Re: gcc stop compiling a large stap generated c file

[Alan Modra <amodra at au1 dot ibm dot com>]

It is correct that both ppc32 and ppc64 gcc have a limitiation in the size
of their toc/got sections.  Compiling functions with a large number of
static vars will hit the limit.  Newer versions of gcc provide
-fsection-anchors which can help quite a lot.

Vara Prasad <prasadav@us.ibm.com> wrote on 12/10/2006 00:04:17:

> Looking at the gcc bug explanation from Alan looks like there is a
> limitation on the power platform hence there may not be an immediate fix
> from the compiler/linker side. Alan, please feel free to correct me if i
> am wrong. I guess that leaves us with only option to generate better
> code on our end.
>
> Li Guanglei can you open a bug for this in the bugzilla.
>
> Frank, can we have this bug looked at bit higher than normal priority, I
> think we should definitely fix this before RHEL 5.
>
> Li Guanglei wrote:
>
> > Hi,
> >
> >   I tried:  stap -e 'probe addevent.* {}' -bM -v
> > on ppc64/RHEL4u4/gcc-3.4.6,  and got a lot of errors of "operand out
> > of range".
> >
> >   the generated c file is really big:
> >
> > root:/tmp/stapRl4mJy> ll -h
> > total 7.5M
> > -rw-r--r--  1 root root  128 Oct  9 17:53 Makefile
> > -rw-r--r--  1 root root 6.3M Oct  9 17:53 stap_11644.c
> > -rw-r--r--  1 root root 714K Oct  9 17:53 stap-symbols.h
> > -rw-r--r--  1 root root 527K Oct  9 17:53 symbols.sorted
> >
> >   I searched gcc bugzilla, and found someone reported the same kind of
> > error on gcc 4.1:
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28904
> >
> >   I think it's common for SystemTap to generate a large c file if the
> > number of probes and functions turned on is big. I tried on i386 and
> > it doesn't have this error. Does anyone know if there is any
> > alternative to avoid such error for ppc64?
> >
> >   thanks.
> >
> > - Guanglei
> >
> >------------------------------------------------------------------------
> >
> >Running grep " [tT] " /proc/kallsyms | sort -k 1,8 -s -o
> /tmp/stapRl4mJy/symbols.sorted
> >Pass 3: translated to C into "/tmp/stapRl4mJy/stap_11644.c" in
> 1180usr/200sys/1614real ms.
> >Running make -C "/lib/modules/2.6.17.9/build" M="/tmp/stapRl4mJy"
modules V=1
> >make: Entering directory `/usr/src/linux-2.6.17.9'
> >mkdir -p /tmp/stapRl4mJy/.tmp_versions
> >rm -f /tmp/stapRl4mJy/.tmp_versions/*
> >make -f scripts/Makefile.build obj=/tmp/stapRl4mJy
> >  gcc -m64 -Wp,-MD,/tmp/stapRl4mJy/.stap_11644.o.d  -nostdinc -
> isystem /usr/lib/gcc/ppc64-redhat-linux/3.4.6/include -D__KERNEL__ -
> Iinclude  -include include/linux/autoconf.h  -Wall -Wundef -Wstrict-
> prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Os -
> fomit-frame-pointer -g -msoft-float -pipe -mminimal-toc -
> mtraceback=none  -mcall-aixdesc -mtune=power4 -mno-altivec -funit-
> at-a-time -mstring -Wa,-maltivec -Wdeclaration-after-statement  -
> freorder-blocks -Wno-unused -Werror -
> I"/usr/local/share/systemtap/runtime"   -DMODULE -D"KBUILD_STR(s)
> =#s" -D"KBUILD_BASENAME=KBUILD_STR(stap_11644)"  -
> D"KBUILD_MODNAME=KBUILD_STR(stap_11644)" -c -o /tmp/stapRl4mJy/.
> tmp_stap_11644.o /tmp/stapRl4mJy/stap_11644.c
> >{standard input}: Assembler messages:
> >{standard input}:642879: Error: operand out of range
> (0x0000000000008000 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >{standard input}:642895: Error: operand out of range
> (0x0000000000008008 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >{standard input}:643196: Error: operand out of range
> (0x0000000000008018 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >{standard input}:643197: Error: operand out of range
> (0x0000000000008010 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >{standard input}:643284: Error: operand out of range
> (0x0000000000008020 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >{standard input}:643300: Error: operand out of range
> (0x0000000000008028 is not between 0xffffffffffff8000 and
0x0000000000007fff)
> >...
> >
> >
>
>