On 11/23/19 10:14 AM, John Paul Adrian Glaubitz wrote:
> Hi Jeff!
>
>> On 11/13/19 6:23 AM, Bernd Schmidt wrote:
>>> Once more with patch.
>>>
>>>
>>> Bernd
>>>
>>>
>>> m68k-2.diff
>>>
>>> PR target/91851
>>> * config/m68k/m68k-protos.h (output-dbcc_and_branch): Adjust
>>> declaration.
>>> (m68k_init_cc): New declaration.
>>> (m68k_output_compare_di, m68k_output_compare_si,
>>> m68k_output_compare_hi, m68k_output_compare_qi,
>>> m68k_output_compare_fp, m68k_output_btst, m68k_output_bftst,
>>> m68k_find_flags_value, m68k_output_scc, m68k_output_scc_float,
>>> m68k_output_branch_integer, m68k_output_branch_integer_rev.
>>> m68k_output_branch_float, m68k_output_branch_float_rev):
>>> Likewise.
>>> (valid_dbcc_comparison_p_2, flags_in_68881,
>>> output_btst): Remove declaration.
>>> * config/m68k/m68k.c (INCLDUE_STRING): Define.
>>> (TARGET_ASM_FINAL_POSTSCAN_INSN): Define.
>>> (valid_dbcc_comparison_p_2, flags_in_68881): Delete functions.
>>> (flags_compare_op0, flags_compare_op1, flags_operand1,
>>> flags_operand2, flags_valid): New static variables.
>>> (m68k_find_flags_value, m68k_init_cc): New functions.
>>> (handle_flags_for_move, m68k_asm_final_postscan_insn,
>>> remember_compare_flags): New static functions.
>>> (output_dbcc_and_branch): New argument CODE. Use it, and add
>>> PLUS and MINUS to the possible codes. All callers changed.
>>> (m68k_output_btst): Renamed from output_btst. Remove OPERANDS
>>> and INSN arguments, add CODE arg. Return the comparison code
>>> to use. All callers changed. Use CODE instead of
>>> next_insn_tests_no_inequality, and replace cc_status management
>>> with changing the return code.
>>> (m68k_rtx_costs): Instead of testing for COMPARE, test for
>>> RTX_COMPARE or RTX_COMM_COMPARE.
>>> (output_move_simode, output_move_qimode): Call
>>> handle_flags_for_move.
>>> (notice_update_cc): Delete function.
>>> (m68k_output_bftst, m68k_output_compare_di,
>>> m68k_output_compare_si,
>>> m68k_output_compare_hi, m68k_output_compare_qi,
>>> m68k_output_compare_fp, m68k_output_branch_integer,
>>> m68k_output_branch_integer_rev, m68k_output_scc,
>>> m68k_output_branch_float, m68k_output_branch_float_rev,
>>> m68k_output_scc_float): New functions.
>>> (output_andsi3, output_iorsi3, output_xorsi3): Call
>>> CC_STATUS_INIT
>>> once at the start, and set flags_valid and flags_operand1 if the
>>> flags are usable.
>>> * config/m68k/m68k.h (CC_IN_68881, NOTICE_UPDATE_CC,
>>> CC_OVERFLOW_UNUSABLE, CC_NO_CARRY, OUTPUT_JUMP): Remove
>>> definitions.
>>> (CC_STATUS_INIT): Define.
>>> * config/m68k/m68k.md (flags_valid): New define_attr.
>>> (tstdi, tstsi_internal_68020_cf, tstsi_internal, tsthi_internal,
>>> tstqi_internal, tst<mode>_68881, tst<mode>_cf, cmpdi_internal,
>>> cmpdi, unnamed cmpsi/cmphi/cmpqi patterns, cmpsi_cf,
>>> cmp<mode>_68881, cmp<mode>_cf, unnamed btst patterns,
>>> tst_bftst_reg, tst_bftst_reg, unnamed scc patterns, scc,
>>> sls, sordered_1, sunordered_1, suneq_1, sunge_1, sungt_1,
>>> sunle_1, sunlt_1, sltgt_1, fsogt_1, fsoge_1, fsolt_1, fsole_1,
>>> bge0_di, blt0_di, beq, bne, bgt, bgtu, blt, bltu, bge, bgeu,
>>> ble, bleu, bordered, bunordered, buneq, bunge, bungt, bunle,
>>> bunlt, bltgt, beq_rev, bne_rev, bgt_rev, bgtu_rev,
>>> blt_rev, bltu_rev, bge_rev, bgeu_rev, ble_rev, bleu_rev,
>>> bordered_rev, bunordered_rev, buneq_rev, bunge_rv, bungt_rev,
>>> bunle_rev, bunlt_rev, bltgt_rev, ctrapdi4, ctrapsi4, ctraphi4,
>>> ctrapqi4, conditional_trap): Delete patterns.
>>> (cbranchdi4_insn): New pattern.
>>> (cbranchdi4): Don't generate cc0 patterns. When testing LT or
>>> GE,
>>> test high part only. When testing EQ or NE, generate beq0_di
>>> and bne0_di patterns directly.
>>> (cstoredi4): When testing LT or GE, test high part only.
>>> (both sets of cbranch<mode>4, cstore<mode>4): Don't generate cc0
>>> patterns.
>>> (scc0_constraints, cmp1_constraints, cmp2_constraints,
>>> scc0_cf_constraints, cmp1_cf_constraints, cmp2_cf_constraints,
>>> cmp2_cf_predicate): New define_mode_attrs.
>>> (cbranch<mode>4_insn, cbranch<mode>4_insn_rev,
>>> cbranch<mode>4_insn_cf, cbranch<mode>4_insn_cf_rev,
>>> cstore<mode>4_insn, cstore<mode>4_insn_cf for integer modes)
>>> New patterns.
