第5章 CPU 性能验证
5.1 性能验证数学模型及算法程序 
本实验采用的数学模式如下:a、b、c、d分别为4个数组,它们的取值公式由下面的示
例给出,现要求求得c、d数组中各个数字的值,并依次将其输出。
a[m],b[m],c[m],d[m]; 
a[0]=0.0; 
b[0]=1.0; 
a[i]=a[i-1]+i; 
b[i]=b[i-1]+3i; 
c[i]= 
a[i], 0≤i≤9 
a[i]+b[i], 10≤i≤29 
(a[i]*b[i]).1, 30≤i≤49 
ì
.
í
.. 
.. 
d[i]= 
b[i]+c[i], 0≤i≤9 
a[i]*c[i], 10≤i≤29 
c[i]*b[i]/(d[i-1].1), 30≤i≤49 
ì
.
í
.. 
.. 
C语言示例代码如图5.1所示。 
#include "../include/minicrt.h" 
#include "../include/system.h" 
#include "../include/gpio.h" 
int kk =5; 
static unsigned int gpio_data =0; 
static unsigned int gpio_tri =0; 
int a[50],b[50],c[50],d[50]; 
int i; 
void test_app() 
{ 
for(i =0;i<=49;i++) 
{ 
if(i ==0) 
{ 
a[i]=0; 
b[i]=1; 
c[i]=a[i]; 
d[i]=b[i]+c[i];
图5.1 C语言具体实现

50 
} 
else{ 
a[i]=a[i-1]+i; 
b[i]=b[i-1]+3*i; 
if(i<=9) 
{ 
c[i]=a[i]; 
d[i]=b[i]+c[i]; 
} 
else if(i<=29) 
{ 
c[i]=a[i]+b[i]; 
d[i]=a[i]*c[i]; 
} 
else 
{ 
c[i]= ((a[i]*b[i])) <<1; 
d[i]=c[i]*b[i]/((d[i-1])>>1); 
} 
} 
} 
}
//设置gpio 是输出还是输入
void set_gpio_tri(unsigned int value,bool is_input){ 
unsigned int* gpio_tri_addr = GPIO_TRI_ADDR; 
if(is_input ==true){ 
//这个设计的目的是保证其他位的值不变 
//例如设置第1 位为输入,is_input = true,value = 0x0000 0001; 
*gpio_tri_addr = gpio_tri | value; 
} else{ 
//这个设计的目的是保证其他位的值不变 
//例如设置第1 位为输出,is_input = false,value = 0xffff fffe; 
*gpio_tri_addr = gpio_tri & value; 
} 
}
void write_gpio(void){ 
unsigned int* gpio_data_addr = GPIO_DATA_ADDR; 
*gpio_data_addr = gpio_data; 
}
void digital_led(int id,int digital_num){ 
unsigned int seg =0; 
switch(digital_num){ 
case 0: seg =0x03;break; //0000 0011 
case 1: seg =0x9f;break; //1001 1111 
图5.1 (续)

51 
case 2: seg =0x25;break; //0010 0101 
case 3: seg =0x0d;break; //0000 1101 
case 4: seg =0x99;break; //1001 1001 
case 5: seg =0x49;break; //0100 1001 
case 6: seg =0x41;break; //0100 0001 
case 7: seg =0x1f;break; //0001 1111 
case 8: seg =0x01;break; //0000 0001 
case 9: seg =0x09;break; //0000 1001 
case 10: seg =0x11;break; //0001 0001 
default: seg =0x00; 
} 
switch(id){ 
case 0: seg =0xfe00| seg;break; //1111 1110 fe 
case 1: seg =0xfd00| seg;break; //1111 1101 fd 
case 2: seg =0xfb00| (seg&0xfe);break; //1111 1011 fb 
case 3: seg =0xf700| seg;break; //1111 0111 f7 
case 4: seg =0xef00| seg;break; //1110 1111 ef 
case 5: seg =0xdf00| seg;break; //1101 1111 df 
case 6: seg =0xbf00| seg;break; //1011 1111 bf 
case 7: seg =0x7f00| seg;break; //0111 1111 7f 
default: seg =0x00; 
} 
gpio_data = gpio_data & 0xffff0000; 
gpio_data = gpio_data | seg; 
write_gpio(); 
}
int main() 
{ 
set_gpio_tri(0xffff0000,false); 
int send,oldsend; 
int cal_time; 
send =get_seconds(); 
oldsend = send; 
while(1) 
{ 
cal_time =0; 
send =get_seconds(); 
while(send == oldsend) 
{ 
send =get_seconds(); 
test_app(); 
cal_time++; 
} 
oldsend = send; 
for(i=0;i<8;i++) 
{ 
图5.1 (续)

