mozglue/build/mips.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 /* compile-time and runtime tests for whether to use MIPS-specific extensions */
   6
   7 #include "mips.h"
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 enum {
  14   MIPS_FLAG_LOONGSON3 = 1,
  15 };
  16
  17 static unsigned get_mips_cpu_flags(void) {
  18   unsigned flags = 0;
  19   FILE* fin;
  20
  21   fin = fopen("/proc/cpuinfo", "r");
  22   if (fin != nullptr) {
  23     char buf[1024];
  24     memset(buf, 0, sizeof(buf));
  25     fread(buf, sizeof(char), sizeof(buf) - 1, fin);
  26     fclose(fin);
  27     if (strstr(buf, "Loongson-3")) flags |= MIPS_FLAG_LOONGSON3;
  28   }
  29   return flags;
  30 }
  31
  32 static bool check_loongson3(void) {
  33   // Cache a local copy so we only have to read /proc/cpuinfo once.
  34   static unsigned mips_cpu_flags = get_mips_cpu_flags();
  35   return (mips_cpu_flags & MIPS_FLAG_LOONGSON3) != 0;
  36 }
  37
  38 namespace mozilla {
  39 namespace mips_private {
  40 bool isLoongson3 = check_loongson3();
  41 }  // namespace mips_private
  42 }  // namespace mozilla