diff options
| -rw-r--r-- | include/llvm/Target/TargetInstrInfo.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h index 4663cfd46b..30843ea287 100644 --- a/include/llvm/Target/TargetInstrInfo.h +++ b/include/llvm/Target/TargetInstrInfo.h @@ -273,6 +273,20 @@ public: return true; // safe but very conservative } + + /// createNOPinstr - returns the target's implementation of NOP, which is + /// usually a pseudo-instruction, implemented by a degenerate version of + /// another instruction, e.g. X86: xchg ax, ax; SparcV9: sethi g0, 0 + /// + virtual MachineInstr* createNOPinstr() const = 0; + + /// isNOPinstr - since we no longer have a special NOP opcode, we need to know + /// if a given instruction is interpreted as an `official' NOP instr, i.e., + /// there may be more than one way to `do nothing' but only one canonical + /// way to slack off. + /// + virtual bool isNOPinstr(const MachineInstr &MI) const = 0; + //------------------------------------------------------------------------- // Code generation support for creating individual machine instructions // |