52 
digital_led(i,cal_time%10); 
udelay(2000); 
cal_time = cal_time/10; 
} 
} 
return0; 
} 
图5.1 (续) 
汇编语言示例代码如下,注释供参考。 
.text 
.align 2 
.globl main 
.set nomips16 
.set nomicromips 
j main 
exc: 
nop 
j exc 
main: 
addi $t1,$0,0 #$t1 = a[0]= 0 
addi $t2,$0,1 #$t2 = b[0]= 1 
addi $t5,$0,0 #init $t5 = i = 0 
addi $t3,$t1,0 #$t3 = c[0]= a[0] 
addi $t4,$t2,1 #$t4 = d[0]= b[0] 
addi $t6,$0,10 #$t6 = 20 = 结束条件1 
addi $t7,$0,30 #$t7 = 40 = 结束条件2 
addi $t8,$0,50 #$t8 = 60 = 结束条件3 
loop: 
addi $t5,$t5,1 #i = i + 1 
add $t1,$t1,$t5 #a[i]= a[i-1]+ i 
add $t2,$t2,$t5 
add $t2,$t2,$t5 
add $t2,$t2,$t5 #b[i]= b[i-1]+ 3i 
less_than_9: 
bge $t5,$t6,less_than_29 #if(i >= 20) jump 
addi $t3,$t1,0 #c[i]= a[i]+ 0 
addi $t4,$t2,0 #d[i]= b[i]+ 0 
j loop 
less_than_29: 
bge $t5,$t7,less_than_49 #if(i == 40) jump 
add $t3,$t1,$t2 #c[i]= a[i]+b[i] 
mul $t4,$t1,$t3 #d[i]= a[i]*c[i]

53 
j loop 
less_than_49: 
beq $t5,$t8,exc #if(i == 60) jump 
mul $t3,$t1,$t2 #c[i]= a[i]*b[i] 
sll $t3,$t3,1 #c[i]= c[i]<< 1 
mul $t9,$t3,$t2 #tmp = c[i]*b[i] 
sra $t4,$t4,1 #d[i-1]= d[i-1]>>1 
div $t4,$t9,$t4 #d[i]= tmp/d[i-1] 
j loop 
5.2 性能验证程序下板测试过程与实现
5.2.1 下板过程 
(1)编译C语言程序为目标程序。
打开cmd窗口,进入toolchain文件夹下的build目录下,然后使用makeclean & 
make命令编译成bin文件。编译过程如图5.2所示。
图5.2 cmd窗口运行结果

(2)进行synthesis(综合)以及implementation(布线)然后生成bit流。
(3)将tes.in文件烧入开发板的fla如图5.
tbsh中,3所示。


图5.in文件烧入开发板中

3 将b

(4)将FPGA 程序烧入开发板中运行,4所示。
结果如图5.


图5.

4 开发板下板结
果
可以看到该程序每秒运行的次数
。


5.2 
程序性能分析
2.
查看此C语言程序中性能测试函数的汇编代码,查看运行一次该函数大概要运行多

54 

55 
少次定点运算。
机器代码如下。 
bfc00490 <test_app>: 
bfc00490: 27bdfff8 addiu sp,sp,-8 
bfc00494: afbe0004 sw s8,4(sp) 
bfc00498: 03a0f025 move s8,sp 
bfc0049c: 3c02c000 lui v0,0xc000 
bfc004a0: ac400158 sw zero,344(v0) 
bfc004a4: 10000101 b bfc008ac <test_app+0x41c> 
bfc004a8: 00000000 nop 
bfc004ac: 3c02c000 lui v0,0xc000 
bfc004b0: 8c420158 lw v0,344(v0) 
bfc004b4: 14400036 bnez v0,bfc00590 <test_app+0x100> 
bfc004b8: 00000000 nop 
bfc004bc: 3c02c000 lui v0,0xc000 
bfc004c0: 8c430158 lw v1,344(v0) 
bfc004c4: 3c02c000 lui v0,0xc000 
bfc004c8: 00031880 sll v1,v1,0x2 
bfc004cc: 244202ec addiu v0,v0,748 
bfc004d0: 00621021 addu v0,v1,v0 
bfc004d4: ac400000 sw zero,0(v0) 
bfc004d8: 3c02c000 lui v0,0xc000 
bfc004dc: 8c430158 lw v1,344(v0) 
bfc004e0: 3c02c000 lui v0,0xc000 
bfc004e4: 00031880 sll v1,v1,0x2 
bfc004e8: 24420090 addiu v0,v0,144 
bfc004ec: 00621021 addu v0,v1,v0 
bfc004f0: 24030001 li v1,1 
bfc004f4: ac430000 sw v1,0(v0) 
bfc004f8: 3c02c000 lui v0,0xc000 
bfc004fc: 8c440158 lw a0,344(v0) 
bfc00500: 3c02c000 lui v0,0xc000 
bfc00504: 8c430158 lw v1,344(v0) 
bfc00508: 3c02c000 lui v0,0xc000 
bfc0050c: 00031880 sll v1,v1,0x2 
bfc00510: 244202ec addiu v0,v0,748 
bfc00514: 00621021 addu v0,v1,v0 
bfc00518: 8c430000 lw v1,0(v0) 
bfc0051c: 3c02c000 lui v0,0xc000 
bfc00520: 00042080 sll a0,a0,0x2 
bfc00524: 2442015c addiu v0,v0,348 
bfc00528: 00821021 addu v0,a0,v0 
bfc0052c: ac430000 sw v1,0(v0)

