Re: [dpdk-dev] [PATCH v6] eal/x86: add 128-bit atomic compare exchange

[Thomas Monjalon <thomas@monjalon.net>]

04/04/2019 14:14, Eads, Gage:
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > 04/04/2019 14:08, Thomas Monjalon:
> > > 04/04/2019 13:47, Ferruh Yigit:
> > > > .../dpdk/x86_64-native-linuxapp-gcc/include/rte_atomic_64.h:223:3:
> > > > error: ISO C does not support ‘__int128’ types [-Werror=pedantic]
> > >
> > > We can try this kind of workaround (disable pedantic locally):
> > >
> > https://github.com/HowardHinnant/date/pull/38/commits/177032852d5b46
> > 14
> > > 112ca1ab3ef42d6b41824816
> > 
> > Or better:
> > __extension__ typedef __int128 int128;
> > 
> 
> Taking that one step further -- RTE_STD_C11 evaluates to __extension__ (when the STD C version is sufficiently old).

I don't think __int128 is part of C11. Is it?

Ferruh, I cannot reproduce the compiler error. What is your compiler?
Please, could you test this patch?

--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
@@ -220,7 +220,7 @@ typedef struct {
        RTE_STD_C11
        union {
                uint64_t val[2];
-               __int128 int128;
+               __extension__ __int128 int128;
        };
 } __rte_aligned(16) rte_int128_t;