>>> (cbranch<mode>4_insn_68881, cbranch<mode>4_insn_rev_68881):
>>> (cbranch<mode>4_insn_cf, cbranch<mode>4_insn_rev_cf,
>>> cstore<mode>4_insn_68881, cstore<mode>4_insn_cf for FP):
>>> New patterns.
>>> (cbranchsi4_btst_mem_insn, cbranchsi4_btst_reg_insn,
>>> cbranchsi4_btst_mem_insn_1, cbranchsi4_btst_reg_insn_1):
>>> Likewise.
>>> (BTST): New define_mode_iterator.
>>> (btst_predicate, btst_constraint, btst_range): New
>>> define_mode_attrs.
>>> (cbranch_bftst<mode>_insn, cstore_bftst<mode>_insn): New
>>> patterns.
>>> (movsi_m68k_movsi_m68k2, movsi_cf, unnamed movstrict patterns,
>>> unnamed movhi and movqi patterns, unnamed movsf, movdf and movxf
>>> patterns): Set attr "flags_valid".
>>> (truncsiqi2, trunchiqi2, truncsihi2): Remove manual CC_STATUS
>>> management. Set attr "flags_valid".
>>> (extendsidi2, extendplussidi, unnamed float_extendsfdf pattern,
>>> extendsfdf2_cf, fix_truncdfsi2, fix_truncdfhi2, fix_truncdfqi2,
>>> addi_sexthishl32, adddi_dilshr32, adddi_dilshr32_cf,
>>> addi_dishl32, subdi_sexthishl32, subdi_dishl32, subdi3): Remove
>>> manual CC_STATUS management.
>>> (addsi3_internal, addhi3, addqi3, subsi3, subhi3, subqi3,
>>> unnamed strict_lowpart subhi and subqi patterns): Set attr
>>> "flags_valid".
>>> (unnamed strict_lowpart addhi3 and addqi3 patterns): Likewise.
>>> Remove code to operate on address regs and assert the case
>>> does not occur.
>>> (unnamed mulsidi patterns, divmodhi4, udivmodhi4): Remove
>>> manual CC_STATUS_INIT.
>>> (andsi3_internal, andhi3, andqi3, iorsi3_internal, iorhi3,
>>> iorqi3,
>>> xorsi3_internal, xorhi3, xorqi3, negsi2_internal,
>>> negsi2_5200, neghi2, negqi2, one_cmplsi2_internal, one_cmplhi2,
>>> one_cmplqi2, unnamed strict_lowpart patterns
>>> for andhi, andqi, iorhi, iorqi, xorhi, xorqi, neghi, negqi,
>>> one_cmplhi and one_cmplqi): Set attr "flags_valid".
>>> (iorsi_zext_ashl16, iorsi_zext): Remove manual CC_STATUS_INIT.
>>> (ashldi_sexthi, ashlsi_16, ashlsi_17_24): Remove manual
>>> CC_STATUS_INIT.
>>> (ashlsi3, ashlhi3, ashlqi3, ashrsi3, ashrhi3, ashrqi3, lshrsi3,
>>> lshrhi3, shrqi3, rotlsi3, rotlhi3, rotlhi3_lowpart, rotlqi3,
>>> rotlqi3_lowpart, rotrsi3, rotrhi3, rotrhi_lowpart, rotrqi3,
>>> unnamed strict_low_part patterns for HI and
>>> QI versions): Set attr "flags_valid".
>>> (bsetmemqi, bsetmemqi_ext, bsetdreg, bchgdreg, bclrdreg,
>>> bclrmemqi, extzv_8_16_reg, extzv_bfextu_mem, insv_bfchg_mem,
>>> insv_bfclr_mem, insv_bfset_mem, extv_bfextu_reg,
>>> insv_bfclr_reg, insv_bfset_reg, dbne_hi, dbne_si, dbge_hi,
>>> dbge_si, extendsfxf2, extenddfxf2, ): Remove manual cc_status
>>> management.
>>> (various unnamed peepholes): Adjust compare/branch sequences
>>> for new cbranch patterns.
>>> (dbcc peepholes): Likewise, and output the comparison here
>>> as well.
>>> * config/m68k/predicates.md (valid_dbcc_comparison_p): Delete.
>>> (fp_src_operand): Allow constant zero.
>>> (address_reg_operand): New predicate.
>>>
>>> * rtl.h (inequality_comparisons_p): Remove declaration.
>>> * recog.h (next_insn_tests_no_inequality): Likewise.
>>> * rtlanal.c (inequality_comparisons_p): Delete function.
>>> * recog.c (next_insn_tests_no_inequality): Likewise.
>> My inclination is to ACK this as-is and let us iterate on any bugs that
>> pop up. Bernd has a long history with GCC and I absolutely trust his
>> ability, judgment and commitment to addressing any issues.
>>
>> While scanning this patch I did notice the introduction of
>> CC_STATUS_INIT in output_{and,ior,xor}si. You might want to check that.
>>
>> So unless there's objections over the next say 48-72 hrs, let's get the
>> kit in and we can iterate if there's further issues that need resolving.
>
> Any news on this? I would be in favor of merging these patches as I have
> tested them successfully on Debian by building the gcc-snapshot package
> with the patches applied. I used all four patches plus the additional one
> required to be able to build the kernel.
Not really. I've already indicated to Bernd that he should go ahead and
commit the changes and we can iterate on any problems that arise.
>
> I did not see the bootstrap problems that Mikael reported and Andreas has
> reported that the issues is not reliably reproducible on Aranym. He suspected
> that it might be a bug in the MMU emulation in Aranym which only triggers
> randomly depending on the current memory layout.
Good to know it wasn't reproducible and might ultimately be a bug in aranym.
Jeff
