YJIT: Add a specialized codegen function for `Class#superclass`. (#10613)

Add a specialized codegen function for `Class#superclass`.

Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
Co-authored-by: Takashi Kokubun (k0kubun) <takashikkbn@gmail.com>
Co-authored-by: Randy Stauner <randy.stauner@shopify.com>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>

3 files changed, 34 insertions, 0 deletions

diff --git a/yjit/bindgen/src/main.rs b/yjit/bindgen/src/main.rs
index c58df7c377..c16617b3f0 100644
--- a/yjit/bindgen/src/main.rs
+++ b/yjit/bindgen/src/main.rs
@@ -174,6 +174,7 @@ fn main() {
         .allowlist_var("rb_cThread")
         .allowlist_var("rb_cArray")
         .allowlist_var("rb_cHash")
+        .allowlist_var("rb_cClass")
 
         // From include/ruby/internal/fl_type.h
         .allowlist_type("ruby_fl_type")
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index a7bf2e06f6..a927aa9684 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -6060,6 +6060,36 @@ fn gen_block_given(
     asm.mov(out_opnd, block_given);
 }
 
+// Codegen for rb_class_superclass()
+fn jit_rb_class_superclass(
+    jit: &mut JITState,
+    asm: &mut Assembler,
+    _ocb: &mut OutlinedCb,
+    _ci: *const rb_callinfo,
+    cme: *const rb_callable_method_entry_t,
+    _block: Option<crate::codegen::BlockHandler>,
+    _argc: i32,
+    _known_recv_class: Option<VALUE>,
+) -> bool {
+    extern "C" {
+        fn rb_class_superclass(klass: VALUE) -> VALUE;
+    }
+
+    if !jit_prepare_lazy_frame_call(jit, asm, cme, StackOpnd(0)) {
+        return false;
+    }
+
+    asm_comment!(asm, "Class#superclass");
+    let recv_opnd = asm.stack_opnd(0);
+    let ret = asm.ccall(rb_class_superclass as *const u8, vec![recv_opnd]);
+
+    asm.stack_pop(1);
+    let ret_opnd = asm.stack_push(Type::Unknown);
+    asm.mov(ret_opnd, ret);
+
+    true
+}
+
 fn jit_thread_s_current(
     _jit: &mut JITState,
     asm: &mut Assembler,
@@ -10072,6 +10102,8 @@ pub fn yjit_reg_method_codegen_fns() {
         yjit_reg_method(rb_mKernel, "respond_to?", jit_obj_respond_to);
         yjit_reg_method(rb_mKernel, "block_given?", jit_rb_f_block_given_p);
 
+        yjit_reg_method(rb_cClass, "superclass", jit_rb_class_superclass);
+
         yjit_reg_method(rb_singleton_class(rb_cThread), "current", jit_thread_s_current);
     }
 }
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs
index 359227d60d..bdaee0534c 100644
--- a/yjit/src/cruby_bindings.inc.rs
+++ b/yjit/src/cruby_bindings.inc.rs
@@ -962,6 +962,7 @@ extern "C" {
     pub static mut rb_mKernel: VALUE;
     pub static mut rb_cBasicObject: VALUE;
     pub static mut rb_cArray: VALUE;
+    pub static mut rb_cClass: VALUE;
     pub static mut rb_cFalseClass: VALUE;
     pub static mut rb_cFloat: VALUE;
     pub static mut rb_cHash: VALUE;