[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compaitbility with Clang

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compaitbility with Clang

[jmuizelaar at mozilla dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

Jeff Muizelaar <jmuizelaar at mozilla dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jmuizelaar at mozilla dot com

--- Comment #3 from Jeff Muizelaar <jmuizelaar at mozilla dot com> ---
As heads up, we're also starting to use __builtin_shufflevector in Firefox:
https://searchfox.org/mozilla-central/source/gfx/wr/swgl/src/vector_type.h

We have a fallback for gcc, but it is not pretty.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compaitbility with Clang

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jeff Muizelaar from comment #3)
> As heads up, we're also starting to use __builtin_shufflevector in Firefox:
> https://searchfox.org/mozilla-central/source/gfx/wr/swgl/src/vector_type.h
> 
> We have a fallback for gcc, but it is not pretty.

GCC has __builtin_shuffle but that is different from __builtin_shufflevector.
__builtin_shufflevector seems like a hack though.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compatibility with Clang

[shawn at git dot icu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

Shawn Landden <shawn at git dot icu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |shawn at git dot icu

--- Comment #5 from Shawn Landden <shawn at git dot icu> ---
We don't care if both are hacks. What we care about is an end to egregious
compiler incompatibilities.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compatibility with Clang

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-05-21
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine for __builtin_shufflevector.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compatibility with Clang

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:ef8176e0fac935c095cc39f4ecdfd43cdb8cb3f3

commit r12-1128-gef8176e0fac935c095cc39f4ecdfd43cdb8cb3f3
Author: Richard Biener <rguenther@suse.de>
Date:   Fri May 21 11:33:30 2021 +0200

    c++/88601 - [C/C++] __builtin_shufflevector support

    This adds support for the clang __builtin_shufflevector extension to
    the C and C++ frontends.  The builtin is lowered to VEC_PERM_EXPR.
    Because VEC_PERM_EXPR does not support different sized vector inputs
    or result or the special permute index of -1 (don't-care)
    c_build_shufflevector applies lowering by widening inputs and output
    to the widest vector, replacing -1 by a defined index and
    subsetting the final vector if we produced a wider result than
    desired.

    Code generation thus can be sub-optimal, followup patches will
    aim to fix that by recovering from part of the missing features
    during RTL expansion and by relaxing the constraints of the GIMPLE
    IL with regard to VEC_PERM_EXPR.

    2021-05-21  Richard Biener  <rguenther@suse.de>

            PR c++/88601
    gcc/c-family/
            * c-common.c: Include tree-vector-builder.h and
            vec-perm-indices.h.
            (c_common_reswords): Add __builtin_shufflevector.
            (c_build_shufflevector): New funtion.
            * c-common.h (enum rid): Add RID_BUILTIN_SHUFFLEVECTOR.
            (c_build_shufflevector): Declare.

    gcc/c/
            * c-decl.c (names_builtin_p): Handle RID_BUILTIN_SHUFFLEVECTOR.
            * c-parser.c (c_parser_postfix_expression): Likewise.

    gcc/cp/
            * cp-objcp-common.c (names_builtin_p): Handle
            RID_BUILTIN_SHUFFLEVECTOR.
            * cp-tree.h (build_x_shufflevector): Declare.
            * parser.c (cp_parser_postfix_expression): Handle
            RID_BUILTIN_SHUFFLEVECTOR.
            * pt.c (tsubst_copy_and_build): Handle IFN_SHUFFLEVECTOR.
            * typeck.c (build_x_shufflevector): Build either a lowered
            VEC_PERM_EXPR or an unlowered shufflevector via a temporary
            internal function IFN_SHUFFLEVECTOR.

    gcc/
            * internal-fn.c (expand_SHUFFLEVECTOR): Define.
            * internal-fn.def (SHUFFLEVECTOR): New.
            * internal-fn.h (expand_SHUFFLEVECTOR): Declare.
            * doc/extend.texi: Document __builtin_shufflevector.

    gcc/testsuite/
            * c-c++-common/builtin-shufflevector-2.c: New testcase.
            * c-c++-common/torture/builtin-shufflevector-1.c: Likewise.
            * g++.dg/ext/builtin-shufflevector-1.C: Likewise.
            * g++.dg/ext/builtin-shufflevector-2.C: Likewise.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compatibility with Clang

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |12.0
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for GCC 12.

[Bug c++/88601] We may consider adding __builtin_convertvector and __builtin_shufflevector for better compatibility with Clang

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88601

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0