Date: Sun, 24 Apr 2011 16:03:11 +0200 (CEST) From: Gerald Pfeifer <gerald@pfeifer.com> To: freebsd-toolchain@freebsd.org Subject: x86_64 -profile option patch (fwd) Message-ID: <alpine.LNX.2.00.1104241602140.5419@gerinyyl.fvgr>
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Hi guys,
just wondering whether any of you has input/guidance on the mail
below regarding FreeBSD and profile handing in GCC?
Feel free to let Joseph know directly (cc:ing me), or I'll be
happy to relay back anything.
Gerald
---------- Forwarded message ----------
From: Joseph S. Myers <joseph@codesourcery.com>
To: gcc-patches@gcc.gnu.org
Cc: rth@redhat.com, jh@suse.cz, ubizjak@gmail.com, ljrittle@acm.org
Date: Tue, 15 Feb 2011 01:11:40 +0000 (UTC)
Subject: x86_64 -profile option patch
config/i386/x86-64.h defines CC1_SPEC to handle the -profile option.
This option (link with a profiling version of libc) is OS-specific so
should not be in such an OS-independent spec.
The affected targets (those using this definition) are: x86_64-*-elf*,
x86_64-*-freebsd*, x86_64-*-netbsd*, i[34567]86-*-linux*
--enable-targets=all, x86_64-*-linux* | x86_64-*-kfreebsd*-gnu |
x86_64-*-knetbsd*-gnu, i[34567]86-*-solaris2*. Of these, only the
GNU-userspace targets and FreeBSD generally have any specs handling
-profile, and so only for those targets have I added it to .opt
files. This patch removes the problem CC1_SPEC definition, adding
definitions to i386/freebsd64.h and i386/linux64.h to cover the subset
of affected targets where this definition is actually appropriate.
Bootstrapped with no regressions on x86_64-unknown-linux-gnu. Also
tested building cc1 and xgcc for crosses to: x86_64-elf
x86_64-freebsd8 x86_64-netbsd i686-pc-linux-gnu (--enable-targets=all)
x86_64-kfreebsd-gnu x86_64-knetbsd-gnu i686-solaris2.10. OK to
commit?
A general note on profiling options and their effects:
There are three options for gprof-style function profiling (as opposed
to basic block profiling): -p (profiling with prof), -pg (profiling
with gprof), -profile (profiling with gprof, and link with a profiling
version of libc so that libc functions get profiled as well). The
last option is undocumented and OS-specific (for GNU userspace and
FreeBSD targets).
The only option known to cc1 is -p; the differences between the three
options are only around linking except insofar as other specs
distinguish between them. -pg is unconditionally mapped to -p for cc1
(gcc.c:cc1_options); -profile relies on CC1_SPEC for compile-time
effect (meaning that even for targets where it is nominally supported
there may well be inconsistency depending on what's in CC1_SPEC).
Many specs handle -p and -pg identically; I don't know what targets
relevant to current GCC actually have "prof" so that handling them
differently makes sense, but surely not most of them.
Whether -profile really makes sense for FreeBSD, or whether -profile
specs for FreeBSD should be removed, seems unclear. I added it to
freebsd.opt on the basis of freebsd-spec.h:FBSD_STARTFILE_SPEC;
FBSD_LIB_SPEC doesn't handle it, but links with -lc_p unconditionally
for -pg. I don't know what's in -lc_p on FreeBSD (whether it's just
profiling support code, or whether as with glibc it has profiling
enabled for all the libc functions).
cp/g++spec.c and go/gospec.c know about linking with different
versions of certain libraries (in particular libm) for profiling on
certain targets; for that driver code, profiling means -p or -pg and
-profile is unknown.
(I do not have specific recommendations for cleaning things up in this
area.)
2011-02-14 Joseph Myers <joseph@codesourcery.com>
* config/i386/freebsd64.h (CC1_SPEC): Define.
* config/i386/linux64.h (CC1_SPEC): Define.
* config/i386/x86-64.h (CC1_SPEC): Don't define.
Index: gcc/config/i386/x86-64.h
===================================================================
--- gcc/config/i386/x86-64.h (revision 170150)
+++ gcc/config/i386/x86-64.h (working copy)
@@ -1,5 +1,6 @@
/* OS independent definitions for AMD x86-64.
- Copyright (C) 2001, 2005, 2007, 2009, 2010 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2005, 2007, 2009, 2010, 2011
+ Free Software Foundation, Inc.
Contributed by Bo Thorsen <bo@suse.de>.
This file is part of GCC.
@@ -48,9 +49,6 @@ see the files COPYING3 and COPYING.RUNTI
#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE 32
-#undef CC1_SPEC
-#define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
-
#undef ASM_SPEC
#define ASM_SPEC "%{m32:--32} %{m64:--64}"
Index: gcc/config/i386/freebsd64.h
===================================================================
--- gcc/config/i386/freebsd64.h (revision 170150)
+++ gcc/config/i386/freebsd64.h (working copy)
@@ -1,5 +1,5 @@
/* Definitions for AMD x86-64 running FreeBSD with ELF format
- Copyright (C) 2002, 2004, 2007, 2010 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2004, 2007, 2010, 2011 Free Software Foundation, Inc.
Contributed by David O'Brien <obrien@FreeBSD.org>
This file is part of GCC.
@@ -25,6 +25,9 @@ along with GCC; see the file COPYING3.
#define SUBTARGET_EXTRA_SPECS \
{ "fbsd_dynamic_linker", FBSD_DYNAMIC_LINKER }
+#undef CC1_SPEC
+#define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
+
/* Provide a LINK_SPEC appropriate for the FreeBSD/x86-64 ELF target.
This is a copy of LINK_SPEC from <i386/freebsd.h> tweaked for
the x86-64 target. */
Index: gcc/config/i386/linux64.h
===================================================================
--- gcc/config/i386/linux64.h (revision 170150)
+++ gcc/config/i386/linux64.h (working copy)
@@ -1,5 +1,5 @@
/* Definitions for AMD x86-64 running Linux-based GNU systems with ELF format.
- Copyright (C) 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ Copyright (C) 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Jan Hubicka <jh@suse.cz>, based on linux.h.
@@ -40,6 +40,9 @@ see the files COPYING3 and COPYING.RUNTI
#undef CPP_SPEC
#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
+#undef CC1_SPEC
+#define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
+
/* The svr4 ABI for the i386 says that records and unions are returned
in memory. In the 64bit compilation we will turn this flag off in
ix86_option_override_internal, as we never do pcc_struct_return
--
Joseph S. Myers
joseph@codesourcery.com
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