Hi Uros,
As you've requested/suggested, here's a patch that tidies up and
unifies doubleword handling in i386.md; converting all doubleword
splitters for logic operations to post-reload form, generalizing
their define_insn_and_split templates to <dwi> form (supporting
TARGET_64BIT ? TImode : DImode), and where required tweaking the
corresponding expanders to use SDWIM to support TImode doubleword
operations.  These changes incorporate your feedback from
https://gcc.gnu.org/pipermail/gcc-patches/2022-June/596205.html
where I included many/several of these clean-ups, in a patch to
add a new optimization.  I agree, it's better to split these out
(this patch), and I'll resubmit the (smaller) optimization patch
as a follow-up.

This patch has been tested on x86_64-pc-linux-gnu with make bootstrap
and make -k check, both with and without --target_board=unix{-m32},
with no new failures.  Ok for mainline?


2022-06-28  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
        * config/i386/i386.md (general_szext_operand): Add TImode
        support using x86_64_hilo_general_operand predicate.
        (*cmp<dwi>_doubleword): Use x86_64_hilo_general_operand predicate.
        (*add<dwi>3_doubleword): Improved optimization of zero addition.
        (and<mode>3): Use SDWIM mode iterator to add support for double
        word bit-wise AND in TImode.  Use force_reg when double word
        immediate operand isn't x86_64_hilo_general_operand.
        (and<dwi>3_doubleword): Generalized from anddi3_doubleword and
        converted into a post-reload splitter.
        (*andn<mode>3_doubleword): Generalized from *andndi3_doubleword.
        (define_split): Generalize DImode splitters for andn to <DWI>.
        One splitter for TARGET_BMI, the other for !TARGET_BMI.
        (<any_or><mode>3): Use SDWIM mode iterator to add suppport for
        double word bit-wise XOR and bit-wise IOR in TImode.  Use
        force_reg when double word immediate operand isn't
        x86_64_hilo_general_operand.
        (*<any_or>di3_doubleword): Generalized from <any_or>di3_doubleword.
        (one_cmpl<mode>2): Use SDWIM mode iterator to add support for
        double word bit-wise NOT in TImode.
        (one_cmpl<dwi>2_doubleword): Generalize from one_cmpldi2_doubleword
        and converted into a post-reload splitter.


Thanks again,
Roger
--