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 */
34static double
35now_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 */
44static void
45fir_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
64static 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
68static short        fir_output[FIR_OUTPUT_SIZE];
69static short        fir_input_0[FIR_INPUT_SIZE];
70static const short* fir_input = fir_input_0 + (FIR_KERNEL_SIZE/2);
71static 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 */
79jstring
80Java_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 */
161EXIT:
162    return (*env)->NewStringUTF(env, buffer);
163}
164