[PATCH] D98757: [AMX] Not fold constant bitcast into amx intrisic

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm added a comment.

In D98757#2630968 <https://reviews.llvm.org/D98757#2630968>, @lebedev.ri wrote:

> I think that is a traditional backend problem that the pass will just have to be updated to deal with.

Hi @lebedev.ri , seems there is some mistakes, let me first point out the problem:

1. All AMX operation should use AMX intrinsic,

So we need specially handle the bitcast from Constant vector to AMX type. (Not use normal load / store)
This work is done at Back-End pass "Lower AMX type for Load/Store" by checking the bitcast instruction.

2. If Mid-End fold this bitcast into a instruction, currently, the Back-End pass "Lower AMX type for Load/Store" will no find it.

(of course, we can check every operands of every instruction to find out the amx bitcast, but it not good job, directly let it not folding in mid-end is better)


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D98757/new/

https://reviews.llvm.org/D98757