Bug 12538

Summary:	%l7 is call-clobbered with -mflat -fpic
Product:	gcc	Reporter:	Fergus Henderson <fjh>
Component:	target	Assignee:	Eric Botcazou <ebotcazou>
Status:	RESOLVED FIXED
Severity:	normal	CC:	gcc-bugs
Priority:	P2
Version:	3.3.1
Target Milestone:	3.4.0
Host:	sparc-sun-solaris2.8	Target:	sparc-sun-solaris2.8
Build:	sparc-sun-solaris2.8	Known to work:
Known to fail:		Last reconfirmed:	2003-10-09 07:40:47
Attachments:	test case part 1 test case part 2: x.c test case part 3: y.c

Description Fergus Henderson 2003-10-08 09:38:24 UTC

The attached source files demonstrate a bug with gcc-2.95.1 and gcc 3.2
on SPARCs.
The bug is that if you compile one file with no special options
(or with just `-mflat', or just `-fpic', but not both), and
another file with `-mflat -fpic', and link the two together, then in
the file compiled with no special options it treats register l7 as
a callee-save register, but in the file compiled with `-mflat -fpic'
it clobbers register l7 without saving it.

The attached program should output "1,2,3,4,5,6,7,8,9,10",
but on my system the program gets a Segmentation Fault instead.

Comment 1 Fergus Henderson 2003-10-08 09:40:55 UTC

Created attachment 4898 [details]
test case part 1

Comment 2 Fergus Henderson 2003-10-08 09:42:06 UTC

Created attachment 4899 [details]
test case part 2: x.c

Comment 3 Fergus Henderson 2003-10-08 09:42:40 UTC

Created attachment 4900 [details]
test case part 3: y.c

Comment 4 Andrew Pinski 2003-10-08 15:29:13 UTC

Can you try 3.3.1 as 3.2 is old?

Comment 5 Eric Botcazou 2003-10-09 07:40:47 UTC

Confirmed with all GCC versions I tested.

Comment 6 CVS Commits 2003-10-13 09:57:57 UTC

Subject: Bug 12538

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	ebotcazou@gcc.gnu.org	2003-10-13 09:57:53

Modified files:
	gcc            : ChangeLog 
	gcc/config/sparc: sparc.c 

Log message:
	PR target/12538
	* config/sparc/sparc.c (MUST_SAVE_REGISTER): Delete.
	(sparc_flat_must_save_register_p): New function to decide whether
	a register must be saved/restored in the function prologue/epilogue.
	(sparc_flat_compute_frame_size): Use it instead of MUST_SAVE_REGISTER.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.1398&r2=2.1399
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/sparc/sparc.c.diff?cvsroot=gcc&r1=1.263&r2=1.264

Comment 7 Eric Botcazou 2003-10-13 10:01:47 UTC

Fixed for GCC 3.4, see http://gcc.gnu.org/ml/gcc-patches/2003-10/msg00889.html