ack/mach/con_float

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/* $Header$ */

/* #define NOFLOAT for machines without floating point
   #define ACKFLOAT for machines using the ACK floating point software
   #define IEEEFLOAT for machines using IEEE floating point format
   #define OWNFLOAT to use floating point format of machine on which
		    the code generator runs
   If none of these are defined, PDP-11 format is generated.
*/

#ifdef NOFLOAT
con_float() {

static int been_here;
	if (argval != 4 && argval != 8)
		fatal("bad fcon size");
	fputs(".data4\t", codefile);
	if (argval == 8)
		fputs("0,", codefile);
	fputs("0 !dummy float\n", codefile);
	if ( !been_here++) {
		fputs("Warning : dummy float-constant(s)\n", stderr);
	}
}
#else /* NOFLOAT */

#include <ctype.h>
#ifndef OWNFLOAT
#include <flt_arith.h>
#endif /* OWNFLOAT */

con_float() {
	int i, j;
	char *p;
#ifdef OWNFLOAT
	float fl;
	double f;
	double atof();
#else /* OWNFLOAT */
	int overflow = 0;
	flt_arith e;
	char buf[8];
#endif /* OWNFLOAT */

	if (argval!= 4 && argval!= 8)	{
		fprintf(stderr,"float constant size = %d\n",argval);
		fatal("bad fcon size");
	}
	fprintf(codefile,"!float %s sz %d\n", str, argval);
#ifdef OWNFLOAT
	f = atof(str);
	if (argval == 4) {
		fl = f;
		p = (char *) &fl;
	}
	else {
		p = (char *) &f;
	}
	fprintf(codefile, ".data1 0%o", *p++ & 0377);
	for (i = argval-1; i; i--) {
		fprintf(codefile,",0%o", *p++ & 0377);
	}
#else /* OWNFLOAT */
	flt_str2flt(str, &e);
#if IEEEFLOAT+ACKFLOAT
	if (argval == 4) {
#endif
		e.flt_exp += 127;
#ifndef IEEEFLOAT
		e.flt_exp += 2;
#endif
		if (e.flt_mantissa.flt_h_32 == 0) e.flt_exp = 0;
#if IEEEFLOAT+ACKFLOAT
		if (e.flt_exp >= 255) {
			overflow = 1;
			e.flt_exp = 255;
			e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
		}
		if (e.flt_exp <= 0) {
#if IEEEFLOAT
			flt_b64_sft(&(e.flt_mantissa), 1);
			if (e.flt_exp < 0) {
				flt_b64_sft(&(e.flt_mantissa), -e.flt_exp);
				e.flt_exp = 0;
			}
#else
			e.flt_exp = 0;
			e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
#endif
		}
#endif
		buf[0] = (e.flt_sign << 7) | (e.flt_exp >> 1);
		buf[1] = ((e.flt_exp&1) << 7) |
				((e.flt_mantissa.flt_h_32 & 0x7fffffff) >> 24);
		buf[2] = e.flt_mantissa.flt_h_32 >> 16;
		buf[3] = e.flt_mantissa.flt_h_32 >> 8;
		if (argval == 8) {
			buf[4] = e.flt_mantissa.flt_h_32;
			buf[5] = e.flt_mantissa.flt_l_32 >> 24;
			buf[6] = e.flt_mantissa.flt_l_32 >> 16;
			buf[7] = e.flt_mantissa.flt_l_32 >> 8;
			flt_b64_sft(&(e.flt_mantissa), -56);
		}
		else	flt_b64_sft(&(e.flt_mantissa), -24);
#if IEEEFLOAT+ACKFLOAT
	}
	else {
		e.flt_exp += 1023;
#ifndef IEEEFLOAT
		e.flt_exp += 2;
#endif
		if (e.flt_mantissa.flt_h_32 == 0) e.flt_exp = 0;
		if (e.flt_exp >= 2047) {
			overflow = 1;
			e.flt_exp = 2047;
			e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
		}
		if (e.flt_exp <= 0) {
#if IEEEFLOAT
			flt_b64_sft(&(e.flt_mantissa), 1);
			if (e.flt_exp < 0) {
				flt_b64_sft(&(e.flt_mantissa), -e.flt_exp);
				e.flt_exp = 0;
			}
#else
			e.flt_exp = 0;
			e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
#endif
		}
		buf[0] = (e.flt_sign << 7) | (e.flt_exp >> 4);
		buf[1] = ((e.flt_exp & 017)<< 4) | ((e.flt_mantissa.flt_h_32 >> 27) & 017);
		buf[2] = e.flt_mantissa.flt_h_32 >> 19;
		buf[3] = e.flt_mantissa.flt_h_32 >> 11;
		buf[4] = e.flt_mantissa.flt_h_32 >> 3;
		buf[5] = (e.flt_mantissa.flt_h_32 << 5) | ((e.flt_mantissa.flt_l_32 >> 27) & 037);
		buf[6] = e.flt_mantissa.flt_l_32 >> 19;
		buf[7] = e.flt_mantissa.flt_l_32 >> 11;
		flt_b64_sft(&(e.flt_mantissa), -53);
	}
#endif
	i = argval-1;
	if (! overflow && (e.flt_mantissa.flt_h_32 & 0x80000000)) for (; i>=0; i--) {
		if ((buf[i] &0377) != 0377) {
			buf[i]++;
			break;
		}
		else buf[i] = 0;
	}
	if (overflow || i < 0) {
		fprintf(stderr, "Warning: overflow in floating point constant %s\n", str);
	}
	for (i = 0; i < argval; i++) {
		fprintf(codefile,
			i != 0 ? ",0%o" : ".data1 0%o", 
			buf[i]&0377);
	}
#endif /* OWNFLOAT */
	putc('\n', codefile);
}
#endif /* NOFLOAT */