From 178e9a69ae7937f41aba11cc0b9e8efe278e9d3d Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 22 May 2014 00:26:18 -0700
Subject: [PATCH] add stub dsp/enc_avx2.c

VP8EncDspInitAVX2 is included in sse2 builds for now, later a configure
flag should be added to avoid the stub when avx2 is unavailable/disabled

Change-Id: I6127b687c273f46f41652aaf8e3b86ae3cfb8108
---
 Android.mk          |  1 +
 Makefile.vc         |  1 +
 makefile.unix       |  1 +
 src/dsp/Makefile.am | 13 ++++++++++---
 src/dsp/enc.c       |  7 +++++++
 src/dsp/enc_avx2.c  | 24 ++++++++++++++++++++++++
 6 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 src/dsp/enc_avx2.c

diff --git a/Android.mk b/Android.mk
index 1035c3e2..36808db3 100644
--- a/Android.mk
+++ b/Android.mk
@@ -39,6 +39,7 @@ LOCAL_SRC_FILES := \
     src/dsp/dec_neon.$(NEON) \
     src/dsp/dec_sse2.c \
     src/dsp/enc.c \
+    src/dsp/enc_avx2.c \
     src/dsp/enc_mips32.c \
     src/dsp/enc_neon.$(NEON) \
     src/dsp/enc_sse2.c \
diff --git a/Makefile.vc b/Makefile.vc
index 7a70e9f8..760bc91c 100644
--- a/Makefile.vc
+++ b/Makefile.vc
@@ -184,6 +184,7 @@ DSP_DEC_OBJS = \
 
 DSP_ENC_OBJS = \
     $(DIROBJ)\dsp\enc.obj \
+    $(DIROBJ)\dsp\enc_avx2.obj \
     $(DIROBJ)\dsp\enc_mips32.obj \
     $(DIROBJ)\dsp\enc_neon.obj \
     $(DIROBJ)\dsp\enc_sse2.obj \
diff --git a/makefile.unix b/makefile.unix
index 17b1d451..8b413900 100644
--- a/makefile.unix
+++ b/makefile.unix
@@ -119,6 +119,7 @@ DSP_DEC_OBJS = \
 
 DSP_ENC_OBJS = \
     src/dsp/enc.o \
+    src/dsp/enc_avx2.o \
     src/dsp/enc_mips32.o \
     src/dsp/enc_neon.o \
     src/dsp/enc_sse2.o \
diff --git a/src/dsp/Makefile.am b/src/dsp/Makefile.am
index 24fb75d7..b6de081b 100644
--- a/src/dsp/Makefile.am
+++ b/src/dsp/Makefile.am
@@ -1,5 +1,5 @@
 AM_CPPFLAGS = -I$(top_srcdir)/src
-noinst_LTLIBRARIES = libwebpdsp.la
+noinst_LTLIBRARIES = libwebpdsp.la libwebpdsp_avx2.la
 
 if BUILD_LIBWEBPDECODER
   noinst_LTLIBRARIES += libwebpdspdecode.la
@@ -35,18 +35,25 @@ ENC_SOURCES += enc_mips32.c
 ENC_SOURCES += enc_neon.c
 ENC_SOURCES += enc_sse2.c
 
+libwebpdsp_avx2_la_SOURCES =
+libwebpdsp_avx2_la_SOURCES += enc_avx2.c
+libwebpdsp_avx2_la_CPPFLAGS = $(libwebpdsp_la_CPPFLAGS)
+libwebpdsp_avx2_la_CFLAGS = $(AM_CFLAGS) $(AVX2_FLAGS)
+
 libwebpdsp_la_SOURCES = $(COMMON_SOURCES) $(ENC_SOURCES)
 
 noinst_HEADERS =
 noinst_HEADERS += ../dec/decode_vp8.h
 noinst_HEADERS += ../webp/decode.h
 
-libwebpdsp_la_LDFLAGS = -lm
 libwebpdsp_la_CPPFLAGS = $(USE_EXPERIMENTAL_CODE) $(USE_SWAP_16BIT_CSP)
+libwebpdsp_la_LDFLAGS = -lm
+libwebpdsp_la_LIBADD = libwebpdsp_avx2.la
 
 if BUILD_LIBWEBPDECODER
   libwebpdspdecode_la_SOURCES = $(COMMON_SOURCES)
 
-  libwebpdspdecode_la_LDFLAGS = $(libwebpdsp_la_LDFLAGS)
   libwebpdspdecode_la_CPPFLAGS = $(libwebpdsp_la_CPPFLAGS)
+  libwebpdspdecode_la_LDFLAGS = $(libwebpdsp_la_LDFLAGS)
+  libwebpdspdecode_la_LIBADD = libwebpdsp_avx2.la
 endif
diff --git a/src/dsp/enc.c b/src/dsp/enc.c
index 66f3a6a9..d9b25904 100644
--- a/src/dsp/enc.c
+++ b/src/dsp/enc.c
@@ -688,6 +688,7 @@ VP8QuantizeBlockWHT VP8EncQuantizeBlockWHT;
 VP8BlockCopy VP8Copy4x4;
 
 extern void VP8EncDspInitSSE2(void);
+extern void VP8EncDspInitAVX2(void);
 extern void VP8EncDspInitNEON(void);
 extern void VP8EncDspInitMIPS32(void);
 
@@ -719,6 +720,12 @@ void VP8EncDspInit(void) {
     if (VP8GetCPUInfo(kSSE2)) {
       VP8EncDspInitSSE2();
     }
+    // TODO(jzern): this should be conditionally included based on a configure
+    // (HAVE_AVX2) define. We can't use WEBP_USE_AVX2/__AVX2__ here as -mavx2
+    // won't be defined for this file.
+    if (VP8GetCPUInfo(kAVX2)) {
+      VP8EncDspInitAVX2();
+    }
 #elif defined(WEBP_USE_NEON)
     if (VP8GetCPUInfo(kNEON)) {
       VP8EncDspInitNEON();
diff --git a/src/dsp/enc_avx2.c b/src/dsp/enc_avx2.c
new file mode 100644
index 00000000..372e6169
--- /dev/null
+++ b/src/dsp/enc_avx2.c
@@ -0,0 +1,24 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// AVX2 version of speed-critical encoding functions.
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_AVX2)
+
+#endif  // WEBP_USE_AVX2
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8EncDspInitAVX2(void);
+
+void VP8EncDspInitAVX2(void) {
+}