diff options
Diffstat (limited to 'include/llvm/CodeGen/LiveInterval.h')
| -rw-r--r-- | include/llvm/CodeGen/LiveInterval.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h index a52919d..0cb7e90 100644 --- a/include/llvm/CodeGen/LiveInterval.h +++ b/include/llvm/CodeGen/LiveInterval.h @@ -40,14 +40,14 @@ namespace llvm { /// Care must be taken in interpreting the def index of the value. The /// following rules apply: /// - /// If the isDefAccurate() method returns false then the def index does not - /// actually point to the defining MachineInstr, or even (necessarily) a - /// valid MachineInstr at all. In general such a def index should not be - /// used as an index to obtain a MachineInstr. The exception is Values - /// defined by PHI instructions, after PHI elimination has occured. In this - /// case the def should point to the start of the block in which the PHI - /// existed. This fact can be used to insert code dealing with the PHI value - /// at the merge point (e.g. to spill or split it). + /// If the isDefAccurate() method returns false then def does not contain the + /// index of the defining MachineInstr, or even (necessarily) to a + /// MachineInstr at all. In general such a def index is not meaningful + /// and should not be used. The exception is that, for values originally + /// defined by PHI instructions, after PHI elimination def will contain the + /// index of the MBB in which the PHI originally existed. This can be used + /// to insert code (spills or copies) which deals with the value, which will + /// be live in to the block. class VNInfo { private: |