diff options
| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-03-31 17:55:25 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-03-31 17:55:25 +0000 |
| commit | 280ea1a7466751c6d27ff343072c65e59a950053 (patch) | |
| tree | 0e34572eb68616124c6cfc322fd93d89a024f0b8 | |
| parent | 8901e6ff3da1c1a68ee5c1c24f21e8572ceb57b6 (diff) | |
Don't completely eliminate identity copies that also modify super register liveness.
Turn them into noop KILL instructions instead. This lets the scavenger know when
super-registers are killed and defined.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128645 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/VirtRegMap.cpp | 18 | ||||
| -rw-r--r-- | test/CodeGen/Blackfin/2009-08-04-LowerExtract-Live.ll | 1 |
2 files changed, 13 insertions, 6 deletions
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp index 61d6ac88ed..7a7ea69e27 100644 --- a/lib/CodeGen/VirtRegMap.cpp +++ b/lib/CodeGen/VirtRegMap.cpp @@ -309,12 +309,18 @@ void VirtRegMap::rewrite(SlotIndexes *Indexes) { // Finally, remove any identity copies. if (MI->isIdentityCopy()) { - DEBUG(dbgs() << "Deleting identity copy.\n"); - RemoveMachineInstrFromMaps(MI); - if (Indexes) - Indexes->removeMachineInstrFromMaps(MI); - // It's safe to erase MI because MII has already been incremented. - MI->eraseFromParent(); + if (MI->getNumOperands() == 2) { + DEBUG(dbgs() << "Deleting identity copy.\n"); + RemoveMachineInstrFromMaps(MI); + if (Indexes) + Indexes->removeMachineInstrFromMaps(MI); + // It's safe to erase MI because MII has already been incremented. + MI->eraseFromParent(); + } else { + // Transform identity copy to a KILL to deal with subregisters. + MI->setDesc(TII->get(TargetOpcode::KILL)); + DEBUG(dbgs() << "Identity copy: " << *MI); + } } } } diff --git a/test/CodeGen/Blackfin/2009-08-04-LowerExtract-Live.ll b/test/CodeGen/Blackfin/2009-08-04-LowerExtract-Live.ll index 3ee5e8df99..50fccb4409 100644 --- a/test/CodeGen/Blackfin/2009-08-04-LowerExtract-Live.ll +++ b/test/CodeGen/Blackfin/2009-08-04-LowerExtract-Live.ll @@ -1,4 +1,5 @@ ; RUN: llc < %s -march=bfin -join-liveintervals=0 -verify-machineinstrs +; RUN: llc < %s -march=bfin -join-liveintervals=0 -verify-machineinstrs -regalloc=greedy ; Provoke an error in LowerSubregsPass::LowerExtract where the live range of a ; super-register is illegally extended. |