[llvm] [AMDGPU] Enable serializing of allocated preload kernarg SGPRs info (PR #168374)

[Quentin Colombet via llvm-commits]

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+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -stop-after=amdgpu-isel %s -o - | FileCheck --check-prefix=MIR %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -stop-after=amdgpu-isel -o %t.mir %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -start-after=amdgpu-isel -verify-machineinstrs %t.mir -o - | FileCheck --check-prefix=ASM %s
+
+; Test that kernarg preloading information is correctly serialized to MIR and
+; can be round-tripped through MIR serialization/deserialization.
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qcolombet wrote:

👍

https://github.com/llvm/llvm-project/pull/168374