/* !!DESCRIPTION!! C-Manual Chapter 4: what's in a name? !!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; #ifdef NO_IMPLICIT_FUNC_PROTOTYPES int s4(struct defs *pd0); int svtest(int n); zero(); testev(); setev(); #endif #ifndef NO_OLD_FUNC_DECL s4(pd0) /* 4. What's in a name? */ struct defs *pd0; { #else int s4(struct defs *pd0) { #endif static char s4er[] = "s4,er%d\n"; static char qs4[8] = "s4 "; char *ps, *pt; int j, rc; short sint; /* short integer, for size test */ int pint; /* plain */ long lint; /* long */ unsigned target; unsigned int mask; rc = 0; ps = qs4; pt = pd0->rfs; while(*pt++ = *ps++); /* There are four declarable storage classes: automatic, static, external, and register. Automatic variables have been dealt with extensively thus far, and will not be specif- ically treated in this section. Register variables are treated in section s81. Static variables are local to a block, but retain their values upon reentry to a block, even after control has left the block. */ for (j=0; j<3; j++) if(svtest(j) != zero()){ rc = 1; if(pd0->flgd != 0) printf(s4er,1); } ; /* External variables exist and retain their values throughout the execution of the entire program, and may be used for comm- unication between functions, even separately compiled functions. */ setev(); if(testev() != 0){ rc=rc+2; if(pd0->flgd != 0) printf(s4er,2); } /* Characters have been tested elsewhere (in s243). Up to three sizes of integer, declared short int, int, and long int, are available. Longer integers provide no less storage than shorter ones, but implementation may make either short integers, or long integers, or both, equivalent to plain integers. */ if(sizeof lint < sizeof pint || sizeof pint < sizeof sint){ rc = rc+4; if(pd0->flgd != 0) printf(s4er,4); } /* Unsigned integers, declared unsigned, obey the laws of arithmetic modulo 2**n, where n is the number of bits in the implementation */ target = ~0U; mask = 1; printf("sizeof target: %08x pd0->cbits: %08x\n", sizeof target, pd0->cbits); printf("mask: %08x target: %08x\n", mask, target); for(j=0; j<(sizeof target)*pd0->cbits; j++){ mask = mask⌖ target = target>>1; printf("mask: %08x target: %08x\n", mask, target); } if(mask != 1 || target != 0){ rc = rc+8; if(pd0->flgd != 0) printf(s4er,8); } return rc; } #ifndef NO_OLD_FUNC_DECL svtest(n) int n; { #else int svtest(int n) { #endif static k; int rc; switch (n) { case 0: k = 1978; rc = 0; break; case 1: if(k != 1978) rc = 1; else{ k = 1929; rc = 0; } break; case 2: if(k != 1929) rc = 1; else rc = 0; break; } return rc; } zero(){ /* Returns a value of zero, possibly */ static k; /* with side effects, as it's called */ int rc; /* alternately with svtest, above, */ k = 2; /* and has the same internal storage */ rc = 0; /* requirements. */ return rc; } testev(){ if(extvar != 1066) return 1; else return 0; } /* Sets an external variable. Used */ /* by s4, and should be compiled */ /* separately from s4. */ setev(){ #ifndef NO_SLOPPY_EXTERN extern int extvar; #endif extvar = 1066; } /********************************************************************************************* 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 s4(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