Add r=4 C code

This commit is contained in:
James Stine 2022-06-15 11:44:09 -05:00
parent 11b252a735
commit 535a9a04ee
5 changed files with 421 additions and 0 deletions

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CC = gcc
CFLAGS = -lm
LIBS =
OBJS = disp.o srt4div.o
srt4div: $(OBJS)
$(CC) -g -O3 -o srt4div $(OBJS) $(CFLAGS)
disp.o: disp.h disp.c
$(CC) -g -c -o disp.o disp.c $(CFLAGS)
srt4div.o: srt4div.c
$(CC) -g -c -o srt4div.o srt4div.c $(CFLAGS)
clean:
rm -f *.o *~
rm -f core

60
pipelined/srt/stine/disp.c Executable file
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#include "disp.h"
double rnd_zero(double x, double bits) {
if (x < 0)
return ceiling(x, bits);
else
return flr(x, bits);
}
double rne(double x, double precision) {
double scale, x_round;
scale = pow(2.0, precision);
x_round = rint(x * scale) / scale;
return x_round;
}
double flr(double x, double precision) {
double scale, x_round;
scale = pow(2.0, precision);
x_round = floor(x * scale) / scale;
return x_round;
}
double ceiling(double x, double precision) {
double scale, x_round;
scale = pow(2.0, precision);
x_round = ceil(x * scale) / scale;
return x_round;
}
void disp_bin(double x, int bits_to_left, int bits_to_right, FILE *out_file) {
double diff;
int i;
if (fabs(x) < pow(2.0, -bits_to_right)) {
for (i = -bits_to_left + 1; i <= bits_to_right; i++) {
fprintf(out_file,"0");
}
return;
}
if (x < 0.0) {
// fprintf(out_file, "-");
// x = - x;
x = pow(2.0, ((double) bits_to_left)) + x;
}
for (i = -bits_to_left + 1; i <= bits_to_right; i++) {
diff = pow(2.0, -i);
if (x < diff) {
fprintf(out_file, "0");
}
else {
fprintf(out_file, "1");
x -= diff;
}
if (i == 0) {
fprintf(out_file, ".");
}
}
}

18
pipelined/srt/stine/disp.h Executable file
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#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#ifndef DISP
#define DISP
double rnd_zero(double x, double bits);
double rne(double x, double precision);
double flr(double x, double precision);
double ceiling(double x, double precision);
void disp_bin(double x, int bits_to_left, int bits_to_right, FILE *out_file);
#endif

