From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. J. Lu" To: Greg Schafer , kelledin@users.sourceforge.net Cc: gcc@gcc.gnu.org, law@redhat.com, gcc-patches@gcc.gnu.org, gcc-bugs@gcc.gnu.org Subject: Re: optimization/7591: function-related struct copy bug Date: Sun, 18 Aug 2002 08:36:00 -0000 Message-id: <20020818083604.A20945@lucon.org> References: <20020818093401.A15946@tigers-lfs.nsw.bigpond.net.au> <20020817184800.A2198@lucon.org> <20020818152009.A29717@tigers-lfs.nsw.bigpond.net.au> <20020818000921.B5909@lucon.org> <20020818080617.A20366@lucon.org> <20020818081443.A20617@lucon.org> X-SW-Source: 2002-08/msg01049.html On Sun, Aug 18, 2002 at 08:14:43AM -0700, H. J. Lu wrote: > On Sun, Aug 18, 2002 at 08:06:17AM -0700, H. J. Lu wrote: > > On Sun, Aug 18, 2002 at 12:09:21AM -0700, H. J. Lu wrote: > > > On Sun, Aug 18, 2002 at 03:20:09PM +1000, Greg Schafer wrote: > > > > On Sat, Aug 17, 2002 at 06:48:00PM -0700, H. J. Lu wrote: > > > > > On Sun, Aug 18, 2002 at 09:34:01AM +1000, Greg Schafer wrote: > > > > > > Hello there > > > > > > > > > > > > I notice that your gcc test results do not fail the test > > > > > > gcc.c-torture/execute/20020307-2.c > > > > > > but just about everyone else in the world on i686-pc-linux-gnu > > > > > > seems to fail that test. > > > > > > > > > > > > Do you know the reason for this? Do you use a local patch or something? > > > > > > > > > > > > > > > > http://gcc.gnu.org/ml/gcc-patches/2002-07/msg01561.html > > > > > > > > Ahhh, thanks. Not only did it fix that test but it also made > > > > "gcc.dg/sequence-pt-1.c" pass for me which was failing otherwise. > > > > > > > > Unfortunately, It doesn't fix the testcase in Gnats PR 7591 which you > > > > pointed out seems to be caused by -maccumulate-outgoing-args in > > > > combination with -mcpu=i686 > > > > > > I think it is unrelated. Jeff, I think your patch > > > > > > http://gcc.gnu.org/ml/gcc-patches/1999-02n/msg00379.html > > > > > > may be the cause for that bug. The problem is you mark the stack > > > slots being used before they are used by the memcpy libcall: > > > > > > 1. expand_call calls store_one_arg. > > > 2. store_one_arg marks the stack slots used by arg are being used. > > > 3. store_one_arg calls emit_push_insn to push arg. > > > 4. emit_push_insn calls emit_library_call to copy arg onto stack. > > > 5. emit_library_call calls emit_library_call_value_1 to emit memcpy. > > > 6. emit_library_call_value_1 finds the stack slots it is supposed > > > to fill are used. > > > 7. emit_library_call_value_1 does save/restore around memcpy. > > > > > > It doesn't work on x86. > > > > > > > I am testing this patch now. I partially reverted Jeff's patch and > > move setting stack_usage_map just before expand_expr, which is needed > > according to Jeff's orignal message. > > > > Never mind. It doesn't work. I guess we need to find a way only to do > it when it is necessary, like for mn102/mn103. > I am testing this now. H.J.