[llvm] [AMDGPU] Rewrite GFX12 SGPR hazard handling to dedicated pass (PR #118750)

[Carl Ritson via llvm-commits]

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@@ -1696,6 +1696,20 @@ The AMDGPU backend supports the following LLVM IR attributes.
                                              as hidden. Hidden arguments are managed by the compiler and are not part of
                                              the explicit arguments supplied by the user.
 
+     "amdgpu-sgpr-hazard-wait"               Disabled SGPR hazard wait insertion if set to 0.
+                                             Exists for testing performance impact of SGPR hazard waits only.
+
+     "amdgpu-sgpr-hazard-boundary-cull"      Enable insertion of SGPR hazard cull sequences at function call boundaries.
+                                             Cull sequence reduces future hazard waits, but has a performance cost.
+
+     "amdgpu-sgpr-hazard-mem-wait-cull"      Enable insertion of SGPR hazard cull sequences before memory waits.
+                                             Cull sequence reduces future hazard waits, but has a performance cost.
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perlfu wrote:

Fixed.

https://github.com/llvm/llvm-project/pull/118750