From: Andrea Corallo <andrea_corallo@yahoo.it>
Date: Sun, 16 Jun 2019 10:40:23 +0000 (+0200)
Subject: BdiscardN support
X-Git-Tag: emacs-28.0.90~2727^2~1472
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=0c7115c7b894c8e1655a0d5e482cc7ed8b231506;p=emacs.git

BdiscardN support
---

diff --git a/src/comp.c b/src/comp.c
index fd7e7beda1e..f19fc84479b 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -1197,20 +1197,16 @@ compile_f (const char *f_name, ptrdiff_t bytestr_length,
 	case Bstack_ref3:
 	case Bstack_ref4:
 	case Bstack_ref5:
-	  {
-	    PUSH_LVAL (stack_base[(stack - stack_base) - (op - Bstack_ref) - 1]);
-	    break;
-	  }
+	  PUSH_LVAL (stack_base[(stack - stack_base) - (op - Bstack_ref) - 1]);
+	  break;
+
 	case Bstack_ref6:
-	  {
-	    PUSH_LVAL (stack_base[(stack - stack_base) - FETCH - 1]);
-	    break;
-	  }
+	  PUSH_LVAL (stack_base[(stack - stack_base) - FETCH - 1]);
+	  break;
+
 	case Bstack_ref7:
-	  {
-	    PUSH_LVAL (stack_base[(stack - stack_base) - FETCH2 - 1]);
-	    break;
-	  }
+	  PUSH_LVAL (stack_base[(stack - stack_base) - FETCH2 - 1]);
+	  break;
 
 	case Bvarref7:
 	  op = FETCH2;
@@ -1966,8 +1962,20 @@ compile_f (const char *f_name, ptrdiff_t bytestr_length,
 	case Bstack_set2:
 	  error ("Bstack_set2 not supported");
 	  break;
+
 	case BdiscardN:
-	  error ("BdiscardN not supported");
+	  op = FETCH;
+	  if (op & 0x80)
+	    {
+	      op &= 0x7F;
+	      POP1;
+	      gcc_jit_block_add_assignment (comp.bblock->gcc_bb,
+					    NULL,
+					    *(stack - op - 1),
+					    args[0]);
+	    }
+
+	  stack -= op;
 	  break;
 	case Bswitch:
 	  error ("Bswitch not supported");
@@ -1978,6 +1986,7 @@ compile_f (const char *f_name, ptrdiff_t bytestr_length,
 	     a constant on the stack.  */
 	  goto fail;
 	  break;
+
 	default:
 	case Bconstant:
 	  {
diff --git a/test/src/comp-tests.el b/test/src/comp-tests.el
index 9d1ee65e4ee..f1acc42b8ca 100644
--- a/test/src/comp-tests.el
+++ b/test/src/comp-tests.el
@@ -307,6 +307,20 @@
   (should (eq (comp-tests-numberp-f 'a) nil))
   (should (eq (comp-tests-numberp-f 3.5) t)))
 
+(ert-deftest comp-tests-stack ()
+  "Test some stack operation."
+  (defun comp-tests-discardn-f (x)
+    ;; BdiscardN
+    (1+ (let ((a 1)
+            (_b)
+            (_c))
+        a)))
+
+  (byte-compile #'comp-tests-discardn-f)
+  (native-compile #'comp-tests-discardn-f)
+
+  (should (= (comp-tests-discardn-f 10) 2)))
+
 (ert-deftest comp-tests-gc ()
   "Try to do some longer computation to let the gc kick in."
   (dotimes (_ 100000)