[llvm] r225652 - RegisterCoalescer: Turn some impossible conditions into asserts
Matthias Braun
matze at braunis.de
Mon Jan 12 11:10:17 PST 2015
Author: matze
Date: Mon Jan 12 13:10:17 2015
New Revision: 225652
URL: http://llvm.org/viewvc/llvm-project?rev=225652&view=rev
Log:
RegisterCoalescer: Turn some impossible conditions into asserts
This is a fixed version of reverted r225500. It fixes the too early
if() continue; of the last patch and adds a comment to the unorthodox
loop.
Modified:
llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=225652&r1=225651&r2=225652&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Mon Jan 12 13:10:17 2015
@@ -621,13 +621,12 @@ bool RegisterCoalescer::removeCopyByComm
// the example above.
SlotIndex CopyIdx = LIS->getInstructionIndex(CopyMI).getRegSlot();
VNInfo *BValNo = IntB.getVNInfoAt(CopyIdx);
- if (!BValNo || BValNo->def != CopyIdx)
- return false;
+ assert(BValNo != nullptr && BValNo->def == CopyIdx);
// AValNo is the value number in A that defines the copy, A3 in the example.
VNInfo *AValNo = IntA.getVNInfoAt(CopyIdx.getRegSlot(true));
- assert(AValNo && "COPY source not live");
- if (AValNo->isPHIDef() || AValNo->isUnused())
+ assert(AValNo && !AValNo->isUnused() && "COPY source not live");
+ if (AValNo->isPHIDef())
return false;
MachineInstr *DefMI = LIS->getInstructionFromIndex(AValNo->def);
if (!DefMI)
@@ -707,10 +706,12 @@ bool RegisterCoalescer::removeCopyByComm
// Update uses of IntA of the specific Val# with IntB.
for (MachineRegisterInfo::use_iterator UI = MRI->use_begin(IntA.reg),
UE = MRI->use_end();
- UI != UE;) {
+ UI != UE; /* ++UI is below because of possible MI removal */) {
MachineOperand &UseMO = *UI;
- MachineInstr *UseMI = UseMO.getParent();
++UI;
+ if (UseMO.isUndef())
+ continue;
+ MachineInstr *UseMI = UseMO.getParent();
if (UseMI->isDebugValue()) {
// FIXME These don't have an instruction index. Not clear we have enough
// info to decide whether to do this replacement or not. For now do it.
@@ -719,7 +720,8 @@ bool RegisterCoalescer::removeCopyByComm
}
SlotIndex UseIdx = LIS->getInstructionIndex(UseMI).getRegSlot(true);
LiveInterval::iterator US = IntA.FindSegmentContaining(UseIdx);
- if (US == IntA.end() || US->valno != AValNo)
+ assert(US != IntA.end() && "Use must be live");
+ if (US->valno != AValNo)
continue;
// Kill flags are no longer accurate. They are recomputed after RA.
UseMO.setIsKill(false);
@@ -770,11 +772,7 @@ bool RegisterCoalescer::removeCopyByComm
SlotIndex AIdx = CopyIdx.getRegSlot(true);
for (LiveInterval::SubRange &SA : IntA.subranges()) {
VNInfo *ASubValNo = SA.getVNInfoAt(AIdx);
- if (ASubValNo == nullptr) {
- DEBUG(dbgs() << "No A Range at " << AIdx << " with mask "
- << format("%04X", SA.LaneMask) << "\n");
- continue;
- }
+ assert(ASubValNo != nullptr);
unsigned AMask = SA.LaneMask;
for (LiveInterval::SubRange &SB : IntB.subranges()) {
@@ -826,11 +824,7 @@ bool RegisterCoalescer::removeCopyByComm
SlotIndex AIdx = CopyIdx.getRegSlot(true);
for (LiveInterval::SubRange &SA : IntA.subranges()) {
VNInfo *ASubValNo = SA.getVNInfoAt(AIdx);
- if (ASubValNo == nullptr) {
- DEBUG(dbgs() << "No A Range at " << AIdx << " with mask "
- << format("%04X", SA.LaneMask) << "\n");
- continue;
- }
+ assert(ASubValNo != nullptr);
SA.removeValNo(ASubValNo);
}
}
More information about the llvm-commits
mailing list