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author | Pirama Arumuga Nainar <pirama@google.com> | 2015-05-06 11:46:36 -0700 |
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committer | Pirama Arumuga Nainar <pirama@google.com> | 2015-05-18 10:52:30 -0700 |
commit | 2c3e0051c31c3f5b2328b447eadf1cf9c4427442 (patch) | |
tree | c0104029af14e9f47c2ef58ca60e6137691f3c9b /lib/CodeGen/LiveInterval.cpp | |
parent | e1bc145815f4334641be19f1c45ecf85d25b6e5a (diff) | |
download | external_llvm-2c3e0051c31c3f5b2328b447eadf1cf9c4427442.zip external_llvm-2c3e0051c31c3f5b2328b447eadf1cf9c4427442.tar.gz external_llvm-2c3e0051c31c3f5b2328b447eadf1cf9c4427442.tar.bz2 |
Update aosp/master LLVM for rebase to r235153
Change-Id: I9bf53792f9fc30570e81a8d80d296c681d005ea7
(cherry picked from commit 0c7f116bb6950ef819323d855415b2f2b0aad987)
Diffstat (limited to 'lib/CodeGen/LiveInterval.cpp')
-rw-r--r-- | lib/CodeGen/LiveInterval.cpp | 56 |
1 files changed, 42 insertions, 14 deletions
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp index 2afd7fa..d75e441 100644 --- a/lib/CodeGen/LiveInterval.cpp +++ b/lib/CodeGen/LiveInterval.cpp @@ -816,23 +816,45 @@ static VNInfo *searchForVNI(const SlotIndexes &Indexes, LiveRange &LR, static void determineMissingVNIs(const SlotIndexes &Indexes, LiveInterval &LI) { SmallPtrSet<const MachineBasicBlock*, 5> Visited; - for (LiveRange::Segment &S : LI.segments) { - if (S.valno != nullptr) - continue; - // This can only happen at the begin of a basic block. - assert(S.start.isBlock() && "valno should only be missing at block begin"); - - Visited.clear(); - const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(S.start); - for (const MachineBasicBlock *Pred : MBB->predecessors()) { - VNInfo *VNI = searchForVNI(Indexes, LI, Pred, Visited); - if (VNI != nullptr) { - S.valno = VNI; - break; + + LiveRange::iterator OutIt; + VNInfo *PrevValNo = nullptr; + for (LiveRange::iterator I = LI.begin(), E = LI.end(); I != E; ++I) { + LiveRange::Segment &S = *I; + // Determine final VNI if necessary. + if (S.valno == nullptr) { + // This can only happen at the begin of a basic block. + assert(S.start.isBlock() && "valno should only be missing at block begin"); + + Visited.clear(); + const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(S.start); + for (const MachineBasicBlock *Pred : MBB->predecessors()) { + VNInfo *VNI = searchForVNI(Indexes, LI, Pred, Visited); + if (VNI != nullptr) { + S.valno = VNI; + break; + } } + assert(S.valno != nullptr && "could not determine valno"); + } + // Merge with previous segment if it has the same VNI. + if (PrevValNo == S.valno && OutIt->end == S.start) { + OutIt->end = S.end; + } else { + // Didn't merge. Move OutIt to next segment. + if (PrevValNo == nullptr) + OutIt = LI.begin(); + else + ++OutIt; + + if (OutIt != I) + *OutIt = *I; + PrevValNo = S.valno; } - assert(S.valno != nullptr && "could not determine valno"); } + // If we merged some segments chop off the end. + ++OutIt; + LI.segments.erase(OutIt, LI.end()); } void LiveInterval::constructMainRangeFromSubranges( @@ -955,6 +977,12 @@ void LiveInterval::constructMainRangeFromSubranges( NeedVNIFixup = true; } + // In rare cases we can produce adjacent segments with the same value + // number (if they come from different subranges, but happen to have + // the same defining instruction). VNIFixup will fix those cases. + if (!empty() && segments.back().end == Pos && + segments.back().valno == VNI) + NeedVNIFixup = true; CurrentSegment.start = Pos; CurrentSegment.valno = VNI; ConstructingSegment = true; |