Re: [MIPS][LS2][5/5] Support for native MIPS GCC

[Maxim Kuvyrkov <maxim at codesourcery dot com>]

Richard Sandiford wrote:
> Maxim Kuvyrkov <maxim@codesourcery.com> writes:
> > This patch adds support for -march=native and -mtune=native options.
> >
> > File driver-st.c contains a routine that checks "cpu model" line in 
> > /proc/cpuinfo and appends a proper option to compiler command line.
> >
> > This patch also specifies layout for Loongson multilibs.
>
> OK, the obvious question here is: should the -march=native support
> be specific to mips*-st*-linux* configurations, or should it apply
> to all mips*-linux* configurations?  I can imagine you discussed
> this internally; if you did, why settle on the former?

The rationale was to avoid testing on all the different MIPSes out there.

> My gut feeling was that -march=native ought to be supported for all
> mips*-linux* configurations, and that mips*-st*-linux* ought simply to
> specify a particular selection of multilibs (and associated multilib
> layout).  Thus driver-st.c would be called something more generic and
> would be included by config/mips/linux.h.  We could then add other
> names to the list as the need arises.

Fixed thusly.

> I think it would be worth adding a comment saying that, if we can't
> detect a known processor, we simply discard the -march or -mtune option.
> This is in contrast to x86, where we force a lowest common demoninator.
> (For the record, I agree the behaviour you've got makes sense.)
>
> You need to document the new option.
>
> The implementation itself looks fine, thanks.

With help of Daniel Jacobowitz I updated the patch to be less 
loongson-specific and provide -march/mtune=native for all processors (at 
the moment, however, only Loongson 2E/2F CPUs can be detected).  Does 
the attached patch look ok to you?


Thanks,

Maxim
2008-06-16  Daniel Jacobowitz  <dan@codesourcery.com>
	    Kazu Hirata  <kazu@codesourcery.com>
	    Maxim Kuvyrkov  <maxim@codesourcery.com

	* config.gcc (mips64el-st-linux-gnu): Use mips/st.h and mips/t-st.
	* config.host: Use driver-native.o and mips/x-native for mips*-linux*.
	* config/mips/linux.h (host_detect_local_cpu): Declare, add to
	EXTRA_SPEC_FUNCTIONS.
	(MARCH_MTUNE_NATIVE_SPECS): New macro.
	(DRIVER_SELF_SPECS): Adjust.
	* config/mips/linux64.h (DRIVER_SELF_SPECS): Update.
	* config/mips/st.h, config/mips/t-st: New.
	* config/mips/driver-native.c, config/mips/x-native: New.

--- gcc/config.gcc	(/local/gcc-4)	(revision 613)
+++ gcc/config.gcc	(/local/gcc-5)	(revision 613)
@@ -1523,6 +1523,12 @@ mips64*-*-linux*)
 	tm_file="dbxelf.h elfos.h svr4.h linux.h ${tm_file} mips/linux.h mips/linux64.h"
 	tmake_file="${tmake_file} mips/t-linux64"
 	tm_defines="${tm_defines} MIPS_ABI_DEFAULT=ABI_N32"
+	case ${target} in
+		mips64el-st-linux-gnu)
+			tm_file="${tm_file} mips/st.h"
+			tmake_file="${tmake_file} mips/t-st"
+			;;
+	esac
 	gnu_ld=yes
 	gas=yes
 	test x$with_llsc != x || with_llsc=yes
--- gcc/config.host	(/local/gcc-4)	(revision 613)
+++ gcc/config.host	(/local/gcc-5)	(revision 613)
@@ -104,6 +104,14 @@ case ${host} in
 	;;
     esac
     ;;
+  mips*-*-linux*)
+    case ${target} in
+      mips*-*-linux*)
+	host_extra_gcc_objs="driver-native.o"
+	host_xmake_file="${host_xmake_file} mips/x-native"
+      ;;
+    esac
+    ;;
 esac
 
