diff --git a/error.c b/error.c
index ed66e6c8488d0f..e1a01b985aae16 100644
--- a/error.c
+++ b/error.c
@@ -4163,7 +4163,7 @@ rb_error_frozen_object(VALUE frozen_obj)
     rb_yjit_lazy_push_frame(GET_EC()->cfp->pc);
 
     VALUE mesg = rb_sprintf("can't modify frozen %"PRIsVALUE": ",
-                            CLASS_OF(frozen_obj));
+                            rb_obj_class(frozen_obj));
     VALUE exc = rb_exc_new_str(rb_eFrozenError, mesg);
 
     rb_ivar_set(exc, id_recv, frozen_obj);
diff --git a/eval.c b/eval.c
index 4fbb0e799735d4..ee5bc43f9cc4c1 100644
--- a/eval.c
+++ b/eval.c
@@ -428,40 +428,10 @@ rb_class_modify_check(VALUE klass)
         rb_class_set_initialized(klass);
     }
     if (OBJ_FROZEN(klass)) {
-        const char *desc;
-
         if (RCLASS_SINGLETON_P(klass)) {
-            desc = "object";
             klass = RCLASS_ATTACHED_OBJECT(klass);
-            if (!SPECIAL_CONST_P(klass)) {
-                switch (BUILTIN_TYPE(klass)) {
-                  case T_MODULE:
-                  case T_ICLASS:
-                    desc = "Module";
-                    break;
-                  case T_CLASS:
-                    desc = "Class";
-                    break;
-                  default:
-                    break;
-                }
-            }
-        }
-        else {
-            switch (BUILTIN_TYPE(klass)) {
-              case T_MODULE:
-              case T_ICLASS:
-                desc = "module";
-                break;
-              case T_CLASS:
-                desc = "class";
-                break;
-              default:
-                Check_Type(klass, T_CLASS);
-                UNREACHABLE;
-            }
         }
-        rb_frozen_error_raise(klass, "can't modify frozen %s: %"PRIsVALUE, desc, klass);
+        rb_error_frozen_object(klass);
     }
 }
 
diff --git a/spec/ruby/core/exception/frozen_error_spec.rb b/spec/ruby/core/exception/frozen_error_spec.rb
index 51eb79cacef6ae..af2e92566192eb 100644
--- a/spec/ruby/core/exception/frozen_error_spec.rb
+++ b/spec/ruby/core/exception/frozen_error_spec.rb
@@ -26,9 +26,11 @@ def o.x; end
     object = Object.new
     object.freeze
 
+    msg_class = ruby_version_is("4.0") ? "Object" : "object"
+
     -> {
       def object.x; end
-    }.should raise_error(FrozenError, "can't modify frozen object: #{object}")
+    }.should raise_error(FrozenError, "can't modify frozen #{msg_class}: #{object}")
 
     object = [].freeze
     -> { object << nil }.should raise_error(FrozenError, "can't modify frozen Array: []")
diff --git a/spec/ruby/language/def_spec.rb b/spec/ruby/language/def_spec.rb
index 296d4787d01c45..0cf1790791a0fb 100644
--- a/spec/ruby/language/def_spec.rb
+++ b/spec/ruby/language/def_spec.rb
@@ -97,7 +97,8 @@ def foo(a); end
         def foo; end
       end
     }.should raise_error(FrozenError) { |e|
-      e.message.should == "can't modify frozen module: #{e.receiver}"
+      msg_class = ruby_version_is("4.0") ? "Module" : "module"
+      e.message.should == "can't modify frozen #{msg_class}: #{e.receiver}"
     }
 
     -> {
@@ -106,7 +107,8 @@ def foo; end
         def foo; end
       end
     }.should raise_error(FrozenError){ |e|
-      e.message.should == "can't modify frozen class: #{e.receiver}"
+      msg_class = ruby_version_is("4.0") ? "Class" : "class"
+      e.message.should == "can't modify frozen #{msg_class}: #{e.receiver}"
     }
   end
 end
@@ -283,7 +285,8 @@ def obj.==(other)
   it "raises FrozenError with the correct class name" do
     obj = Object.new
     obj.freeze
-    -> { def obj.foo; end }.should raise_error(FrozenError, "can't modify frozen object: #{obj}")
+    msg_class = ruby_version_is("4.0") ? "Object" : "object"
+    -> { def obj.foo; end }.should raise_error(FrozenError, "can't modify frozen #{msg_class}: #{obj}")
 
     obj = Object.new
     c = obj.singleton_class
diff --git a/test/ruby/test_allocation.rb b/test/ruby/test_allocation.rb
index 6ade391c951848..90d7c04f9b0a2b 100644
--- a/test/ruby/test_allocation.rb
+++ b/test/ruby/test_allocation.rb
@@ -527,6 +527,59 @@ def self.splat_and_keyword_splat(*b, **kw#{block}); end
       RUBY
     end
 
+    def test_anonymous_splat_parameter
+      only_block = block.empty? ? block : block[2..]
+      check_allocations(<<~RUBY)
+        def self.anon_splat(*#{block}); end
+
+        check_allocations(1, 1, "anon_splat(1, a: 2#{block})")
+        check_allocations(1, 1, "anon_splat(1, *empty_array, a: 2#{block})")
+        check_allocations(1, 1, "anon_splat(1, a:2, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(1, **empty_hash, a: 2#{block})")
+
+        check_allocations(1, 0, "anon_splat(1, **nil#{block})")
+        check_allocations(1, 0, "anon_splat(1, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(1, **hash1#{block})")
+        check_allocations(1, 1, "anon_splat(1, *empty_array, **hash1#{block})")
+        check_allocations(1, 1, "anon_splat(1, **hash1, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(1, **empty_hash, **hash1#{block})")
+
+        check_allocations(1, 0, "anon_splat(1, *empty_array#{block})")
+        check_allocations(1, 0, "anon_splat(1, *empty_array, *empty_array, **empty_hash#{block})")
+
+        check_allocations(1, 1, "anon_splat(*array1, a: 2#{block})")
+
+        check_allocations(0, 0, "anon_splat(*nil, **nill#{block})")
+        check_allocations(0, 0, "anon_splat(*array1, **nill#{block})")
+        check_allocations(0, 0, "anon_splat(*array1, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(*array1, **hash1#{block})")
+        check_allocations(1, 1, "anon_splat(*array1, *empty_array, **hash1#{block})")
+
+        check_allocations(1, 0, "anon_splat(*array1, *empty_array#{block})")
+        check_allocations(1, 0, "anon_splat(*array1, *empty_array, **empty_hash#{block})")
+
+        check_allocations(1, 1, "anon_splat(*array1, *empty_array, a: 2, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(*array1, *empty_array, **hash1, **empty_hash#{block})")
+
+        check_allocations(0, 0, "anon_splat(#{only_block})")
+        check_allocations(1, 1, "anon_splat(a: 2#{block})")
+        check_allocations(0, 0, "anon_splat(**empty_hash#{block})")
+
+        check_allocations(1, 1, "anon_splat(1, *empty_array, a: 2, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(1, *empty_array, **hash1, **empty_hash#{block})")
+        check_allocations(1, 1, "anon_splat(*array1, **empty_hash, a: 2#{block})")
+        check_allocations(1, 1, "anon_splat(*array1, **hash1, **empty_hash#{block})")
+
+        unless defined?(RubyVM::YJIT.enabled?) && RubyVM::YJIT.enabled?
+          check_allocations(0, 0, "anon_splat(*array1, **nil#{block})")
+          check_allocations(1, 0, "anon_splat(*r2k_empty_array#{block})")
+          check_allocations(1, 1, "anon_splat(*r2k_array#{block})")
+          check_allocations(1, 0, "anon_splat(*r2k_empty_array1#{block})")
+          check_allocations(1, 1, "anon_splat(*r2k_array1#{block})")
+        end
+      RUBY
+    end
+
     def test_anonymous_splat_and_anonymous_keyword_splat_parameters
       only_block = block.empty? ? block : block[2..]
       check_allocations(<<~RUBY)
diff --git a/test/ruby/test_call.rb b/test/ruby/test_call.rb
index 7843f3b476e6c9..1b30ed34d8826f 100644
--- a/test/ruby/test_call.rb
+++ b/test/ruby/test_call.rb
@@ -423,6 +423,35 @@ def self.s(*, kw: 0, **kws) [*->(*a){a}.call(*), kw, kws] end
     assert_equal([1, 2, {}], s(*r2ka))
   end
 
