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| author | Evan Cheng <evan.cheng@apple.com> | 2011-11-14 21:11:15 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2011-11-14 21:11:15 +0000 |
| commit | 8aee7d8f9eab71a29f8f3a5a541144bef4fb5ac4 (patch) | |
| tree | d614105281911e21261f66fc8540bd97e05c8913 /lib/CodeGen/TwoAddressInstructionPass.cpp | |
| parent | 41e00172c51a1666cbcda5df2c6f45d685068fbb (diff) | |
| download | llvm-8aee7d8f9eab71a29f8f3a5a541144bef4fb5ac4.tar.gz llvm-8aee7d8f9eab71a29f8f3a5a541144bef4fb5ac4.tar.bz2 llvm-8aee7d8f9eab71a29f8f3a5a541144bef4fb5ac4.tar.xz | |
Avoid dereferencing off the beginning of lists.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144569 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/TwoAddressInstructionPass.cpp')
| -rw-r--r-- | lib/CodeGen/TwoAddressInstructionPass.cpp | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp index a702c6c840..6796312649 100644 --- a/lib/CodeGen/TwoAddressInstructionPass.cpp +++ b/lib/CodeGen/TwoAddressInstructionPass.cpp @@ -999,10 +999,8 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB, } // Move debug info as well. - if (From != MBB->begin()) { - while (llvm::prior(From)->isDebugValue()) - --From; - } + while (From != MBB->begin() && llvm::prior(From)->isDebugValue()) + --From; // Copies following MI may have been moved as well. nmi = To; @@ -1146,9 +1144,8 @@ TwoAddressInstructionPass::RescheduleKillAboveMI(MachineBasicBlock *MBB, // Move the old kill above MI, don't forget to move debug info as well. MachineBasicBlock::iterator InsertPos = mi; - if (InsertPos != MBB->begin()) - while (llvm::prior(InsertPos)->isDebugValue()) - --InsertPos; + while (InsertPos != MBB->begin() && llvm::prior(InsertPos)->isDebugValue()) + --InsertPos; MachineBasicBlock::iterator From = KillMI; MachineBasicBlock::iterator To = llvm::next(From); while (llvm::prior(From)->isDebugValue()) |