--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/config/arm/driver-arm.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,165 @@
+/* Subroutines for the gcc driver.
+   Copyright (C) 2011-2017 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"
+#include "coretypes.h"
+#include "tm.h"
+#include "configargs.h"
+
+struct vendor_cpu {
+  const char *part_no;
+  const char *arch_name;
+  const char *cpu_name;
+};
+
+static struct vendor_cpu arm_cpu_table[] = {
+    {"0x926", "armv5te", "arm926ej-s"},
+    {"0xa26", "armv5te", "arm1026ej-s"},
+    {"0xb02", "armv6k", "mpcore"},
+    {"0xb36", "armv6j", "arm1136j-s"},
+    {"0xb56", "armv6t2", "arm1156t2-s"},
+    /* armv6kz is the correct spelling for ARMv6KZ but may not be supported in
+       the version of binutils used.  The incorrect spelling is supported in
+       legacy and current binutils so that is used instead.  */
+    {"0xb76", "armv6zk", "arm1176jz-s"},
+    {"0xc05", "armv7-a", "cortex-a5"},
+    {"0xc07", "armv7ve", "cortex-a7"},
+    {"0xc08", "armv7-a", "cortex-a8"},
+    {"0xc09", "armv7-a", "cortex-a9"},
+    {"0xc0d", "armv7ve", "cortex-a12"},
+    {"0xc0e", "armv7ve", "cortex-a17"},
+    {"0xc0f", "armv7ve", "cortex-a15"},
+    {"0xd01", "armv8-a+crc", "cortex-a32"},
+    {"0xd04", "armv8-a+crc", "cortex-a35"},
+    {"0xd03", "armv8-a+crc", "cortex-a53"},
+    {"0xd07", "armv8-a+crc", "cortex-a57"},
+    {"0xd08", "armv8-a+crc", "cortex-a72"},
+    {"0xd09", "armv8-a+crc", "cortex-a73"},
+    {"0xd05", "armv8.2-a+fp16", "cortex-a55"},
+    {"0xd0a", "armv8.2-a+fp16", "cortex-a75"},
+    {"0xc14", "armv7-r", "cortex-r4"},
+    {"0xc15", "armv7-r", "cortex-r5"},
+    {"0xc17", "armv7-r", "cortex-r7"},
+    {"0xc18", "armv7-r", "cortex-r8"},
+    {"0xd13", "armv8-r+crc", "cortex-r52"},
+    {"0xc20", "armv6-m", "cortex-m0"},
+    {"0xc21", "armv6-m", "cortex-m1"},
+    {"0xc23", "armv7-m", "cortex-m3"},
+    {"0xc24", "armv7e-m", "cortex-m4"},
+    {NULL, NULL, NULL}
+};
+
+static struct {
+  const char *vendor_no;
+  const struct vendor_cpu *vendor_parts;
+} vendors[] = {
+    {"0x41", arm_cpu_table},
+    {NULL, NULL}
+};
+
+/* 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", "cpu" or "tune" as argument depending on if
+   -march=native, -mcpu=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=armv7-a" on a Cortex-A8 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 *val = NULL;
+  char buf[128];
+  FILE *f = NULL;
+  bool arch;
+  const struct vendor_cpu *cpu_table = NULL;
+
+  if (argc < 1)
+    goto not_found;
+
+  arch = strcmp (argv[0], "arch") == 0;
+  if (!arch && strcmp (argv[0], "cpu") != 0 && strcmp (argv[0], "tune"))
+    goto not_found;
+
+  f = fopen ("/proc/cpuinfo", "r");
+  if (f == NULL)
+    goto not_found;
+
+  while (fgets (buf, sizeof (buf), f) != NULL)
+    {
+      /* Ensure that CPU implementer is ARM (0x41).  */
+      if (strncmp (buf, "CPU implementer", sizeof ("CPU implementer") - 1) == 0)
+	{
+	  int i;
+	  for (i = 0; vendors[i].vendor_no != NULL; i++)
+	    if (strstr (buf, vendors[i].vendor_no) != NULL)
+	      {
+		cpu_table = vendors[i].vendor_parts;
+		break;
+	      }
+	}
+
+      /* Detect arch/cpu.  */
+      if (strncmp (buf, "CPU part", sizeof ("CPU part") - 1) == 0)
+	{
+	  int i;
+
+	  if (cpu_table == NULL)
+	    goto not_found;
+
+	  for (i = 0; cpu_table[i].part_no != NULL; i++)
+	    if (strstr (buf, cpu_table[i].part_no) != NULL)
+	      {
+		val = arch ? cpu_table[i].arch_name : cpu_table[i].cpu_name;
+		break;
+	      }
+	  break;
+	}
+    }
+
+  if (val)
+    {
+      fclose (f);
+      return concat ("-m", argv[0], "=", val, NULL);
+     }
+
+not_found:
+  {
+    unsigned int i;
+    unsigned int opt;
+    const char *search[] = {NULL, "arch"};
+
+    if (f)
+      fclose (f);
+
+    search[0] = argv[0];
+    for (opt = 0; opt < ARRAY_SIZE (search); opt++)
+      for (i = 0; i < ARRAY_SIZE (configure_default_options); i++)
+	if (strcmp (configure_default_options[i].name, search[opt]) == 0)
+	  return concat ("-m", search[opt], "=",
+			 configure_default_options[i].value, NULL);
+    return NULL;
+  }
+}