Merging r182385:

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r182385 | hfinkel | 2013-05-21 07:21:09 -0700 (Tue, 21 May 2013) | 9 lines

Fix PPC branch selection for counter-based branches

Although I had added some support for the BDZ/BDNZ branches into the selector
(in r158204), I had not correctly adjusted the condition at the top of the
loop. As a result, these branches were still essentially unsupported.

This fixes PR16086. Unfortunately, any test case would be very large (because
it would need to force the loop backedge to exceed the range of the 16-bit
immediate).
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_33@182431 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2013-05-21 22:11:11 +00:00
parent 629c73232c
commit 3d3a37ed4d

View File

@ -112,15 +112,21 @@ bool PPCBSel::runOnMachineFunction(MachineFunction &Fn) {
unsigned MBBStartOffset = 0;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
I != E; ++I) {
if (I->getOpcode() != PPC::BCC || I->getOperand(2).isImm()) {
MachineBasicBlock *Dest = 0;
if (I->getOpcode() == PPC::BCC && !I->getOperand(2).isImm())
Dest = I->getOperand(2).getMBB();
else if ((I->getOpcode() == PPC::BDNZ8 || I->getOpcode() == PPC::BDNZ ||
I->getOpcode() == PPC::BDZ8 || I->getOpcode() == PPC::BDZ) &&
!I->getOperand(0).isImm())
Dest = I->getOperand(0).getMBB();
if (!Dest) {
MBBStartOffset += TII->GetInstSizeInBytes(I);
continue;
}
// Determine the offset from the current branch to the destination
// block.
MachineBasicBlock *Dest = I->getOperand(2).getMBB();
int BranchSize;
if (Dest->getNumber() <= MBB.getNumber()) {
// If this is a backwards branch, the delta is the offset from the