Optimize Integer#[]

lib/ruby_vm/mjit/insn_compiler.rb

@@ -1778,6 +1778,29 @@ module RubyVM::MJIT
       true
     end
 
+    # @param jit [RubyVM::MJIT::JITState]
+    # @param ctx [RubyVM::MJIT::Context]
+    # @param asm [RubyVM::MJIT::Assembler]
+    def jit_rb_int_aref(jit, ctx, asm, argc)
+      return false if argc != 1
+      return false unless two_fixnums_on_stack?(jit)
+
+      side_exit = side_exit(jit, ctx)
+      guard_two_fixnums(jit, ctx, asm, side_exit)
+
+      asm.comment('rb_int_aref')
+      y_opnd = ctx.stack_pop
+      x_opnd = ctx.stack_pop
+
+      asm.mov(C_ARGS[0], x_opnd)
+      asm.mov(C_ARGS[1], y_opnd)
+      asm.call(C.rb_fix_aref)
+
+      ret_opnd = ctx.stack_push
+      asm.mov(ret_opnd, C_RET)
+      true
+    end
+
     # @param jit [RubyVM::MJIT::JITState]
     # @param ctx [RubyVM::MJIT::Context]
     # @param asm [RubyVM::MJIT::Assembler]
@@ -1810,6 +1833,7 @@ module RubyVM::MJIT
       register_cfunc_method(Integer, :===, :jit_rb_int_equal)
       register_cfunc_method(Integer, :*, :jit_rb_int_mul)
       register_cfunc_method(Integer, :/, :jit_rb_int_div)
+      register_cfunc_method(Integer, :[], :jit_rb_int_aref)
 
       register_cfunc_method(Array, :<<, :jit_rb_ary_push)
     end

mjit_c.rb

@@ -297,6 +297,13 @@ module RubyVM::MJIT # :nodoc: all
       Primitive.cexpr! 'SIZET2NUM((size_t)rb_ary_push)'
     end
 
+    def rb_fix_aref
+      Primitive.cstmt! %{
+        extern VALUE rb_fix_aref(VALUE fix, VALUE idx);
+        return SIZET2NUM((size_t)rb_fix_aref);
+      }
+    end
+
     #========================================================================================
     #
     # Old stuff