[PATCH] D70821: [SystemZ] Implement the packed stack layout

[Ulrich Weigand via Phabricator via llvm-commits]

uweigand added a comment.

In D70821#1763719 <https://reviews.llvm.org/D70821#1763719>, @jonpa wrote:

> As long as we return our table of fixed offsets from getCalleeSavedSpillSlots() a register included there will get that offset in assignCalleeSavedSpillSlots(), instead of a created on-fixed object. I thought about changing SystemZFrameLowering::getCalleeSavedSpillSlots(), for instance by returning a NumEntries that could just be 4 less since the FP arg regs are last... But that method does currently not have MF as an argument, and I thought maybe it wouldn't be so bad to just put them below the GPRs... This is called before spillCalleeSavedRegisters() which is where we compute the range of GPRs to save...


I see.  Maybe it would be better then to just not use the static "getCalleeSavedSpillSlots" method at all, and instead use the dynamic "assignCalleeSavedSpillSlots" method instead (like most other targets) ...

> We could add a setOffsetOfLocalArea(), to set it to a new smaller value if we also could make sure to always set it correctly for each function. But I think your idea of just adding the fixed objects as needed sounds better, so maybe I should give that a try..?

Agreed.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70821/new/

https://reviews.llvm.org/D70821