Return to bcmch.c CVS log

Up to [MW Coherent from dump] / coherent / d / bin / bc

Annotation of coherent/d/bin/bc/bcmch.c, revision 1.1

1.1     ! root        1: #include <stdio.h>
        !             2: #include <assert.h>
        !             3: #include "bc.h"
        !             4: 
        !             5: /*
        !             6:  *     Sscale takes the rvalue pointed to by lval and sets
        !             7:  *     the scale register to it if it is in range (ie. non-negative
        !             8:  *     and small enough to fit in an int).
        !             9:  */
        !            10: 
        !            11: sscale(lval)
        !            12: rvalue *lval;
        !            13: {
        !            14:        register int    res;
        !            15: 
        !            16:        res = rtoint(lval);
        !            17:        if (res < 0)
        !            18:                bcmerr("Invalid scale register value");
        !            19:        scale = res;
        !            20: }
        !            21: 
        !            22: /*
        !            23:  *     Bcclean frees up the automatic variables and parameters on
        !            24:  *     function exit.  `fnc' is the function from which we are returning
        !            25:  *     and `stkp' is a pointer to the top thing to remove.
        !            26:  */
        !            27: 
        !            28: bcclean(fnc, stkp)
        !            29: func   *fnc;
        !            30: stkent *stkp;
        !            31: {
        !            32:        register type   *tp;
        !            33:        register int    left;
        !            34: 
        !            35:        tp = &fnc->types[fnc->nautos + fnc->nparams];
        !            36:        for (left = fnc->nautos; --left >= 0; --stkp)
        !            37:                switch (*--tp) {
        !            38:                case SCALAR:
        !            39:                        mvfree(&stkp->rvalue.mantissa);
        !            40:                        break;
        !            41:                case ARRAY:
        !            42:                        arfree(stkp->alvalue);
        !            43:                        mpfree(stkp->alvalue);
        !            44:                        break;
        !            45:                default:
        !            46:                        assert(FALSE);
        !            47:                }
        !            48:        for (left = fnc->nparams; --left >= 0; --stkp)
        !            49:                switch (*--tp) {
        !            50:                case SCALAR:
        !            51:                        mvfree(&stkp->rvalue.mantissa);
        !            52:                        break;
        !            53:                case ARRAY:
        !            54:                        break;
        !            55:                default:
        !            56:                        assert(FALSE);
        !            57:                }
        !            58: }
        !            59: 
        !            60: /*
        !            61:  *     Bcadd adds the rvalue pointed to by `src' to that pointed to
        !            62:  *     by `dst'.  Note that `src' is freed.
        !            63:  */
        !            64: 
        !            65: bcadd(src, dst)
        !            66: register rvalue        *src, *dst;
        !            67: {
        !            68:        if (dst->scale >= src->scale)
        !            69:                rescale(src, dst->scale);
        !            70:        else
        !            71:                rescale(dst, src->scale);
        !            72:        madd(&dst->mantissa, &src->mantissa, &dst->mantissa);
        !            73:        mvfree(&src->mantissa);
        !            74: }
        !            75: 
        !            76: /*
        !            77:  *     Bcmul multiplies the rvalue pointed to by `dst' by that
        !            78:  *     pointed to by `src'.  Note that `src' is freed.
        !            79:  *     The scale factor of the result is set to
        !            80:  *     min( src->scale + dst->scale, max(scale, src->scale, dst->scale)).
        !            81:  */
        !            82: 
        !            83: bcmul(src, dst)
        !            84: register rvalue *src, *dst;
        !            85: {
        !            86:        register int    scl;
        !            87: 
        !            88:        mult(&dst->mantissa, &src->mantissa, &dst->mantissa);
        !            89:        mvfree(&src->mantissa);
        !            90:        scl = src->scale;
        !            91:        if (scl < scale)
        !            92:                scl = scale;
        !            93:        if (scl < dst->scale)
        !            94:                scl = dst->scale;
        !            95:        dst->scale += src->scale;
        !            96:        if (scl < dst->scale)
        !            97:                rescale(dst, scl);
        !            98: }
        !            99: 
        !           100: /*
        !           101:  *     Bcdiv divides the rvalue pointed to by `dst' by that pointed
        !           102:  *     to by `src'.  Note that `src' is freed.  The scale of the
        !           103:  *     result is alway equal to the value of the scale register.
        !           104:  */
        !           105: 
        !           106: bcdiv(src, dst)
        !           107: register rvalue        *src, *dst;
        !           108: {
        !           109:        if (zerop(&src->mantissa))
        !           110:                bcmerr("Division by zero");
        !           111:        rescale(dst, src->scale + scale);
        !           112:        mdiv(&dst->mantissa, &src->mantissa, &dst->mantissa, &src->mantissa);
        !           113:        dst->scale = scale;
        !           114:        mvfree(&src->mantissa);
        !           115: }
        !           116: 
        !           117: /*
        !           118:  *     Bcrem sets the rvalue pointed to by `dst' to the remainder one
