The first argument to rte_bsf32_safe was incorrectly declared as
a 64 bit value. The code only works on 32 bit values and the underlying
function rte_bsf32 only accepts 32 bit values. This was a mistake
introduced when the safe version was added and probaly cause
by copy/paste from the 64 bit version.
The bug passed silently under the radar until some other code was
built with -Wall and -Wextra in C++ and C++ complains about the
missing cast.
Yes, this is a API signature change, but the original code was wrong.
It is an inline so not an ABI change.
Fixes: 4e261f551986 ("eal: add 64-bit bsf and 32-bit safe bsf functions")
Cc: anatoly.bura...@intel.com
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
Acked-By: Tyler Retzlaff <roret...@linux.microsoft.com>
---
v2 - add suggested release note
doc/guides/rel_notes/release_21_08.rst | 4 ++++
lib/eal/include/rte_common.h | 2 +-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/doc/guides/rel_notes/release_21_08.rst
b/doc/guides/rel_notes/release_21_08.rst
index e2c5ccbf7d90..148405891fcb 100644
--- a/doc/guides/rel_notes/release_21_08.rst
+++ b/doc/guides/rel_notes/release_21_08.rst
@@ -196,6 +196,10 @@ API Changes
to be thread safe; all Rx queues affected by the API will now need to be
stopped before making any changes to the power management scheme.
+* eal: ``rte_bsf32_safe`` now takes a 32 bit value for its first
+ argument. This fixes warnings about loss of precision when used
+ with some compilers settings.
+
ABI Changes
-----------
diff --git a/lib/eal/include/rte_common.h b/lib/eal/include/rte_common.h
index d5a32c66a5fe..99eb5f1820ae 100644
--- a/lib/eal/include/rte_common.h
+++ b/lib/eal/include/rte_common.h
@@ -623,7 +623,7 @@ rte_bsf32(uint32_t v)
* Returns 0 if ``v`` was 0, otherwise returns 1.
*/
static inline int
-rte_bsf32_safe(uint64_t v, uint32_t *pos)
+rte_bsf32_safe(uint32_t v, uint32_t *pos)
{
if (v == 0)
return 0;
--
2.30.2
