Add the mips_dsp_rev build variable.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 55dad682914fad01bb2479694cc3e2a5c37d3069..d73e84c053e9954d53016ca5f431e0f3f089f677 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -184,6 +184,12 @@
         # below for MIPS targets.
         'mips_arch_variant%': '',
 
+        # MIPS DSP ASE revision. Possible values are:
+        #   0: unavailable
+        #   1: revision 1
+        #   2: revision 2
+        'mips_dsp_rev%': 0,
+
         'conditions': [
           # Ash needs Aura.
           ['use_aura==0', {
@@ -276,6 +282,7 @@
       'target_arch%': '<(target_arch)',
       'target_subarch%': '<(target_subarch)',
       'mips_arch_variant%': '<(mips_arch_variant)',
+      'mips_dsp_rev%': '<(mips_dsp_rev)',
       'toolkit_views%': '<(toolkit_views)',
       'desktop_linux%': '<(desktop_linux)',
       'use_aura%': '<(use_aura)',
@@ -1062,6 +1069,7 @@
     'target_arch%': '<(target_arch)',
     'target_subarch%': '<(target_subarch)',
     'mips_arch_variant%': '<(mips_arch_variant)',
+    'mips_dsp_rev%': '<(mips_dsp_rev)',
     'host_arch%': '<(host_arch)',
     'toolkit_views%': '<(toolkit_views)',
     'ui_compositor_image_transport%': '<(ui_compositor_image_transport)',
@@ -2282,6 +2290,9 @@
       ['target_arch=="mipsel" and mips_arch_variant=="r2" and android_webview_build==0', {

[wtc, 2015/02/24 21:26:30]

Petar: for mips_fpu_mode, is it correct to check for mips_arch_variant=="r2"?

[petarj, 2015/02/26 01:35:43]

Yes, that seems correct.

         'mips_fpu_mode%': 'fp32',
       }],
+      ['target_arch=="mipsel" and mips_arch_variant!="r6" and android_webview_build==0', {

[petarj, 2015/02/24 18:49:14]

'hard' should be default mips_float_abi, we should not check for
mips_arch_variant here.
Further, this change could/should be applicable for MIPS64 as well, though
MIPS64 part does not necessary need to be included in this change (we can add it
later).
Any webRTC specific changes should go into webRTC gypi/gni files.

[wtc, 2015/02/24 21:26:30]

Done.

Could you please take a look at the companion WebRTC CL and see if the
mips_arch_variant!="r6" checks in it should be removed?

[petarj, 2015/02/26 01:35:43]

I did, and that part should remain in WebRTC build files, since it
excludes some optimizations changes that are not applicable for MIPS32R6
variants.

+        'mips_float_abi%': 'hard',
+      }],
 
       ['android_webview_build==1', {
         # The WebView build gets its cpu-specific flags from the Android build system.
@@ -2291,6 +2302,7 @@
         'arm_float_abi%': '',
         'arm_thumb%': 0,
         'mips_fpu_mode%': '',
+        'mips_float_abi%': '',
       }],
 
       # Enable brlapi by default for chromeos.
@@ -4030,20 +4042,43 @@
             'target_conditions': [
               ['_toolset=="target"', {
                 'conditions': [
-                  ['android_webview_build==0 and mips_arch_variant=="r6"', {
-                    'cflags': ['-mips32r6', '-Wa,-mips32r6'],
+                  ['android_webview_build==0', {
                     'conditions': [
-                      ['OS=="android"', {
-                        'ldflags': ['-mips32r6', '-Wl,-melf32ltsmip',],
+                      ['mips_arch_variant=="r6"', {
+                        'cflags': ['-mips32r6', '-Wa,-mips32r6'],
+                        'conditions': [
+                          ['OS=="android"', {
+                            'ldflags': ['-mips32r6', '-Wl,-melf32ltsmip',],
+                          }],
+                        ],
+                      }, { # mips_arch_variant!="r6"
+                        'cflags': ['-m<(mips_float_abi)-float'],

[wtc, 2015/02/23 20:15:51]

Here I imitate the arm_float_abi code and use variable substitution. Would you
prefer that I use a conditions block and spell out '-mhard-float' and
'-msoft-float' in the two cases? I think it will allow people to search for
these flags by name.

[petarj, 2015/02/24 18:49:14]

mips_float_abi should not be interlinked with mips_arch_variant

[wtc, 2015/02/24 21:26:30]

Done.

+                      }],
+                      ['mips_arch_variant=="r2"', {
+                        'conditions': [
+                          ['mips_fpu_mode=="fp32"', {
+                            'cflags': ['-mfp32'],
+                          }],
+                          ['mips_fpu_mode=="fp64"', {
+                            'cflags': ['-mfp64'],
+                          }],
+                          ['mips_fpu_mode=="fpxx"', {
+                            'cflags': ['-mfpxx'],
+                          }],
+                        ],
+                        'cflags': ['-mips32r2', '-Wa,-mips32r2'],
+                      }],
+                      ['mips_arch_variant=="r1"', {
+                        'cflags': ['-mips32', '-Wa,-mips32'],
+                      }],
+                      ['mips_dsp_rev==1', {
+                        'cflags': ['-mdsp'],
+                      }],
+                      ['mips_dsp_rev==2', {
+                        'cflags': ['-mdspr2'],
                       }],
                     ],
                   }],
-                  ['android_webview_build==0 and mips_arch_variant=="r2"', {
-                    'cflags': ['-mips32r2', '-Wa,-mips32r2'],
-                  }],
-                  ['android_webview_build==0 and mips_arch_variant=="r1"', {
-                    'cflags': ['-mips32', '-Wa,-mips32'],
-                  }],
                 ],
                 'ldflags': [
                   '-Wl,--no-keep-memory'