+  def test_anon_splat_mutated_bug_21757
+    args = [1, 2]
+    kw = {bug: true}
+
+    def self.m(*); end
+    m(*args, bug: true)
+    assert_equal(2, args.length)
+
+    proc = ->(*) { }
+    proc.(*args, bug: true)
+    assert_equal(2, args.length)
+
+    def self.m2(*); end
+    m2(*args, **kw)
+    assert_equal(2, args.length)
+
+    proc = ->(*) { }
+    proc.(*args, **kw)
+    assert_equal(2, args.length)
+
+    def self.m3(*, **nil); end
+    assert_raise(ArgumentError) { m3(*args, bug: true) }
+    assert_equal(2, args.length)
+
+    proc = ->(*, **nil) { }
+    assert_raise(ArgumentError) { proc.(*args, bug: true) }
+    assert_equal(2, args.length)
+  end
+
   def test_kwsplat_block_eval_order
     def self.t(**kw, &b) [kw, b] end
 
diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 1faecd0cb25e13..22078514ad5cd3 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -601,7 +601,7 @@ def test_singleton_class_of_frozen_object
     obj = Object.new
     c = obj.singleton_class
     obj.freeze
-    assert_raise_with_message(FrozenError, /frozen object/) {
+    assert_raise_with_message(FrozenError, /frozen Object/) {
       c.class_eval {def f; end}
     }
   end
diff --git a/test/ruby/test_frozen.rb b/test/ruby/test_frozen.rb
index 2918a2afd822c7..6721cb112863f3 100644
--- a/test/ruby/test_frozen.rb
+++ b/test/ruby/test_frozen.rb
@@ -27,4 +27,20 @@ def test_setting_ivar_on_frozen_string_with_ivars
     str.freeze
     assert_raise(FrozenError) { str.instance_variable_set(:@b, 1) }
   end
+
+  def test_setting_ivar_on_frozen_string_with_singleton_class
+    str = "str"
+    str.singleton_class
+    str.freeze
+    assert_raise_with_message(FrozenError, "can't modify frozen String: \"str\"") { str.instance_variable_set(:@a, 1) }
+  end
+
+  class A
+    freeze
+  end
+
+  def test_setting_ivar_on_frozen_class
+    assert_raise_with_message(FrozenError, "can't modify frozen Class: TestFrozen::A") { A.instance_variable_set(:@a, 1) }
+    assert_raise_with_message(FrozenError, "can't modify frozen Class: #<Class:TestFrozen::A>") { A.singleton_class.instance_variable_set(:@a, 1) }
+  end
 end
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 62b2a7164fb4ff..3a47c2551a813e 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -3016,17 +3016,17 @@ def test_frozen_visibility
     bug11532 = '[ruby-core:70828] [Bug #11532]'
 
     c = Class.new {const_set(:A, 1)}.freeze
-    assert_raise_with_message(FrozenError, /frozen class/, bug11532) {
+    assert_raise_with_message(FrozenError, /frozen Class/, bug11532) {
       c.class_eval {private_constant :A}
     }
 
     c = Class.new {const_set(:A, 1); private_constant :A}.freeze
-    assert_raise_with_message(FrozenError, /frozen class/, bug11532) {
+    assert_raise_with_message(FrozenError, /frozen Class/, bug11532) {
       c.class_eval {public_constant :A}
     }
 
     c = Class.new {const_set(:A, 1)}.freeze
-    assert_raise_with_message(FrozenError, /frozen class/, bug11532) {
+    assert_raise_with_message(FrozenError, /frozen Class/, bug11532) {
       c.class_eval {deprecate_constant :A}
     }
   end
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index bdc6667b8e81fe..209e55294b1889 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -1933,6 +1933,29 @@ module PublicCows
     end;
   end
 
+  def test_public_in_refine_for_method_in_superclass
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+      bug21446 = '[ruby-core:122558] [Bug #21446]'
+
+      class CowSuper
+        private
+        def moo() "Moo"; end
+      end
+      class Cow < CowSuper
+      end
+
+      module PublicCows
+        refine(Cow) {
+          public :moo
+        }
+      end
+
+      using PublicCows
+      assert_equal("Moo", Cow.new.moo, bug21446)
+    end;
+  end
+
   module SuperToModule
     class Parent
     end
diff --git a/test/ruby/test_zjit.rb b/test/ruby/test_zjit.rb
index 81d940407063f1..49b3616425ecd3 100644
--- a/test/ruby/test_zjit.rb
+++ b/test/ruby/test_zjit.rb
@@ -2057,7 +2057,7 @@ def self.test = @@x = 42
   end
 
   def test_setclassvariable_raises
-    assert_compiles '"can\'t modify frozen #<Class:Foo>: Foo"', %q{
+    assert_compiles '"can\'t modify frozen Class: Foo"', %q{
       class Foo
         def self.test = @@x = 42
         freeze
diff --git a/thread_pthread.c b/thread_pthread.c
index 93b32e55c0f72b..0a19f7f0310af1 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -1459,7 +1459,7 @@ rb_ractor_sched_barrier_start(rb_vm_t *vm, rb_ractor_t *cr)
         vm->ractor.sync.lock_owner = cr;
     }
 
-    // do not release ractor_sched_lock and threre is no newly added (resumed) thread
+    // do not release ractor_sched_lock and there is no newly added (resumed) thread
     // thread_sched_setup_running_threads
 }
 
diff --git a/vm_args.c b/vm_args.c
index 64ed88d0e1dcce..8d4042e35566ae 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -638,12 +638,26 @@ setup_parameters_complex(rb_execution_context_t * const ec, const rb_iseq_t * co
                 given_argc == ISEQ_BODY(iseq)->param.lead_num + (kw_flag ? 2 : 1) &&
                 !ISEQ_BODY(iseq)->param.flags.has_opt &&
                 !ISEQ_BODY(iseq)->param.flags.has_post &&
-                !ISEQ_BODY(iseq)->param.flags.ruby2_keywords &&
-                (!kw_flag ||
-                !ISEQ_BODY(iseq)->param.flags.has_kw ||
-                !ISEQ_BODY(iseq)->param.flags.has_kwrest ||
-                !ISEQ_BODY(iseq)->param.flags.accepts_no_kwarg)) {
-            args->rest_dupped = true;
+                !ISEQ_BODY(iseq)->param.flags.ruby2_keywords) {
+            if (kw_flag) {
+                if (ISEQ_BODY(iseq)->param.flags.has_kw ||
+                    ISEQ_BODY(iseq)->param.flags.has_kwrest) {
+                    args->rest_dupped = true;
+                }
+                else if (kw_flag & VM_CALL_KW_SPLAT) {
+                    VALUE kw_hash = locals[args->argc - 1];
+                    if (kw_hash == Qnil ||
+                            (RB_TYPE_P(kw_hash, T_HASH) && RHASH_EMPTY_P(kw_hash))) {
+                        args->rest_dupped = true;
+                    }
+                }
+
+            }
+            else if (!ISEQ_BODY(iseq)->param.flags.has_kw &&
+                    !ISEQ_BODY(iseq)->param.flags.has_kwrest &&
+                    !ISEQ_BODY(iseq)->param.flags.accepts_no_kwarg) {
+                args->rest_dupped = true;
+            }
         }
     }
 
diff --git a/vm_method.c b/vm_method.c
index c4f391b5afe38a..dbc5ad97eded92 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -1281,6 +1281,7 @@ check_override_opt_method(VALUE klass, VALUE mid)
     }
 }
 
+static inline rb_method_entry_t* search_method0(VALUE klass, ID id, VALUE *defined_class_ptr, bool skip_refined);
 /*
  * klass->method_table[mid] = method_entry(defined_class, visi, def)
  *
@@ -1321,7 +1322,12 @@ rb_method_entry_make(VALUE klass, ID mid, VALUE defined_class, rb_method_visibil
 
     if (RB_TYPE_P(klass, T_MODULE) && FL_TEST(klass, RMODULE_IS_REFINEMENT)) {
         VALUE refined_class = rb_refinement_module_get_refined_class(klass);
+        bool search_superclass = type == VM_METHOD_TYPE_ZSUPER && !lookup_method_table(refined_class, mid);
         rb_add_refined_method_entry(refined_class, mid);
+        if (search_superclass) {
+            rb_method_entry_t *me = lookup_method_table(refined_class, mid);
+            me->def->body.refined.orig_me = search_method0(refined_class, mid, NULL, true);
+        }
     }
     if (type == VM_METHOD_TYPE_REFINED) {
         rb_method_entry_t *old_me = lookup_method_table(RCLASS_ORIGIN(klass), mid);
diff --git a/zjit.c b/zjit.c
index 7731bc908f6ab9..75cca281a45a91 100644
--- a/zjit.c
+++ b/zjit.c
@@ -315,6 +315,7 @@ VALUE rb_zjit_stats(rb_execution_context_t *ec, VALUE self, VALUE target_key);
 VALUE rb_zjit_reset_stats_bang(rb_execution_context_t *ec, VALUE self);
 VALUE rb_zjit_stats_enabled_p(rb_execution_context_t *ec, VALUE self);
 VALUE rb_zjit_print_stats_p(rb_execution_context_t *ec, VALUE self);
+VALUE rb_zjit_get_stats_file_path_p(rb_execution_context_t *ec, VALUE self);
 VALUE rb_zjit_trace_exit_locations_enabled_p(rb_execution_context_t *ec, VALUE self);
 VALUE rb_zjit_get_exit_locations(rb_execution_context_t *ec, VALUE self);
 
diff --git a/zjit.rb b/zjit.rb
index d128adead6fe39..e2aa55f764eb9a 100644
--- a/zjit.rb
+++ b/zjit.rb
@@ -10,6 +10,9 @@ module RubyVM::ZJIT
   # Blocks that are called when YJIT is enabled
   @jit_hooks = []
   # Avoid calling a Ruby method here to avoid interfering with compilation tests
+  if Primitive.rb_zjit_get_stats_file_path_p
+    at_exit { print_stats_file }
+  end
   if Primitive.rb_zjit_print_stats_p
     at_exit { print_stats }
   end
@@ -333,6 +336,14 @@ def print_stats
     $stderr.write stats_string
   end
 
+  # Print ZJIT stats to file
+  def print_stats_file
+    filename = Primitive.rb_zjit_get_stats_file_path_p
+    File.open(filename, "wb") do |file|
+      file.write stats_string
+    end
+  end
+
   def dump_locations # :nodoc:
     return unless trace_exit_locations_enabled?
 
diff --git a/zjit/src/hir.rs b/zjit/src/hir.rs
index 6d1fe70e271869..4e597db936c345 100644
--- a/zjit/src/hir.rs
+++ b/zjit/src/hir.rs
@@ -643,6 +643,40 @@ pub enum SendFallbackReason {
     Uncategorized(ruby_vminsn_type),
 }
 
+impl Display for SendFallbackReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            SendWithoutBlockPolymorphic => write!(f, "SendWithoutBlock: polymorphic call site"),
+            SendWithoutBlockMegamorphic => write!(f, "SendWithoutBlock: megamorphic call site"),
+            SendWithoutBlockNoProfiles => write!(f, "SendWithoutBlock: no profile data available"),
+            SendWithoutBlockCfuncNotVariadic => write!(f, "SendWithoutBlock: C function is not variadic"),
+            SendWithoutBlockCfuncArrayVariadic => write!(f, "SendWithoutBlock: C function expects array variadic"),
+            SendWithoutBlockNotOptimizedMethodType(method_type) => write!(f, "SendWithoutBlock: unsupported method type {:?}", method_type),
+            SendWithoutBlockNotOptimizedMethodTypeOptimized(opt_type) => write!(f, "SendWithoutBlock: unsupported optimized method type {:?}", opt_type),
+            SendWithoutBlockBopRedefined => write!(f, "SendWithoutBlock: basic operation was redefined"),
+            SendWithoutBlockOperandsNotFixnum => write!(f, "SendWithoutBlock: operands are not fixnums"),
+            SendWithoutBlockDirectKeywordMismatch => write!(f, "SendWithoutBlockDirect: keyword mismatch"),
+            SendWithoutBlockDirectOptionalKeywords => write!(f, "SendWithoutBlockDirect: optional keywords"),
+            SendWithoutBlockDirectKeywordCountMismatch => write!(f, "SendWithoutBlockDirect: keyword count mismatch"),
+            SendWithoutBlockDirectMissingKeyword => write!(f, "SendWithoutBlockDirect: missing keyword"),
+            SendPolymorphic => write!(f, "Send: polymorphic call site"),
+            SendMegamorphic => write!(f, "Send: megamorphic call site"),
+            SendNoProfiles => write!(f, "Send: no profile data available"),
+            SendCfuncVariadic => write!(f, "Send: C function is variadic"),
+            SendCfuncArrayVariadic => write!(f, "Send: C function expects array variadic"),
+            SendNotOptimizedMethodType(method_type) => write!(f, "Send: unsupported method type {:?}", method_type),
+            CCallWithFrameTooManyArgs => write!(f, "CCallWithFrame: too many arguments"),
+            ObjToStringNotString => write!(f, "ObjToString: result is not a string"),
+            TooManyArgsForLir => write!(f, "Too many arguments for LIR"),
+            BmethodNonIseqProc => write!(f, "Bmethod: Proc object is not defined by an ISEQ"),
+            ArgcParamMismatch => write!(f, "Argument count does not match parameter count"),
+            ComplexArgPass => write!(f, "Complex argument passing"),
+            UnexpectedKeywordArgs => write!(f, "Unexpected Keyword Args"),
+            Uncategorized(insn) => write!(f, "Uncategorized({})", insn_name(*insn as usize)),
+        }
+    }
+}
+
 /// An instruction in the SSA IR. The output of an instruction is referred to by the index of
 /// the instruction ([`InsnId`]). SSA form enables this, and [`UnionFind`] ([`Function::find`])
 /// helps with editing.
@@ -1203,11 +1237,12 @@ impl<'a> std::fmt::Display for InsnPrinter<'a> {
             Insn::Jump(target) => { write!(f, "Jump {target}") }
             Insn::IfTrue { val, target } => { write!(f, "IfTrue {val}, {target}") }
             Insn::IfFalse { val, target } => { write!(f, "IfFalse {val}, {target}") }
-            Insn::SendWithoutBlock { recv, cd, args, .. } => {
+            Insn::SendWithoutBlock { recv, cd, args, reason, .. } => {
                 write!(f, "SendWithoutBlock {recv}, :{}", ruby_call_method_name(*cd))?;
                 for arg in args {
                     write!(f, ", {arg}")?;
                 }
+                write!(f, " # SendFallbackReason: {reason}")?;
                 Ok(())
             }
             Insn::SendWithoutBlockDirect { recv, cd, iseq, args, .. } => {
@@ -1217,7 +1252,7 @@ impl<'a> std::fmt::Display for InsnPrinter<'a> {
                 }
                 Ok(())
             }
-            Insn::Send { recv, cd, args, blockiseq, .. } => {
+            Insn::Send { recv, cd, args, blockiseq, reason, .. } => {
                 // For tests, we want to check HIR snippets textually. Addresses change
                 // between runs, making tests fail. Instead, pick an arbitrary hex value to
                 // use as a "pointer" so we can check the rest of the HIR.
@@ -1225,27 +1260,31 @@ impl<'a> std::fmt::Display for InsnPrinter<'a> {
                 for arg in args {
                     write!(f, ", {arg}")?;
                 }
+                write!(f, " # SendFallbackReason: {reason}")?;
                 Ok(())
             }
-            Insn::SendForward { recv, cd, args, blockiseq, .. } => {
+            Insn::SendForward { recv, cd, args, blockiseq, reason, .. } => {
                 write!(f, "SendForward {recv}, {:p}, :{}", self.ptr_map.map_ptr(blockiseq), ruby_call_method_name(*cd))?;
                 for arg in args {
                     write!(f, ", {arg}")?;
                 }
+                write!(f, " # SendFallbackReason: {reason}")?;
                 Ok(())
             }
-            Insn::InvokeSuper { recv, blockiseq, args, .. } => {
+            Insn::InvokeSuper { recv, blockiseq, args, reason, .. } => {
                 write!(f, "InvokeSuper {recv}, {:p}", self.ptr_map.map_ptr(blockiseq))?;
                 for arg in args {
                     write!(f, ", {arg}")?;
                 }
+                write!(f, " # SendFallbackReason: {reason}")?;
                 Ok(())
             }
-            Insn::InvokeBlock { args, .. } => {
+            Insn::InvokeBlock { args, reason, .. } => {
                 write!(f, "InvokeBlock")?;
                 for arg in args {
                     write!(f, ", {arg}")?;
                 }
+                write!(f, " # SendFallbackReason: {reason}")?;
                 Ok(())
             }
             Insn::InvokeBuiltin { bf, args, leaf, .. } => {
@@ -2044,7 +2083,7 @@ impl Function {
     /// Update DynamicSendReason for the instruction at insn_id
     fn set_dynamic_send_reason(&mut self, insn_id: InsnId, dynamic_send_reason: SendFallbackReason) {
         use Insn::*;
-        if get_option!(stats) {
+        if get_option!(stats) || get_option!(dump_hir_opt).is_some() || cfg!(test) {
             match self.insns.get_mut(insn_id.0).unwrap() {
                 Send { reason, .. }
                 | SendForward { reason, .. }
diff --git a/zjit/src/hir/opt_tests.rs b/zjit/src/hir/opt_tests.rs
index 0a0737469371d7..3e2db528158090 100644
--- a/zjit/src/hir/opt_tests.rs
+++ b/zjit/src/hir/opt_tests.rs
@@ -812,7 +812,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = SendWithoutBlock v6, :foo
+          v11:BasicObject = SendWithoutBlock v6, :foo # SendFallbackReason: SendWithoutBlock: unsupported method type Null
           CheckInterrupts
           Return v11
         ");
@@ -2444,7 +2444,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v10:Fixnum[1] = Const Value(1)
           v12:Fixnum[0] = Const Value(0)
-          v14:BasicObject = SendWithoutBlock v10, :itself, v12
+          v14:BasicObject = SendWithoutBlock v10, :itself, v12 # SendFallbackReason: SendWithoutBlock: unsupported method type Cfunc
           CheckInterrupts
           Return v14
         ");
@@ -2670,7 +2670,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = Send v6, 0x1000, :foo
+          v11:BasicObject = Send v6, 0x1000, :foo # SendFallbackReason: Send: unsupported method type Iseq
           CheckInterrupts
           Return v11
         ");
@@ -2702,7 +2702,7 @@ mod hir_opt_tests {
         bb2(v8:BasicObject, v9:NilClass):
           v13:Fixnum[1] = Const Value(1)
           SetLocal :a, l0, EP@3, v13
-          v19:BasicObject = Send v8, 0x1000, :foo
+          v19:BasicObject = Send v8, 0x1000, :foo # SendFallbackReason: Send: unsupported method type Iseq
           v20:BasicObject = GetLocal :a, l0, EP@3
           v24:BasicObject = GetLocal :a, l0, EP@3
           CheckInterrupts
@@ -2730,7 +2730,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v11:Fixnum[1] = Const Value(1)
           IncrCounter complex_arg_pass_param_rest
-          v13:BasicObject = SendWithoutBlock v6, :foo, v11
+          v13:BasicObject = SendWithoutBlock v6, :foo, v11 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v13
         ");
@@ -2755,7 +2755,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v11:Fixnum[10] = Const Value(10)
           IncrCounter complex_arg_pass_param_post
-          v13:BasicObject = SendWithoutBlock v6, :foo, v11
+          v13:BasicObject = SendWithoutBlock v6, :foo, v11 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v13
         ");
@@ -2871,7 +2871,7 @@ mod hir_opt_tests {
           v11:Fixnum[0] = Const Value(0)
           v13:Fixnum[2] = Const Value(2)
           IncrCounter complex_arg_pass_param_kw_opt
-          v15:BasicObject = SendWithoutBlock v6, :foo, v11, v13
+          v15:BasicObject = SendWithoutBlock v6, :foo, v11, v13 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v15
         ");
@@ -2936,7 +2936,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v11:Fixnum[2] = Const Value(2)
           IncrCounter complex_arg_pass_param_kw_opt
-          v13:BasicObject = SendWithoutBlock v6, :foo, v11
+          v13:BasicObject = SendWithoutBlock v6, :foo, v11 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v13
         ");
@@ -2962,7 +2962,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v11:Fixnum[1] = Const Value(1)
           IncrCounter complex_arg_pass_param_kwrest
-          v13:BasicObject = SendWithoutBlock v6, :foo, v11
+          v13:BasicObject = SendWithoutBlock v6, :foo, v11 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v13
         ");
@@ -2987,7 +2987,7 @@ mod hir_opt_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           IncrCounter complex_arg_pass_param_kw_opt
-          v11:BasicObject = SendWithoutBlock v6, :foo
+          v11:BasicObject = SendWithoutBlock v6, :foo # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v11
         ");
@@ -3012,7 +3012,7 @@ mod hir_opt_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           IncrCounter complex_arg_pass_param_kwrest
-          v11:BasicObject = SendWithoutBlock v6, :foo
+          v11:BasicObject = SendWithoutBlock v6, :foo # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v11
         ");
@@ -3038,7 +3038,7 @@ mod hir_opt_tests {
           v11:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v12:StringExact = StringCopy v11
           v14:Fixnum[1] = Const Value(1)
-          v16:BasicObject = SendWithoutBlock v6, :sprintf, v12, v14
+          v16:BasicObject = SendWithoutBlock v6, :sprintf, v12, v14 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v16
         ");
@@ -3072,7 +3072,7 @@ mod hir_opt_tests {
           SetLocal :a, l0, EP@3, v16
           v22:TrueClass = Const Value(true)
           IncrCounter complex_arg_pass_caller_kwarg
-          v24:BasicObject = Send v11, 0x1000, :each_line, v22
+          v24:BasicObject = Send v11, 0x1000, :each_line, v22 # SendFallbackReason: Complex argument passing
           v25:BasicObject = GetLocal :s, l0, EP@4
           v26:BasicObject = GetLocal :a, l0, EP@3
           v30:BasicObject = GetLocal :a, l0, EP@3
@@ -3337,7 +3337,7 @@ mod hir_opt_tests {
           v46:HashExact = ObjectAllocClass Hash:VALUE(0x1008)
           IncrCounter complex_arg_pass_param_block
           IncrCounter complex_arg_pass_param_kw_opt
-          v20:BasicObject = SendWithoutBlock v46, :initialize
+          v20:BasicObject = SendWithoutBlock v46, :initialize # SendFallbackReason: Complex argument passing
           CheckInterrupts
           CheckInterrupts
           Return v46
@@ -3541,7 +3541,7 @@ mod hir_opt_tests {
         bb2(v8:BasicObject, v9:BasicObject):
           GuardBlockParamProxy l0
           v15:HeapObject[BlockParamProxy] = Const Value(VALUE(0x1000))
-          v17:BasicObject = Send v8, 0x1008, :tap, v15
+          v17:BasicObject = Send v8, 0x1008, :tap, v15 # SendFallbackReason: Uncategorized(send)
           CheckInterrupts
           Return v17
         ");
@@ -4018,7 +4018,7 @@ mod hir_opt_tests {
           PatchPoint MethodRedefined(Hash@0x1000, dup@0x1008, cme:0x1010)
           PatchPoint NoSingletonClass(Hash@0x1000)
           v22:BasicObject = CCallWithFrame v10, :Kernel#dup@0x1038
-          v14:BasicObject = SendWithoutBlock v22, :freeze
+          v14:BasicObject = SendWithoutBlock v22, :freeze # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v14
         ");
@@ -4041,7 +4041,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v10:HashExact = NewHash
           v12:NilClass = Const Value(nil)
-          v14:BasicObject = SendWithoutBlock v10, :freeze, v12
+          v14:BasicObject = SendWithoutBlock v10, :freeze, v12 # SendFallbackReason: SendWithoutBlock: unsupported method type Cfunc
           CheckInterrupts
           Return v14
         ");
@@ -4111,7 +4111,7 @@ mod hir_opt_tests {
           PatchPoint MethodRedefined(Array@0x1000, dup@0x1008, cme:0x1010)
           PatchPoint NoSingletonClass(Array@0x1000)
           v22:BasicObject = CCallWithFrame v10, :Kernel#dup@0x1038
-          v14:BasicObject = SendWithoutBlock v22, :freeze
+          v14:BasicObject = SendWithoutBlock v22, :freeze # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v14
         ");
@@ -4134,7 +4134,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v10:ArrayExact = NewArray
           v12:NilClass = Const Value(nil)
-          v14:BasicObject = SendWithoutBlock v10, :freeze, v12
+          v14:BasicObject = SendWithoutBlock v10, :freeze, v12 # SendFallbackReason: SendWithoutBlock: unsupported method type Cfunc
           CheckInterrupts
           Return v14
         ");
@@ -4205,7 +4205,7 @@ mod hir_opt_tests {
           PatchPoint MethodRedefined(String@0x1008, dup@0x1010, cme:0x1018)
           PatchPoint NoSingletonClass(String@0x1008)
           v23:BasicObject = CCallWithFrame v11, :String#dup@0x1040
-          v15:BasicObject = SendWithoutBlock v23, :freeze
+          v15:BasicObject = SendWithoutBlock v23, :freeze # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v15
         ");
@@ -4229,7 +4229,7 @@ mod hir_opt_tests {
           v10:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v11:StringExact = StringCopy v10
           v13:NilClass = Const Value(nil)
-          v15:BasicObject = SendWithoutBlock v11, :freeze, v13
+          v15:BasicObject = SendWithoutBlock v11, :freeze, v13 # SendFallbackReason: SendWithoutBlock: unsupported method type Cfunc
           CheckInterrupts
           Return v15
         ");
@@ -4300,7 +4300,7 @@ mod hir_opt_tests {
           PatchPoint MethodRedefined(String@0x1008, dup@0x1010, cme:0x1018)
           PatchPoint NoSingletonClass(String@0x1008)
           v23:BasicObject = CCallWithFrame v11, :String#dup@0x1040
-          v15:BasicObject = SendWithoutBlock v23, :-@
+          v15:BasicObject = SendWithoutBlock v23, :-@ # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v15
         ");
@@ -4805,7 +4805,7 @@ mod hir_opt_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           v11:Fixnum[100] = Const Value(100)
-          v13:BasicObject = SendWithoutBlock v6, :identity, v11
+          v13:BasicObject = SendWithoutBlock v6, :identity, v11 # SendFallbackReason: Bmethod: Proc object is not defined by an ISEQ
           CheckInterrupts
           Return v13
         ");
@@ -4828,7 +4828,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = Send v6, 0x1000, :bmethod
+          v11:BasicObject = Send v6, 0x1000, :bmethod # SendFallbackReason: Send: unsupported method type Bmethod
           CheckInterrupts
           Return v11
         ");
@@ -5667,7 +5667,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = SendWithoutBlock v6, :foo
+          v11:BasicObject = SendWithoutBlock v6, :foo # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v11
         ");
@@ -5710,7 +5710,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v14:BasicObject = SendWithoutBlock v9, :foo
+          v14:BasicObject = SendWithoutBlock v9, :foo # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v14
         ");
@@ -5844,7 +5844,7 @@ mod hir_opt_tests {
           GuardBlockParamProxy l0
           v16:HeapObject[BlockParamProxy] = Const Value(VALUE(0x1000))
           IncrCounter complex_arg_pass_caller_blockarg
-          v18:BasicObject = Send v13, 0x1008, :map, v16
+          v18:BasicObject = Send v13, 0x1008, :map, v16 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v18
         ");
@@ -5870,7 +5870,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = Send v6, 0x1000, :foo
+          v11:BasicObject = Send v6, 0x1000, :foo # SendFallbackReason: Send: unsupported method type Iseq
           CheckInterrupts
           Return v11
         ");
@@ -7589,7 +7589,7 @@ mod hir_opt_tests {
           v12:Fixnum[3] = Const Value(3)
           v14:Fixnum[3] = Const Value(3)
           v16:Fixnum[3] = Const Value(3)
-          v18:BasicObject = SendWithoutBlock v10, :foo, v12, v14, v16
+          v18:BasicObject = SendWithoutBlock v10, :foo, v12, v14, v16 # SendFallbackReason: Argument count does not match parameter count
           CheckInterrupts
           Return v18
         ");
@@ -7639,7 +7639,7 @@ mod hir_opt_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           v10:Fixnum[0] = Const Value(0)
-          v12:BasicObject = SendWithoutBlock v10, :foo
+          v12:BasicObject = SendWithoutBlock v10, :foo # SendFallbackReason: Argument count does not match parameter count
           CheckInterrupts
           Return v12
         ");
@@ -7662,7 +7662,7 @@ mod hir_opt_tests {
         bb2(v6:BasicObject):
           v10:Fixnum[4] = Const Value(4)
           v12:Fixnum[1] = Const Value(1)
-          v14:BasicObject = SendWithoutBlock v10, :succ, v12
+          v14:BasicObject = SendWithoutBlock v10, :succ, v12 # SendFallbackReason: SendWithoutBlock: unsupported method type Cfunc
           CheckInterrupts
           Return v14
         ");
@@ -7816,7 +7816,7 @@ mod hir_opt_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v17:BasicObject = SendWithoutBlock v11, :^
+          v17:BasicObject = SendWithoutBlock v11, :^ # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v17
         ");
@@ -8491,17 +8491,17 @@ mod hir_opt_tests {
           v13:ArrayExact = NewArray
           v19:ArrayExact = ToArray v13
           IncrCounter complex_arg_pass_caller_splat
-          v21:BasicObject = SendWithoutBlock v8, :foo, v19
+          v21:BasicObject = SendWithoutBlock v8, :foo, v19 # SendFallbackReason: Complex argument passing
           v25:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v26:StringExact = StringCopy v25
           PatchPoint NoEPEscape(test)
           v31:ArrayExact = ToArray v13
           IncrCounter complex_arg_pass_caller_splat
-          v33:BasicObject = SendWithoutBlock v26, :display, v31
+          v33:BasicObject = SendWithoutBlock v26, :display, v31 # SendFallbackReason: Complex argument passing
           PatchPoint NoEPEscape(test)
           v41:ArrayExact = ToArray v13
           IncrCounter complex_arg_pass_caller_splat
-          v43:BasicObject = SendWithoutBlock v8, :itself, v41
+          v43:BasicObject = SendWithoutBlock v8, :itself, v41 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v43
         ");
@@ -9186,7 +9186,7 @@ mod hir_opt_tests {
           IncrCounter complex_arg_pass_param_block
           IncrCounter complex_arg_pass_param_kwrest
           IncrCounter complex_arg_pass_param_kw_opt
-          v13:BasicObject = SendWithoutBlock v6, :fancy, v11
+          v13:BasicObject = SendWithoutBlock v6, :fancy, v11 # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v13
         ");
@@ -9210,7 +9210,7 @@ mod hir_opt_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           IncrCounter complex_arg_pass_param_forwardable
-          v11:BasicObject = SendWithoutBlock v6, :forwardable
+          v11:BasicObject = SendWithoutBlock v6, :forwardable # SendFallbackReason: Complex argument passing
           CheckInterrupts
           Return v11
         ");
diff --git a/zjit/src/hir/tests.rs b/zjit/src/hir/tests.rs
index 7ef7671fa444f6..49f092337e9816 100644
--- a/zjit/src/hir/tests.rs
+++ b/zjit/src/hir/tests.rs
@@ -524,7 +524,7 @@ pub mod hir_build_tests {
         bb2(v6:BasicObject):
           v10:Fixnum[1] = Const Value(1)
           v12:Fixnum[2] = Const Value(2)
-          v15:BasicObject = SendWithoutBlock v10, :+, v12
+          v15:BasicObject = SendWithoutBlock v10, :+, v12 # SendFallbackReason: Uncategorized(opt_plus)
           CheckInterrupts
           Return v15
         ");
@@ -777,11 +777,11 @@ pub mod hir_build_tests {
           SetLocal :l1, l1, EP@3, v10
           v15:BasicObject = GetLocal :l1, l1, EP@3
           v17:BasicObject = GetLocal :l2, l2, EP@4
-          v20:BasicObject = SendWithoutBlock v15, :+, v17
+          v20:BasicObject = SendWithoutBlock v15, :+, v17 # SendFallbackReason: Uncategorized(opt_plus)
           SetLocal :l2, l2, EP@4, v20
           v25:BasicObject = GetLocal :l2, l2, EP@4
           v27:BasicObject = GetLocal :l3, l3, EP@5
-          v30:BasicObject = SendWithoutBlock v25, :+, v27
+          v30:BasicObject = SendWithoutBlock v25, :+, v27 # SendFallbackReason: Uncategorized(opt_plus)
           SetLocal :l3, l3, EP@5, v30
           CheckInterrupts
           Return v30
@@ -1102,7 +1102,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :+, v12
+          v19:BasicObject = SendWithoutBlock v11, :+, v12 # SendFallbackReason: Uncategorized(opt_plus)
           CheckInterrupts
           Return v19
         ");
@@ -1127,7 +1127,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :-, v12
+          v19:BasicObject = SendWithoutBlock v11, :-, v12 # SendFallbackReason: Uncategorized(opt_minus)
           CheckInterrupts
           Return v19
         ");
@@ -1152,7 +1152,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :*, v12
+          v19:BasicObject = SendWithoutBlock v11, :*, v12 # SendFallbackReason: Uncategorized(opt_mult)
           CheckInterrupts
           Return v19
         ");
@@ -1177,7 +1177,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :/, v12
+          v19:BasicObject = SendWithoutBlock v11, :/, v12 # SendFallbackReason: Uncategorized(opt_div)
           CheckInterrupts
           Return v19
         ");
@@ -1202,7 +1202,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :%, v12
+          v19:BasicObject = SendWithoutBlock v11, :%, v12 # SendFallbackReason: Uncategorized(opt_mod)
           CheckInterrupts
           Return v19
         ");
@@ -1227,7 +1227,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :==, v12
+          v19:BasicObject = SendWithoutBlock v11, :==, v12 # SendFallbackReason: Uncategorized(opt_eq)
           CheckInterrupts
           Return v19
         ");
@@ -1252,7 +1252,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :!=, v12
+          v19:BasicObject = SendWithoutBlock v11, :!=, v12 # SendFallbackReason: Uncategorized(opt_neq)
           CheckInterrupts
           Return v19
         ");
@@ -1277,7 +1277,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :<, v12
+          v19:BasicObject = SendWithoutBlock v11, :<, v12 # SendFallbackReason: Uncategorized(opt_lt)
           CheckInterrupts
           Return v19
         ");
@@ -1302,7 +1302,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :<=, v12
+          v19:BasicObject = SendWithoutBlock v11, :<=, v12 # SendFallbackReason: Uncategorized(opt_le)
           CheckInterrupts
           Return v19
         ");
@@ -1327,7 +1327,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :>, v12
+          v19:BasicObject = SendWithoutBlock v11, :>, v12 # SendFallbackReason: Uncategorized(opt_gt)
           CheckInterrupts
           Return v19
         ");
@@ -1368,7 +1368,7 @@ pub mod hir_build_tests {
         bb4(v26:BasicObject, v27:BasicObject, v28:BasicObject):
           PatchPoint NoEPEscape(test)
           v34:Fixnum[0] = Const Value(0)
-          v37:BasicObject = SendWithoutBlock v28, :>, v34
+          v37:BasicObject = SendWithoutBlock v28, :>, v34 # SendFallbackReason: Uncategorized(opt_gt)
           CheckInterrupts
           v40:CBool = Test v37
           IfTrue v40, bb3(v26, v27, v28)
@@ -1379,9 +1379,9 @@ pub mod hir_build_tests {
         bb3(v53:BasicObject, v54:BasicObject, v55:BasicObject):
           PatchPoint NoEPEscape(test)
           v62:Fixnum[1] = Const Value(1)
-          v65:BasicObject = SendWithoutBlock v54, :+, v62
+          v65:BasicObject = SendWithoutBlock v54, :+, v62 # SendFallbackReason: Uncategorized(opt_plus)
           v70:Fixnum[1] = Const Value(1)
-          v73:BasicObject = SendWithoutBlock v55, :-, v70
+          v73:BasicObject = SendWithoutBlock v55, :-, v70 # SendFallbackReason: Uncategorized(opt_minus)
           Jump bb4(v53, v65, v73)
         ");
     }
@@ -1405,7 +1405,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :>=, v12
+          v19:BasicObject = SendWithoutBlock v11, :>=, v12 # SendFallbackReason: Uncategorized(opt_ge)
           CheckInterrupts
           Return v19
         ");
@@ -1472,7 +1472,7 @@ pub mod hir_build_tests {
         bb2(v6:BasicObject):
           v11:Fixnum[2] = Const Value(2)
           v13:Fixnum[3] = Const Value(3)
-          v15:BasicObject = SendWithoutBlock v6, :bar, v11, v13
+          v15:BasicObject = SendWithoutBlock v6, :bar, v11, v13 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v15
         ");
@@ -1500,7 +1500,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v14:BasicObject = Send v9, 0x1000, :each
+          v14:BasicObject = Send v9, 0x1000, :each # SendFallbackReason: Uncategorized(send)
           v15:BasicObject = GetLocal :a, l0, EP@3
           CheckInterrupts
           Return v14
@@ -1559,7 +1559,7 @@ pub mod hir_build_tests {
           v18:StringExact = StringCopy v17
           v20:StringExact[VALUE(0x1010)] = Const Value(VALUE(0x1010))
           v21:StringExact = StringCopy v20
-          v23:BasicObject = SendWithoutBlock v6, :unknown_method, v12, v15, v18, v21
+          v23:BasicObject = SendWithoutBlock v6, :unknown_method, v12, v15, v18, v21 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v23
         ");
@@ -1582,7 +1582,7 @@ pub mod hir_build_tests {
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
           v15:ArrayExact = ToArray v9
-          v17:BasicObject = SendWithoutBlock v8, :foo, v15
+          v17:BasicObject = SendWithoutBlock v8, :foo, v15 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v17
         ");
@@ -1604,7 +1604,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = Send v8, 0x1000, :foo, v9
+          v15:BasicObject = Send v8, 0x1000, :foo, v9 # SendFallbackReason: Uncategorized(send)
           CheckInterrupts
           Return v15
         ");
@@ -1627,7 +1627,7 @@ pub mod hir_build_tests {
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
           v14:Fixnum[1] = Const Value(1)
-          v16:BasicObject = SendWithoutBlock v8, :foo, v14
+          v16:BasicObject = SendWithoutBlock v8, :foo, v14 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v16
         ");
@@ -1649,7 +1649,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = SendWithoutBlock v8, :foo, v9
+          v15:BasicObject = SendWithoutBlock v8, :foo, v9 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v15
         ");
@@ -1672,7 +1672,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = InvokeSuper v6, 0x1000
+          v11:BasicObject = InvokeSuper v6, 0x1000 # SendFallbackReason: Uncategorized(invokesuper)
           CheckInterrupts
           Return v11
         ");
@@ -1693,7 +1693,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v11:BasicObject = InvokeSuper v6, 0x1000
+          v11:BasicObject = InvokeSuper v6, 0x1000 # SendFallbackReason: Uncategorized(invokesuper)
           CheckInterrupts
           Return v11
         ");
@@ -1715,7 +1715,7 @@ pub mod hir_build_tests {
           Jump bb2(v4)
         bb2(v6:BasicObject):
           v11:NilClass = Const Value(nil)
-          v13:BasicObject = InvokeSuper v6, 0x1000, v11
+          v13:BasicObject = InvokeSuper v6, 0x1000, v11 # SendFallbackReason: Uncategorized(invokesuper)
           CheckInterrupts
           Return v13
         ");
@@ -1782,12 +1782,12 @@ pub mod hir_build_tests {
           v14:Class[VMFrozenCore] = Const Value(VALUE(0x1000))
           v16:HashExact = NewHash
           PatchPoint NoEPEscape(test)
-          v21:BasicObject = SendWithoutBlock v14, :core#hash_merge_kwd, v16, v9
+          v21:BasicObject = SendWithoutBlock v14, :core#hash_merge_kwd, v16, v9 # SendFallbackReason: Uncategorized(opt_send_without_block)
           v23:Class[VMFrozenCore] = Const Value(VALUE(0x1000))
           v26:StaticSymbol[:b] = Const Value(VALUE(0x1008))
           v28:Fixnum[1] = Const Value(1)
-          v30:BasicObject = SendWithoutBlock v23, :core#hash_merge_ptr, v21, v26, v28
-          v32:BasicObject = SendWithoutBlock v8, :foo, v30
+          v30:BasicObject = SendWithoutBlock v23, :core#hash_merge_ptr, v21, v26, v28 # SendFallbackReason: Uncategorized(opt_send_without_block)
+          v32:BasicObject = SendWithoutBlock v8, :foo, v30 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v32
         ");
@@ -1812,7 +1812,7 @@ pub mod hir_build_tests {
           v15:ArrayExact = ToNewArray v9
           v17:Fixnum[1] = Const Value(1)
           ArrayPush v15, v17
-          v21:BasicObject = SendWithoutBlock v8, :foo, v15
+          v21:BasicObject = SendWithoutBlock v8, :foo, v15 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v21
         ");
@@ -1834,7 +1834,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = SendForward v8, 0x1000, :foo, v9
+          v15:BasicObject = SendForward v8, 0x1000, :foo, v9 # SendFallbackReason: Uncategorized(sendforward)
           CheckInterrupts
           Return v15
         ");
@@ -1891,11 +1891,11 @@ pub mod hir_build_tests {
           v16:CBool = IsMethodCFunc v11, :new
           IfFalse v16, bb3(v6, v13, v11)
           v18:HeapBasicObject = ObjectAlloc v11
-          v20:BasicObject = SendWithoutBlock v18, :initialize
+          v20:BasicObject = SendWithoutBlock v18, :initialize # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Jump bb4(v6, v18, v20)
         bb3(v24:BasicObject, v25:NilClass, v26:BasicObject):
-          v29:BasicObject = SendWithoutBlock v26, :new
+          v29:BasicObject = SendWithoutBlock v26, :new # SendFallbackReason: Uncategorized(opt_send_without_block)
           Jump bb4(v24, v29, v25)
         bb4(v32:BasicObject, v33:BasicObject, v34:BasicObject):
           CheckInterrupts
@@ -2008,7 +2008,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           SideExit UnhandledNewarraySend(MIN)
         ");
     }
@@ -2040,13 +2040,13 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           PatchPoint BOPRedefined(ARRAY_REDEFINED_OP_FLAG, BOP_HASH)
           v32:Fixnum = ArrayHash v15, v16
           PatchPoint NoEPEscape(test)
           v39:ArrayExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v40:ArrayExact = ArrayDup v39
-          v42:BasicObject = SendWithoutBlock v14, :puts, v40
+          v42:BasicObject = SendWithoutBlock v14, :puts, v40 # SendFallbackReason: Uncategorized(opt_send_without_block)
           PatchPoint NoEPEscape(test)
           CheckInterrupts
           Return v32
@@ -2082,7 +2082,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           SideExit PatchPoint(BOPRedefined(ARRAY_REDEFINED_OP_FLAG, BOP_HASH))
         ");
     }
@@ -2114,7 +2114,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           v31:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v32:StringExact = StringCopy v31
           SideExit UnhandledNewarraySend(PACK)
@@ -2148,7 +2148,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           v29:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v30:StringExact = StringCopy v29
           v36:StringExact[VALUE(0x1008)] = Const Value(VALUE(0x1008))
@@ -2192,7 +2192,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           v29:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v30:StringExact = StringCopy v29
           v36:StringExact[VALUE(0x1008)] = Const Value(VALUE(0x1008))
@@ -2229,13 +2229,13 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           PatchPoint BOPRedefined(ARRAY_REDEFINED_OP_FLAG, BOP_INCLUDE_P)
           v33:BoolExact = ArrayInclude v15, v16 | v16
           PatchPoint NoEPEscape(test)
           v40:ArrayExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
           v41:ArrayExact = ArrayDup v40
-          v43:BasicObject = SendWithoutBlock v14, :puts, v41
+          v43:BasicObject = SendWithoutBlock v14, :puts, v41 # SendFallbackReason: Uncategorized(opt_send_without_block)
           PatchPoint NoEPEscape(test)
           CheckInterrupts
           Return v33
@@ -2276,7 +2276,7 @@ pub mod hir_build_tests {
           v12:NilClass = Const Value(nil)
           Jump bb2(v8, v9, v10, v11, v12)
         bb2(v14:BasicObject, v15:BasicObject, v16:BasicObject, v17:NilClass, v18:NilClass):
-          v25:BasicObject = SendWithoutBlock v15, :+, v16
+          v25:BasicObject = SendWithoutBlock v15, :+, v16 # SendFallbackReason: Uncategorized(opt_plus)
           SideExit PatchPoint(BOPRedefined(ARRAY_REDEFINED_OP_FLAG, BOP_INCLUDE_P))
         ");
     }
@@ -2355,7 +2355,7 @@ pub mod hir_build_tests {
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
           v18:ArrayExact = NewArray v11, v12
-          v21:BasicObject = SendWithoutBlock v18, :length
+          v21:BasicObject = SendWithoutBlock v18, :length # SendFallbackReason: Uncategorized(opt_length)
           CheckInterrupts
           Return v21
         ");
@@ -2380,7 +2380,7 @@ pub mod hir_build_tests {
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
           v18:ArrayExact = NewArray v11, v12
-          v21:BasicObject = SendWithoutBlock v18, :size
+          v21:BasicObject = SendWithoutBlock v18, :size # SendFallbackReason: Uncategorized(opt_size)
           CheckInterrupts
           Return v21
         ");
@@ -2685,7 +2685,7 @@ pub mod hir_build_tests {
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
           v16:NilClass = Const Value(nil)
           v20:Fixnum[1] = Const Value(1)
-          v24:BasicObject = SendWithoutBlock v11, :[]=, v12, v20
+          v24:BasicObject = SendWithoutBlock v11, :[]=, v12, v20 # SendFallbackReason: Uncategorized(opt_aset)
           CheckInterrupts
           Return v20
         ");
@@ -2709,7 +2709,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :[], v12
+          v19:BasicObject = SendWithoutBlock v11, :[], v12 # SendFallbackReason: Uncategorized(opt_aref)
           CheckInterrupts
           Return v19
         ");
@@ -2732,7 +2732,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = SendWithoutBlock v9, :empty?
+          v15:BasicObject = SendWithoutBlock v9, :empty? # SendFallbackReason: Uncategorized(opt_empty_p)
           CheckInterrupts
           Return v15
         ");
@@ -2755,7 +2755,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = SendWithoutBlock v9, :succ
+          v15:BasicObject = SendWithoutBlock v9, :succ # SendFallbackReason: Uncategorized(opt_succ)
           CheckInterrupts
           Return v15
         ");
@@ -2779,7 +2779,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :&, v12
+          v19:BasicObject = SendWithoutBlock v11, :&, v12 # SendFallbackReason: Uncategorized(opt_and)
           CheckInterrupts
           Return v19
         ");
@@ -2803,7 +2803,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :|, v12
+          v19:BasicObject = SendWithoutBlock v11, :|, v12 # SendFallbackReason: Uncategorized(opt_or)
           CheckInterrupts
           Return v19
         ");
@@ -2826,7 +2826,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v5, v6)
         bb2(v8:BasicObject, v9:BasicObject):
-          v15:BasicObject = SendWithoutBlock v9, :!
+          v15:BasicObject = SendWithoutBlock v9, :! # SendFallbackReason: Uncategorized(opt_not)
           CheckInterrupts
           Return v15
         ");
@@ -2850,7 +2850,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v19:BasicObject = SendWithoutBlock v11, :=~, v12
+          v19:BasicObject = SendWithoutBlock v11, :=~, v12 # SendFallbackReason: Uncategorized(opt_regexpmatch2)
           CheckInterrupts
           Return v19
         ");
@@ -2880,7 +2880,7 @@ pub mod hir_build_tests {
           v12:BasicObject = PutSpecialObject CBase
           v14:StaticSymbol[:aliased] = Const Value(VALUE(0x1008))
           v16:StaticSymbol[:__callee__] = Const Value(VALUE(0x1010))
-          v18:BasicObject = SendWithoutBlock v10, :core#set_method_alias, v12, v14, v16
+          v18:BasicObject = SendWithoutBlock v10, :core#set_method_alias, v12, v14, v16 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v18
         ");
@@ -2980,7 +2980,7 @@ pub mod hir_build_tests {
           CheckInterrupts
           v16:CBool = IsNil v9
           IfTrue v16, bb3(v8, v9, v9)
-          v19:BasicObject = SendWithoutBlock v9, :itself
+          v19:BasicObject = SendWithoutBlock v9, :itself # SendFallbackReason: Uncategorized(opt_send_without_block)
           Jump bb3(v8, v9, v19)
         bb3(v21:BasicObject, v22:BasicObject, v23:BasicObject):
           CheckInterrupts
@@ -3065,7 +3065,7 @@ pub mod hir_build_tests {
           v35:CBool[true] = Test v32
           IfFalse v35, bb3(v16, v17, v18, v19, v20, v25)
           PatchPoint NoEPEscape(open)
-          v42:BasicObject = InvokeBlock, v25
+          v42:BasicObject = InvokeBlock, v25 # SendFallbackReason: Uncategorized(invokeblock)
           v45:BasicObject = InvokeBuiltin dir_s_close, v16, v25
           CheckInterrupts
           Return v42
@@ -3190,12 +3190,12 @@ pub mod hir_build_tests {
           v13:NilClass = Const Value(nil)
           v16:Fixnum[0] = Const Value(0)
           v18:Fixnum[1] = Const Value(1)
-          v21:BasicObject = SendWithoutBlock v9, :[], v16, v18
+          v21:BasicObject = SendWithoutBlock v9, :[], v16, v18 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           v25:CBool = Test v21
           IfTrue v25, bb3(v8, v9, v13, v9, v16, v18, v21)
           v29:Fixnum[2] = Const Value(2)
-          v32:BasicObject = SendWithoutBlock v9, :[]=, v16, v18, v29
+          v32:BasicObject = SendWithoutBlock v9, :[]=, v16, v18, v29 # SendFallbackReason: Uncategorized(opt_send_without_block)
           CheckInterrupts
           Return v29
         bb3(v38:BasicObject, v39:BasicObject, v40:NilClass, v41:BasicObject, v42:Fixnum[0], v43:Fixnum[1], v44:BasicObject):
@@ -3398,7 +3398,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v4)
         bb2(v6:BasicObject):
-          v10:BasicObject = InvokeBlock
+          v10:BasicObject = InvokeBlock # SendFallbackReason: Uncategorized(invokeblock)
           CheckInterrupts
           Return v10
         ");
@@ -3423,7 +3423,7 @@ pub mod hir_build_tests {
           EntryPoint JIT(0)
           Jump bb2(v6, v7, v8)
         bb2(v10:BasicObject, v11:BasicObject, v12:BasicObject):
-          v18:BasicObject = InvokeBlock, v11, v12
+          v18:BasicObject = InvokeBlock, v11, v12 # SendFallbackReason: Uncategorized(invokeblock)
           CheckInterrupts
           Return v18
         ");
@@ -3547,7 +3547,7 @@ pub mod hir_build_tests {
           IfTrue v19, bb3(v10, v11, v12)
           v22:Fixnum[1] = Const Value(1)
           v24:Fixnum[1] = Const Value(1)
-          v27:BasicObject = SendWithoutBlock v22, :+, v24
+          v27:BasicObject = SendWithoutBlock v22, :+, v24 # SendFallbackReason: Uncategorized(opt_plus)
           PatchPoint NoEPEscape(test)
           Jump bb3(v10, v27, v12)
         bb3(v32:BasicObject, v33:BasicObject, v34:BasicObject):
diff --git a/zjit/src/options.rs b/zjit/src/options.rs
index b7e2c71cefcd65..ea9dc3249b82ff 100644
--- a/zjit/src/options.rs
+++ b/zjit/src/options.rs
@@ -51,6 +51,9 @@ pub struct Options {
     /// Print stats on exit (when stats is also true)
     pub print_stats: bool,
 
+    /// Print stats to file on exit (when stats is also true)
+    pub print_stats_file: Option<std::path::PathBuf>,
+
     /// Enable debug logging
     pub debug: bool,
 
@@ -103,6 +106,7 @@ impl Default for Options {
             num_profiles: DEFAULT_NUM_PROFILES,
             stats: false,
             print_stats: false,
+            print_stats_file: None,
             debug: false,
             disable: false,
             disable_hir_opt: false,
@@ -131,7 +135,10 @@ pub const ZJIT_OPTIONS: &[(&str, &str)] = &[
                      "Number of calls to trigger JIT (default: 30)."),
     ("--zjit-num-profiles=num",
                      "Number of profiled calls before JIT (default: 5)."),
-    ("--zjit-stats[=quiet]", "Enable collecting ZJIT statistics (=quiet to suppress output)."),
+    ("--zjit-stats-quiet",
+                     "Collect ZJIT stats and suppress output."),
+    ("--zjit-stats[=file]",
+                     "Collect ZJIT stats (=file to write to a file)."),
     ("--zjit-disable",
                      "Disable ZJIT for lazily enabling it with RubyVM::ZJIT.enable."),
     ("--zjit-perf",  "Dump ISEQ symbols into /tmp/perf-{}.map for Linux perf."),
@@ -303,13 +310,28 @@ fn parse_option(str_ptr: *const std::os::raw::c_char) -> Option<()> {
             Err(_) => return None,
         },
 
