diff options
Diffstat (limited to 'contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h')
| -rw-r--r-- | contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h index bbe1329..f1f3f0b 100644 --- a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h +++ b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.h @@ -30,28 +30,41 @@ class PPCFrameLowering: public TargetFrameLowering { const unsigned BasePointerSaveOffset; /** - * \brief Find a register that can be used in function prologue and epilogue + * \brief Find register[s] that can be used in function prologue and epilogue * - * Find a register that can be use as the scratch register in function + * Find register[s] that can be use as scratch register[s] in function * prologue and epilogue to save various registers (Link Register, Base - * Pointer, etc.). Prefer R0, if it is available. If it is not available, - * then choose a different register. + * Pointer, etc.). Prefer R0/R12, if available. Otherwise choose whatever + * register[s] are available. * - * This method will return true if an available register was found (including - * R0). If no available registers are found, the method returns false and sets - * ScratchRegister to R0, as per the recommendation in the ABI. + * This method will return true if it is able to find enough unique scratch + * registers (1 or 2 depending on the requirement). If it is unable to find + * enough available registers in the block, it will return false and set + * any passed output parameter that corresponds to a required unique register + * to PPC::NoRegister. * * \param[in] MBB The machine basic block to find an available register for * \param[in] UseAtEnd Specify whether the scratch register will be used at * the end of the basic block (i.e., will the scratch * register kill a register defined in the basic block) - * \param[out] ScratchRegister The scratch register to use - * \return true if a scratch register was found. false of a scratch register - * was not found and R0 is being used as the default. + * \param[in] TwoUniqueRegsRequired Specify whether this basic block will + * require two unique scratch registers. + * \param[out] SR1 The scratch register to use + * \param[out] SR2 The second scratch register. If this pointer is not null + * the function will attempt to set it to an available + * register regardless of whether there is a hard requirement + * for two unique scratch registers. + * \return true if the required number of registers was found. + * false if the required number of scratch register weren't available. + * If either output parameter refers to a required scratch register + * that isn't available, it will be set to an invalid value. */ bool findScratchRegister(MachineBasicBlock *MBB, bool UseAtEnd, - unsigned *ScratchRegister) const; + bool TwoUniqueRegsRequired = false, + unsigned *SR1 = nullptr, + unsigned *SR2 = nullptr) const; + bool twoUniqueScratchRegsRequired(MachineBasicBlock *MBB) const; public: PPCFrameLowering(const PPCSubtarget &STI); |
