[Bug target/111060] New: [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[Bug target/111060] New: [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[slyfox at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

            Bug ID: 111060
           Summary: [14 Regression] i686-linux bootstrap failure:
                    i686-unknown-linux-gnu/libstdc++-v3/include/limits:198
                    6:1: error: SSE register return with SSE2 disabled
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at gcc dot gnu.org
  Target Milestone: ---

Noticed bootstrap failure on r14-3320-g7f8d730a563983 today:

$ ~/dev/git/gcc/configure --build=i686-unknown-linux-gnu
--host=i686-unknown-linux-gnu --target=i686-unknown-linux-gnu && make
...
/tmp/gb/./gcc/xgcc -shared-libgcc -B/tmp/gb/./gcc -nostdinc++
-L/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/src
-L/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/src/.libs
-L/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/libsupc++/.libs
-B/usr/local/i686-unknown-linux-gnu/bin/
-B/usr/local/i686-unknown-linux-gnu/lib/ -isystem
/usr/local/i686-unknown-linux-gnu/include -isystem
/usr/local/i686-unknown-linux-gnu/sys-include   -fno-checking -x c++-header
-nostdinc++ -g -O2 -D_GNU_SOURCE 
-I/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/include/i686-unknown-linux-gnu
-I/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/include
-I/home/slyfox/dev/git/gcc/libstdc++-v3/libsupc++  -O2 -g -std=gnu++0x
/home/slyfox/dev/git/gcc/libstdc++-v3/include/precompiled/stdc++.h \
-o i686-unknown-linux-gnu/bits/stdc++.h.gch/O2ggnu++0x.gch
In file included from
/home/slyfox/dev/git/gcc/libstdc++-v3/include/precompiled/stdc++.h:55:
/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/include/limits: In static member
function 'static constexpr _Float16 std::numeric_limits<_Float16>::min()':
/tmp/gb/i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE
register return with SSE2 disabled

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-08-18

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Ah, looks like the 16-bit types still need to be enabled conditionally.

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Created attachment 55756
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55756&action=edit
Revert pre-C++23 support for 16-bit float types

I'll test this patch as soon as I can get an i686 system set up.

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[slyfox at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

--- Comment #3 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
The patch fixed gcc buid on i686-linux for me. Thank you!

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:

https://gcc.gnu.org/g:27d0cfcb2b33de07351d9cb26f62d04d7416716c

commit r14-3329-g27d0cfcb2b33de07351d9cb26f62d04d7416716c
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Aug 18 13:10:15 2023 +0100

    libstdc++: Revert pre-C++23 support for 16-bit float types [PR111060]

    In r14-3304-g1a566fddea212a and r14-3305-g6cf214b4fc97f5 I tried to
    enable std::format for 16-bit float types before C++23. This causes
    errors for targets where the types are defined but can't actually be
    used, e.g. i686 without sse2.

    Make the std::numeric_limits and std::formatter specializations for
    _Float16 and __bfloat16_t depend on the __STDCPP_FLOAT16_T__ and
    __STDCPP_BFLOAT16_T__ macros again, so they're only defined for C++23
    when the type is fully supported. This is OK because the main point of
    my earlier commits was to add better support for _Float32 and _Float64.
    It seems fine for the new 16-bit types to only be supported for C++23,
    as they were never present before GCC 13 anyway.

    libstdc++-v3/ChangeLog:

            PR target/111060
            * include/std/format (formatter): Only define specializations
            for 16-bit floating-point types for C++23.
            * include/std/limits (numeric_limits): Likewise.

[Bug target/111060] [14 Regression] i686-linux bootstrap failure: i686-unknown-linux-gnu/libstdc++-v3/include/limits:1986:1: error: SSE register return with SSE2 disabled

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111060

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Fixed, thanks for the report.