+
+        ("stats-quiet", _) => {
+            options.stats = true;
+            options.print_stats = false;
+        }
+
         ("stats", "") => {
             options.stats = true;
             options.print_stats = true;
         }
-        ("stats", "quiet") => {
+        ("stats", path) => {
+            // Truncate the file if it exists
+            std::fs::OpenOptions::new()
+                .create(true)
+                .write(true)
+                .truncate(true)
+                .open(path)
+                .map_err(|e| eprintln!("Failed to open file '{}': {}", path, e))
+                .ok();
+            let canonical_path = std::fs::canonicalize(opt_val).unwrap_or_else(|_| opt_val.into());
             options.stats = true;
-            options.print_stats = false;
+            options.print_stats_file = Some(canonical_path);
         }
 
         ("trace-exits", exits) => {
@@ -488,3 +510,14 @@ pub extern "C" fn rb_zjit_print_stats_p(_ec: EcPtr, _self: VALUE) -> VALUE {
         Qfalse
     }
 }
+
+/// Return path if stats should be printed at exit to a specified file, else Qnil.
+#[unsafe(no_mangle)]
+pub extern "C" fn rb_zjit_get_stats_file_path_p(_ec: EcPtr, _self: VALUE) -> VALUE {
+    if let Some(opts) = unsafe { OPTIONS.as_ref() } {
+        if let Some(ref path) = opts.print_stats_file {
+            return rust_str_to_ruby(path.as_os_str().to_str().unwrap());
+        }
+    }
+    Qnil
+}