doc: Mention that XXH64 is used for checksumming

diff --git a/doc/MANUAL.adoc b/doc/MANUAL.adoc
index 2ba5aab105fb685c9947f79d67c40a22851efb7b..156442de640476230436748038bb2017439ac856 100644 (file)
--- a/doc/MANUAL.adoc
+++ b/doc/MANUAL.adoc
@@ -909,7 +909,9 @@ hashing different kinds of information that should be unique for the
 compilation and then using the hash sum to identify the cached output. ccache
 uses BLAKE2b, a very fast cryptographic hash algorithm, for the hashing. On a
 cache hit, ccache is able to supply all of the correct compiler outputs
-(including all warnings, dependency file, etc) from the cache.
+(including all warnings, dependency file, etc) from the cache. Data stored in
+the cache is checksummed with XXH64, an extremely fast non-cryptographic
+algorithm, to detect corruption.
 
 ccache has two ways of gathering information used to look up results in the
 cache: