[PATCH] D92483: AMDGPU - Use MUBUF instructions for global address space access

Wed Dec 16 13:01:37 PST 2020

rampitec added a comment.

In D92483#2458659 <https://reviews.llvm.org/D92483#2458659>, @rampitec wrote:

> In D92483#2458152 <https://reviews.llvm.org/D92483#2458152>, @pvellien wrote:
>
>> if mcpu is specified, set Gen to the correct generation that cpu belongs to, by initializing it with SOUTHERN_ISLANDS.
>> if mcpu is not specified (in this case GPU = "generic-hsa"), set Gen to the SEA_LANDS to be in parity with previous code> Comments inline
>
> You are forcing SI for any SPECIFIED GPU instead:
>
>   !GPU.contains("generic") ? SOUTHERN_ISLANDS 
>
> Read this code line: if CPU is NOT generic, force it to SI.

Ugh. I see what you mean now, it took debugger to understand. The real value of Gen is assigned below in the GCNSubtarget::initializeSubtargetDependencies().

But I still do not think this is a right thing to do to accept amdhsa on SI, even if you turn off flat instructions. SI does not support HSA.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D92483/new/

https://reviews.llvm.org/D92483