[PATCH 1/2] eal: provide macro for GCC builtin constant intrinsic

[Tyler Retzlaff]

MSVC does not have a __builtin_constant_p intrinsic so provide
__rte_constant(e) that expands false for MSVC and to the intrinsic for
GCC.

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
---
 lib/eal/include/rte_common.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/eal/include/rte_common.h b/lib/eal/include/rte_common.h
index 298a5c6..d520be6 100644
--- a/lib/eal/include/rte_common.h
+++ b/lib/eal/include/rte_common.h
@@ -44,6 +44,12 @@
 #endif
 #endif
 
+#ifdef RTE_TOOLCHAIN_MSVC
+#define __rte_constant(e) 0
+#else
+#define __rte_constant(e) __extension__(__builtin_constant_p(e))
+#endif
+
 /*
  * RTE_TOOLCHAIN_GCC is defined if the target is built with GCC,
  * while a host application (like pmdinfogen) may have another compiler.
-- 
1.8.3.1