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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 | 9d5bda9be150500db82055e8aeb20efc0c235425 (patch) | |
| tree | 187cc0951d48ce7b0e8b8a0f0274559312048941 /llvm/lib/CodeGen/RegisterCoalescer.cpp | |
| parent | b0e6c8a3500c16f35bae030d5add46c942639ef7 (diff) | |
| download | bcm5719-llvm-9d5bda9be150500db82055e8aeb20efc0c235425.tar.gz bcm5719-llvm-9d5bda9be150500db82055e8aeb20efc0c235425.zip | |
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.
llvm-svn: 141138
Diffstat (limited to 'llvm/lib/CodeGen/RegisterCoalescer.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/RegisterCoalescer.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp index 990ef370bb3..361ae7a63f0 100644 --- a/llvm/lib/CodeGen/RegisterCoalescer.cpp +++ b/llvm/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 |
