[PATCH] D123528: [AVR] Always expand STDSPQRr & STDWSPQRr

[Ben Shi via Phabricator via llvm-commits]

benshi001 added inline comments.


================
Comment at: llvm/lib/Target/AVR/AVRFrameLowering.cpp:369
-      // instructions.
-      fixStackStores(MBB, MI, TII, AVR::R31R30);
-    } else {
----------------
benshi001 wrote:
> benshi001 wrote:
> > I do not think the removal of `fixStackStores` at here is good, since we seperate the preparation of `R31R30` and the substitution of `STDWSPQRr`-> `STDWPtrQRr`. It makes the code hard to understand, and I also concern there might be other issues introduced.
> > 
> > So I suggest we keep this `fixStackStores` call.
> I suggest a moderate way:
> 
> Keep the second `fixStackStores` (with R31R30) and remove the first one (R29R28). And in the `expand<AVR::STDWSPQRr>`, add an extra line 
> 
> ```
> assert(STI.getFrameLowering()->hasReservedCallFrame(MF) &&
>        "unexpected STDWSPQRr pseudo instruction");
> ```
Then we only substitute `SP` with `R29R28`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D123528/new/

https://reviews.llvm.org/D123528