[Bug target/89474] [9 Regression] ice in df_reg_chain_verify_unmarked, at df-scan.c:3995

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89474

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I admit I don't know much about df infrastructure, but it looks completely
wrong to me to first modify the various instructions to refer to at that point
created, but uninitialized v4sf_const0 pseudo, including df_insn_rescan etc.,
then df_analyze including DF_DU_CHAIN | DF_UD_CHAIN etc. and finally add an
initializer for that pseudo.  I'd say df_analyze shouldn't be called if the IL
is in so inconsistent state.