[dpdk-dev] [PATCH v3 03/24] rte_common.h: cast gcc builtin result to avoid complaints

Andy Green andy at warmcat.com
Sat May 12 03:58:57 CEST 2018


/projects/lagopus/src/dpdk/build/include/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.

Signed-off-by: Andy Green <andy at warmcat.com>
---
 lib/librte_eal/common/include/rte_common.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 69e5ed1e3..679f2f184 100644
--- 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);
 }
 
 /**



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