[llvm] [AMDGPU] Strengthen preload intrinsics to noundef and nonnull (PR #92801)

[Krzysztof Drewniak via llvm-commits]

================
@@ -1116,10 +1116,29 @@ define amdgpu_kernel void @kern_noalias_global_ptr_x2(ptr addrspace(1) noalias %
   ret void
 }
 
+define amdgpu_kernel void @kern_noundef_global_ptr(ptr addrspace(1) noundef %ptr) #0 {
+; HSA-LABEL: @kern_noundef_global_ptr(
+; HSA-NEXT:    [[KERN_NOUNDEF_GLOBAL_PTR_KERNARG_SEGMENT:%.*]] = call align 16 dereferenceable(264) ptr addrspace(4) @llvm.amdgcn.kernarg.segment.ptr()
+; HSA-NEXT:    [[PTR_KERNARG_OFFSET:%.*]] = getelementptr inbounds i8, ptr addrspace(4) [[KERN_NOUNDEF_GLOBAL_PTR_KERNARG_SEGMENT]], i64 0
+; HSA-NEXT:    [[PTR_LOAD:%.*]] = load ptr addrspace(1), ptr addrspace(4) [[PTR_KERNARG_OFFSET]], align 16, !invariant.load [[META1]]
+; HSA-NEXT:    store volatile ptr addrspace(1) [[PTR_LOAD]], ptr addrspace(1) undef, align 8
+; HSA-NEXT:    ret void
+;
+; MESA-LABEL: @kern_noundef_global_ptr(
+; MESA-NEXT:    [[KERN_NOUNDEF_GLOBAL_PTR_KERNARG_SEGMENT:%.*]] = call align 16 dereferenceable(264) ptr addrspace(4) @llvm.amdgcn.kernarg.segment.ptr()
+; MESA-NEXT:    [[PTR_KERNARG_OFFSET:%.*]] = getelementptr inbounds i8, ptr addrspace(4) [[KERN_NOUNDEF_GLOBAL_PTR_KERNARG_SEGMENT]], i64 36
+; MESA-NEXT:    [[PTR_LOAD:%.*]] = load ptr addrspace(1), ptr addrspace(4) [[PTR_KERNARG_OFFSET]], align 4, !invariant.load [[META1]]
+; MESA-NEXT:    store volatile ptr addrspace(1) [[PTR_LOAD]], ptr addrspace(1) undef, align 8
+; MESA-NEXT:    ret void
+;
+  store volatile ptr addrspace(1) %ptr, ptr addrspace(1) undef
----------------
krzysz00 wrote:

Was following existing tests, I can swap this for a poison

https://github.com/llvm/llvm-project/pull/92801