https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114799
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- _10 is created during pattern recognition: patt_10 = (unsigned short) y.0_1; #0 vect_convert_input (vinfo=0x3a883e0, stmt_info=0x3be5410, type=<integer_type 0x7fffea2db540>, unprom=0x7fffffffcc80, vectype=<vector_type 0x7fffea2db930>, subtype=optab_default) at ../../gcc/tree-vect-patterns.cc:926 #1 0x00000000026dcede in vect_convert_inputs (vinfo=0x3a883e0, stmt_info=0x3be5410, n=2, result=0x7fffffffcc50, type=<integer_type 0x7fffea2db540>, unprom=0x7fffffffcc80, vectype=<vector_type 0x7fffea2db930>, subtype=optab_default) at ../../gcc/tree-vect-patterns.cc:977 #2 0x00000000026e35f5 in vect_recog_over_widening_pattern (vinfo=0x3a883e0, last_stmt_info=0x3be5410, type_out=0x7fffffffce48) at ../../gcc/tree-vect-patterns.cc:3155 #3 0x00000000026f250a in vect_pattern_recog_1 (vinfo=0x3a883e0, recog_func=0x385ae30 <vect_vect_recog_func_ptrs+48>, stmt_info=0x3be5410) at ../../gcc/tree-vect-patterns.cc:7181 #4 0x00000000026f29fb in vect_pattern_recog (vinfo=0x3a883e0) at ../../gcc/tree-vect-patterns.cc:7338 #5 0x00000000011663ac in vect_slp_analyze_bb_1 (bb_vinfo=0x3a883e0, n_stmts=9, fatal=@0x7fffffffd2cb: false, Python Exception <class 'gdb.error'>: There is no member or method named m_vecpfx. dataref_groups=0x7fffffffd760) at ../../gcc/tree-vect-slp.cc:7722 #6 0x00000000011668b6 in vect_slp_region (bbs=..., datarefs=..., Python Exception <class 'gdb.error'>: There is no member or method named m_vecpfx. dataref_groups=0x7fffffffd760, n_stmts=9, orig_loop=0x0) at ../../gcc/tree-vect-slp.cc:7831 #7 0x000000000116791f in vect_slp_bbs (bbs=..., orig_loop=0x0) at ../../gcc/tree-vect-slp.cc:8042 Unfortunately, I'm afraid I know next to nothing about SLP handling of patterns, just loop vectorization :(