mirror of
https://github.com/gcc-mirror/gcc.git
synced 2026-05-06 14:59:39 +02:00
1bac7d31a1
Recently we changed the PROFILE_HOOK _mcount call to pass in the link
register as an argument. This actually does not work when the _mcount
call uses a PLT because the GOT register setup code ends up getting
inserted before the PROFILE_HOOK and clobbers the link register
argument.
These glibc tests are failing:
gmon/tst-gmon-pie-gprof
gmon/tst-gmon-static-gprof
This patch fixes this by saving the instruction that stores the Link
Register to the _mcount argument and then inserts the GOT register setup
instructions after that.
For example:
main.c:
extern int e;
int f2(int a) {
return a + e;
}
int f1(int a) {
return f2 (a + a);
}
int main(int argc, char ** argv) {
return f1 (argc);
}
Compiled:
or1k-smh-linux-gnu-gcc -Wall -c -O2 -fPIC -pg -S main.c
Before Fix:
main:
l.addi r1, r1, -16
l.sw 8(r1), r2
l.sw 0(r1), r16
l.addi r2, r1, 16 # Keeping FP, but not needed
l.sw 4(r1), r18
l.sw 12(r1), r9
l.jal 8 # GOT Setup clobbers r9 (Link Register)
l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_-4)
l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+0)
l.add r16, r16, r9
l.or r18, r3, r3
l.or r3, r9, r9 # This is not the original LR
l.jal plt(_mcount)
l.nop
l.jal plt(f1)
l.or r3, r18, r18
l.lwz r9, 12(r1)
l.lwz r16, 0(r1)
l.lwz r18, 4(r1)
l.lwz r2, 8(r1)
l.jr r9
l.addi r1, r1, 16
After the fix:
main:
l.addi r1, r1, -12
l.sw 0(r1), r16
l.sw 4(r1), r18
l.sw 8(r1), r9
l.or r18, r3, r3
l.or r3, r9, r9 # We now have r9 (LR) set early
l.jal 8 # Clobbers r9 (Link Register)
l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_-4)
l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+0)
l.add r16, r16, r9
l.jal plt(_mcount)
l.nop
l.jal plt(f1)
l.or r3, r18, r18
l.lwz r9, 8(r1)
l.lwz r16, 0(r1)
l.lwz r18, 4(r1)
l.jr r9
l.addi r1, r1, 12
Fixes: 308531d148 ("or1k: Add return address argument to _mcount call")
gcc/ChangeLog:
* config/or1k/or1k-protos.h (or1k_profile_hook): New function.
* config/or1k/or1k.h (PROFILE_HOOK): Change macro to reference
new function or1k_profile_hook.
* config/or1k/or1k.c (struct machine_function): Add new field
set_mcount_arg_insn.
(or1k_profile_hook): New function.
(or1k_init_pic_reg): Update to inject pic rtx after _mcount arg
when profiling.
(or1k_frame_pointer_required): Frame pointer no longer needed
when profiling.
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.