Re: [Qemu-devel] [PATCH v3 2/2] avx2 configure: Use primitives in test

[Aaron Lindsay <alindsay@codeaurora.org>]

On Jun 10 12:16, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Use the avx2 primitives during the test, thus making sure that the
> compiler and assembler could actually use avx2.
> 
> This also detects the failure case on gcc 4.8.x with -save-temps
> and avoids the need for the gcc version check in cutils.

I'm getting a segfault when running the latest tip compiled with gcc
4.8.4 on Ubuntu 14.04 and I've bisected it to this commit.

# gcc --version
gcc (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4

I'm configuring with:
# ./configure \
    --static \
	--disable-gtk \
	--target-list=aarch64-softmmu

When run under gdb, I get:
Program received signal SIGSEGV, Segmentation fault.
buffer_find_nonzero_offset_ifunc () at ./util/cutils.c:333
333     {
(gdb) bt
#0  buffer_find_nonzero_offset_ifunc () at ./util/cutils.c:333
#1  0x0000000000939c58 in __libc_start_main ()
#2  0x0000000000419337 in _start ()

I confess I don't understand the intricacies here, but I'm willing to
test fixes if you have any ideas for how to make this also work for my
compiler without blindly excluding all gcc < 4.9.

-Aaron