From 573a32d4870ff4af7f59fc020caf07fb6ef61e37 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Thu, 15 Sep 2011 04:37:18 +0000 Subject: [PATCH] Leave hasPHIKill flags alone in LiveInterval::RenumberValues. It is conservatively correct to keep the hasPHIKill flags, even after deleting PHI-defs. The calculation can be very expensive after taildup has created a quadratic number of indirectbr edges in the CFG, and the hasPHIKill flag isn't used for anything after RenumberValues(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139780 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/LiveInterval.h | 1 - lib/CodeGen/LiveInterval.cpp | 21 --------------------- 2 files changed, 22 deletions(-) diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h index 0daaf82fe1c..2df2edd210a 100644 --- a/include/llvm/CodeGen/LiveInterval.h +++ b/include/llvm/CodeGen/LiveInterval.h @@ -313,7 +313,6 @@ namespace llvm { /// RenumberValues - Renumber all values in order of appearance and remove /// unused values. - /// Recalculate phi-kill flags in case any phi-def values were removed. void RenumberValues(LiveIntervals &lis); /// isOnlyLROfValNo - Return true if the specified live range is the only diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp index 2f787f3b408..b69945aea98 100644 --- a/lib/CodeGen/LiveInterval.cpp +++ b/lib/CodeGen/LiveInterval.cpp @@ -148,7 +148,6 @@ void LiveInterval::markValNoForDeletion(VNInfo *ValNo) { /// remaining unused values. void LiveInterval::RenumberValues(LiveIntervals &lis) { SmallPtrSet Seen; - bool seenPHIDef = false; valnos.clear(); for (const_iterator I = begin(), E = end(); I != E; ++I) { VNInfo *VNI = I->valno; @@ -157,26 +156,6 @@ void LiveInterval::RenumberValues(LiveIntervals &lis) { assert(!VNI->isUnused() && "Unused valno used by live range"); VNI->id = (unsigned)valnos.size(); valnos.push_back(VNI); - VNI->setHasPHIKill(false); - if (VNI->isPHIDef()) - seenPHIDef = true; - } - - // Recompute phi kill flags. - if (!seenPHIDef) - return; - for (const_vni_iterator I = vni_begin(), E = vni_end(); I != E; ++I) { - VNInfo *VNI = *I; - if (!VNI->isPHIDef()) - continue; - const MachineBasicBlock *PHIBB = lis.getMBBFromIndex(VNI->def); - assert(PHIBB && "No basic block for phi-def"); - for (MachineBasicBlock::const_pred_iterator PI = PHIBB->pred_begin(), - PE = PHIBB->pred_end(); PI != PE; ++PI) { - VNInfo *KVNI = getVNInfoAt(lis.getMBBEndIdx(*PI).getPrevSlot()); - if (KVNI) - KVNI->setHasPHIKill(true); - } } }