Add setclassvariable to yjit (#5127)

Implements setclassvariable in yjit. Note that this version is not
faster than the standard version because we aren't handling the inline
cache in assembly. This is still important to implement because it will
prevent yjit from exiting in methods that call both a cvar setter and
other code that yjit can compile.

Co-authored-by: Aaron Patterson tenderlove@ruby-lang.org

test/ruby/test_yjit.rb

@@ -52,6 +52,11 @@ class TestYJIT < Test::Unit::TestCase
     assert_in_out_err([yjit_child_env, '-e p RubyVM::YJIT.enabled?'], '', ['true'])
   end
 
+  def test_compile_setclassvariable
+    script = 'class Foo; def self.foo; @@foo = 1; end; end; Foo.foo'
+    assert_compiles(script, insns: %i[setclassvariable], result: 1)
+  end
+
   def test_compile_getclassvariable
     script = 'class Foo; @@foo = 1; def self.foo; @@foo; end; end; Foo.foo'
     assert_compiles(script, insns: %i[getclassvariable], result: 1)

vm_insnhelper.c

@@ -1367,6 +1367,12 @@ vm_setclassvariable(const rb_iseq_t *iseq, const rb_control_frame_t *reg_cfp, ID
     update_classvariable_cache(iseq, klass, id, ic);
 }
 
+void
+rb_vm_setclassvariable(const rb_iseq_t *iseq, const rb_control_frame_t *cfp, ID id, VALUE val, ICVARC ic)
+{
+    vm_setclassvariable(iseq, cfp, id, val, ic);
+}
+
 static inline VALUE
 vm_getinstancevariable(const rb_iseq_t *iseq, VALUE obj, ID id, IVC ic)
 {

yjit_codegen.c

@@ -4488,6 +4488,26 @@ gen_getclassvariable(jitstate_t* jit, ctx_t* ctx, codeblock_t* cb)
     return YJIT_KEEP_COMPILING;
 }
 
+VALUE
+rb_vm_setclassvariable(const rb_iseq_t *iseq, const rb_control_frame_t *cfp, ID id, VALUE val, ICVARC ic);
+
+static codegen_status_t
+gen_setclassvariable(jitstate_t* jit, ctx_t* ctx, codeblock_t* cb)
+{
+    // rb_vm_setclassvariable can raise exceptions.
+    jit_prepare_routine_call(jit, ctx, REG0);
+
+    mov(cb, C_ARG_REGS[0], member_opnd(REG_CFP, rb_control_frame_t, iseq));
+    mov(cb, C_ARG_REGS[1], REG_CFP);
+    mov(cb, C_ARG_REGS[2], imm_opnd(jit_get_arg(jit, 0)));
+    mov(cb, C_ARG_REGS[3], ctx_stack_pop(ctx, 1));
+    mov(cb, C_ARG_REGS[4], imm_opnd(jit_get_arg(jit, 1)));
+
+    call_ptr(cb, REG0, (void *)rb_vm_setclassvariable);
+
+    return YJIT_KEEP_COMPILING;
+}
+
 static codegen_status_t
 gen_opt_getinlinecache(jitstate_t *jit, ctx_t *ctx, codeblock_t *cb)
 {
@@ -4886,6 +4906,7 @@ yjit_init_codegen(void)
     yjit_reg_op(BIN(toregexp), gen_toregexp);
     yjit_reg_op(BIN(getspecial), gen_getspecial);
     yjit_reg_op(BIN(getclassvariable), gen_getclassvariable);
+    yjit_reg_op(BIN(setclassvariable), gen_setclassvariable);
 
     yjit_method_codegen_table = st_init_numtable();