/* time.c -- produce a 1-page summary of cpu times of various C constructs
 * To port to a new machine, change the following:
 *	BASEN:	Start around 10000, increase by *10 until no question marks
 *	Macro processor: define ANSIIMAC 1 for Ansii C, undef for old C
 *	Times: probably change CLOCKS_PER_SEC, may change jobclicks()
 *	WARNRANGE: print ? after CPU time if max clicks - min clicks >
 *		   WARNRANGE * mean clicks
 */

#include <stdio.h>
#include <limits.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#undef ANSIIMAC
#define ANSIIMAC 1
#define BASEN 1000000
#define WARNRANGE 0.4

struct stacknode {
	int val;
	struct stacknode *next;
};
typedef struct stacknode *Stackp;
Stackp	stackroot;

void push(int i)
{
	Stackp p;

	p = (Stackp) malloc(sizeof(struct stacknode));
	p->val = i;
	p->next = stackroot;
	stackroot = p;
}

int pop()
{
	Stackp p;
	int	i;

	p = stackroot;
	i = stackroot->val;
	stackroot = stackroot->next;
	free(p);
	return i;
}

/* Objects associated with CPU times -- may have to change
 * CLOCKS_PER_SEC is defined as HZ on many systems
 *	Typical values of CLOCKS_PER_SEC: Vax=60  Cray=105296000
 *	For large values, also change %5d in macro loop1, 99999 in minclicks;
 */

#include <time.h>

int jobclicks()
{
	/* supposedly this returns a value in microseconds */
	/* convert to seconds with CLOCKS_PER_SEC */
	return (int) clock();
}

/* Main macros for experiments */

#ifdef ANSIIMAC
#define quoted(TEXT) #TEXT
#else
#define quoted(TEXT) "TEXT"
#endif

#define loop1(CODE) loop1ctr++; \
	for (i = 0; i < n; i++) { CODE; } \
	loop1next = jobclicks(); \
	thisclicks = loop1next - loop1start; \
	sumclicks += thisclicks; \
	if (thisclicks < minclicks) minclicks = thisclicks; \
	if (thisclicks > maxclicks) maxclicks = thisclicks; \
	printf("%7d ", loop1next - loop1start); \
	loop1start = loop1next;

#define loop(CODE) printf("  %-30s", quoted(CODE)); \
	minclicks = INT_MAX; maxclicks = -1; sumclicks = 0; \
	loop1ctr = 0; \
	loop1start = jobclicks(); \
	loop1(CODE) \
	loop1(CODE) \
	i0 = i1 + i2 + i3; \
	loop1(CODE) \
	i0 = i1 + i2 + i3 - i1 - i2 - i3; \
	loop1(CODE) \
	i0 = i1 + i2 + i3 + i1*i2 + i2*i3 + i1*i3; \
	loop1(CODE) \
	queststr = ""; \
	if (loop1ctr * (maxclicks - minclicks) > WARNRANGE *  sumclicks) \
		queststr = "?"; \
	lastmics = sumclicks * 1000000.0 / ((double) CLOCKS_PER_SEC * n * loop1ctr); \
	printf("%10.2f%s\n", lastmics - basemics, queststr);

#define title(TEXT) printf("%s (n=%d)\n", TEXT, n);

/* The experiment */

int sum1(int a) { return a; }
int sum2(int a, int b) { return a + b; }
int sum3(int a, int b, int c) { return a + b + c; }

int main()
{
	int	loop1start, loop1next, loop1ctr;
	double	lastmics, basemics;
	int	minclicks, maxclicks, sumclicks, thisclicks, startclicks;
	int	i, n, basen;
	volatile int	i0, i1, i2, i3, i4;
	volatile float	f0, f1, f2, f3;
	int	*v;
	char	*queststr;
	char	s[100];
	char	fname[20];
	FILE	*fp;
	/* The following strings are variables because some macro processors
		don't handle quoted strings in quoted arguments */
	/* also, these have to be writable, so don't use char *; */
	char	s0123456789[] = "0123456789";
	char	sa123456789[] = "a123456789";
	char	s12345[] = "12345";
	char	s123_45[] = "123.45";
	char	sd[] = "%d";
	char	sdn[] = "%d\n";
	char	sf[] = "%f";
	char	sf62[] = "%f6.2";

