eal: explicit cast in constant byte swap

GCC 8.1 warns:

rte_byteorder.h: In function 'rte_constant_bswap16':
rte_byteorder.h:54:45: warning: conversion from
'int' to 'uint16_t' {aka 'short unsigned int'}
may change value [-Wconversion]
  ((((uint16_t)(v) & UINT16_C(0x00ff)) << 8) | \
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
   (((uint16_t)(v) & UINT16_C(0xff00)) >> 8))
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rte_byteorder.h:126:9: note: in expansion of macro
'RTE_STATIC_BSWAP16'
  return RTE_STATIC_BSWAP16(x);
         ^~~~~~~~~~~~~~~~~~

The other two sizes are going to be afflicted the
same, so get the same fix.

Fixes: b75667ef9f7e ("eal: add static endianness conversion macros")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>

diff --git a/lib/librte_eal/common/include/generic/rte_byteorder.h b/lib/librte_eal/common/include/generic/rte_byteorder.h
index 9bed85c..7d9a146 100644 (file)
--- a/lib/librte_eal/common/include/generic/rte_byteorder.h
+++ b/lib/librte_eal/common/include/generic/rte_byteorder.h
@@ -123,7 +123,7 @@ typedef uint64_t rte_le64_t; /**< 64-bit little-endian value. */
 static inline uint16_t
 rte_constant_bswap16(uint16_t x)
 {
-       return RTE_STATIC_BSWAP16(x);
+       return (uint16_t)RTE_STATIC_BSWAP16(x);
 }
 
 /*
@@ -135,7 +135,7 @@ rte_constant_bswap16(uint16_t x)
 static inline uint32_t
 rte_constant_bswap32(uint32_t x)
 {
-       return RTE_STATIC_BSWAP32(x);
+       return (uint32_t)RTE_STATIC_BSWAP32(x);
 }
 
 /*
@@ -147,7 +147,7 @@ rte_constant_bswap32(uint32_t x)
 static inline uint64_t
 rte_constant_bswap64(uint64_t x)
 {
-       return RTE_STATIC_BSWAP64(x);
+       return (uint64_t)RTE_STATIC_BSWAP64(x);
 }