prfp.c

来自「mips架构的bootloader,99左右的版本 但源代码现在没人更新了」· C语言 代码 · 共 105 行

/*************************************************************
 * File: tools/prfp.c
 * Purpose: print floating-point values
 * Author: Phil Bunce ([e-mail])
 * Revision History:
 *	970518	Start of revision history
 */

#include <stdio.h>

int fflag;
char *a1,*a2;
char *usage[] = {
	"prfp -- Print floating point",
	"usage: prfp {[-f] fpvalue | [hexvalue] hexvalue}",
	"",
	"Examples:",
	"% prfp 3.142",
	"400922d0 e5604189 dp=3.142000e+00",
	"",
	"% prfp -f 3.142",
	"40491687 sp=3.142000e+00",
	"",
	"% prfp 400922d0 e5604189",
	"400922d0 e5604189 dp=3.142000e+00",
	"",
	"% prfp 40491687",
	"40491687 sp=3.142000e+00",
	0};


/*************************************************************
*  main(argc,argv)
*/
main(argc,argv)
int argc;
char *argv[];
{
double d;
float s;
unsigned long *sp,*dp;
int i;

for (i=1;i<argc;i++) {
	if (argv[i][0] == '-') {
		if (argv[i][1] == 'f') fflag = 1;
		else {
			fprintf(stderr,"%c: unknown option\n",argv[i][1]);
			help();
			exit(1);
			}
		}
	else {
		if (a1 == 0) a1 = argv[i];
		else if (a2 == 0) a2 = argv[i];
		else {
			fprintf(stderr,"Too many args\n");
			help();
			exit(1);
			}
		}
	}

dp = (unsigned long *)&d;
sp = (unsigned long *)&s;

if (a1 == 0) {
	fprintf(stderr,"Too few args\n");
	help();
	exit(1);
	}

if (a2 == 0) { 
	if (strchr(a1,'.')) { /* fp */
		if (fflag) { /* sp */
			sscanf(a1,"%f",&s);
			printf("%08lx sp=%e\n",*sp,s);
			}
		else { /* dp */
			sscanf(a1,"%lf",&d);
			printf("%08lx %08lx dp=%e\n",dp[0],dp[1],d);
			}
		}
	else { /* hex sp */
		sscanf(a1,"%lx",sp);
		printf("%08lx sp=%e\n",*sp,s);
		}
	}
else { /* hex dp */
	sscanf(a1,"%lx",dp);
	sscanf(a2,"%lx",&dp[1]);
	printf("%08lx %08lx dp=%e\n",dp[0],dp[1],d);
	}
}

/*************************************************************
*  help()
*/
help()
{
int i;

for (i=0;usage[i];i++) printf("%s\n",usage[i]);
}