[PATCH 1/3] lib/eal: add rte_atomic128_cmp_exchange compatible with MSVC

[Andre Muezerie <andremue@linux.microsoft.com>]

MSVC does not support inline assembly, which is used by the
implementation of rte_atomic128_cmp_exchange and is needed
by lib/stack.

Error printed by MSVC:

stack_rte_stack_lf.c.obj : error LNK2019:
    unresolved external symbol rte_atomic128_cmp_exchange referenced
    in function __rte_stack_lf_push_elems

Fix is to provide an implementation for rte_atomic128_cmp_exchange
which uses an intrinsic function, which is used when compiling with
MSVC. For other compilers the existing implementation continues to
be used.

Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
---
 lib/eal/x86/include/rte_atomic.h    |  4 ++--
 lib/eal/x86/include/rte_atomic_64.h | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/lib/eal/x86/include/rte_atomic.h b/lib/eal/x86/include/rte_atomic.h
index c72c47c83e..e8e0e4c33c 100644
--- a/lib/eal/x86/include/rte_atomic.h
+++ b/lib/eal/x86/include/rte_atomic.h
@@ -288,12 +288,12 @@ static inline int rte_atomic32_dec_and_test(rte_atomic32_t *v)
 
 #endif
 
+#endif /* RTE_TOOLCHAIN_MSVC */
+
 #ifdef RTE_ARCH_I686
 #include "rte_atomic_32.h"
 #else
 #include "rte_atomic_64.h"
 #endif
 
-#endif
-
 #endif /* _RTE_ATOMIC_X86_H_ */
diff --git a/lib/eal/x86/include/rte_atomic_64.h b/lib/eal/x86/include/rte_atomic_64.h
index 0a7a2131e0..26c87a2da6 100644
--- a/lib/eal/x86/include/rte_atomic_64.h
+++ b/lib/eal/x86/include/rte_atomic_64.h
@@ -182,6 +182,23 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v)
 
 /*------------------------ 128 bit atomic operations -------------------------*/
 
+#ifdef RTE_TOOLCHAIN_MSVC
+static inline int
+rte_atomic128_cmp_exchange(rte_int128_t *dst,
+			   rte_int128_t *exp,
+			   const rte_int128_t *src,
+			   unsigned int weak,
+			   int success,
+			   int failure)
+{
+	return (int)_InterlockedCompareExchange128(
+		(int64_t volatile *) dst,
+		src->val[1], /* exchange high */
+		src->val[0], /* exchange low */
+		(int64_t *) exp /* comparand result */
+	);
+}
+#else
 static inline int
 rte_atomic128_cmp_exchange(rte_int128_t *dst,
 			   rte_int128_t *exp,
@@ -212,5 +229,6 @@ rte_atomic128_cmp_exchange(rte_int128_t *dst,
 
 	return res;
 }
+#endif /* RTE_TOOLCHAIN_MSVC */
 
 #endif /* _RTE_ATOMIC_X86_64_H_ */
-- 
2.47.0.vfs.0.3