[dpdk-dev] [PATCH v2] net/i40e: fix avx code error on MinGW

[Dmitry Kozlyuk]

On Tue,  2 Feb 2021 22:32:58 +0800, Leyi Rong wrote:
> Adds extra cflags '-fno-asynchronous-unwind-tables'
> to avoid the MinGW build error:
> 	Error: invalid register for .seh_savexmm
> 
> Fixes: 5c38c33f7880 ("net/i40e: disable AVX512 with MinGW")
> 
> Signed-off-by: Leyi Rong <leyi.rong at intel.com>

Tested-by: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>

Re: -fno-asynchronous-unwind-tables, when cross-compiling from Linux, I
observe bit-to-bit identical i40e_rxtx_vec_avx512.c.obj. My guess it that this
option somehow affects GCC inlining heuristics. Similar issue existed in
librte_acl (at least a year ago win GCC 6, I believe), where GCC generated
incorrect code unless certain functions had been inlined (caught by test
app). No an AVX expert, just my 2c.