diff options
| -rw-r--r-- | include/llvm/CodeGen/LiveInterval.h | 2 | ||||
| -rw-r--r-- | lib/CodeGen/LiveInterval.cpp | 4 | ||||
| -rw-r--r-- | lib/CodeGen/PreAllocSplitting.cpp | 20 |
3 files changed, 22 insertions, 4 deletions
diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h index 7bcc4c7cb8..fb74486357 100644 --- a/include/llvm/CodeGen/LiveInterval.h +++ b/include/llvm/CodeGen/LiveInterval.h @@ -276,7 +276,7 @@ namespace llvm { /// are found to be equivalent. This eliminates V1, replacing all /// LiveRanges with the V1 value number with the V2 value number. This can /// cause merging of V1/V2 values numbers and compaction of the value space. - void MergeValueNumberInto(VNInfo *V1, VNInfo *V2); + VNInfo* MergeValueNumberInto(VNInfo *V1, VNInfo *V2); /// MergeInClobberRanges - For any live ranges that are not defined in the /// current interval, but are defined in the Clobbers interval, mark them diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp index 6341b9cd50..40f8cd4388 100644 --- a/lib/CodeGen/LiveInterval.cpp +++ b/lib/CodeGen/LiveInterval.cpp @@ -591,7 +591,7 @@ void LiveInterval::MergeInClobberRanges(const LiveInterval &Clobbers, /// are found to be equivalent. This eliminates V1, replacing all /// LiveRanges with the V1 value number with the V2 value number. This can /// cause merging of V1/V2 values numbers and compaction of the value space. -void LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { +VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { assert(V1 != V2 && "Identical value#'s are always equivalent!"); // This code actually merges the (numerically) larger value number into the @@ -652,6 +652,8 @@ void LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { } else { V1->def = ~1U; } + + return V2; } void LiveInterval::Copy(const LiveInterval &RHS, diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp index a538db8be0..99fdb840cc 100644 --- a/lib/CodeGen/PreAllocSplitting.cpp +++ b/lib/CodeGen/PreAllocSplitting.cpp @@ -654,8 +654,24 @@ PreAllocSplitting::PerformPHIConstructionFallBack(MachineBasicBlock::iterator Us } if (MBB->pred_size() == 1 && !RetVNI->hasPHIKill) { - LI->MergeValueNumberInto(RetVNI, IncomingVNs.begin()->second); - Phis[MBB] = RetVNI = IncomingVNs.begin()->second; + VNInfo* OldVN = RetVNI; + VNInfo* NewVN = IncomingVNs.begin()->second; + VNInfo* MergedVN = LI->MergeValueNumberInto(OldVN, NewVN); + if (MergedVN == OldVN) std::swap(OldVN, NewVN); + + for (DenseMap<MachineBasicBlock*, VNInfo*>::iterator LOI = LiveOut.begin(), + LOE = LiveOut.end(); LOI != LOE; ++LOI) + if (LOI->second == OldVN) + LOI->second = MergedVN; + for (DenseMap<MachineInstr*, VNInfo*>::iterator NVI = NewVNs.begin(), + NVE = NewVNs.end(); NVI != NVE; ++NVI) + if (NVI->second == OldVN) + NVI->second = MergedVN; + for (DenseMap<MachineBasicBlock*, VNInfo*>::iterator PI = Phis.begin(), + PE = Phis.end(); PI != PE; ++PI) + if (PI->second == OldVN) + PI->second = MergedVN; + RetVNI = MergedVN; } else { // Otherwise, merge the incoming VNInfos with a phi join. Create a new // VNInfo to represent the joined value. |