[Bug target/104456] nvptx: prevent_branch_around_nothing doesn't handle asm ("")

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104456

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tom de Vries <vr...@gcc.gnu.org>:

https://gcc.gnu.org/g:fd64b09217fbe8fa33b559e61564071e8aca71e5

commit r12-7190-gfd64b09217fbe8fa33b559e61564071e8aca71e5
Author: Tom de Vries <tdevr...@suse.de>
Date:   Thu Feb 10 11:26:16 2022 +0100

    [nvptx] Handle asm insn in prevent_branch_around_nothing

    With GOMP_NVPTX_JIT=-00 and -mptx=3.1, I run into:
    ...
    FAIL: libgomp.oacc-c/../libgomp.oacc-c-c++-common/acc_prof-version-1.c \
      -DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2 \
      execution test
    ...

    The problem is that we're generating a diverging branch around nothing:
    ...
            {
                    .reg.u32        %x;
                    mov.u32 %x, %tid.x;
                    setp.ne.u32     %r23, %x, 0;
            }
            @%r23   bra     $L2;
    $L2:
    ...
    which the driver JIT has problems with at -O0, so consequently we run into
the
    nvptx_uniform_warp_check.

    Fix this by handling asm ("") and alike in prevent_branch_around_nothing.

    Tested on x86_64 with nvptx accelerator.

    gcc/ChangeLog:

    2022-02-10  Tom de Vries  <tdevr...@suse.de>

            PR target/104456
            * config/nvptx/nvptx.cc (prevent_branch_around_nothing): Handle asm
            insn.