Re: [dpdk-dev] [PATCH v3 0/3] AVX512 vPMD on i40e

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

On Tue, 26 Jan 2021 16:51:19 +0000, Ferruh Yigit wrote:
> On 1/26/2021 4:48 PM, Thomas Monjalon wrote:
> > 26/01/2021 17:39, Ferruh Yigit:  
> >> On 1/26/2021 4:22 PM, Thomas Monjalon wrote:  
> >>> 26/01/2021 17:17, Rong, Leyi:  
> >>>>>> On 1/20/2021 11:21 PM, Ferruh Yigit wrote:
> >>>>>>
> >>>>>> And for the mingw, I have same result with Ali, I can reproduce with (Fedora  
> >>>>> MinGW 9.2.1-6.fc32).  
> >>>>>>
> >>>>>> But different from the CI, I am getting the error [1] for all following files:
> >>>>>> rte_random.c
> >>>>>> i40e_rxtx_vec_sse.c
> >>>>>> i40e_rxtx_vec_avx512.c
> >>>>>> i40e_rxtx_vec_avx2.c
> >>>>>> rte_ethdev.c  
> >>> [...]  
> >>>> Send patch https://patchwork.dpdk.org/patch/87349/ to disable avx512 on windows as the workaround.
> >>>> Pallavi also tested with this patch, and passed the mingw and clang build. Will try to see if has better way to fix.  
> >>>
> >>> Ferruh mentioned errors with other files outside of i40e.
> >>>  
> >>
> >> The patch globally disables the avx512 for windows cross build, not just for
> >> i40e, so I confirm it fixes the build errors in my environment.
> >>
> >> But disabling avx512 like this is not best option.  
> > 
> > Some may argue that AVX512 is not the best option ;)
> >   
> 
> flame war mode activated.

I found the following fix working:

--- a/drivers/net/i40e/meson.build
+++ b/drivers/net/i40e/meson.build
@@ -60,6 +60,9 @@ if arch_subdir == 'x86'
 		if cc.has_argument('-march=skylake-avx512')
 			avx512_args += '-march=skylake-avx512'
 		endif
+		if is_windows and cc.get_id() == 'gcc'
+			avx512_args += '-fno-asynchronous-unwind-tables'
+		endif
 		i40e_avx512_lib = static_library('i40e_avx512_lib',
 				'i40e_rxtx_vec_avx512.c',
 				dependencies: [static_rte_ethdev,

It's admittedly from StackOverflow, but after reading about
-fno-asynchronous-unwind-tables I see no harm disabling it, at least for just
one file.