devices: vhost: simplify string copies for GCC-10

[vpp.git] / src / vppinfra / clib.h

diff --git a/src/vppinfra/clib.h b/src/vppinfra/clib.h
index 95dadd9..bdea43b 100644 (file)
--- a/src/vppinfra/clib.h
+++ b/src/vppinfra/clib.h
@@ -40,6 +40,10 @@
 
 #include <vppinfra/config.h>
 
+#ifdef  __x86_64__
+#include <x86intrin.h>
+#endif
+
 /* Standalone means to not assume we are running on a Unix box. */
 #if ! defined (CLIB_STANDALONE) && ! defined (CLIB_LINUX_KERNEL)
 #define CLIB_UNIX
@@ -81,6 +85,9 @@
 #define CLIB_PACKED(x) x __attribute__ ((packed))
 #define CLIB_UNUSED(x) x __attribute__ ((unused))
 
+/* similar to CLIB_CACHE_LINE_ALIGN_MARK() but with arbitrary alignment */
+#define CLIB_ALIGN_MARK(name, alignment) u8 name[0] __attribute__((aligned(alignment)))
+
 /* Make a string from the macro's argument */
 #define CLIB_STRING_MACRO(x) #x
 
@@ -108,6 +115,14 @@
 #define PREDICT_FALSE(x) __builtin_expect((x),0)
 #define PREDICT_TRUE(x) __builtin_expect((x),1)
 
+/*
+ * Compiler barrier
+ *   prevent compiler to reorder memory access accross this boundary
+ *   prevent compiler to cache values in register (force reload)
+ * Not to be confused with CPU memory barrier below
+ */
+#define CLIB_COMPILER_BARRIER() asm volatile ("":::"memory")
+
 /* Full memory barrier (read and write). */
 #define CLIB_MEMORY_BARRIER() __sync_synchronize ()
 
@@ -282,6 +297,15 @@ flt_round_to_multiple (f64 x, f64 f)
   return f * flt_round_nearest (x / f);
 }
 
+always_inline uword
+extract_bits (uword x, int start, int count)
+{
+#ifdef __BMI__
+  return _bextr_u64 (x, start, count);
+#endif
+  return (x >> start) & pow2_mask (count);
+}
+
 #define clib_max(x,y)                          \
 ({                                             \
   __typeof__ (x) _x = (x);                     \