MIPS64: Add big-endian support for mips64.

build/toolchain.gypi

 # Copyright 2013 the V8 project authors. All rights reserved.
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 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
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 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
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@@ skipping 323 matching lines @@
           'V8_TARGET_ARCH_IA32',
         ],
       }],  # v8_target_arch=="ia32"
       ['v8_target_arch=="x87"', {
         'defines': [
           'V8_TARGET_ARCH_X87',
         ],
         'cflags': ['-march=i586'],
       }],  # v8_target_arch=="x87"
       ['(v8_target_arch=="mips" or v8_target_arch=="mipsel" \
         or v8_target_arch=="mips64el") and v8_target_arch==target_arch', {

[paul.l..., 2015/09/15 00:06:41]

Please add 'or v8_target_arch=="mips64"' clause here. We are not getting the
r-path and ldso-path set properly.

[dusan.milosavljevic, 2015/09/15 12:58:09]

Done.

         'target_conditions': [
           ['_toolset=="target"', {
             # Target built with a Mips CXX compiler.
             'variables': {
               'ldso_path%': '<!(/bin/echo -n $LDSO_PATH)',
               'ld_r_path%': '<!(/bin/echo -n $LD_R_PATH)',
             },
             'conditions': [
               ['ldso_path!=""', {
                 'ldflags': ['-Wl,--dynamic-linker=<(ldso_path)'],
@@ skipping 381 matching lines @@
               ['mips_arch_variant=="loongson"', {
                 'defines': [
                   '_MIPS_ARCH_LOONGSON',
                   'FPU_MODE_FP32',
                 ],
               }],
             ]
           }],
         ],
       }],  # v8_target_arch=="mipsel"
-      ['v8_target_arch=="mips64el"', {
+      ['v8_target_arch=="mips64el" or v8_target_arch=="mips64"', {
         'defines': [
           'V8_TARGET_ARCH_MIPS64',
         ],
         'conditions': [
           [ 'v8_can_use_fpu_instructions=="true"', {
             'defines': [
               'CAN_USE_FPU_INSTRUCTIONS',
             ],
           }],
+          [ 'v8_host_byteorder=="little"', {
+            'defines': [
+              'V8_TARGET_ARCH_MIPS64_LE',

[paul.l..., 2015/09/15 00:06:41]

Per MIPS conventions, this should probably be called V8_TARGET_ARCH_MIPS64_EL.

Also, this defintion does not appear to be used, so maybe unnecessary?

[dusan.milosavljevic, 2015/09/15 12:58:09]

Not based on MIPS convention, I used these names to be consistent with other
ports (ppc).

+            ],
+          }],
+          [ 'v8_host_byteorder=="big"', {
+            'defines': [
+              'V8_TARGET_ARCH_MIPS64_BE',

[paul.l..., 2015/09/15 00:06:41]

Should be  ..._EB, as above. While you use this in build_config.h, I don't
understand the reason why. Maybe you can elaborate on the comment in that file.

[dusan.milosavljevic, 2015/09/15 12:58:09]

This is used to detect host byte-order in addition to detection of target
toolchain flags. This enables correct build on be hosts.

+            ],
+          }],
           [ 'v8_use_mips_abi_hardfloat=="true"', {
             'defines': [
               '__mips_hard_float=1',
               'CAN_USE_FPU_INSTRUCTIONS',
             ],
           }, {
             'defines': [
               '__mips_soft_float=1'
             ],
           }],
          ],
         'target_conditions': [
           ['_toolset=="target"', {
             'conditions': [
               ['v8_target_arch==target_arch', {
                 'cflags': [
-                  '-EL',
                   '-Wno-error=array-bounds',  # Workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273
                 ],
-                'ldflags': ['-EL'],
                 'conditions': [
+                  ['v8_target_arch=="mips64el"', {
+                    'cflags': ['-EL'],
+                    'ldflags': ['-EL'],
+                  }],
+                  ['v8_target_arch=="mips64"', {
+                    'cflags': ['-EB'],
+                    'ldflags': ['-EB'],
+                  }],
                   [ 'v8_use_mips_abi_hardfloat=="true"', {
                     'cflags': ['-mhard-float'],
                     'ldflags': ['-mhard-float'],
                   }, {
                     'cflags': ['-msoft-float'],
                     'ldflags': ['-msoft-float'],
                   }],
                   ['mips_arch_variant=="r6"', {
                     'defines': ['_MIPS_ARCH_MIPS64R6',],
                     'cflags': ['-mips64r6', '-mabi=64', '-Wa,-mips64r6'],
@@ skipping 469 matching lines @@
           ['v8_enable_slow_dchecks==1', {
             'defines': [
               'ENABLE_SLOW_DCHECKS',
             ],
           }],
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }