ZJIT: Count writes to the VM frame (#14597)

This is a) a lot of memory traffic and b) is another good proxy for our
ability to strength reduce method calls.

1 files changed, 5 insertions, 0 deletions

diff --git a/zjit.rb b/zjit.rb
index 7d2fd3a10e..f0c988d5a0 100644
--- a/zjit.rb
+++ b/zjit.rb
@@ -58,6 +58,11 @@ class << RubyVM::ZJIT
       :gc_time_ns,
       :invalidation_time_ns,
 
+      :vm_write_pc_count,
+      :vm_write_sp_count,
+      :vm_write_locals_count,
+      :vm_write_stack_count,
+
       :code_region_bytes,
       :side_exit_count,
       :total_insn_count,