diff options
| -rw-r--r-- | lib/CodeGen/MachineVerifier.cpp | 17 | ||||
| -rw-r--r-- | test/CodeGen/Generic/undef-phi.ll | 26 |
2 files changed, 37 insertions, 6 deletions
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp index 92d9356e83..a443b51d15 100644 --- a/lib/CodeGen/MachineVerifier.cpp +++ b/lib/CodeGen/MachineVerifier.cpp @@ -1049,7 +1049,7 @@ void MachineVerifier::visitMachineFunctionAfter() { // Now check liveness info if available calcRegsRequired(); - if (MRI->isSSA() && !MF->empty()) { + if (!MF->empty()) { BBInfo &MInfo = MBBInfoMap[&MF->front()]; for (RegSet::iterator I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E; @@ -1332,15 +1332,18 @@ void MachineVerifier::verifyLiveIntervals() { ++MFI; continue; } + + // Is VNI a PHI-def in the current block? + bool IsPHI = VNI->isPHIDef() && + VNI->def == LiveInts->getMBBStartIdx(MFI); + // Check that VNI is live-out of all predecessors. for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(), PE = MFI->pred_end(); PI != PE; ++PI) { SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI); const VNInfo *PVNI = LI.getVNInfoBefore(PEnd); - if (VNI->isPHIDef() && VNI->def == LiveInts->getMBBStartIdx(MFI)) - continue; - + // All predecessors must have a live-out value. if (!PVNI) { report("Register not marked live out of predecessor", *PI); *OS << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber() @@ -1349,12 +1352,14 @@ void MachineVerifier::verifyLiveIntervals() { continue; } - if (PVNI != VNI) { + // Only PHI-defs can take different predecessor values. + if (!IsPHI && PVNI != VNI) { report("Different value live out of predecessor", *PI); *OS << "Valno #" << PVNI->id << " live out of BB#" << (*PI)->getNumber() << '@' << PEnd << "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber() - << '@' << LiveInts->getMBBStartIdx(MFI) << " in " << LI << '\n'; + << '@' << LiveInts->getMBBStartIdx(MFI) << " in " + << PrintReg(Reg) << ": " << LI << '\n'; } } if (&*MFI == EndMBB) diff --git a/test/CodeGen/Generic/undef-phi.ll b/test/CodeGen/Generic/undef-phi.ll new file mode 100644 index 0000000000..10899f9fa2 --- /dev/null +++ b/test/CodeGen/Generic/undef-phi.ll @@ -0,0 +1,26 @@ +; RUN: llc < %s -verify-machineinstrs -verify-coalescing +; +; This function has a PHI with one undefined input. Verify that PHIElimination +; inserts an IMPLICIT_DEF instruction in the predecessor so all paths to the use +; pass through a def. + +%struct.xx_stack = type { i32, %struct.xx_stack* } + +define i32 @push(%struct.xx_stack* %stack) nounwind uwtable readonly ssp { +entry: + %tobool1 = icmp eq %struct.xx_stack* %stack, null + br i1 %tobool1, label %for.end, label %for.body + +for.body: + %stack.addr.02 = phi %struct.xx_stack* [ %0, %for.body ], [ %stack, %entry ] + %next = getelementptr inbounds %struct.xx_stack* %stack.addr.02, i64 0, i32 1 + %0 = load %struct.xx_stack** %next, align 8 + %tobool = icmp eq %struct.xx_stack* %0, null + br i1 %tobool, label %for.end, label %for.body + +for.end: + %top.0.lcssa = phi %struct.xx_stack* [ undef, %entry ], [ %stack.addr.02, %for.body ] + %first = getelementptr inbounds %struct.xx_stack* %top.0.lcssa, i64 0, i32 0 + %1 = load i32* %first, align 4 + ret i32 %1 +} |