Author: resistor
Date: Sun Nov 11 20:13:07 2007
New Revision: 44005
URL: http://llvm.org/viewvc/llvm-project?rev=44005&view=rev
Log:
Fix rewriting of PHI nodes.
Could someone more familiar with machine-level stuff review this for me?
Modified:
llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h
Modified: llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h?rev=44005&r1=44004&r2=44005&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h (original)
+++ llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h Sun Nov 11
20:13:07 2007
@@ -52,16 +52,27 @@
break;
}
- // Scan the operands of this branch, replacing any uses of dst with
- // crit_mbb.
+ // Scan the operands of this branch, finding all uses of this MBB
+ std::vector<unsigned> toRemove;
+ unsigned reg = 0;
for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) {
MachineOperand & mo = mii->getOperand(i);
if (mo.isMachineBasicBlock() &&
- mo.getMachineBasicBlock() == dst) {
- found_branch = true;
- mo.setMachineBasicBlock(crit_mbb);
- }
+ mo.getMachineBasicBlock() == dst)
+ reg = mii->getOperand(i-1).getReg();
+ toRemove.push_back(i-1);
}
+
+ // Remove all uses of this MBB
+ for (std::vector<unsigned>::reverse_iterator I = toRemove.rbegin(),
+ E = toRemove.rend(); I != E; ++I) {
+ mii->RemoveOperand(*I+1);
+ mii->RemoveOperand(*I);
+ }
+
+ // Add a single use corresponding to the new MBB
+ mii->addRegOperand(reg, false);
+ mii->addMachineBasicBlockOperand(crit_mbb);
}
// TODO: This is tentative. It may be necessary to fix this code. Maybe
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