diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index 4a4ef37b00..bc73b6841c 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -139,8 +139,23 @@ void LiveVariables::HandleVirtRegUse(unsigned reg, MachineBasicBlock *MBB, assert(VRInfo.Kills[i]->getParent() != MBB && "entry should be at end!"); #endif - assert(MBB != MRI->getVRegDef(reg)->getParent() && - "Should have kill for defblock!"); + // This situation can occur: + // + // ,------. + // | | + // | v + // | t2 = phi ... t1 ... + // | | + // | v + // | t1 = ... + // | ... = ... t1 ... + // | | + // `------' + // + // where there is a use in a PHI node that's a predecessor to the defining + // block. We don't want to mark all predecessors as having the value "alive" + // in this case. + if (MBB == MRI->getVRegDef(reg)->getParent()) return; // Add a new kill entry for this basic block. If this virtual register is // already marked as alive in this basic block, that means it is alive in at |