diff options
| -rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 19 | ||||
| -rw-r--r-- | test/CodeGen/PowerPC/2008-06-23-LiveVariablesCrash.ll | 25 |
2 files changed, 42 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 diff --git a/test/CodeGen/PowerPC/2008-06-23-LiveVariablesCrash.ll b/test/CodeGen/PowerPC/2008-06-23-LiveVariablesCrash.ll new file mode 100644 index 0000000000..d3238d23c0 --- /dev/null +++ b/test/CodeGen/PowerPC/2008-06-23-LiveVariablesCrash.ll @@ -0,0 +1,25 @@ +; RUN: llvm-as < %s | llc -march=ppc32 +; <rdar://problem/6020042> + +define i32 @bork() nounwind { +entry: + br i1 true, label %bb1, label %bb3 + +bb1: + %tmp1 = load i8* null, align 1 + %tmp2 = icmp eq i8 %tmp1, 0 + br label %bb2 + +bb2: + %val1 = phi i32 [ 0, %bb1 ], [ %val2, %bb2 ] + %val2 = select i1 %tmp2, i32 -1, i32 %val1 + switch i32 %val2, label %bb2 [ + i32 -1, label %bb3 + i32 0, label %bb1 + i32 1, label %bb3 + i32 2, label %bb1 + ] + +bb3: + ret i32 -1 +} |