[llvm-commits] [llvm] r127368 - in /llvm/trunk: include/llvm/Target/TargetRegisterInfo.h lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp lib/Target/X86/X86RegisterInfo.cpp

[Jakob Stoklund Olesen]

On Mar 9, 2011, at 2:47 PM, Evan Cheng wrote:

> -  /// in the specified class to or from. Returns NULL if it is possible to copy
> -  /// between a two registers of the specified class.
> +  /// in the specified class to or from. If it is possible to copy the register
> +  /// directly without using a cross register class copy, return the specified
> +  /// RC. Returns NULL if it is not possible to copy between a two registers of
> +  /// the specified class.
>   virtual const TargetRegisterClass *
>   getCrossCopyRegClass(const TargetRegisterClass *RC) const {
>     return NULL;

Perhaps you should make sure the default implementation doesn't change meaning.

This default impl says no register classes can be copied.

/jakob