[Bug target/94678] aarch64: unexpected result with -mgeneral-regs-only and sve

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94678

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Sandiford <rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:154ae7d4e921d704118d6a16ee5cc2a10b9047da

commit r10-7891-g154ae7d4e921d704118d6a16ee5cc2a10b9047da
Author: Fei Yang <felix.yang@huawei.com>
Date:   Wed Apr 22 18:24:59 2020 +0100

    aarch64: unexpected result with -mgeneral-regs-only and sve [PR94678]

    As the two testcases for PR94678 show, -mgeneral-regs-only is handled
    properly with SVE.  We should issue an error message instead of expanding
    SVE builtin funtions when -mgeneral-regs-only option is specified.

    The middle end should never try to use vector patterns when the vector
    modes have been disabled by !have_regs_of_mode.  But it's still wrong
    for the target to provide patterns that would inevitably lead to spill
    failure due to lack of registers.  So we should also add check for
    !TARGET_GENERAL_REGS_ONLY in TARGET_SVE and other SVE related macros.

    2020-04-22  Felix Yang  <felix.yang@huawei.com>

    gcc/
            PR target/94678
            * config/aarch64/aarch64.h (TARGET_SVE):
            Add && !TARGET_GENERAL_REGS_ONLY.
            (TARGET_SVE2): Add && TARGET_SVE.
            (TARGET_SVE2_AES, TARGET_SVE2_BITPERM, TARGET_SVE2_SHA3,
            TARGET_SVE2_SM4): Add && TARGET_SVE2.
            * config/aarch64/aarch64-sve-builtins.h
            (sve_switcher::m_old_general_regs_only): New member.
            * config/aarch64/aarch64-sve-builtins.cc
(check_required_registers):
            New function.
            (reported_missing_registers_p): New variable.
            (check_required_extensions): Call check_required_registers before
            return if all required extenstions are present.
            (sve_switcher::sve_switcher): Save TARGET_GENERAL_REGS_ONLY in
            m_old_general_regs_only and clear MASK_GENERAL_REGS_ONLY in
            global_options.x_target_flags.
            (sve_switcher::~sve_switcher): Set MASK_GENERAL_REGS_ONLY in
            global_options.x_target_flags if m_old_general_regs_only is true.

    gcc/testsuite/
            PR target/94678
            * gcc.target/aarch64/sve/acle/general/nosve_6.c: New test.