automatic import of gccopeneuler24.03_LTS_SP1

1 files changed, 92 insertions, 0 deletions

diff --git a/0137-Backport-SME-mode-switching-Tweak-entry-exit-handlin.patch b/0137-Backport-SME-mode-switching-Tweak-entry-exit-handlin.patch
new file mode 100644
index 0000000..8444847
--- /dev/null
+++ b/0137-Backport-SME-mode-switching-Tweak-entry-exit-handlin.patch
@@ -0,0 +1,92 @@
+From c0aaf329d9c547b249ac120a8d1995d8546a1edb Mon Sep 17 00:00:00 2001
+From: Richard Sandiford <richard.sandiford@arm.com>
+Date: Sat, 11 Nov 2023 17:28:57 +0000
+Subject: [PATCH 038/157] [Backport][SME] mode-switching: Tweak entry/exit
+ handling
+
+Reference: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=e59ec35276599805cdc6c3979d8a167b027d286e
+
+An entity isn't transparent in a block that requires a specific mode.
+optimize_mode_switching took that into account for normal insns,
+but didn't for the exit block.  Later patches misbehaved because
+of this.
+
+In contrast, an entity was correctly marked as non-transparent
+in the entry block, but the reasoning seemed a bit convoluted.
+It also referred to a function that no longer exists.
+Since KILL = ~TRANSP, the entity is by definition not transparent
+in a block that defines the entity, so I think we can make it so
+without comment.
+
+Finally, the exit handling was nested in the entry handling,
+but that doesn't seem necessary.  A target could say that an
+entity is undefined on entry but must be defined on return,
+on a "be liberal in what you accept, be conservative in what
+you do" principle.
+
+gcc/
+	* mode-switching.cc (optimize_mode_switching): Mark the exit
+	block as nontransparent if it requires a specific mode.
+	Handle the entry and exit mode as sibling rather than nested
+	concepts.  Remove outdated comment.
+---
+ gcc/mode-switching.cc | 34 +++++++++++++++-------------------
+ 1 file changed, 15 insertions(+), 19 deletions(-)
+
+diff --git a/gcc/mode-switching.cc b/gcc/mode-switching.cc
+index 4d2b9e284..4761c2ff0 100644
+--- a/gcc/mode-switching.cc
++++ b/gcc/mode-switching.cc
+@@ -649,34 +649,30 @@ optimize_mode_switching (void)
+ 	}
+       if (targetm.mode_switching.entry && targetm.mode_switching.exit)
+ 	{
+-	  int mode = targetm.mode_switching.entry (e);
+-
+ 	  info[post_entry->index].mode_out =
+ 	    info[post_entry->index].mode_in = no_mode;
+-	  if (pre_exit)
+-	    {
+-	      info[pre_exit->index].mode_out =
+-		info[pre_exit->index].mode_in = no_mode;
+-	    }
+ 
++	  int mode = targetm.mode_switching.entry (e);
+ 	  if (mode != no_mode)
+ 	    {
+-	      bb = post_entry;
+-
+-	      /* By always making this nontransparent, we save
+-		 an extra check in make_preds_opaque.  We also
+-		 need this to avoid confusing pre_edge_lcm when
+-		 antic is cleared but transp and comp are set.  */
+-	      bitmap_clear_bit (transp_all, bb->index);
+-
+ 	      /* Insert a fake computing definition of MODE into entry
+ 		 blocks which compute no mode. This represents the mode on
+ 		 entry.  */
+-	      info[bb->index].computing = mode;
++	      info[post_entry->index].computing = mode;
++	      bitmap_clear_bit (transp_all, post_entry->index);
++	    }
+ 
+-	      if (pre_exit)
+-		info[pre_exit->index].seginfo->mode =
+-		  targetm.mode_switching.exit (e);
++	  if (pre_exit)
++	    {
++	      info[pre_exit->index].mode_out =
++		info[pre_exit->index].mode_in = no_mode;
++
++	      int mode = targetm.mode_switching.exit (e);
++	      if (mode != no_mode)
++		{
++		  info[pre_exit->index].seginfo->mode = mode;
++		  bitmap_clear_bit (transp_all, pre_exit->index);
++		}
+ 	    }
+ 	}
+ 
+-- 
+2.33.0
+