YJIT: Fixup kwrest stack base

I was a little rushed and didn't notice that it was still using the
final stack size even though we don't grow the stack before kwrest
handling anymore. Oh well, we got a new test out of it.

Fix: cbdabd5890

2 files changed, 13 insertions, 2 deletions

diff --git a/bootstraptest/test_yjit.rb b/bootstraptest/test_yjit.rb
index d5427588e0..753b1920d7 100644
--- a/bootstraptest/test_yjit.rb
+++ b/bootstraptest/test_yjit.rb
@@ -4538,3 +4538,14 @@ assert_normal_exit %q{
 
   Foo.new.try
 }
+
+# a kwrest case
+assert_equal '[1, 2, {:complete=>false}]', %q{
+  def rest(foo: 1, bar: 2, **kwrest)
+    [foo, bar, kwrest]
+  end
+
+  def callsite = rest(complete: false)
+
+  callsite
+}
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index 327e4fc05c..1180210aa3 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -7085,7 +7085,7 @@ fn gen_send_iseq(
             gen_save_sp(asm);
 
             // Build the kwrest hash. `struct rb_callinfo_kwarg` is malloc'd, so no GC concerns.
-            let kwargs_start = asm.lea(asm.ctx.sp_opnd(-(kwargs_order.len() as i32 * SIZEOF_VALUE_I32) as isize));
+            let kwargs_start = asm.lea(asm.ctx.sp_opnd(-(caller_keyword_len_i32 * SIZEOF_VALUE_I32) as isize));
             let kwrest = asm.ccall(
                 build_kw_rest as _,
                 vec![rest_mask.into(), kwargs_start, Opnd::const_ptr(ci_kwarg.cast())]
@@ -7098,7 +7098,7 @@ fn gen_send_iseq(
             // first before putting kwrest there. Use `rest_collected_idx` because that value went
             // into kwrest so the slot is now free.
             let kwrest_idx = callee_kw_count + usize::from(callee_kw_count > 0);
-            if let (Some(rest_collected_idx), true) = (rest_collected_idx, kwrest_idx < kwargs_order.len()) {
+            if let (Some(rest_collected_idx), true) = (rest_collected_idx, kwrest_idx < caller_keyword_len) {
                 let rest_collected = asm.stack_opnd(kwargs_stack_base - rest_collected_idx);
                 let mapping = asm.ctx.get_opnd_mapping(stack_kwrest.into());
                 asm.mov(rest_collected, stack_kwrest);