/* !!DESCRIPTION!! C-Manual Chapter 6.2: Float and double, 6.3 Floating and integral, 6.4 Pointers and integers, 6.5 Unsigned, 6.6 Arithmetic conversions !!ORIGIN!! LCC 4.1 Testsuite !!LICENCE!! own, freely distributeable for non-profit. read CPYRIGHT.LCC */ #include "common.h" struct defs { int cbits; /* No. of bits per char */ int ibits; /* int */ int sbits; /* short */ int lbits; /* long */ int ubits; /* unsigned */ int fbits; /* float */ int dbits; /* double */ #ifndef NO_FLOATS float fprec; /* Smallest number that can be */ float dprec; /* significantly added to 1. */ #endif int flgs; /* Print return codes, by section */ int flgm; /* Announce machine dependencies */ int flgd; /* give explicit diagnostics */ int flgl; /* Report local return codes. */ int rrc; /* recent return code */ int crc; /* Cumulative return code */ char rfs[8]; /* Return from section */ }; int lbits; /* long */ int ubits; /* unsigned */ int fbits; /* float */ int dbits; /* double */ #ifndef NO_FLOATS float fprec; /* Smallest number that can be */ float dprec; /* significantly added to 1. */ #endif int flgs; /* Print return codes, by section */ int flgm; /* Announce machine dependencies */ int flgd; /* give explicit diagnostics */ int flgl; /* Report local return codes. */ int rrc; /* recent return code */ int crc; /* Cumulative return code */ char rfs[8]; /* Return from section */ #define CQ26_INCLUDED /* section s26, which pokes around at the hardware trying to figure out the characteristics of the machine that it is running on, saves information that is subsequently used by sections s626, s72, and s757. If this program is to be broken up into smallish pieces, say for running on a microcomputer, take care to see that s26 is called before calling any of the latter three sections. */ /* 2.6 Hardware Characteristics */ #ifndef NO_OLD_FUNC_DECL s26(pd0) struct defs *pd0; { #else s26(struct defs *pd0) { #endif static char qs26[8] = "s26 "; char *ps, *pt; char c0, c1; #ifndef NO_FLOATS float temp, one, delta; double tempd, oned; #endif static char s[] = "%3d bits in %ss.\n"; static char s2[] = "%e is the least number that can be added to 1. (%s).\n"; ps = qs26; pt = pd0->rfs; while(*pt++ = *ps++); /* Here, we shake the machinery a little to see what falls out. First, we find out how many bits are in a char. */ pd0->cbits = 0; c0 = 0; c1 = 1; while(c0 != c1) { c1 = c1<<1; pd0->cbits = pd0->cbits+1; } /* That information lets us determine the size of everything else. */ pd0->ibits = pd0->cbits * sizeof(int); pd0->sbits = pd0->cbits * sizeof(short); pd0->lbits = pd0->cbits * sizeof(long); pd0->ubits = pd0->cbits * sizeof(unsigned); #ifndef NO_FLOATS pd0->fbits = pd0->cbits * sizeof(float); pd0->dbits = pd0->cbits * sizeof(double); #endif /* We have now almost reconstructed the table in section 2.6, the exception being the range of the floating point hardware. Now there are just so many ways to conjure up a floating point representation system that it's damned near impossible to guess what's going on by writing a program to interpret bit patterns. Further, the information isn't all that useful, if we consider the fact that machines that won't handle numbers between 10**30 and 10**-30 are very hard to find, and that people playing with numbers outside that range have a lot more to worry about than just the capacity of the characteristic. A much more useful measure is the precision, which can be ex- pressed in terms of the smallest number that can be added to 1. without loss of significance. We calculate that here, for float and double. */ #ifndef NO_FLOATS one = 1.; delta = 1.; temp = 0.; while(temp != one) { temp = one+delta; delta = delta/2.; } pd0->fprec = delta * 