Increment max_iv_count on class based on number of set_iv in initialize (#6788)

We can loosely predict the number of ivar sets on a class based on the
number of iv set instructions in the initialize method. This should give
us a more accurate estimate to use for initial size pool allocation,
which should in turn give us more cache hits.

1 files changed, 1 insertions, 0 deletions

diff --git a/vm_core.h b/vm_core.h
index 3364089f79..9c016de8fd 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -1158,6 +1158,7 @@ rb_iseq_t *rb_iseq_new_with_callback(const struct rb_iseq_new_with_callback_call
 
 VALUE rb_iseq_disasm(const rb_iseq_t *iseq);
 int rb_iseq_disasm_insn(VALUE str, const VALUE *iseqval, size_t pos, const rb_iseq_t *iseq, VALUE child);
+attr_index_t rb_estimate_iv_count(VALUE klass, const rb_iseq_t * initialize_iseq);
 
 VALUE rb_iseq_coverage(const rb_iseq_t *iseq);