Be more systematic about _setjmp vs setjmp.

* alloc.c (test_setjmp, mark_stack):
* image.c (PNG_LONGJMP) [PNG_LIBPNG_VER < 10500]:
(PNG_JMPBUF) [! (PNG_LIBPNG_VER < 10500)]:
(png_load, my_error_exit, jpeg_load):
* process.c (send_process_trap, send_process):
Uniformly prefer _setjmp and _longjmp to setjmp and longjmp.
The underscored versions are up to 30x faster on some hosts.
Formerly, the code used setjmp+longjmp sometimes and
_setjmp+_longjmp at other times, with no particular reason to
prefer setjmp+longjmp.

4 files changed, 26 insertions, 12 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 17dec525156..a8d6a4026a0 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,17 @@
+2012-09-04  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Be more systematic about _setjmp vs setjmp.
+        * alloc.c (test_setjmp, mark_stack):
+        * image.c (PNG_LONGJMP) [PNG_LIBPNG_VER < 10500]:
+        (PNG_JMPBUF) [! (PNG_LIBPNG_VER < 10500)]:
+        (png_load, my_error_exit, jpeg_load):
+        * process.c (send_process_trap, send_process):
+        Uniformly prefer _setjmp and _longjmp to setjmp and longjmp.
+        The underscored versions are up to 30x faster on some hosts.
+        Formerly, the code used setjmp+longjmp sometimes and
+        _setjmp+_longjmp at other times, with no particular reason to
+        prefer setjmp+longjmp.
+
 2012-09-03  Paul Eggert  <eggert@cs.ucla.edu>
 
         Fix minor problem found by static checking.
diff --git a/src/alloc.c b/src/alloc.c
index 188a514376d..edecd51f1ac 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -4764,7 +4764,7 @@ test_setjmp (void)
   x = strlen (buf);
   x = 2 * x - 1;
 
-  setjmp (jbuf);
+  _setjmp (jbuf);
   if (longjmps_done == 1)
     {
       /* Came here after the longjmp at the end of the function.
@@ -4789,7 +4789,7 @@ test_setjmp (void)
   ++longjmps_done;
   x = 2;
   if (longjmps_done == 1)
-    longjmp (jbuf, 1);
+    _longjmp (jbuf, 1);
 }
 
 #endif /* not GC_SAVE_REGISTERS_ON_STACK && not GC_SETJMP_WORKS */
@@ -4931,7 +4931,7 @@ mark_stack (void)
     }
 #endif /* GC_SETJMP_WORKS */
 
-  setjmp (j.j);
+  _setjmp (j.j);
   end = stack_grows_down_p ? (char *) &j + sizeof j : (char *) &j;
 #endif /* not GC_SAVE_REGISTERS_ON_STACK */
 #endif /* not HAVE___BUILTIN_UNWIND_INIT */
diff --git a/src/image.c b/src/image.c
index a067dae7737..3e021677e09 100644
--- a/src/image.c
+++ b/src/image.c
@@ -5517,13 +5517,13 @@ init_png_functions (Lisp_Object libraries)
 
 
 #if (PNG_LIBPNG_VER < 10500)
-#define PNG_LONGJMP(ptr) (longjmp ((ptr)->jmpbuf, 1))
+#define PNG_LONGJMP(ptr) (_longjmp ((ptr)->jmpbuf, 1))
 #define PNG_JMPBUF(ptr) ((ptr)->jmpbuf)
 #else
 /* In libpng version 1.5, the jmpbuf member is hidden. (Bug#7908)  */
 #define PNG_LONGJMP(ptr) (fn_png_longjmp ((ptr), 1))
 #define PNG_JMPBUF(ptr) \
-  (*fn_png_set_longjmp_fn ((ptr), longjmp, sizeof (jmp_buf)))
+  (*fn_png_set_longjmp_fn ((ptr), _longjmp, sizeof (jmp_buf)))
 #endif
 
 /* Error and warning handlers installed when the PNG library
@@ -5696,7 +5696,7 @@ png_load (struct frame *f, struct image *img)
 
   /* Set error jump-back.  We come back here when the PNG library
      detects an error.  */
-  if (setjmp (PNG_JMPBUF (png_ptr)))
+  if (_setjmp (PNG_JMPBUF (png_ptr)))
     {
     error:
       if (png_ptr)
@@ -6114,7 +6114,7 @@ static _Noreturn void
 my_error_exit (j_common_ptr cinfo)
 {
   struct my_jpeg_error_mgr *mgr = (struct my_jpeg_error_mgr *) cinfo->err;
-  longjmp (mgr->setjmp_buffer, 1);
+  _longjmp (mgr->setjmp_buffer, 1);
 }
 
 
@@ -6365,7 +6365,7 @@ jpeg_load (struct frame *f, struct image *img)
   cinfo.err = fn_jpeg_std_error (&mgr.pub);
   mgr.pub.error_exit = my_error_exit;
 
-  if ((rc = setjmp (mgr.setjmp_buffer)) != 0)
+  if ((rc = _setjmp (mgr.setjmp_buffer)) != 0)
     {
       if (rc == 1)
         {
@@ -6411,12 +6411,12 @@ jpeg_load (struct frame *f, struct image *img)
   if (!check_image_size (f, width, height))
     {
       image_error ("Invalid image size (see `max-image-size')", Qnil, Qnil);
-      longjmp (mgr.setjmp_buffer, 2);
+      _longjmp (mgr.setjmp_buffer, 2);
     }
 
   /* Create X image and pixmap.  */
   if (!x_create_x_image_and_pixmap (f, width, height, 0, &ximg, &img->pixmap))
-    longjmp (mgr.setjmp_buffer, 2);
+    _longjmp (mgr.setjmp_buffer, 2);
 
   /* Allocate colors.  When color quantization is used,
      cinfo.actual_number_of_colors has been set with the number of
diff --git a/src/process.c b/src/process.c
index 04b6abe50a7..2d144b410ed 100644
--- a/src/process.c
+++ b/src/process.c
@@ -5431,7 +5431,7 @@ send_process_trap (int ignore)
 {
   SIGNAL_THREAD_CHECK (SIGPIPE);
   sigunblock (sigmask (SIGPIPE));
-  longjmp (send_process_frame, 1);
+  _longjmp (send_process_frame, 1);
 }
 
 /* In send_process, when a write fails temporarily,
@@ -5634,7 +5634,7 @@ send_process (volatile Lisp_Object proc, const char *volatile buf,
   /* 2000-09-21: Emacs 20.7, sparc-sun-solaris-2.6, GCC 2.95.2,
      CFLAGS="-g -O": The value of the parameter `proc' is clobbered
      when returning with longjmp despite being declared volatile.  */
-  if (!setjmp (send_process_frame))
+  if (!_setjmp (send_process_frame))
     {
       p = XPROCESS (proc);  /* Repair any setjmp clobbering.  */
       process_sent_to = proc;