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authorMatheus Tavares Bernardino <quic_mathbern@quicinc.com>2023-03-13 15:58:19 -0300
committerJuan Quintela <quintela@redhat.com>2023-03-16 16:07:07 +0100
commitd84a78d15d3af9ff28ceec6906a4b101bd545b55 (patch)
tree68b03cf41f925795e8ca59e711326959e3313664
parenta5382214d8b099bb2fe60b206097567762861800 (diff)
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migration/xbzrle: use ctz64 to avoid undefined result
__builtin_ctzll() produces undefined results when the argument is 0. This can be seen through test-xbzrle, which produces the following warning: ../migration/xbzrle.c:265: runtime error: passing zero to ctz(), which is not a valid argument Replace __builtin_ctzll() with our ctz64() wrapper which properly handles 0. Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
-rw-r--r--migration/xbzrle.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/migration/xbzrle.c b/migration/xbzrle.c
index 05366e8..21b92d4 100644
--- a/migration/xbzrle.c
+++ b/migration/xbzrle.c
@@ -12,6 +12,7 @@
*/
#include "qemu/osdep.h"
#include "qemu/cutils.h"
+#include "qemu/host-utils.h"
#include "xbzrle.h"
/*
@@ -233,7 +234,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen,
break;
}
never_same = false;
- num = __builtin_ctzll(~comp);
+ num = ctz64(~comp);
num = (num < bytes_to_check) ? num : bytes_to_check;
zrun_len += num;
bytes_to_check -= num;
@@ -262,7 +263,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen,
nzrun_len += 64;
break;
}
- num = __builtin_ctzll(comp);
+ num = ctz64(comp);
num = (num < bytes_to_check) ? num : bytes_to_check;
nzrun_len += num;
bytes_to_check -= num;