56 
bfc00530: 3c02c000 lui v0,0xc000 
bfc00534: 8c440158 lw a0,344(v0) 
bfc00538: 3c02c000 lui v0,0xc000 
bfc0053c: 8c430158 lw v1,344(v0) 
bfc00540: 3c02c000 lui v0,0xc000 
bfc00544: 00031880 sll v1,v1,0x2 
bfc00548: 24420090 addiu v0,v0,144 
bfc0054c: 00621021 addu v0,v1,v0 
bfc00550: 8c430000 lw v1,0(v0) 
bfc00554: 3c02c000 lui v0,0xc000 
bfc00558: 8c450158 lw a1,344(v0) 
bfc0055c: 3c02c000 lui v0,0xc000 
bfc00560: 00052880 sll a1,a1,0x2 
bfc00564: 2442015c addiu v0,v0,348 
bfc00568: 00a21021 addu v0,a1,v0 
bfc0056c: 8c420000 lw v0,0(v0) 
bfc00570: 00621821 addu v1,v1,v0 
bfc00574: 3c02c000 lui v0,0xc000 
bfc00578: 00042080 sll a0,a0,0x2 
bfc0057c: 24420224 addiu v0,v0,548 
bfc00580: 00821021 addu v0,a0,v0 
bfc00584: ac430000 sw v1,0(v0) 
bfc00588: 100000c3 b bfc00898 <test_app+0x408> 
bfc0058c: 00000000 nop 
bfc00590: 3c02c000 lui v0,0xc000 
bfc00594: 8c440158 lw a0,344(v0) 
bfc00598: 3c02c000 lui v0,0xc000 
bfc0059c: 8c420158 lw v0,344(v0) 
bfc005a0: 2443ffff addiu v1,v0,-1 
bfc005a4: 3c02c000 lui v0,0xc000 
bfc005a8: 00031880 sll v1,v1,0x2 
bfc005ac: 244202ec addiu v0,v0,748 
bfc005b0: 00621021 addu v0,v1,v0 
bfc005b4: 8c430000 lw v1,0(v0) 
bfc005b8: 3c02c000 lui v0,0xc000 
bfc005bc: 8c420158 lw v0,344(v0) 
bfc005c0: 00621821 addu v1,v1,v0 
bfc005c4: 3c02c000 lui v0,0xc000 
bfc005c8: 00042080 sll a0,a0,0x2 
bfc005cc: 244202ec addiu v0,v0,748 
bfc005d0: 00821021 addu v0,a0,v0 
bfc005d4: ac430000 sw v1,0(v0) 
bfc005d8: 3c02c000 lui v0,0xc000 
bfc005dc: 8c440158 lw a0,344(v0)

