1 files changed, 24 insertions, 23 deletions
diff --git a/lib/ruby_vm/mjit/compiler.rb b/lib/ruby_vm/mjit/compiler.rb
index 75314501c1..9383c189b2 100644
--- a/lib/ruby_vm/mjit/compiler.rb
+++ b/lib/ruby_vm/mjit/compiler.rb
@@ -9,9 +9,6 @@ module RubyVM::MJIT
   EndBlock = :end_block
 
   class Compiler
-    # Ruby constants
-    Qundef = Fiddle::Qundef
-
     attr_accessor :write_pos
 
     # @param mem_block [Integer] JIT buffer address
@@ -24,7 +21,11 @@ module RubyVM::MJIT
     # @param iseq [RubyVM::MJIT::CPointer::Struct]
     def call(iseq)
       return if iseq.body.location.label == '<main>'
-      iseq.body.jit_func = compile_block(iseq)
+
+      asm = X86Assembler.new
+      compile_prologue(asm)
+      compile_block(asm, iseq)
+      iseq.body.jit_func = compile(asm)
     rescue Exception => e
       $stderr.puts e.full_message # TODO: check verbose
     end
@@ -35,25 +36,13 @@ module RubyVM::MJIT
 
     private
 
-    def compile(asm)
-      start_addr = write_addr
-
-      C.mjit_mark_writable
-      @write_pos += asm.compile(start_addr)
-      C.mjit_mark_executable
-
-      end_addr = write_addr
-      if C.mjit_opts.dump_disasm && start_addr < end_addr
-        dump_disasm(start_addr, end_addr)
-      end
-      start_addr
+    #  ec: rdi
+    # cfp: rsi
+    def compile_prologue(asm)
+      asm.mov(:rbx, [:rsi, C.rb_control_frame_t.offsetof(:sp)]) # rbx = cfp->sp
     end
 
-    # ec -> RDI, cfp -> RSI
-    def compile_block(iseq)
-      addr = write_addr
-      asm = X86Assembler.new
-
+    def compile_block(asm, iseq)
       index = 0
       while index < iseq.body.iseq_size
         insn = decode_insn(iseq.body.iseq_encoded[index])
@@ -63,8 +52,6 @@ module RubyVM::MJIT
         end
         index += insn.len
       end
-
-      compile(asm)
     end
 
     def compile_insn(asm, insn)
@@ -75,6 +62,20 @@ module RubyVM::MJIT
       end
     end
 
+    def compile(asm)
+      start_addr = write_addr
+
+      C.mjit_mark_writable
+      @write_pos += asm.compile(start_addr)
+      C.mjit_mark_executable
+
+      end_addr = write_addr
+      if C.mjit_opts.dump_disasm && start_addr < end_addr
+        dump_disasm(start_addr, end_addr)
+      end
+      start_addr
+    end
+
     def decode_insn(encoded)
       INSNS.fetch(C.rb_vm_insn_decode(encoded))
     end