        !           119:  *     would get when divideing `dst' by `src'.  Note that `src' is freed.
        !           120:  */
        !           121: 
        !           122: bcrem(src, dst)
        !           123: register rvalue *src, *dst;
        !           124: {
        !           125:        if (zerop(&src->mantissa))
        !           126:                bcmerr("Modulo zero");
        !           127:        rescale(dst, src->scale + scale);
        !           128:        mdiv(&dst->mantissa, &src->mantissa, &src->mantissa, &dst->mantissa);
        !           129:        mvfree(&src->mantissa);
        !           130: }
        !           131: 
        !           132: /*
        !           133:  *     Bcexp raises the rvalue pointed to by `dst' to the `src' power.
        !           134:  *     Note that first `src' is truncated to an integer.  Note that
        !           135:  *     `src' is freed.  The scale factor of the result is as if the
        !           136:  *     corresponding multiplications had been done.
        !           137:  *     Negative exponents are computed by inverting dst.
        !           138:  */
        !           139: 
        !           140: bcexp(src, dst)
        !           141: register rvalue        *src, *dst;
        !           142: {
        !           143:        register int    limit;
        !           144:        rvalue          temp;
        !           145:        int             rem;
        !           146: 
        !           147:        minit(&temp.mantissa);
        !           148:        if ( ! ispos(&src->mantissa)) {
        !           149:                mneg(&src->mantissa, &src->mantissa);
        !           150:                mcopy(mone, &temp.mantissa);
        !           151:                temp.scale = 0;
        !           152:                bcdiv(dst, &temp);
        !           153:                *dst = temp;
        !           154:                minit(&temp.mantissa);
        !           155:        }
        !           156:        shift(&src->mantissa, - src->scale, &temp.mantissa);
        !           157:        sdiv(&temp.mantissa, 2, &temp.mantissa, &rem);
        !           158:        if (rem == 0) {
        !           159:                mvfree(&src->mantissa);
        !           160:                *src = *dst;
        !           161:                minit(&dst->mantissa);
        !           162:                mcopy(mone, &dst->mantissa);
        !           163:                dst->scale = 0;
        !           164:        } else {
        !           165:                mcopy(&dst->mantissa, &src->mantissa);
        !           166:                src->scale = dst->scale;
        !           167:        }
        !           168:        limit = (src->scale > scale ? src->scale : scale);
        !           169:        while (!zerop(&temp.mantissa)) {
        !           170:                mult(&src->mantissa, &src->mantissa, &src->mantissa);
        !           171:                src->scale *= 2;
        !           172:                if (src->scale > limit)
        !           173:                        rescale(src, limit);
        !           174:                sdiv(&temp.mantissa, 2, &temp.mantissa, &rem);
        !           175:                if (rem != 0) {
        !           176:                        mult(&src->mantissa, &dst->mantissa, &dst->mantissa);
        !           177:                        dst->scale += src->scale;
        !           178:                        if (dst->scale > limit)
        !           179:                                rescale(dst, limit);
        !           180:                }
        !           181:        }
        !           182:        mvfree(&temp.mantissa);
        !           183:        mvfree(&src->mantissa);
        !           184: }
        !           185: 
        !           186: /*
        !           187:  *     Bcsqrt relaces the rvalue pointed to by `dst' with its
        !           188:  *     square root.  The scale factor of the result is the maximum
        !           189:  *     of the scale register and of the scale of the argument.
        !           190:  */
        !           191: 
        !           192: bcsqrt(dst)
        !           193: register rvalue        *dst;
        !           194: {
        !           195:        register int    prec;
        !           196:        mint            temp;
        !           197: 
        !           198:        if ( ! ispos(&dst->mantissa))
        !           199:                bcmerr("Square root of negative");
        !           200:        prec = scale;
        !           201:        if (prec < dst->scale)
        !           202:                prec = dst->scale;
        !           203:        rescale(dst, 2 * prec);
        !           204:        minit(&temp);
        !           205:        msqrt(&dst->mantissa, &dst->mantissa, &temp);
        !           206:        mvfree(&temp);
        !           207:        dst->scale = prec;
        !           208: }
        !           209: 
        !           210: /*
        !           211:  *     Bccmp returns an int which compares to zero as the rvalue `dst'
        !           212:  *     compares to the rvalue `src'.  Note that both `src' and `dst'
        !           213:  *     are freed.
        !           214:  */
        !           215: 
        !           216: bccmp(src, dst)
        !           217: register rvalue        *src, *dst;
        !           218: {
        !           219:        register int    res;
        !           220: 
        !           221:        if (dst->scale >= src->scale)
        !           222:                rescale(src, dst->scale);
        !           223:        else
        !           224:                rescale(dst, src->scale);
        !           225:        res = mcmp(&dst->mantissa, &src->mantissa);
        !           226:        mvfree(&src->mantissa);
        !           227:        mvfree(&dst->mantissa);
        !           228:        return (res);
        !           229: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.