1 files changed, 30 insertions, 0 deletions
diff --git a/lib/ruby_vm/rjit/context.rb b/lib/ruby_vm/rjit/context.rb
new file mode 100644
index 0000000000..e834b42999
--- /dev/null
+++ b/lib/ruby_vm/rjit/context.rb
@@ -0,0 +1,30 @@
+module RubyVM::MJIT
+  class Context < Struct.new(
+    :stack_size,  # @param [Integer] The number of values on the stack
+    :sp_offset,   # @param [Integer] JIT sp offset relative to the interpreter's sp
+    :chain_depth, # @param [Integer] jit_chain_guard depth
+  )
+    def initialize(stack_size: 0, sp_offset: 0, chain_depth: 0) = super
+
+    def stack_push(size = 1)
+      self.stack_size += size
+      self.sp_offset += size
+      stack_opnd(0)
+    end
+
+    def stack_pop(size = 1)
+      opnd = stack_opnd(0)
+      self.stack_size -= size
+      self.sp_offset -= size
+      opnd
+    end
+
+    def stack_opnd(depth_from_top)
+      [SP, C.VALUE.size * (self.sp_offset - 1 - depth_from_top)]
+    end
+
+    def sp_opnd(offset_bytes = 0)
+      [SP, (C.VALUE.size * self.sp_offset) + offset_bytes]
+    end
+  end
+end