Roll opus to opus-HEAD-66611f1.

third_party/opus/BUILD.gn

Index: third_party/opus/BUILD.gn
diff --git a/third_party/opus/BUILD.gn b/third_party/opus/BUILD.gn
index 2905a4922b30a1a882f4a379c2794ebb642b5932..8f51d09ffd4bd6f8808bf4054fbcb919465b4795 100644
--- a/third_party/opus/BUILD.gn
+++ b/third_party/opus/BUILD.gn
@@ -3,13 +3,20 @@
 # found in the LICENSE file.
 
 import("//build/config/arm.gni")
+import("//build/config/mips.gni")
 
 # If fixed point implementation shall be used (otherwise float).
-use_opus_fixed_point = cpu_arch == "arm" || cpu_arch == "arm64"
+# TODO(wtc): change "mipselx" to "mipsel" in this file when the compilation
+# errors in the MIPS optimizations are fixed.
+use_opus_fixed_point =
+    cpu_arch == "arm" || cpu_arch == "arm64" || cpu_arch == "mipselx"

[wtc, 2015/01/29 00:39:25]

This matches the "FIXED_POINT=1" setting in third_party/opus/src/Makefile.mips

 
 # If ARM optimizations shall be used to accelerate performance.
 use_opus_arm_optimization = cpu_arch == "arm"
 
+# If MIPS optimizations shall be used to accelerate performance.
+use_opus_mips_optimization = cpu_arch == "mipselx"
+
 # If OPUS Run Time CPU Detections (RTCD) shall be used.
 # Based on the conditions in celt/arm/armcpu.c:
 # defined(_MSC_VER) || defined(__linux__).
@@ -135,6 +142,29 @@ source_set("opus") {
       ]
     }
   }
+
+  if (use_opus_mips_optimization) {
+    sources += [
+      "src/celt/mips/celt_mipsr1.h",
+      "src/celt/mips/fixed_generic_mipsr1.h",
+      "src/celt/mips/kiss_fft_mipsr1.h",
+      "src/celt/mips/mdct_mipsr1.h",
+      "src/celt/mips/pitch_mipsr1.h",
+      "src/celt/mips/vq_mipsr1.c",
+      "src/celt/mips/vq_mipsr1.h",
+      "src/silk/fixed/mips/noise_shape_analysis_FIX_mipsr1.h",
+      "src/silk/fixed/mips/prefilter_FIX_mipsr1.h",
+      "src/silk/fixed/mips/warped_autocorrelation_FIX_mipsr1.h",
+      "src/silk/mips/NSQ_del_dec_mipsr1.h",
+      "src/silk/mips/macros_mipsr1.h",
+      "src/silk/mips/sigproc_fix_mipsr1.h",
+    ]
+
+    defines += [
+      "MIPSr1_ASM",
+      "USE_ALLOCA",

[wtc, 2015/01/29 00:39:25]

These two macros match the settings in third_party/opus/src/Makefile.mips.

+    ]
+  }
 }
 
 executable("opus_compare") {