1 files changed, 77 insertions, 0 deletions
diff --git a/llvm/test/Transforms/StructurizeCFG/AMDGPU/backedge-id-bug-xfail.ll b/llvm/test/Transforms/StructurizeCFG/AMDGPU/backedge-id-bug-xfail.ll
new file mode 100644
index 00000000000..e9c54151cf2
--- /dev/null
+++ b/llvm/test/Transforms/StructurizeCFG/AMDGPU/backedge-id-bug-xfail.ll
@@ -0,0 +1,77 @@
+; XFAIL: *
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -S -structurizecfg -verify-region-info %s
+
+; FIXME: Merge into backedge-id-bug
+; Variant which has an issue with region construction
+
+define amdgpu_kernel void @loop_backedge_misidentified_alt(i32 addrspace(1)* %arg0) #0 {
+entry:
+  %tmp = load volatile <2 x i32>, <2 x i32> addrspace(1)* undef, align 16
+  %load1 = load volatile <2 x float>, <2 x float> addrspace(1)* undef
+  %tid = call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds i32, i32 addrspace(1)* %arg0, i32 %tid
+  %i.initial = load volatile i32, i32 addrspace(1)* %gep, align 4
+  br label %LOOP.HEADER
+
+LOOP.HEADER:
+  %i = phi i32 [ %i.final, %END_ELSE_BLOCK ], [ %i.initial, %entry ]
+  call void asm sideeffect "s_nop 0x100b ; loop $0 ", "r,~{memory}"(i32 %i) #0
+  %tmp12 = zext i32 %i to i64
+  %tmp13 = getelementptr inbounds <4 x i32>, <4 x i32> addrspace(1)* null, i64 %tmp12
+  %tmp14 = load <4 x i32>, <4 x i32> addrspace(1)* %tmp13, align 16
+  %tmp15 = extractelement <4 x i32> %tmp14, i64 0
+  %tmp16 = and i32 %tmp15, 65535
+  %tmp17 = icmp eq i32 %tmp16, 1
+  br i1 %tmp17, label %bb18, label %bb62
+
+bb18:
+  %tmp19 = extractelement <2 x i32> %tmp, i64 0
+  %tmp22 = lshr i32 %tmp19, 16
+  %tmp24 = urem i32 %tmp22, 52
+  %tmp25 = mul nuw nsw i32 %tmp24, 52
+  br label %INNER_LOOP
+
+INNER_LOOP:
+  %inner.loop.j = phi i32 [ %tmp25, %bb18 ], [ %inner.loop.j.inc, %INNER_LOOP ]
+  call void asm sideeffect "; inner loop body", ""() #0
+  %inner.loop.j.inc = add nsw i32 %inner.loop.j, 1
+  %inner.loop.cmp = icmp eq i32 %inner.loop.j, 0
+  br i1 %inner.loop.cmp, label %INNER_LOOP_BREAK, label %INNER_LOOP
+
+INNER_LOOP_BREAK:
+  %tmp59 = extractelement <4 x i32> %tmp14, i64 2
+  call void asm sideeffect "s_nop 23 ", "~{memory}"() #0
+  br label %END_ELSE_BLOCK
+
+bb62:
+  %load13 = icmp ult i32 %tmp16, 271
+  ;br i1 %load13, label %bb64, label %INCREMENT_I
+  ; branching directly to the return avoids the bug
+  br i1 %load13, label %RETURN, label %INCREMENT_I
+
+
+bb64:
+  call void asm sideeffect "s_nop 42", "~{memory}"() #0
+  br label %RETURN
+
+INCREMENT_I:
+  %inc.i = add i32 %i, 1
+  call void asm sideeffect "s_nop 0x1336 ; increment $0", "v,~{memory}"(i32 %inc.i) #0
+  br label %END_ELSE_BLOCK
+
+END_ELSE_BLOCK:
+  %i.final = phi i32 [ %tmp59, %INNER_LOOP_BREAK ], [ %inc.i, %INCREMENT_I ]
+  call void asm sideeffect "s_nop 0x1337 ; end else block $0", "v,~{memory}"(i32 %i.final) #0
+  %cmp.end.else.block = icmp eq i32 %i.final, -1
+  br i1 %cmp.end.else.block, label %RETURN, label %LOOP.HEADER
+
+RETURN:
+  call void asm sideeffect "s_nop 0x99 ; ClosureEval return", "~{memory}"() #0
+  store volatile <2 x float> %load1, <2 x float> addrspace(1)* undef, align 8
+  ret void
+}
+
+declare i32 @llvm.amdgcn.workitem.id.x() #1
+
+attributes #0 = { convergent nounwind }
+attributes #1 = { convergent nounwind readnone }