| Message ID | fb99bf2f5a70c60f262469a6d55d59390afe7564.1470015604.git.segher@kernel.crashing.org |
|---|---|
| State | New |
| Headers | show |
On 07/31/2016 07:42 PM, Segher Boessenkool wrote: > 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. I think this (and the prior patches) are masking a deeper issue. It's almost as if we don't have correct lifetime information and the various return points. I'd really like to see a deeper analysis of these issues. jeff
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 (); }