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| author | Silviu Baranga <silviu.baranga@arm.com> | 2016-09-06 10:10:21 +0000 |
|---|---|---|
| committer | Silviu Baranga <silviu.baranga@arm.com> | 2016-09-06 10:10:21 +0000 |
| commit | 0b7c4af35904070513a2beba4f4e647acba33274 (patch) | |
| tree | 3d4e0d2ffc0f6865043f57c0156d092fa6f1c031 /llvm/lib/CodeGen/RegisterScavenging.cpp | |
| parent | 5cf1ece222936a0b7d6cc053c6db71a1956412d9 (diff) | |
| download | llvm-0b7c4af35904070513a2beba4f4e647acba33274.zip llvm-0b7c4af35904070513a2beba4f4e647acba33274.tar.gz llvm-0b7c4af35904070513a2beba4f4e647acba33274.tar.bz2 | |
[RegisterScavenger] Remove aliasing registers of operands from the candidate set
Summary:
In addition to not including the register operand of the current
instruction also don't include any aliasing registers. We can't consider
these as candidates because using them will clobber the corresponding
register operand of the current instruction.
This change doesn't include a test case and it would probably be difficult
to produce a stable one since the bug depends on the results of register
allocation.
Reviewers: MatzeB, qcolombet, hfinkel
Subscribers: hfinkel, llvm-commits
Differential Revision: https://reviews.llvm.org/D24130
llvm-svn: 280698
Diffstat (limited to 'llvm/lib/CodeGen/RegisterScavenging.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/RegisterScavenging.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/RegisterScavenging.cpp b/llvm/lib/CodeGen/RegisterScavenging.cpp index 953e535..be56861 100644 --- a/llvm/lib/CodeGen/RegisterScavenging.cpp +++ b/llvm/lib/CodeGen/RegisterScavenging.cpp @@ -419,7 +419,8 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC, for (const MachineOperand &MO : MI.operands()) { if (MO.isReg() && MO.getReg() != 0 && !(MO.isUse() && MO.isUndef()) && !TargetRegisterInfo::isVirtualRegister(MO.getReg())) - Candidates.reset(MO.getReg()); + for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI) + Candidates.reset(*AI); } // Try to find a register that's unused if there is one, as then we won't |