From 483a2d39df48ef17f446f4c41171654a10ce62b2 Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea_corallo@yahoo.it>
Date: Mon, 24 Jun 2019 11:33:44 +0200
Subject: [PATCH] add XUNTAG

---
 src/comp.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/comp.c b/src/comp.c
index 2bffba08334..f754778468b 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -496,6 +496,24 @@ emit_lval_XLP (gcc_jit_lvalue *obj)
 				      comp.lisp_obj_as_ptr);
 }
 
+static gcc_jit_rvalue *
+emit_rval_XUNTAG (gcc_jit_rvalue *a, gcc_jit_type *type, unsigned lisp_word_tag)
+{
+  /* #define XUNTAG(a, type, ctype) ((ctype *)
+     ((char *) XLP (a) - LISP_WORD_TAG (type))) */
+
+  return emit_cast (type,
+	   gcc_jit_context_new_binary_op (
+	     comp.ctxt,
+	     NULL,
+	     GCC_JIT_BINARY_OP_MINUS,
+	     comp.emacs_int_type,
+	     emit_rval_XLI (a),
+	     gcc_jit_context_new_rvalue_from_int (comp.ctxt,
+					   comp.int_type,
+					   lisp_word_tag)));
+}
+
 static gcc_jit_rvalue *
 emit_TAGGEDP (gcc_jit_rvalue *obj, unsigned tag)
 {
-- 
2.39.5