[LLVMdev] Linearscan allocator bug?

[Vladimir Prus]

Chris Lattner wrote:

> > let isTerminator = 1 in
> >     def GOTO : Unknown<"goto">;
> >     def IFEQ : Unknown<"if =0 goto">;
> >     def IFNEQ : Unknown<"if <>0 goto">;
> >     .....
> >
> > Should this work?
>
> Nope, but try this:
>
> let isTerminator = 1 in {
>      def GOTO : Unknown<"goto">;
>      def IFEQ : Unknown<"if =0 goto">;
>      def IFNEQ : Unknown<"if <>0 goto">;
>      .....
> }
>
> ... aka add {}

Uhm ;-) This change seems to fix things.

> Also, if you do 'tblgen target.td' it will spit out all of the records
> to stdout so you can visually inspect them.
>
> > > Also, if you haven't already, you might want to teach TargetInstrInfo
> > > that '=' is a move instruction (implement isMoveInstr), so instructinos
> > > like 'gr1 = gr1' will go away and you'll get coallescing.  :)
> >
> > BTW, is it possible to set some instruction flag, instead of overriding a
> > function? Something like:
> >
> > let isMove = 1 in
> >       def MOVE :.....
>
> That would make sense, but no not currently.  :)  If you wanted to teach
> it how to do that (similar to the isTerminator functionality), it would be
> a great patch.  :)

I'll probably look at the code.

- Volodya