[Bug target/106303] [13 Regression] ICE on valid code at -O3 with -fno-inline-small-functions on x86_64-linux-gnu: in extract_insn, at recog.cc:2791 since r13-1607-gc3ed9e0d6e96d869

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106303

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Roger Sayle <sayle@gcc.gnu.org>:

https://gcc.gnu.org/g:76d6224b944e1a66bfb1195fb7d35d9726f1aed8

commit r13-1811-g76d6224b944e1a66bfb1195fb7d35d9726f1aed8
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Sun Jul 24 12:22:22 2022 +0100

    PR target/106303: Fix TImode STV related failures on x86.

    This patch resolves PR target/106303 (and the related PRs 106347,
    106404, 106407) which are ICEs caused by my improvements to x86_64's
    128-bit TImode to V1TImode Scalar to Vector (STV) pass.  My apologies
    for the breakage.  The issue is that data flow analysis is used to
    partition usage of each TImode pseudo into "chains", where each
    chain is analyzed and if suitable converted to vector operations.
    The problems appears when some chains for a pseudo are converted,
    and others aren't as RTL sharing can result in some mode changes
    leaking into other instructions that aren't/shouldn't/can't be
    converted, which eventually leads to an ICE for mismatched modes.

    My first approach to a fix was to unify more of the STV infrastructure,
    reasoning that if TImode STV was exhibiting these problems, but DImode
    and SImode STV weren't, the issue was likely to be caused/resolved by
    these remaining differences.  This appeared to fix some but not all of
    the reported PRs.  A better solution was then proposed by H.J. Lu in
    Bugzilla, that we need to iterate the removal of candidates in the
    function timode_remove_non_convertible_regs until there are no further
    changes.  As each chain is removed from consideration, it in turn may
    affect whether other insns/chains can safely be converted.

    2022-07-24  Roger Sayle  <roger@nextmovesoftware.com>
                H.J. Lu  <hjl.tools@gmail.com>

    gcc/ChangeLog
            PR target/106303
            PR target/106347
            * config/i386/i386-features.cc (make_vector_copies): Move from
            general_scalar_chain to scalar_chain.
            (convert_reg): Likewise.
            (convert_insn_common): New scalar_chain method split out from
            general_scalar_chain convert_insn.
            (convert_registers): Move from general_scalar_chain to
            scalar_chain.
            (scalar_chain::convert): Call convert_insn_common before calling
            convert_insn.
            (timode_remove_non_convertible_regs): Iterate until there are
            no further changes to the candidates.
            * config/i386/i386-features.h (scalar_chain::hash_map): Move
            from general_scalar_chain.
            (scalar_chain::convert_reg): Likewise.
            (scalar_chain::convert_insn_common): New shared method.
            (scalar_chain::make_vector_copies): Move from general_scalar_chain.
            (scalar_chain::convert_registers): Likewise.  No longer virtual.
            (general_scalar_chain::hash_map): Delete.  Moved to scalar_chain.
            (general_scalar_chain::convert_reg): Likewise.
            (general_scalar_chain::make_vector_copies): Likewise.
            (general_scalar_chain::convert_registers): Delete virtual method.
            (timode_scalar_chain::convert_registers): Likewise.

    gcc/testsuite/ChangeLog
            PR target/106303
            PR target/106347
            * gcc.target/i386/pr106303.c: New test case.
            * gcc.target/i386/pr106347.c: New test case.