4.; oned = 1.; delta = 1.; tempd = 0.; while(tempd != oned) { tempd = oned+delta; delta = delta/2.; } pd0->dprec = delta * 4.; #endif /* Now, if anyone's interested, we publish the results. */ #ifndef CQ26_INCLUDED if(pd0->flgm != 0) { printf(s,pd0->cbits,"char"); printf(s,pd0->ibits,"int"); printf(s,pd0->sbits,"short"); printf(s,pd0->lbits,"long"); printf(s,pd0->ubits,"unsigned"); printf(s,pd0->fbits,"float"); printf(s,pd0->dbits,"double"); #ifndef NO_FLOATS printf(s2,pd0->fprec,"float"); printf(s2,pd0->dprec,"double"); #else printf("NO_FLOATS\n"); #endif } #endif /* Since we are only exploring and perhaps reporting, but not testing any features, we cannot return an error code. */ return 0; } int extvar; #ifndef NO_OLD_FUNC_DECL s626(pd0) /* 6.2 Float and double */ /* 6.3 Floating and integral */ /* 6.4 Pointers and integers */ /* 6.5 Unsigned */ /* 6.6 Arithmetic conversions */ struct defs *pd0; { #else int s626(struct defs *pd0){ #endif static char s626er[] = "s626,er%d\n"; static char qs626[8] = "s626 "; int rc; char *ps, *pt; #ifndef NO_FLOATS float eps, f1, f2, f3, f4, f; #endif long lint1, lint2, l, ls; char c, t[28], t0; short s; int is, i, j; unsigned u, us; #ifndef NO_FLOATS double d, ds; #endif ps = qs626; pt = pd0->rfs; rc = 0; while (*pt++ = *ps++); #ifndef NO_FLOATS /* Conversions of integral values to floating type are well-behaved. */ f1 = 1.; lint1 = 1.; lint2 = 1.; for(j=0;jlbits-2;j++){ f1 = f1*2; lint2 = (lint2<<1)|lint1; } f2 = lint2; f1 = (f1-f2)/f1; if(f1>2.*pd0->fprec){ rc = rc+2; if(pd0->flgd != 0) printf(s626er,2); } /* Pointer-integer combinations are discussed in s74, "Additive operators". The unsigned-int combination appears below. */ c = 125; s = 125; i = 125; is = 15625; u = 125; us = 15625; l = 125; ls = 15625; f = 125.; d = 125.; ds = 15625.; for(j=0;j<28;j++) t[j] = 0; if(c*c != is) t[ 0] = 1; if(s*c != is) t[ 1] = 1; if(s*s != is) t[ 2] = 1; if(i*c != is) t[ 3] = 1; if(i*s != is) t[ 4] = 1; if(i*i != is) t[ 5] = 1; if(u*c != us) t[ 6] = 1; if(u*s != us) t[ 7] = 1; if(u*i != us) t[ 8] = 1; if(u*u != us) t[ 9] = 1; if(l*c != ls) t[10] = 1; if(l*s != ls) t[11] = 1; if(l*i != ls) t[12] = 1; if(l*u != us) t[13] = 1; if(l*l != ls) t[14] = 1; if(f*c != ds) t[15] = 1; if(f*s != ds) t[16] = 1; if(f*i != ds) t[17] = 1; if(f*u != ds) t[18] = 1; if(f*l != ds) t[19] = 1; if(f*f != ds) t[20] = 1; if(d*c != ds) t[21] = 1; if(d*s != ds) t[22] = 1; if(d*i != ds) t[23] = 1; if(d*u != ds) t[24] = 1; if(d*l != ds) t[25] = 1; if(d*f != ds) t[26] = 1; if(d*d != ds) t[27] = 1; t0 = 0; for(j=0; j<28; j++) t0 = t0+t[j]; if(t0 != 0){ rc = rc+4; if(pd0->flgd != 0){ printf(s626er,4); printf(" key="); for(j=0;j<28;j++) printf("%d",t[j]); printf("\n"); } } #endif /* When an unsigned integer is converted to long, the value of the result is the same numerically as that of the unsigned integer. */ l = (unsigned)0100000; if((long)l > (unsigned)0100000){ rc = rc+8; if(pd0->flgd != 0) printf(s626er,8); } return rc; } /********************************************************************************************* the main loop that launches the sections *********************************************************************************************/ #ifndef NO_TYPELESS_STRUCT_PTR int section(int j,struct* pd0){ #else int section(int j,void* pd0){ #endif switch(j){ case 0: return s26(pd0); case 1: return s626(pd0); } } #define cq_sections 2 /* C REFERENCE MANUAL (main) */ #ifndef NO_OLD_FUNC_DECL main(n,args) int n; char **args; { #else int main(int n,char **args) { #endif int j; static struct defs d0, *pd0; d0.flgs = 1; /* These flags dictate */ d0.flgm = 1; /* the verbosity of */ d0.flgd = 1; /* the program. */ d0.flgl = 1; pd0 = &d0; for (j=0; j