BIN
pipelined/srt/stine/srt4div Executable file

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325
pipelined/srt/stine/srt4div.c Executable file
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#include "disp.h"
#include <math.h>
int qslc (double prem, double d) {
int q;
printf("d --> %lg\n", d);
printf("rw --> %lg\n", prem);
if ((d>=0.0)&&(d<1.0)) {
if (prem>=1.0)
q = 2;
else if (prem>=0.25)
q = 1;
else if (prem>=-0.25)
q = 0;
else if (prem >= -1)
q = -1;
else
q = -2;
return q;
}
if ((d>=1.0)&&(d<2.0)) {
if (prem>=2.0)
q = 2;
else if (prem>=0.66667)
q = 1;
else if (prem>=-0.6667)
q = 0;
else if (prem >= -2)
q = -1;
else
q = -2;
return q;
}
if ((d>=2.0)&&(d<3.0)) {
if (prem>=4.0)
q = 2;
else if (prem>=1.25)
q = 1;
else if (prem>=-1.25)
q = 0;
else if (prem >= -4)
q = -1;
else
q = -2;
return q;
}
if ((d>=3.0)&&(d<4.0)) {
if (prem>=5.0)
q = 2;
else if (prem>=2.0)
q = 1;
else if (prem>=-2.0)
q = 0;
else if (prem >= -5)
q = -1;
else
q = -2;
return q;
}
if ((d>=4.0)&&(d<5.0)) {
if (prem>=6.66667)
q = 2;
else if (prem>=2.0)
q = 1;
else if (prem>=-2.0)
q = 0;
else if (prem >= -6.66667)
q = -1;
else
q = -2;
return q;
}
if ((d>=5.0)&&(d<6.0)) {
if (prem>=8.0)
q = 2;
else if (prem>=2.0)
q = 1;
else if (prem>=-2.0)
q = 0;
else if (prem >= -8.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=6.0)&&(d<7.0)) {
if (prem>=10.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -10.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=7.0)&&(d<8.0)) {
if (prem>=11.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -11.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=8.0)&&(d<9.0)) {
if (prem>=12.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -12.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=9.0)&&(d<10.0)) {
if (prem>=15.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -15.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=10.0)&&(d<11.0)) {
if (prem>=15.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -15.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=11.0)&&(d<12.0)) {
if (prem>=16.0)
q = 2;
else if (prem>=4.0)
q = 1;
else if (prem>=-4.0)
q = 0;
else if (prem >= -16.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=12.0)&&(d<13.0)) {
if (prem>=20.0)
q = 2;
else if (prem>=8.0)
q = 1;
else if (prem>=-8.0)
q = 0;
else if (prem >= -20.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=13.0)&&(d<14.0)) {
if (prem>=20.0)
q = 2;
else if (prem>=8.0)
q = 1;
else if (prem>=-8.0)
q = 0;
else if (prem >= -20.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=14.0)&&(d<15.0)) {
if (prem>=20.0)
q = 2;
else if (prem>=8.0)
q = 1;
else if (prem>=-8.0)
q = 0;
else if (prem >= -20.0)
q = -1;
else
q = -2;
return q;
}
if ((d>=15.0)&&(d<16.0)) {
if (prem>=24.0)
q = 2;
else if (prem>=8.0)
q = 1;
else if (prem>=-8.0)
q = 0;
else if (prem >= -24.0)
q = -1;
else
q = -2;
return q;
}
}
/*
This routine performs a radix-4 SRT division
algorithm. The user inputs the numerator, the denominator,
and the number of iterations. It assumes that 0.5 <= D < 1.
*/
int main(int argc, char* argv[]) {
double P, N, D, Q, RQ, RD, RREM, scale;
int q;
int num_iter, i;
int prec;
if (argc < 5) {
fprintf(stderr,
"Usage: %s numerator denominator num_iterations prec\n",
argv[0]);
exit(1);
}
sscanf(argv[1],"%lg", &N);
sscanf(argv[2],"%lg", &D);
sscanf(argv[3],"%d", &num_iter);
sscanf(argv[4],"%d", &prec);
// Round to precision
N = rne(N, prec);
D = rne(D, prec);
printf("N = ");
disp_bin(N, 3, prec, stdout);
printf("\n");
printf("D = ");
disp_bin(D, 3, prec, stdout);
printf("\n");
Q = 0;
P = N*0.25;
printf("N = %lg, D = %lg, N/D = %lg, num_iter = %d \n\n",
N, D, N/D, num_iter);
for (scale = 1, i = 0; i < num_iter; i++) {
// Shift by r
scale = scale*0.25;
q = qslc(flr((4*P)*16,3), D*16);
//q = -q;
printf("4*W[n] = ");
disp_bin(4*P,3,prec,stdout);
printf("\n");
printf("q*D = ");
disp_bin(q*D,3,prec,stdout);
printf("\n");
printf("W[n+1] = ");
disp_bin(P ,3,prec,stdout);
printf("\n");
// Recurrence
P = 4*P - q*D;
// OTFC
Q = Q + q*scale;
printf("i = %d, q = %d, Q = %1.18lf, W = %1.18lf\n", i, q, Q, P);
printf("i = %d, q = %d", i, q);
printf(", Q = ");
disp_bin(Q, 3, prec, stdout);
printf(", W = ");
disp_bin(P, 3, prec, stdout);
printf("\n\n");
}
if (P < 0) {
Q = Q - scale;
P = P + D;
printf("\nCorrecting Negative Remainder\n");
printf("Q = %1.18lf, W = %1.18lf\n", Q, P);
printf("Q = ");
disp_bin(Q, 3, prec, stdout);
printf(", W = ");
disp_bin(P, 3, prec, stdout);
printf("\n");
}
RQ = flr(N/D, (double) prec);
RD = Q*4;
printf("true = %1.18lf, computed = %1.18lf, \n", RQ, RD);
printf("true = ");
disp_bin(RQ, 3, prec, stdout);
printf(", computed = ");
disp_bin(RD, 3, prec, stdout);
printf("\n\n");
printf("REM = %1.18lf \n", P);
printf("REM = ");
disp_bin(P, 3, prec, stdout);
printf("\n\n");
return 0;
}