[Bug rtl-optimization/78669] [7 Regression]: ICE: in combine_and_move_insns, at ira.c:3665 with -Os -fno-tree-ter -mavx512bw

[bernds at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78669

--- Comment #4 from Bernd Schmidt <bernds at gcc dot gnu.org> ---
Something like this perhaps.

Index: ira.c
===================================================================
--- ira.c       (revision 242958)
+++ ira.c       (working copy)
@@ -3705,6 +3705,14 @@ combine_and_move_insns (void)
          remove_death (regno, use_insn);
          SET_REG_N_REFS (regno, 0);
          REG_FREQ (regno) = 0;
+         df_ref use;
+         FOR_EACH_INSN_USE (use, def_insn)
+           {
+             unsigned int use_regno = DF_REF_REGNO (use);
+             if (!HARD_REGISTER_NUM_P (use_regno))
+               reg_equiv[use_regno].replace = 0;
+           }
+
          delete_insn (def_insn);

          reg_equiv[regno].init_insns = NULL;