Re-commit: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541
Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson
Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D45543
The previous commit failed portions of the test-suite on GreenDragon due to
duplicate COPY instructions and iterator invalidation. Both issues have now
been fixed. To assist with this, a helper (cloneVirtualRegister) has been added
to MachineRegisterInfo that can be used to get another register that has the same
type and class/bank as an existing one.
llvm-svn: 343654
diff --git a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
index 0bc5b87..f3f075a 100644
--- a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -25,6 +25,34 @@
using namespace llvm;
+namespace {
+/// This class acts as the glue the joins the CombinerHelper to the overall
+/// Combine algorithm. The CombinerHelper is intended to report the
+/// modifications it makes to the MIR to the CombinerChangeObserver and the
+/// observer subclass will act on these events. In this case, instruction
+/// erasure will cancel any future visits to the erased instruction and
+/// instruction creation will schedule that instruction for a future visit.
+/// Other Combiner implementations may require more complex behaviour from
+/// their CombinerChangeObserver subclass.
+class WorkListMaintainer : public CombinerChangeObserver {
+ using WorkListTy = GISelWorkList<512>;
+ WorkListTy &WorkList;
+
+public:
+ WorkListMaintainer(WorkListTy &WorkList) : WorkList(WorkList) {}
+ virtual ~WorkListMaintainer() {}
+
+ void erasedInstr(MachineInstr &MI) override {
+ LLVM_DEBUG(dbgs() << "Erased: "; MI.print(dbgs()); dbgs() << "\n");
+ WorkList.remove(&MI);
+ }
+ void createdInstr(MachineInstr &MI) override {
+ LLVM_DEBUG(dbgs() << "Created: "; MI.print(dbgs()); dbgs() << "\n");
+ WorkList.insert(&MI);
+ }
+};
+}
+
Combiner::Combiner(CombinerInfo &Info, const TargetPassConfig *TPC)
: CInfo(Info), TPC(TPC) {
(void)this->TPC; // FIXME: Remove when used.
@@ -53,6 +81,7 @@
// down RPOT.
Changed = false;
GISelWorkList<512> WorkList;
+ WorkListMaintainer Observer(WorkList);
for (MachineBasicBlock *MBB : post_order(&MF)) {
if (MBB->empty())
continue;
@@ -72,7 +101,7 @@
while (!WorkList.empty()) {
MachineInstr *CurrInst = WorkList.pop_back_val();
LLVM_DEBUG(dbgs() << "Try combining " << *CurrInst << "\n";);
- Changed |= CInfo.combine(*CurrInst, Builder);
+ Changed |= CInfo.combine(Observer, *CurrInst, Builder);
}
MFChanged |= Changed;
} while (Changed);