 case ${host} in
--- gcc/config/mips/linux.h	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/linux.h	(/local/gcc-5)	(revision 613)
@@ -149,3 +149,23 @@ along with GCC; see the file COPYING3.  
 #else
 #define NO_SHARED_SPECS
 #endif
+
+/* -march=native handling only makes sense with compiler running on
+   a MIPS chip.  */
+#if defined(__mips__)
+extern const char *host_detect_local_cpu (int argc, const char **argv);
+# define EXTRA_SPEC_FUNCTIONS \
+  { "local_cpu_detect", host_detect_local_cpu },
+
+#define MARCH_MTUNE_NATIVE_SPECS				\
+  " %{march=native:%<march=native %:local_cpu_detect(arch)"	\
+  " %{!mtune=*:%<mtune=native %:local_cpu_detect(tune)}}"	\
+  " %{mtune=native:%<mtune=native %:local_cpu_detect(tune)}"
+
+#undef DRIVER_SELF_SPECS
+#define DRIVER_SELF_SPECS			\
+  NO_SHARED_SPECS				\
+  MARCH_MTUNE_NATIVE_SPECS
+#else
+#define MARCH_MTUNE_NATIVE_SPECS
+#endif
--- gcc/config/mips/driver-native.c	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/driver-native.c	(/local/gcc-5)	(revision 613)
@@ -0,0 +1,73 @@
+/* Subroutines for the gcc driver.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+
+/* This will be called by the spec parser in gcc.c when it sees
+   a %:local_cpu_detect(args) construct.  Currently it will be called
+   with either "arch" or "tune" as argument depending on if -march=native
+   or -mtune=native is to be substituted.
+
+   It returns a string containing new command line parameters to be
+   put at the place of the above two options, depending on what CPU
+   this is executed.  E.g. "-march=loongson2f" on a Loongson 2F for
+   -march=native.  If the routine can't detect a known processor,
+   the -march or -mtune option is discarded.
+
+   ARGC and ARGV are set depending on the actual arguments given
+   in the spec.  */
+const char *
+host_detect_local_cpu (int argc, const char **argv)
+{
+  const char *cpu = NULL;
+  char buf[128];
+  FILE *f;
+  bool arch;
+
+  if (argc < 1)
+    return NULL;
+
+  arch = strcmp (argv[0], "arch") == 0;
+  if (!arch && strcmp (argv[0], "tune"))
+    return NULL;
+
+  f = fopen ("/proc/cpuinfo", "r");
+  if (f == NULL)
+    return NULL;
+
+  while (fgets (buf, sizeof (buf), f) != NULL)
+    if (strncmp (buf, "cpu model", sizeof ("cpu model") - 1) == 0)
+      {
+	if (strstr (buf, "Godson2 V0.2") != NULL
+	    || strstr (buf, "Loongson-2 V0.2") != NULL)
+	  cpu = "loongson2e";
+	else if (strstr (buf, "Godson2 V0.3") != NULL
+		 || strstr (buf, "Loongson-2 V0.3") != NULL)
+	  cpu = "loongson2f";
+	break;
+      }
+
+  fclose (f);
+
+  if (cpu == NULL)
+    return NULL;
+
+  return concat ("-m", argv[0], "=", cpu, NULL);
+}
--- gcc/config/mips/t-st	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/t-st	(/local/gcc-5)	(revision 613)
@@ -0,0 +1,14 @@
+MULTILIB_OPTIONS = march=loongson2e/march=loongson2f mabi=n32/mabi=32/mabi=64 
+MULTILIB_DIRNAMES = 2e 2f lib32 lib lib64
+
+MULTILIB_OSDIRNAMES  = march.loongson2e/mabi.n32=../lib32/2e
+MULTILIB_OSDIRNAMES += march.loongson2e/mabi.32=../lib/2e
+MULTILIB_OSDIRNAMES += march.loongson2e/mabi.64=../lib64/2e
+MULTILIB_OSDIRNAMES += march.loongson2f/mabi.n32=../lib32/2f
+MULTILIB_OSDIRNAMES += march.loongson2f/mabi.32=../lib/2f
+MULTILIB_OSDIRNAMES += march.loongson2f/mabi.64=../lib64/2f
+MULTILIB_OSDIRNAMES += mabi.n32=../lib32
+MULTILIB_OSDIRNAMES += mabi.32=../lib
+MULTILIB_OSDIRNAMES += mabi.64=../lib64
+
+EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o crtbeginS.o crtendS.o crtbeginT.o
--- gcc/config/mips/x-native	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/x-native	(/local/gcc-5)	(revision 613)
@@ -0,0 +1,3 @@
+driver-native.o : $(srcdir)/config/mips/driver-native.c \
+  $(CONFIG_H) $(SYSTEM_H)
+	$(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
--- gcc/config/mips/linux64.h	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/linux64.h	(/local/gcc-5)	(revision 613)
@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  
 #undef DRIVER_SELF_SPECS
 #define DRIVER_SELF_SPECS \
 NO_SHARED_SPECS \
+MARCH_MTUNE_NATIVE_SPECS \
 " %{!EB:%{!EL:%(endian_spec)}}" \
 " %{!mabi=*: -mabi=n32}"
 
--- gcc/config/mips/st.h	(/local/gcc-4)	(revision 613)
+++ gcc/config/mips/st.h	(/local/gcc-5)	(revision 613)
@@ -0,0 +1,31 @@
+/* ST 2e / 2f GNU/Linux Configuration.
+   Copyright (C) 2008
+   Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* The various C libraries each have their own subdirectory.  */
+#undef SYSROOT_SUFFIX_SPEC
+#define SYSROOT_SUFFIX_SPEC			\
+  "%{march=loongson2e:/2e ;			\
+     march=loongson2f:/2f}"
+
+#undef STARTFILE_PREFIX_SPEC
+#define STARTFILE_PREFIX_SPEC				\
+  "%{mabi=32: /usr/local/lib/ /lib/ /usr/lib/}		\
+   %{mabi=n32: /usr/local/lib32/ /lib32/ /usr/lib32/}	\
+   %{mabi=64: /usr/local/lib64/ /lib64/ /usr/lib64/}"

Property changes on: 
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Name: svk:merge
  7dca8dba-45c1-47dc-8958-1a7301c5ed47:/local-gcc/md-constraint:113709
  cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-1:597
  cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-2:598
 -cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-3:604
 +cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-3:599
 +cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-4:600
  cd855902-26a6-11dd-a899-33fab5efdf21:/local/gcc-trunk:596
  f367781f-d768-471e-ba66-e306e17dff77:/local/gen-rework-20060122:110130