From b9cb60a911c35650c26995c7e6f7051fdf702d22 Mon Sep 17 00:00:00 2001
From: Baruch Siach <baruch@tkos.co.il>
Date: Tue, 19 Jun 2018 15:31:52 +0300
Subject: [PATCH] portable.h: fix build with gcc older than 4.8

__builtin_bswap16 is available in all gcc architectures only since
version 4.8. Older gcc versions fail to build:

imx_sdp.o: In function `perform_dcd':
.../imx_sdp.c:1138: undefined reference to `__builtin_bswap16'
imx_sdp.o: In function `write_dcd_table_ivt':
.../imx_sdp.c:457: undefined reference to `__builtin_bswap16'
imx_sdp.o: In function `write_dcd':
.../imx_sdp.c:410: undefined reference to `__builtin_bswap16'
imx_sdp.o: In function `init_header':
.../imx_sdp.c:1075: undefined reference to `__builtin_bswap16'

Use a local implementation instead. The implementation suggested by
Arnout Vandecappelle on the Buildroot mailing list.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
Upstream status: https://github.com/boundarydevices/imx_usb_loader/pull/82

 portable.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/portable.h b/portable.h
index 364fe47b212a..b8a302bae400 100644
--- a/portable.h
+++ b/portable.h
@@ -58,7 +58,11 @@ extern int debugmode;
 #ifdef __GNUC__
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define BE32(x) __builtin_bswap32(x)
-#define BE16(x) __builtin_bswap16(x)
+#define BE16(x) \
+({ \
+	typeof(x) __x = (x); \
+	(__x<<8 | __x>>8); \
+})
 #else
 #define BE32(x) x
 #define BE16(x) x
-- 
2.17.1