccessor(B.TargetBB);
CurMBB->addSuccessor(NextMBB);
SDOperand BrAnd = DAG.getNode(ISD::BRCOND, MVT::Other, getControlRoot(),
AndCmp, DAG.getBasicBlock(B.TargetBB));
@ -1659,9 +1664,6 @@ void SelectionDAGLowering::visitBitTestCase(MachineBasicBlock* NextMBB,
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, BrAnd,
DAG.getBasicBlock(NextMBB)));
CurMBB->addSuccessor(B.TargetBB);
CurMBB->addSuccessor(NextMBB);
return;
}
@ -1683,13 +1685,13 @@ void SelectionDAGLowering::visitInvoke(InvokeInst &I) {
CopyValueToVirtualRegister(&I, VMI->second);
}
// Drop into normal successor.
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(),
DAG.getBasicBlock(Return)));
// Update successor info
CurMBB->addSuccessor(Return);
CurMBB->addSuccessor(LandingPad);
// Drop into normal successor.
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(),
DAG.getBasicBlock(Return)));
}
void SelectionDAGLowering::visitUnwind(UnwindInst &I) {
@ -2178,11 +2180,11 @@ void SelectionDAGLowering::visitSwitch(SwitchInst &SI) {
// Update machine-CFG edges.
// If this is not a fall-through branch, emit the branch.
CurMBB->addSuccessor(Default);
if (Default != NextBlock)
DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(),
DAG.getBasicBlock(Default)));
CurMBB->addSuccessor(Default);
return;
}