[LLVMdev] Register Coalescer does not preserve TargetFlag

Jakob Stoklund Olesen
Mon, 06 Aug 2012 17:51:07 -0000

On Aug 6, 2012, at 10:45 AM, Vincent Lejeune <vljn at ovi.com> wrote:

> Is it possible to "customise" INSERT_SUBREG and COPY instructions
to add them an immediate operands ?
> I know that COPY is lowered using copyPhysReg() function in
MachineTargetInstrInfo, but I'm not sure there is something equivalent for
INSERT_SUBREG.

No, these instructions must be pure register copies. They can't have
additional target-specific semantics.

You would need to insert target-specific NEG and ABS instructions instead.

/jakob