eal: explicit cast of builtin for bsf32

rte_common.h:416:9:
warning: conversion to 'uint32_t' {aka 'unsigned int'} from
'int' may change the sign of the result [-Wsign-conversion]
  return __builtin_ctz(v);
         ^~~~~~~~~~~~~~~~

The builtin is defined to return int, but we want to
return it as uint32_t.  Its only defined valid return
values are positive integers or zero, which is OK for
uint32_t.  So just add an explicit cast.

Fixes: 03f6bced5bba ("eal: use intrinsic function")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 69e5ed1..679f2f1 100644 (file)
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -413,7 +413,7 @@ rte_align64prevpow2(uint64_t v)
 static inline uint32_t
 rte_bsf32(uint32_t v)
 {
-       return __builtin_ctz(v);
+       return (uint32_t)__builtin_ctz(v);
 }
 
 /**