This patch adds a small typename cache to ObjectClass. This allows
caching positive casts within each ObjectClass. Benchmarking a
PPC workload provided by Aurelien, this patch eliminates every
single g_hash_table_lookup() happening during the benchmark (which
was about 2 million per-second).
With this patch applied, I get exactly the same performance (within
the margin of error) as with --disable-qom-cast-debug.
N.B. it's safe to cache typenames only from the _assert() macros
because they are always called with string literals.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
035873283b