Be more verbose when detecting dominance problems.

Catch uses of undefined physregs that haven't been added to basic block
live-in lists. Run the verifier to pinpoint the problem.

Also run the verifier when a virtual register use is not jointly
dominated by defs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160207 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2012-07-13 23:39:05 +00:00
parent e08c32249f
commit c8981f2e3d
2 changed files with 29 additions and 7 deletions

View File

@ -95,7 +95,7 @@ void LiveRangeCalc::extendToUses(LiveInterval *LI, unsigned Reg) {
Idx = Idx.getRegSlot(true);
}
}
extend(LI, Idx);
extend(LI, Idx, Reg);
}
}
@ -129,7 +129,8 @@ void LiveRangeCalc::updateLiveIns(VNInfo *OverrideVNI) {
void LiveRangeCalc::extend(LiveInterval *LI,
SlotIndex Kill) {
SlotIndex Kill,
unsigned PhysReg) {
assert(LI && "Missing live range");
assert(Kill.isValid() && "Invalid SlotIndex");
assert(Indexes && "Missing SlotIndexes");
@ -146,7 +147,7 @@ void LiveRangeCalc::extend(LiveInterval *LI,
// multiple values, and we may need to create even more phi-defs to preserve
// VNInfo SSA form. Perform a search for all predecessor blocks where we
// know the dominating VNInfo.
VNInfo *VNI = findReachingDefs(LI, KillMBB, Kill);
VNInfo *VNI = findReachingDefs(LI, KillMBB, Kill, PhysReg);
// When there were multiple different values, we may need new PHIs.
if (!VNI)
@ -169,7 +170,8 @@ void LiveRangeCalc::calculateValues() {
VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
MachineBasicBlock *KillMBB,
SlotIndex Kill) {
SlotIndex Kill,
unsigned PhysReg) {
// Blocks where LI should be live-in.
SmallVector<MachineBasicBlock*, 16> WorkList(1, KillMBB);
@ -180,7 +182,22 @@ VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
// Using Seen as a visited set, perform a BFS for all reaching defs.
for (unsigned i = 0; i != WorkList.size(); ++i) {
MachineBasicBlock *MBB = WorkList[i];
assert(!MBB->pred_empty() && "Value live-in to entry block?");
#ifndef NDEBUG
if (MBB->pred_empty()) {
MBB->getParent()->verify();
llvm_unreachable("Use not jointly dominated by defs.");
}
if (TargetRegisterInfo::isPhysicalRegister(PhysReg) &&
!MBB->isLiveIn(PhysReg)) {
MBB->getParent()->verify();
errs() << "The register needs to be live in to BB#" << MBB->getNumber()
<< ", but is missing from the live-in list.\n";
llvm_unreachable("Invalid global physical register");
}
#endif
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
MachineBasicBlock *Pred = *PI;

View File

@ -105,9 +105,12 @@ class LiveRangeCalc {
/// to be live-in are added to LiveIn. If a unique reaching def is found,
/// its value is returned, if Kill is jointly dominated by multiple values,
/// NULL is returned.
///
/// PhysReg, when set, is used to verify live-in lists on basic blocks.
VNInfo *findReachingDefs(LiveInterval *LI,
MachineBasicBlock *KillMBB,
SlotIndex Kill);
SlotIndex Kill,
unsigned PhysReg);
/// updateSSA - Compute the values that will be live in to all requested
/// blocks in LiveIn. Create PHI-def values as required to preserve SSA form.
@ -157,7 +160,9 @@ public:
/// Kill is not dominated by a single existing value, PHI-defs are inserted
/// as required to preserve SSA form. If Kill is known to be dominated by a
/// single existing value, Alloc may be null.
void extend(LiveInterval *LI, SlotIndex Kill);
///
/// PhysReg, when set, is used to verify live-in lists on basic blocks.
void extend(LiveInterval *LI, SlotIndex Kill, unsigned PhysReg = 0);
/// createDeadDefs - Create a dead def in LI for every def operand of Reg.
/// Each instruction defining Reg gets a new VNInfo with a corresponding