From: Georg-Johann Lay <avr@gjlay.de>
To: gcc-patches@gcc.gnu.org
Cc: Jeff Law <jeffreyalaw@gmail.com>,
Denis Chertykov <chertykov@gmail.com>,
Senthil Kumar Selvaraj <SenthilKumar.Selvaraj@microchip.com>
Subject: Re: [patch,avr] Fix PR109650 wrong code
Date: Fri, 19 May 2023 10:17:45 +0200 [thread overview]
Message-ID: <6a1a13f9-0f34-c4bf-ff30-41d1bf1b068e@gjlay.de> (raw)
In-Reply-To: <48369cc7-884d-9eef-2e16-9bc2bfe825f1@gjlay.de>
Here is a revised version of the patch. The difference to the
previous one is that it adds some combine patterns for *cbranch
insns that were lost in the PR92729 transition. The post-reload
part of the patterns were still there. The new patterns are
slightly more general in that they also handle fixed-point modes.
Apart from that, the patch behaves the same:
Am 15.05.23 um 20:05 schrieb Georg-Johann Lay:
> This patch fixes a wrong-code bug in the wake of PR92729, the transition
> that turned the AVR backend from cc0 to CCmode. In cc0, the insn that
> uses cc0 like a conditional branch always follows the cc0 setter, which
> is no more the case with CCmode where set and use of REG_CC might be in
> different basic blocks.
>
> This patch removes the machine-dependent reorg pass in avr_reorg entirely.
>
> It is replaced by a new, AVR specific mini-pass that runs prior to
> split2. Canonicalization of comparisons away from the "difficult"
> codes GT[U] and LE[U] is now mostly performed by implementing
> TARGET_CANONICALIZE_COMPARISON.
>
> Moreover:
>
> * Text peephole conditions get "dead_or_set_regno_p (*, REG_CC)" as
> needed.
>
> * RTL peephole conditions get "peep2_regno_dead_p (*, REG_CC)" as
> needed.
>
> * Conditional branches no more clobber REG_CC.
>
> * insn output for compares looks ahead to determine the branch mode in
> use. This needs also "dead_or_set_regno_p (*, REG_CC)".
>
> * Add RTL peepholes for decrement-and-branch detection.
>
> Finally, it fixes some of the many indentation glitches left over from
> PR92729.
>
> Ok?
>
> I'd also backport this one because all of v12+ is affected by the wrong
> code.
Johann
--
gcc/
PR target/109650
PR target/97279
* config/avr/avr-passes.def (avr_pass_ifelse): Insert new pass.
* config/avr/avr.cc (avr_pass_ifelse): New RTL pass.
(avr_pass_data_ifelse): New pass_data for it.
(make_avr_pass_ifelse, avr_redundant_compare, avr_cbranch_cost)
(avr_canonicalize_comparison, avr_out_plus_set_ZN)
(avr_out_cmp_ext): New functions.
(compare_condtition): Make sure REG_CC dies in the branch insn.
(avr_rtx_costs_1): Add computation of cbranch costs.
(avr_adjust_insn_length) [ADJUST_LEN_ADD_SET_ZN, ADJUST_LEN_CMP_ZEXT]:
[ADJUST_LEN_CMP_SEXT]Handle them.
(TARGET_CANONICALIZE_COMPARISON): New define.
(avr_simplify_comparison_p, compare_diff_p, avr_compare_pattern)
(avr_reorg_remove_redundant_compare, avr_reorg): Remove functions.
(TARGET_MACHINE_DEPENDENT_REORG): Remove define.
* avr-protos.h (avr_simplify_comparison_p): Remove proto.
(make_avr_pass_ifelse, avr_out_plus_set_ZN, cc_reg_rtx)
(avr_out_cmp_zext): New Protos
* config/avr/avr.md (branch, difficult_branch): Don't split insns.
(*cbranchhi.zero-extend.0", *cbranchhi.zero-extend.1")
(*swapped_tst<mode>, *add.for.eqne.<mode>): New insns.
(*cbranch<mode>4): Rename to cbranch<mode>4_insn.
(define_peephole): Add dead_or_set_regno_p(insn,REG_CC) as needed.
(define_deephole2): Add peep2_regno_dead_p(*,REG_CC) as needed.
Add new RTL peepholes for decrement-and-branch and *swapped_tst<mode>.
Rework signtest-and-branch peepholes for *sbrx_branch<mode>.
(adjust_len) [add_set_ZN, cmp_zext]: New.
(QIPSI): New mode iterator.
(ALLs1, ALLs2, ALLs4, ALLs234): New mode iterators.
(gelt): New code iterator.
(gelt_eqne): New code attribute.
(rvbranch, *rvbranch, difficult_rvbranch, *difficult_rvbranch)
(branch_unspec, *negated_tst<mode>, *reversed_tst<mode>)
(*cmpqi_sign_extend): Remove insns.
(define_c_enum "unspec") [UNSPEC_IDENTITY]: Remove.
* config/avr/avr-dimode.md (cbranch<mode>4): Canonicalize comparisons.
* config/avr/predicates.md (scratch_or_d_register_operand): New.
* config/avr/contraints.md (Yxx): New constraint.
gcc/testsuite/
PR target/109650
* config/avr/torture/pr109650-1.c: New test.
* config/avr/torture/pr109650-2.c: New test.
next prev parent reply other threads:[~2023-05-19 8:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-15 18:05 Georg-Johann Lay
2023-05-19 8:17 ` Georg-Johann Lay [this message]
2023-05-19 8:49 ` Georg-Johann Lay
2023-05-30 13:15 ` Ping #1: " Georg-Johann Lay
2023-06-07 8:39 ` Ping #2: " Georg-Johann Lay
2023-06-10 16:58 ` Jeff Law
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