From: Damjan Marion <damarion@cisco.com>
Date: Sun, 25 Apr 2021 08:55:53 +0000 (+0200)
Subject: vppinfra: add COMPILE_TIME_CONST() macro
X-Git-Tag: v21.10-rc0~196
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=b14c49d2275f6348640572b7b481dad43f3a00d0;p=vpp.git

vppinfra: add COMPILE_TIME_CONST() macro

Type: improvement
Change-Id: I10d7489f57bc60eb92049962b4e6ea84974f17b8
Signed-off-by: Damjan Marion <damarion@cisco.com>
---

diff --git a/src/vppinfra/clib.h b/src/vppinfra/clib.h
index 05af8fe7168..4629a7defb8 100644
--- a/src/vppinfra/clib.h
+++ b/src/vppinfra/clib.h
@@ -120,6 +120,7 @@
 /* Hints to compiler about hot/cold code. */
 #define PREDICT_FALSE(x) __builtin_expect((x),0)
 #define PREDICT_TRUE(x) __builtin_expect((x),1)
+#define COMPILE_TIME_CONST(x) __builtin_constant_p (x)
 
 /*
  * Compiler barrier
diff --git a/src/vppinfra/string.h b/src/vppinfra/string.h
index fb46a0c6a0d..76d345e16bc 100644
--- a/src/vppinfra/string.h
+++ b/src/vppinfra/string.h
@@ -143,7 +143,7 @@ memcpy_s_inline (void *__restrict__ dest, rsize_t dmax,
    * Optimize constant-number-of-bytes calls without asking
    * "too many questions for someone from New Jersey"
    */
-  if (__builtin_constant_p (n))
+  if (COMPILE_TIME_CONST (n))
     {
       clib_memcpy_fast (dest, src, n);
       return EOK;