[llvm] AMDGPU: Add codegen for atomicrmw operations usub_cond and usub_sat (PR #141068)

[Matt Arsenault via llvm-commits]

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@@ -1744,6 +1744,12 @@ Value *SplitPtrStructs::handleMemoryInst(Instruction *I, Value *Arg, Value *Ptr,
     case AtomicRMWInst::FMin:
       IID = Intrinsic::amdgcn_raw_ptr_buffer_atomic_fmin;
       break;
+    case AtomicRMWInst::USubCond:
+      IID = Intrinsic::amdgcn_raw_ptr_buffer_atomic_usub_cond;
+      break;
+    case AtomicRMWInst::USubSat:
+      IID = Intrinsic::amdgcn_raw_ptr_buffer_atomic_usub_sat;
+      break;
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arsenm wrote:

These should be tested in one of the llvm/test/CodeGen/AMDGPU/buffer-fat-pointer-* tests 

https://github.com/llvm/llvm-project/pull/141068