More VNInfo tweaking, plus a little progress on intra-block splitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73750 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Spiller.cpp b/lib/CodeGen/Spiller.cpp
index 55642aa..919a0ce 100644
--- a/lib/CodeGen/Spiller.cpp
+++ b/lib/CodeGen/Spiller.cpp
@@ -39,7 +39,8 @@
VirtRegMap *vrm;
/// Construct a spiller base.
- SpillerBase(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls, VirtRegMap *vrm) :
+ SpillerBase(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls,
+ VirtRegMap *vrm) :
mf(mf), lis(lis), ls(ls), vrm(vrm)
{
mfi = mf->getFrameInfo();
@@ -85,6 +86,7 @@
unsigned insertStoreFor(MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
+
MachineBasicBlock::iterator nextInstItr(mi);
++nextInstItr;
@@ -105,6 +107,23 @@
return storeInstIdx;
}
+ void insertStoreOnInterval(LiveInterval *li,
+ MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+
+ unsigned storeInstIdx = insertStoreFor(mi, ss, vreg, trc);
+ unsigned start = lis->getDefIndex(lis->getInstructionIndex(mi)),
+ end = lis->getUseIndex(storeInstIdx);
+
+ VNInfo *vni =
+ li->getNextValue(storeInstIdx, 0, true, lis->getVNInfoAllocator());
+ vni->kills.push_back(storeInstIdx);
+ LiveRange lr(start, end, vni);
+
+ li->addRange(lr);
+ }
+
/// Insert a load of the given veg from the given stack slot immediately
/// before the given instruction. Returns the base index of the inserted
/// instruction. The caller is responsible for adding an appropriate
@@ -130,6 +149,25 @@
return loadInstIdx;
}
+ void insertLoadOnInterval(LiveInterval *li,
+ MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+
+ unsigned loadInstIdx = insertLoadFor(mi, ss, vreg, trc);
+ unsigned start = lis->getDefIndex(loadInstIdx),
+ end = lis->getUseIndex(lis->getInstructionIndex(mi));
+
+ VNInfo *vni =
+ li->getNextValue(loadInstIdx, 0, true, lis->getVNInfoAllocator());
+ vni->kills.push_back(lis->getInstructionIndex(mi));
+ LiveRange lr(start, end, vni);
+
+ li->addRange(lr);
+ }
+
+
+
/// Add spill ranges for every use/def of the live interval, inserting loads
/// immediately before each use, and stores after each def. No folding is
/// attempted.
@@ -189,29 +227,11 @@
assert(hasUse || hasDef);
if (hasUse) {
- unsigned loadInstIdx = insertLoadFor(mi, ss, newVReg, trc);
- unsigned start = lis->getDefIndex(loadInstIdx),
- end = lis->getUseIndex(lis->getInstructionIndex(mi));
-
- VNInfo *vni =
- newLI->getNextValue(loadInstIdx, 0, true, lis->getVNInfoAllocator());
- vni->kills.push_back(lis->getInstructionIndex(mi));
- LiveRange lr(start, end, vni);
-
- newLI->addRange(lr);
+ insertLoadOnInterval(newLI, mi, ss, newVReg, trc);
}
if (hasDef) {
- unsigned storeInstIdx = insertStoreFor(mi, ss, newVReg, trc);
- unsigned start = lis->getDefIndex(lis->getInstructionIndex(mi)),
- end = lis->getUseIndex(storeInstIdx);
-
- VNInfo *vni =
- newLI->getNextValue(storeInstIdx, 0, true, lis->getVNInfoAllocator());
- vni->kills.push_back(storeInstIdx);
- LiveRange lr(start, end, vni);
-
- newLI->addRange(lr);
+ insertStoreOnInterval(newLI, mi, ss, newVReg, trc);
}
added.push_back(newLI);
@@ -227,13 +247,44 @@
/// folding.
class TrivialSpiller : public SpillerBase {
public:
- TrivialSpiller(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls, VirtRegMap *vrm) :
+
+ TrivialSpiller(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls,
+ VirtRegMap *vrm) :
SpillerBase(mf, lis, ls, vrm) {}
std::vector<LiveInterval*> spill(LiveInterval *li) {
return trivialSpillEverywhere(li);
}
+ std::vector<LiveInterval*> intraBlockSplit(LiveInterval *li, VNInfo *valno) {
+ std::vector<LiveInterval*> spillIntervals;
+ MachineBasicBlock::iterator storeInsertPoint;
+
+ if (valno->isDefAccurate()) {
+ // If we have an accurate def we can just grab an iterator to the instr
+ // after the def.
+ storeInsertPoint =
+ next(MachineBasicBlock::iterator(lis->getInstructionFromIndex(valno->def)));
+ } else {
+ // If the def info isn't accurate we check if this is a PHI def.
+ // If it is then def holds the index of the defining Basic Block, and we
+ // can use that to get an insertion point.
+ if (valno->isPHIDef()) {
+
+ } else {
+ // We have no usable def info. We can't split this value sensibly.
+ // FIXME: Need sensible feedback for "failure to split", an empty
+ // set of spill intervals could be reasonably returned from a
+ // split where both the store and load are folded.
+ return spillIntervals;
+ }
+ }
+
+
+
+ return spillIntervals;
+ }
+
};
}