Change the size of the hash table used to cache IP -> debuginfo to a prime nr

This change is based on rumours/legends/oral transmission of experience/...
that prime nrs are good to use for hash table size :).

If someone has a (short) explanation about why this is useful,
that will be welcome.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13237

diff --git a/coregrind/m_debuginfo/debuginfo.c b/coregrind/m_debuginfo/debuginfo.c
index 95e1ea0409422edb6120b948ca0849b6506f3696..0a4232550cbebdc5d327a4ac9572a3a318570a82 100644 (file)
--- a/coregrind/m_debuginfo/debuginfo.c
+++ b/coregrind/m_debuginfo/debuginfo.c
@@ -2245,7 +2245,8 @@ static void find_DiCfSI ( /*OUT*/DebugInfo** diP,
    records are added all at once, when the debuginfo for an object is
    read, and is not changed ever thereafter. */
 
-#define N_CFSI_CACHE 511
+// Prime number, giving about 3K cache on 32 bits, 6K cache on 64 bits.
+#define N_CFSI_CACHE 509
 
 typedef
    struct { Addr ip; DebugInfo* di; Word ix; }