[PATCH] D126807: [PowerPC] Fix LQ-STQ instructions to use correct offset and base

[Ahsan Saghir via Phabricator via llvm-commits]

saghir added a comment.



In D126807#3581621 <https://reviews.llvm.org/D126807#3581621>, @lkail wrote:

> This fix looks making offset handling more complex. We can make it easier by add `LQX_PSEUDO` and `STQX_PSEUDO` to `ImmToIdxMap`.
>
>   ImmToIdxMap[PPC::LQ]  = PPC::LQX_PSEUDO;
>   ImmToIdxMap[PPC::STQ] = PPC::STQX_PSEUDO;
>
> And expand `PPC::LQX_PSEUDO` and `PPC::STQX_PSEUDO` post RA(They are expanded in `PPCTargetLowering::EmitInstrWithCustomInserter` right now). Something like
>
>   $x6 = LQX_PSEUDO $x0, $x1
>   =>
>   $x3 = ADD $x0, $x1
>   $x6 = LQ 0($x3)
>
> Thus we make `LQ/STQ` fits in how we are handling frame index now, no more code is needed to handling the offset for `LQ/STQ`(When `LQ/STQ` are selected by ISEL, alignment is guaranteed to be 16 bytes since they are for atomic operations).

Thanks for the suggestion. Adding `LQX_PSEUDO` and `STQX_PSEUDO` to `ImmToIdxMap` fixes both cases:

- Offset fits in the instruction
- Offset does not fit in the instruction

I have taken out the test case for the unaligned case since alignment is guaranteed to be 16 bytes for atomic operations.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126807/new/

https://reviews.llvm.org/D126807