[PATCH 5/9] regrename: Don't run if function was separately shrink-wrapped

[Segher Boessenkool <segher@kernel.crashing.org>]

Unfortunately even after the previous patch there are still a few cases
where regrename creates invalid code when used together with separate
shrink-wrapping.  At noreturn exits regrename thinks it can use all
callee-saved registers, but that is not true.  This patch disables
regrename for functions that were separately shrink-wrapped.

2016-06-07  Segher Boessenkool  <segher@kernel.crashing.org>

	* regrename.c (gate): Disable regrename if shrink_wrapped_separate
	is set in crtl.
---
 gcc/regrename.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/regrename.c b/gcc/regrename.c
index 00a5d02..e2d2483 100644
--- a/gcc/regrename.c
+++ b/gcc/regrename.c
@@ -1956,7 +1956,12 @@ public:
   /* opt_pass methods: */
   virtual bool gate (function *)
     {
-      return (optimize > 0 && (flag_rename_registers));
+      /* regrename can decide to use callee-saved registers in places where
+	 those should hold their original contents.  This happens when
+	 separate shrink-wrapping is used.  Disable regrename in that case,
+	 until this problem is fixed.  */
+      return (optimize > 0 && flag_rename_registers
+	      && !crtl->shrink_wrapped_separate);
     }
 
   virtual unsigned int execute (function *) { return regrename_optimize (); }
-- 
1.9.3