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authorDamjan Marion <damarion@cisco.com>2021-04-25 10:58:07 +0200
committerDamjan Marion <damarion@cisco.com>2021-04-25 10:59:42 +0200
commite21a0b26042f615fdbe8d2c6b29612c212079d52 (patch)
treefc261beb3264d8c0f44717c916554fe50cd190a1 /src
parent1ca6c65e5109b220d25dace08ae758c31e5ea5a2 (diff)
vppinfra: add clear_lowest_set_bit() function, use BMI2 if available
Type: improvement Change-Id: I973cacd0cade0ca98e6261c1fb026a5eb38b44d3 Signed-off-by: Damjan Marion <damarion@cisco.com>
Diffstat (limited to 'src')
-rw-r--r--src/vppinfra/clib.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/src/vppinfra/clib.h b/src/vppinfra/clib.h
index 22377c61440..05af8fe7168 100644
--- a/src/vppinfra/clib.h
+++ b/src/vppinfra/clib.h
@@ -159,6 +159,16 @@
#if defined (count_leading_zeros)
always_inline uword
+clear_lowest_set_bit (uword x)
+{
+#ifdef __BMI2__
+ return _blsr_u64 (x);
+#else
+ return x ^ (1ULL << count_trailing_zeros (x));
+#endif
+}
+
+always_inline uword
min_log2 (uword x)
{
uword n;