Add Aarch64 intrinsics for saturated add/subtract.

Signed-off-by: Timothy B. Terriberry <tterribe@xiph.org>

silk/arm/macros_arm64.h

+/***********************************************************************
+Copyright (C) 2015 Vidyo
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifndef SILK_MACROS_ARM64_H
+#define SILK_MACROS_ARM64_H
+
+#include <arm_neon.h>
+
+#undef silk_ADD_SAT32
+#define silk_ADD_SAT32(a, b) (vqadds_s32((a), (b)))
+
+#undef silk_SUB_SAT32
+#define silk_SUB_SAT32(a, b) (vqsubs_s32((a), (b)))
+
+#endif /* SILK_MACROS_ARM64_H */

silk/macros.h

@@ -151,5 +151,9 @@ static OPUS_INLINE opus_int32 silk_CLZ32(opus_int32 in32)
 #include "arm/macros_armv5e.h"
 #endif
 
+#ifdef OPUS_ARM_PRESUME_AARCH64_NEON_INTR
+#include "arm/macros_arm64.h"
+#endif
+
 #endif /* SILK_MACROS_H */
 

silk_headers.mk

@@ -24,6 +24,7 @@ silk/SigProc_FIX.h \
 silk/x86/SigProc_FIX_sse.h \
 silk/arm/macros_armv4.h \
 silk/arm/macros_armv5e.h \
+silk/arm/macros_arm64.h \
 silk/arm/SigProc_FIX_armv4.h \
 silk/arm/SigProc_FIX_armv5e.h \
 silk/arm/NSQ_neon.h \