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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-10-05 00:01:46 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-10-05 00:01:46 +0000 |
| commit | b077cf338bd85a6a7397ec88d65278f02f0ed06f (patch) | |
| tree | 184f5e206bb514fd500b9f5eca5c7100f22ee727 /lib/CodeGen/RegisterCoalescer.cpp | |
| parent | 2fec6c5ff153786744ba7d0d302b73179731c5e9 (diff) | |
| download | llvm-b077cf338bd85a6a7397ec88d65278f02f0ed06f.tar.gz llvm-b077cf338bd85a6a7397ec88d65278f02f0ed06f.tar.bz2 llvm-b077cf338bd85a6a7397ec88d65278f02f0ed06f.tar.xz | |
Also add <def,undef> flags when coalescing sub-registers.
RegisterCoalescer can create sub-register defs when it is joining a
register with a sub-register. Add <undef> flags to these new
sub-register defs where appropriate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141138 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/RegisterCoalescer.cpp')
| -rw-r--r-- | lib/CodeGen/RegisterCoalescer.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp index 990ef370bb..361ae7a63f 100644 --- a/lib/CodeGen/RegisterCoalescer.cpp +++ b/lib/CodeGen/RegisterCoalescer.cpp @@ -967,6 +967,14 @@ RegisterCoalescer::UpdateRegDefsUses(const CoalescerPair &CP) { Kills |= MO.isKill(); Deads |= MO.isDead(); + // Make sure we don't create read-modify-write defs accidentally. We + // assume here that a SrcReg def cannot be joined into a live DstReg. If + // RegisterCoalescer starts tracking partially live registers, we will + // need to check the actual LiveInterval to determine if DstReg is live + // here. + if (SubIdx && !Reads) + MO.setIsUndef(); + if (DstIsPhys) MO.substPhysReg(DstReg, *TRI); else |