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

Thu Mar 18 02:19:30 PDT 2021

fhahn added a comment.

In D98757#2633396 <https://reviews.llvm.org/D98757#2633396>, @xiangzhangllvm wrote:

> In D98757#2631042 <https://reviews.llvm.org/D98757#2631042>, @lebedev.ri wrote:
>
>> The ongoing special-casing of `X86_AMXTy` through the llvm due to the inability of the existing backend passes to handle certain llvm ir constructs.
>
> We have bring up it to llvm-dev.
> BTW,** All the Type should see as target independent.** (Even it support by less targets or 1 target)
>
> Current we see  “ if (Ty.isVectorTy()) {…}” is make sense in Mid-End. 
> Why we can’t see “if (Ty.isX86_AMXTy()){…}” is make sense ?

One thing to note is that there appears to be no documentation of `x86_amx` in the langref (maybe there is, but searching for `x86_amx` did not surface anything). Without that, making any decisions based on the type in general LLVM optimizations seems problematic, because the type is effectively not specified.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D98757/new/

https://reviews.llvm.org/D98757