	setbuf(stdout, (char *) 0);	/* No buffering to watch output */
	printf("  Operation                         Clicks for each trial ");
	printf("   Mics/N\n");
	startclicks = jobclicks();

	basen = BASEN;
	n = basen;
	title("Null Loop")
	i0 = i1 = i2 = i3 = 5;
	f0 = f1 = f2 = f3 = 5.0;
	basemics = 0.0;
	loop({})
	basemics = lastmics;

	title("Int Operations");
	i1 = i2 = i3 = 5;
	loop(i1++)
	i1 = i2 = i3 = 5;
	loop(i1 = i2 + i3)
	i1 = i2 = i3 = 5;
	i1 = i2 = i3 = 5;
	loop(i1 = i2 - i3)
	i1 = i2 = i3 = 5;
	loop(i1 = i2 * i3)
	i1 = i2 = i3 = 5;
	loop(i1 = i2 / i3)
	i1 = i2 = i3 = 5;
	loop(i1 = i2 % i3)

	title("Float Operations");
	f1 = f2 = f3 = 5.0;
	loop(f1 = f2)
	loop(f1 = f2 + f3)
	loop(f1 = f2 - f3)
	loop(f1 = f2 * f3)
	loop(f1 = f2 / f3)

	title("Numeric Conversions");
	f1 = 123456.789;
	i1 = 123456;
	loop(i1 = f1)
	loop(f1 = i1)

	title("Integer Vector Operations");
	v = (int *) malloc(n * sizeof(int));
	for (i = 0; i < n; i++)
		v[i] = 0;
	loop(v[i] = i)
	loop(v[v[i]] = i)
	loop(v[v[v[i]]] = i)
	free(v);

	title("Control Structures");
	i1 = i2 = i3 = 5;
	loop(if (i == 5) i1++)
	loop(if (i != 5) i1++)
	loop(while (i < 0) i1++)
	loop(i1 = sum1(i2))
	loop(i1 = sum2(i2, i3))
	loop(i1 = sum3(i2, i3, i4))

	n = basen/10;
	strcpy(fname, "junk");
	title("Input/Output");
	strcpy(s, "1234\n");
	fp = fopen(fname, "w");
	loop(fputs(s, fp))
	fclose(fp);
	fp = fopen(fname, "r");
	loop(fgets(s, 9, fp))
	fclose(fp);
	fp = fopen(fname, "w");
	loop(fprintf(fp, sdn, i))
	fclose(fp);
	fp = fopen(fname, "r");
	loop(fscanf(fp, sd, &i1))
	fclose(fp);

	n = basen/10;
	title("Malloc");
	loop(free(malloc(8)))
	loop(push(i))
	loop(i1 = pop())

	n = basen;
	title("String Functions");
	loop(strcpy(s, s0123456789))
	loop(i1 = strcmp(s, s))
	loop(i1 = strcmp(s, sa123456789))

	n = basen/100;
	title("String/Number Conversions");
	loop(i1 = atoi(s12345))
	loop(sscanf(s12345, sd, &i1))
	loop(sprintf(s, sd, i))
	loop(f1 = atof(s123_45))
	loop(sscanf(s123_45, sf, &f1))
	loop(sprintf(s, sf62, 123.45))

	n = basen/10;
	title("Math Functions");
	loop(i1 = rand())
	f2 = 5.0;
	loop(f1 = log(f2))
	loop(f1 = exp(f2))
	loop(f1 = sin(f2))
	loop(f1 = sqrt(f2))

	printf("Total Seconds:%10.2f\n", ((float) jobclicks()-startclicks) / CLOCKS_PER_SEC);
	return 0;
}