From c663397f46152e96c548ba392858c730e132dd7a Mon Sep 17 00:00:00 2001
From: Tim Ruffing <crypto@timruffing.de>
Date: Mon, 17 Dec 2018 11:46:54 +0100
Subject: [PATCH] Use __GNUC_PREREQ for detecting __builtin_expect

---
 configure.ac | 6 ------
 src/util.h   | 2 +-
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index 68c45a5..0657b71 100644
--- a/configure.ac
+++ b/configure.ac
@@ -153,12 +153,6 @@ AC_ARG_WITH([asm], [AS_HELP_STRING([--with-asm=x86_64|arm|no|auto]
 
 AC_CHECK_TYPES([__int128])
 
-AC_MSG_CHECKING([for __builtin_expect])
-AC_COMPILE_IFELSE([AC_LANG_SOURCE([[void myfunc() {__builtin_expect(0,0);}]])],
-    [ AC_MSG_RESULT([yes]);AC_DEFINE(HAVE_BUILTIN_EXPECT,1,[Define this symbol if __builtin_expect is available]) ],
-    [ AC_MSG_RESULT([no])
-    ])
-
 if test x"$enable_coverage" = x"yes"; then
     AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code])
     CFLAGS="$CFLAGS -O0 --coverage"
diff --git a/src/util.h b/src/util.h
index e014750..e1f5b76 100644
--- a/src/util.h
+++ b/src/util.h
@@ -36,7 +36,7 @@ static SECP256K1_INLINE void secp256k1_callback_call(const secp256k1_callback *
 } while(0)
 #endif
 
-#ifdef HAVE_BUILTIN_EXPECT
+#if SECP256K1_GNUC_PREREQ(3, 0)
 #define EXPECT(x,c) __builtin_expect((x),(c))
 #else
 #define EXPECT(x,c) (x)