protect label from being optimized

[Ian Lance Taylor]

Kunal Parmar <kunalparmar@gmail.com> writes:

> I am working on porting GCC to a new RISC architecture. The ISA does
> not have a "Jump and Link Register" instruction. So I am simulating
> one by replacing
>          jal [reg]
> by
>          load ra, Lret
>          jr reg
> Lret:
>
> in RTL.
> But my return label is getting optimized away. Could you please tell
> me how to avoid this.

Make sure the load label instruction is using a LABEL_REF.  Look at
sh.md for various examples.

Ian