YJIT: Implement concatarray in yjit (https://github.com/Shopify/ruby/pull/405)

* Create code generation func

* Make rb_vm_concat_array available to use in Rust

* Map opcode to code gen func

* Implement code gen for concatarray

* Add test for concatarray

* Use new asm backend

* Add comment to C func wrapper

bootstraptest/test_yjit.rb

@@ -3245,3 +3245,13 @@ assert_equal 'foo', %q{
   end
   foo { "foo" }.call
 }
+
+assert_equal '[1, 2]', %q{
+  def foo
+    x = [2]
+    [1, *x]
+  end
+
+  foo
+  foo
+}

vm_insnhelper.c

@@ -4380,6 +4380,14 @@ vm_concat_array(VALUE ary1, VALUE ary2st)
     return rb_ary_concat(tmp1, tmp2);
 }
 
+// YJIT implementation is using the C function
+// and needs to call a non-static function
+VALUE
+rb_vm_concat_array(VALUE ary1, VALUE ary2st)
+{
+    return vm_concat_array(ary1, ary2st);
+}
+
 static VALUE
 vm_splat_array(VALUE flag, VALUE ary)
 {
@@ -4395,6 +4403,8 @@ vm_splat_array(VALUE flag, VALUE ary)
     }
 }
 
+// YJIT implementation is using the C function
+// and needs to call a non-static function
 VALUE
 rb_vm_splat_array(VALUE flag, VALUE ary)
 {

yjit/src/codegen.rs

@@ -1256,6 +1256,30 @@ fn gen_splatarray(
     KeepCompiling
 }
 
+// concat two arrays
+fn gen_concatarray(
+    jit: &mut JITState,
+    ctx: &mut Context,
+    asm: &mut Assembler,
+    _ocb: &mut OutlinedCb,
+) -> CodegenStatus {
+    // Save the PC and SP because the callee may allocate
+    // Note that this modifies REG_SP, which is why we do it first
+    jit_prepare_routine_call(jit, ctx, asm);
+
+    // Get the operands from the stack
+    let ary2st_opnd = ctx.stack_pop(1);
+    let ary1_opnd = ctx.stack_pop(1);
+
+    // Call rb_vm_concat_array(ary1, ary2st)
+    let ary = asm.ccall(rb_vm_concat_array as *const u8, vec![ary1_opnd, ary2st_opnd]);
+
+    let stack_ret = ctx.stack_push(Type::Array);
+    asm.mov(stack_ret, ary);
+
+    KeepCompiling
+}
+
 // new range initialized from top 2 values
 fn gen_newrange(
     jit: &mut JITState,
@@ -5862,6 +5886,7 @@ fn get_gen_fn(opcode: VALUE) -> Option<InsnGenFn> {
         YARVINSN_opt_str_freeze => Some(gen_opt_str_freeze),
         YARVINSN_opt_str_uminus => Some(gen_opt_str_uminus),
         YARVINSN_splatarray => Some(gen_splatarray),
+        YARVINSN_concatarray => Some(gen_concatarray),
         YARVINSN_newrange => Some(gen_newrange),
         YARVINSN_putstring => Some(gen_putstring),
         YARVINSN_expandarray => Some(gen_expandarray),

yjit/src/cruby.rs

@@ -112,6 +112,7 @@ pub use autogened::*;
 #[cfg_attr(test, allow(unused))] // We don't link against C code when testing
 extern "C" {
     pub fn rb_vm_splat_array(flag: VALUE, ary: VALUE) -> VALUE;
+    pub fn rb_vm_concat_array(ary1: VALUE, ary2st: VALUE) -> VALUE;
     pub fn rb_vm_defined(
         ec: EcPtr,
         reg_cfp: CfpPtr,