From: hkuang <hkuang@google.com>
Date: Fri, 16 Aug 2013 17:54:56 +0000 (-0700)
Subject: Reduce instructions of idct4x4.
X-Git-Tag: v1.3.0~590^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=df0715204cccc9d9652bf43eb6fc164cca6a0fe4;p=libvpx

Reduce instructions of idct4x4.

Change-Id: Ia26a2526804e7e2f656b0051618a615fca8fc79d
---

diff --git a/vp9/common/arm/neon/vp9_short_idct4x4_add_neon.asm b/vp9/common/arm/neon/vp9_short_idct4x4_add_neon.asm
index 433032237..adc17fc97 100644
--- a/vp9/common/arm/neon/vp9_short_idct4x4_add_neon.asm
+++ b/vp9/common/arm/neon/vp9_short_idct4x4_add_neon.asm
@@ -81,17 +81,15 @@
     ; input[1] * cospi_24_64 - input[3] * cospi_8_64;
     ; input[1] * cospi_8_64  + input[3] * cospi_24_64;
     vmull.s16 q15, d17, d22
-    vmull.s16 q0,  d19, d20
     vmull.s16 q1,  d17, d20
-    vmull.s16 q2,  d19, d22
-    vsub.s32  q3,  q15, q0
-    vadd.s32  q8,  q1,  q2
+    vmlsl.s16 q15, d19, d20
+    vmlal.s16 q1,  d19, d22
 
     ; dct_const_round_shift
     vqrshrn.s32 d26, q13, #14
     vqrshrn.s32 d27, q14, #14
-    vqrshrn.s32 d29, q3,  #14
-    vqrshrn.s32 d28, q8,  #14
+    vqrshrn.s32 d29, q15, #14
+    vqrshrn.s32 d28, q1,  #14
 
     ; stage 2
     ; output[0] = step[0] + step[3];
@@ -132,17 +130,15 @@
     ; input[1] * cospi_24_64 - input[3] * cospi_8_64;
     ; input[1] * cospi_8_64  + input[3] * cospi_24_64;
     vmull.s16 q15, d17, d22
-    vmull.s16 q0,  d19, d20
     vmull.s16 q1,  d17, d20
-    vmull.s16 q2,  d19, d22
-    vsub.s32  q3,  q15, q0
-    vadd.s32  q8,  q1,  q2
+    vmlsl.s16 q15, d19, d20
+    vmlal.s16 q1,  d19, d22
 
     ; dct_const_round_shift
     vqrshrn.s32 d26, q13, #14
     vqrshrn.s32 d27, q14, #14
-    vqrshrn.s32 d29, q3,  #14
-    vqrshrn.s32 d28, q8,  #14
+    vqrshrn.s32 d29, q15, #14
+    vqrshrn.s32 d28, q1,  #14
 
     ; stage 2
     ; output[0] = step[0] + step[3];