Implement dup

2 files changed, 16 insertions, 5 deletions

diff --git a/lib/ruby_vm/mjit/context.rb b/lib/ruby_vm/mjit/context.rb
index 86aa03514a..fb9db212d5 100644
--- a/lib/ruby_vm/mjit/context.rb
+++ b/lib/ruby_vm/mjit/context.rb
@@ -7,16 +7,16 @@ module RubyVM::MJIT
     def initialize(stack_size: 0, sp_offset: 0, chain_depth: 0) = super
 
     def stack_push(size = 1)
-      opnd = [SP, C.VALUE.size * self.sp_offset]
       self.stack_size += size
       self.sp_offset += size
-      opnd
+      stack_opnd(0)
     end
 
     def stack_pop(size = 1)
+      opnd = stack_opnd(0)
       self.stack_size -= size
       self.sp_offset -= size
-      [SP, C.VALUE.size * self.sp_offset]
+      opnd
     end
 
     def stack_opnd(depth_from_top)
diff --git a/lib/ruby_vm/mjit/insn_compiler.rb b/lib/ruby_vm/mjit/insn_compiler.rb
index 6f96e57ff1..368358b916 100644
--- a/lib/ruby_vm/mjit/insn_compiler.rb
+++ b/lib/ruby_vm/mjit/insn_compiler.rb
@@ -56,7 +56,7 @@ module RubyVM::MJIT
       # newhash
       # newrange
       # pop
-      # dup
+      when :dup then dup(jit, ctx, asm)
       # dupn
       # swap
       # opt_reverse
@@ -222,7 +222,18 @@ module RubyVM::MJIT
     # newhash
     # newrange
     # pop
-    # dup
+
+    # @param jit [RubyVM::MJIT::JITState]
+    # @param ctx [RubyVM::MJIT::Context]
+    # @param asm [RubyVM::MJIT::Assembler]
+    def dup(jit, ctx, asm)
+      val1 = ctx.stack_opnd(0)
+      val2 = ctx.stack_push
+      asm.mov(:rax, val1)
+      asm.mov(val2, :rax)
+      KeepCompiling
+    end
+
     # dupn
     # swap
     # opt_reverse