[PATCH] D106879: GlobalISel: Fix infinite loop in legalization artifact combiner

[Petar Avramovic via Phabricator via llvm-commits]

Petar.Avramovic added inline comments.


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Comment at: llvm/test/CodeGen/AMDGPU/GlobalISel/bug-legalization-artifact-combiner-dead-def.mir:115-116
+    ; GFX10: [[INSERT:%[0-9]+]]:_(<2 x s32>) = G_INSERT [[BUILD_VECTOR]], [[EXTRACT]](s32), 32
+    ; GFX10: %dbg_use:_(s32), %11:_(s32) = G_UNMERGE_VALUES [[INSERT]](<2 x s32>)
+    ; GFX10: DBG_VALUE [[EXTRACT1]](s32), $noreg, <0xb6ade0>, !DIExpression(), debug-location !DILocation(line: 1, column: 1, scope: <0xb6aa70>)
+    ; GFX10: G_STORE [[EXTRACT1]](s32), [[COPY]](p5) :: (store (s32), align 8, addrspace 5)
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With use_nodbg_empty, this will look like DBG_VALUE %dbg_use(s32) because we skip combine (replace register with found value). It also seems wrong to mark register as dead in that case. Should we treat DBG instrs in special way in this combine?


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  https://reviews.llvm.org/D106879/new/

https://reviews.llvm.org/D106879