1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 */
17 #include <jni.h>
18 #include <time.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <cpu-features.h>
22 #include "helloneon-intrinsics.h"
23
24 #define DEBUG 0
25
26 #if DEBUG
27 #include <android/log.h>
28 # define D(x...) __android_log_print(ANDROID_LOG_INFO,"helloneon",x)
29 #else
30 # define D(...) do {} while (0)
31 #endif
32
33 /* return current time in milliseconds */
34 static double
now_ms(void)35 now_ms(void)
36 {
37 struct timespec res;
38 clock_gettime(CLOCK_REALTIME, &res);
39 return 1000.0*res.tv_sec + (double)res.tv_nsec/1e6;
40 }
41
42
43 /* this is a FIR filter implemented in C */
44 static void
fir_filter_c(short * output,const short * input,const short * kernel,int width,int kernelSize)45 fir_filter_c(short *output, const short* input, const short* kernel, int width, int kernelSize)
46 {
47 int offset = -kernelSize/2;
48 int nn;
49 for (nn = 0; nn < width; nn++) {
50 int sum = 0;
51 int mm;
52 for (mm = 0; mm < kernelSize; mm++) {
53 sum += kernel[mm]*input[nn+offset+mm];
54 }
55 output[nn] = (short)((sum + 0x8000) >> 16);
56 }
57 }
58
59 #define FIR_KERNEL_SIZE 32
60 #define FIR_OUTPUT_SIZE 2560
61 #define FIR_INPUT_SIZE (FIR_OUTPUT_SIZE + FIR_KERNEL_SIZE)
62 #define FIR_ITERATIONS 600
63
64 static const short fir_kernel[FIR_KERNEL_SIZE] = {
65 0x10, 0x20, 0x40, 0x70, 0x8c, 0xa2, 0xce, 0xf0, 0xe9, 0xce, 0xa2, 0x8c, 070, 0x40, 0x20, 0x10,
66 0x10, 0x20, 0x40, 0x70, 0x8c, 0xa2, 0xce, 0xf0, 0xe9, 0xce, 0xa2, 0x8c, 070, 0x40, 0x20, 0x10 };
67
68 static short fir_output[FIR_OUTPUT_SIZE];
69 static short fir_input_0[FIR_INPUT_SIZE];
70 static const short* fir_input = fir_input_0 + (FIR_KERNEL_SIZE/2);
71 static short fir_output_expected[FIR_OUTPUT_SIZE];
72
73 /* This is a trivial JNI example where we use a native method
74 * to return a new VM String. See the corresponding Java source
75 * file located at:
76 *
77 * apps/samples/hello-neon/project/src/com/example/neon/HelloNeon.java
78 */
79 jstring
Java_com_example_neon_HelloNeon_stringFromJNI(JNIEnv * env,jobject thiz)80 Java_com_example_neon_HelloNeon_stringFromJNI( JNIEnv* env,
81 jobject thiz )
82 {
83 char* str;
84 uint64_t features;
85 char buffer[512];
86 char tryNeon = 0;
87 double t0, t1, time_c, time_neon;
88
89 /* setup FIR input - whatever */
90 {
91 int nn;
92 for (nn = 0; nn < FIR_INPUT_SIZE; nn++) {
93 fir_input_0[nn] = (5*nn) & 255;
94 }
95 fir_filter_c(fir_output_expected, fir_input, fir_kernel, FIR_OUTPUT_SIZE, FIR_KERNEL_SIZE);
96 }
97
98 /* Benchmark small FIR filter loop - C version */
99 t0 = now_ms();
100 {
101 int count = FIR_ITERATIONS;
102 for (; count > 0; count--) {
103 fir_filter_c(fir_output, fir_input, fir_kernel, FIR_OUTPUT_SIZE, FIR_KERNEL_SIZE);
104 }
105 }
106 t1 = now_ms();
107 time_c = t1 - t0;
108
109 asprintf(&str, "FIR Filter benchmark:\nC version : %g ms\n", time_c);
110 strlcpy(buffer, str, sizeof buffer);
111 free(str);
112
113 strlcat(buffer, "Neon version : ", sizeof buffer);
114
115 if (android_getCpuFamily() != ANDROID_CPU_FAMILY_ARM) {
116 strlcat(buffer, "Not an ARM CPU !\n", sizeof buffer);
117 goto EXIT;
118 }
119
120 features = android_getCpuFeatures();
121 if ((features & ANDROID_CPU_ARM_FEATURE_ARMv7) == 0) {
122 strlcat(buffer, "Not an ARMv7 CPU !\n", sizeof buffer);
123 goto EXIT;
124 }
125
126 /* HAVE_NEON is defined in Android.mk ! */
127 #ifdef HAVE_NEON
128 if ((features & ANDROID_CPU_ARM_FEATURE_NEON) == 0) {
129 strlcat(buffer, "CPU doesn't support NEON !\n", sizeof buffer);
130 goto EXIT;
131 }
132
133 /* Benchmark small FIR filter loop - Neon version */
134 t0 = now_ms();
135 {
136 int count = FIR_ITERATIONS;
137 for (; count > 0; count--) {
138 fir_filter_neon_intrinsics(fir_output, fir_input, fir_kernel, FIR_OUTPUT_SIZE, FIR_KERNEL_SIZE);
139 }
140 }
141 t1 = now_ms();
142 time_neon = t1 - t0;
143 asprintf(&str, "%g ms (x%g faster)\n", time_neon, time_c / (time_neon < 1e-6 ? 1. : time_neon));
144 strlcat(buffer, str, sizeof buffer);
145 free(str);
146
147 /* check the result, just in case */
148 {
149 int nn, fails = 0;
150 for (nn = 0; nn < FIR_OUTPUT_SIZE; nn++) {
151 if (fir_output[nn] != fir_output_expected[nn]) {
152 if (++fails < 16)
153 D("neon[%d] = %d expected %d", nn, fir_output[nn], fir_output_expected[nn]);
154 }
155 }
156 D("%d fails\n", fails);
157 }
158 #else /* !HAVE_NEON */
159 strlcat(buffer, "Program not compiled with ARMv7 support !\n", sizeof buffer);
160 #endif /* !HAVE_NEON */
161 EXIT:
162 return (*env)->NewStringUTF(env, buffer);
163 }
164