57 
bfc005e0: 3c02c000 lui v0,0xc000 
bfc005e4: 8c420158 lw v0,344(v0) 
bfc005e8: 2443ffff addiu v1,v0,-1 
bfc005ec: 3c02c000 lui v0,0xc000 
bfc005f0: 00031880 sll v1,v1,0x2 
bfc005f4: 24420090 addiu v0,v0,144 
bfc005f8: 00621021 addu v0,v1,v0 
bfc005fc: 8c450000 lw a1,0(v0) 
bfc00600: 3c02c000 lui v0,0xc000 
bfc00604: 8c430158 lw v1,344(v0) 
bfc00608: 00601025 move v0,v1 
bfc0060c: 00021040 sll v0,v0,0x1 
bfc00610: 00431021 addu v0,v0,v1 
bfc00614: 00a21821 addu v1,a1,v0 
bfc00618: 3c02c000 lui v0,0xc000 
bfc0061c: 00042080 sll a0,a0,0x2 
bfc00620: 24420090 addiu v0,v0,144 
bfc00624: 00821021 addu v0,a0,v0 
bfc00628: ac430000 sw v1,0(v0) 
bfc0062c: 3c02c000 lui v0,0xc000 
bfc00630: 8c420158 lw v0,344(v0) 
bfc00634: 2842000a slti v0,v0,10 
bfc00638: 10400027 beqz v0,bfc006d8 <test_app+0x248> 
bfc0063c: 00000000 nop 
bfc00640: 3c02c000 lui v0,0xc000 
bfc00644: 8c440158 lw a0,344(v0) 
bfc00648: 3c02c000 lui v0,0xc000 
bfc0064c: 8c430158 lw v1,344(v0) 
bfc00650: 3c02c000 lui v0,0xc000 
bfc00654: 00031880 sll v1,v1,0x2 
bfc00658: 244202ec addiu v0,v0,748 
bfc0065c: 00621021 addu v0,v1,v0 
bfc00660: 8c430000 lw v1,0(v0) 
bfc00664: 3c02c000 lui v0,0xc000 
bfc00668: 00042080 sll a0,a0,0x2 
bfc0066c: 2442015c addiu v0,v0,348 
bfc00670: 00821021 addu v0,a0,v0 
bfc00674: ac430000 sw v1,0(v0) 
bfc00678: 3c02c000 lui v0,0xc000 
bfc0067c: 8c440158 lw a0,344(v0) 
bfc00680: 3c02c000 lui v0,0xc000 
bfc00684: 8c430158 lw v1,344(v0) 
bfc00688: 3c02c000 lui v0,0xc000 
bfc0068c: 00031880 sll v1,v1,0x2

58 
bfc00690: 24420090 addiu v0,v0,144 
bfc00694: 00621021 addu v0,v1,v0 
bfc00698: 8c430000 lw v1,0(v0) 
bfc0069c: 3c02c000 lui v0,0xc000 
bfc006a0: 8c450158 lw a1,344(v0) 
bfc006a4: 3c02c000 lui v0,0xc000 
bfc006a8: 00052880 sll a1,a1,0x2 
bfc006ac: 2442015c addiu v0,v0,348 
bfc006b0: 00a21021 addu v0,a1,v0 
bfc006b4: 8c420000 lw v0,0(v0) 
bfc006b8: 00621821 addu v1,v1,v0 
bfc006bc: 3c02c000 lui v0,0xc000 
bfc006c0: 00042080 sll a0,a0,0x2 
bfc006c4: 24420224 addiu v0,v0,548 
bfc006c8: 00821021 addu v0,a0,v0 
bfc006cc: ac430000 sw v1,0(v0) 
bfc006d0: 10000071 b bfc00898 <test_app+0x408> 
bfc006d4: 00000000 nop 
bfc006d8: 3c02c000 lui v0,0xc000 
bfc006dc: 8c420158 lw v0,344(v0) 
bfc006e0: 2842001e slti v0,v0,30 
bfc006e4: 10400030 beqz v0,bfc007a8 <test_app+0x318> 
bfc006e8: 00000000 nop 
bfc006ec: 3c02c000 lui v0,0xc000 
bfc006f0: 8c440158 lw a0,344(v0) 
bfc006f4: 3c02c000 lui v0,0xc000 
bfc006f8: 8c430158 lw v1,344(v0) 
bfc006fc: 3c02c000 lui v0,0xc000 
bfc00700: 00031880 sll v1,v1,0x2 
bfc00704: 244202ec addiu v0,v0,748 
bfc00708: 00621021 addu v0,v1,v0 
bfc0070c: 8c430000 lw v1,0(v0) 
bfc00710: 3c02c000 lui v0,0xc000 
bfc00714: 8c450158 lw a1,344(v0) 
bfc00718: 3c02c000 lui v0,0xc000 
bfc0071c: 00052880 sll a1,a1,0x2 
bfc00720: 24420090 addiu v0,v0,144 
bfc00724: 00a21021 addu v0,a1,v0 
bfc00728: 8c420000 lw v0,0(v0) 
bfc0072c: 00621821 addu v1,v1,v0 
bfc00730: 3c02c000 lui v0,0xc000 
bfc00734: 00042080 sll a0,a0,0x2 
bfc00738: 2442015c addiu v0,v0,348 
bfc0073c: 00821021 addu v0,a0,v0