Simplify the logic for BRTWOWAY_CC handling. The isel code already

simplifies BRTWOWAY into BR if one of the results is a fall-through.
Unless I'm missing something, there is no reason to duplicate this
in the target-specific code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22952 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-08-21 19:03:28 +00:00
parent 2fbb4579d6
commit f913d3f91c

View File

@ -707,10 +707,6 @@ void ISel::SelectBranchCC(SDOperand N)
unsigned CCReg = SelectCC(N.getOperand(2), N.getOperand(3), CC);
unsigned Opc = getBCCForSetCC(CC);
// Iterate to the next basic block
ilist<MachineBasicBlock>::iterator It = BB;
++It;
// If this is a two way branch, then grab the fallthrough basic block argument
// and build a PowerPC branch pseudo-op, suitable for long branch conversion
// if necessary by the branch selection pass. Otherwise, emit a standard
@ -718,19 +714,14 @@ void ISel::SelectBranchCC(SDOperand N)
if (N.getOpcode() == ISD::BRTWOWAY_CC) {
MachineBasicBlock *Fallthrough =
cast<BasicBlockSDNode>(N.getOperand(5))->getBasicBlock();
if (Dest != It) {
BuildMI(BB, PPC::COND_BRANCH, 4).addReg(CCReg).addImm(Opc)
.addMBB(Dest).addMBB(Fallthrough);
if (Fallthrough != It)
BuildMI(BB, PPC::B, 1).addMBB(Fallthrough);
} else {
if (Fallthrough != It) {
Opc = PPC32InstrInfo::invertPPCBranchOpcode(Opc);
BuildMI(BB, PPC::COND_BRANCH, 4).addReg(CCReg).addImm(Opc)
.addMBB(Fallthrough).addMBB(Dest);
}
}
BuildMI(BB, PPC::COND_BRANCH, 4).addReg(CCReg).addImm(Opc)
.addMBB(Dest).addMBB(Fallthrough);
BuildMI(BB, PPC::B, 1).addMBB(Fallthrough);
} else {
// Iterate to the next basic block
ilist<MachineBasicBlock>::iterator It = BB;
++It;
// If the fallthrough path is off the end of the function, which would be
// undefined behavior, set it to be the same as the current block because
// we have nothing better to set it to, and leaving it alone will cause the