Enforce stricter liveness rules for PHIs.
Verify that all paths from the entry block to a virtual register read
pass through a def. Enable this check even when MRI->isSSA() is false.
Verify that the live range of a virtual register is live out of all
predecessor blocks, even for PHI-values.
This requires that PHIElimination sometimes inserts IMPLICIT_DEF
instruction in predecessor blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159150 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 92d9356..a443b51 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -1049,7 +1049,7 @@
// 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 @@
++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 @@
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)