Add a LiveRangeEdit delegate callback before shrinking a live range.
The register allocator needs to adjust its live interval unions when that happens.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127774 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index e994d8c..489d88c 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -201,8 +201,11 @@
break;
// Shrink just one live interval. Then delete new dead defs.
- LIS.shrinkToUses(ToShrink.back(), &Dead);
+ LiveInterval *LI = ToShrink.back();
ToShrink.pop_back();
+ if (delegate_)
+ delegate_->LRE_WillShrinkVirtReg(LI->reg);
+ LIS.shrinkToUses(LI, &Dead);
}
}
diff --git a/lib/CodeGen/LiveRangeEdit.h b/lib/CodeGen/LiveRangeEdit.h
index a784826..2bd3461 100644
--- a/lib/CodeGen/LiveRangeEdit.h
+++ b/lib/CodeGen/LiveRangeEdit.h
@@ -39,6 +39,9 @@
/// its deletion from LiveIntervals.
virtual bool LRE_CanEraseVirtReg(unsigned) { return true; }
+ /// Called before shrinking the live range of a virtual register.
+ virtual void LRE_WillShrinkVirtReg(unsigned) {}
+
virtual ~Delegate() {}
};
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 940ed81..6feae47 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -162,6 +162,7 @@
private:
void LRE_WillEraseInstruction(MachineInstr*);
bool LRE_CanEraseVirtReg(unsigned);
+ void LRE_WillShrinkVirtReg(unsigned);
bool checkUncachedInterference(LiveInterval&, unsigned);
LiveInterval *getSingleInterference(LiveInterval&, unsigned);
@@ -260,6 +261,17 @@
return false;
}
+void RAGreedy::LRE_WillShrinkVirtReg(unsigned VirtReg) {
+ unsigned PhysReg = VRM->getPhys(VirtReg);
+ if (!PhysReg)
+ return;
+
+ // Register is assigned, put it back on the queue for reassignment.
+ LiveInterval &LI = LIS->getInterval(VirtReg);
+ unassign(LI, PhysReg);
+ enqueue(&LI);
+}
+
void RAGreedy::releaseMemory() {
SpillerInstance.reset(0);
LRStage.clear();