Fix for PR4124. Make TwoAddressFormPass::FindLastUseInMBB return the real last use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71769 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 2ec0c71..6282a4a 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -316,7 +316,7 @@
MachineInstr *TwoAddressInstructionPass::FindLastUseInMBB(unsigned Reg,
MachineBasicBlock *MBB,
unsigned Dist) {
- unsigned LastUseDist = Dist;
+ unsigned LastUseDist = 0;
MachineInstr *LastUse = 0;
for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(Reg),
E = MRI->reg_end(); I != E; ++I) {
@@ -327,7 +327,10 @@
DenseMap<MachineInstr*, unsigned>::iterator DI = DistanceMap.find(MI);
if (DI == DistanceMap.end())
continue;
- if (MO.isUse() && DI->second < LastUseDist) {
+ if (DI->second >= Dist)
+ continue;
+
+ if (MO.isUse() && DI->second > LastUseDist) {
LastUse = DI->first;
LastUseDist = DI->second;
}