attempt to reduce space usage
- remove unecessary code - ifdef "extra" code - pass data through globals instead of functions accessing static data - functions non-reentrant, locate tmps in xdata
This commit is contained in:
Jeff Wang
@ -7,13 +7,16 @@
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#include "../utils.h"
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#define EXTRA_CHECKS
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//#define DEBUG
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//#define DEBUG_COMPARE_MAGN
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//#define DEBUG_ADD
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//#define DEBUG_MULT
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//#define DEBUG_MULT_ALL //even more verbose
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//#define DEBUG_DIV
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#ifndef DESKTOP
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//#undef EXTRA_CHECKS
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#undef DEBUG
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#undef DEBUG_COMPARE_MAGN
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#undef DEBUG_ADD
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@ -34,9 +37,9 @@
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#include "decn.h"
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#ifdef DESKTOP
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uint8_t num_digits_display = DEC80_NUM_LSU*2;
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static const uint8_t num_digits_display = DEC80_NUM_LSU*2;
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#else
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uint8_t num_digits_display = 16;
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static const uint8_t num_digits_display = 16;
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#endif
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@ -168,7 +171,9 @@ void build_dec80(dec80* dest, const char* signif_str, int16_t exponent){
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if (!SEEN_POINT(curr_sign)){
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//begin tracking number of digits to right of decimal point
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curr_sign |= 1; //seen point
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} else {
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}
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#ifdef EXTRA_CHECKS
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else {
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//multiple '.'s in string
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#ifdef DEBUG
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printf(" ERROR: multiple '.'s in string\n");
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@ -176,6 +181,7 @@ void build_dec80(dec80* dest, const char* signif_str, int16_t exponent){
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set_dec80_NaN(dest);
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return;
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}
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#endif
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} else if (signif_str[i] >= '1' && signif_str[i] <= '9'){
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if (nibble_i < DEC80_NUM_LSU*2){
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if (nibble_i & 1) { //odd
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@ -245,6 +251,7 @@ void build_dec80(dec80* dest, const char* signif_str, int16_t exponent){
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assert(DEC80_NUM_LSU*2 > num_lr_points);
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new_exponent = exponent + (num_lr_points - 1); //1 digit left of implicit point
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//check for overflow
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#ifdef EXTRA_CHECKS
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if (new_exponent < exponent || exponent > DEC80_MAX_EXP){
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#ifdef DEBUG
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printf(" overflow (new_exp, exp)=(%d,%d)\n",
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@ -253,12 +260,14 @@ void build_dec80(dec80* dest, const char* signif_str, int16_t exponent){
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set_dec80_NaN(dest);
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return;
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}
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#endif
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} else if (num_lr_points < 0) { //right count exists
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// (-num_past_point represents #0s right of decimal)
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// (this ends up being a subtraction)
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new_exponent = exponent + num_lr_points;
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new_exponent -= 1; //decimal point after 1st non-zero number
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//check for underflow
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#ifdef EXTRA_CHECKS
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if (new_exponent > exponent || exponent < DEC80_MIN_EXP){
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#ifdef DEBUG
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printf(" underflow (new_exp, exp)=(%d,%d)\n",
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@ -267,6 +276,7 @@ void build_dec80(dec80* dest, const char* signif_str, int16_t exponent){
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set_dec80_NaN(dest);
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return;
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}
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#endif
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} else {
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//no change
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new_exponent = exponent;
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@ -319,6 +329,7 @@ static uint8_t decn_is_zero(const dec80* x){
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return 1;
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}
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#ifdef EXTRA_CHECKS
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void set_dec80_NaN(dec80* dest){
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uint8_t i;
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@ -329,6 +340,7 @@ void set_dec80_NaN(dec80* dest){
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dest->lsu[i] = 0;
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}
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}
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#endif
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void negate_decn(dec80* x){
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static const int16_t xor_val = -(0x7fff) - 1;
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@ -339,7 +351,7 @@ int8_t compare_magn(const dec80* a, const dec80* b){ //a<b: -1, a==b: 0, a>b: 1
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uint8_t a_i, b_i;
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int16_t a_exp=0, b_exp=0;
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int8_t a_signif_b = 0; //a<b: -1, a==b: 0, a>b: 1
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dec80 a_tmp, b_tmp;
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static __xdata dec80 a_tmp, b_tmp;
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//copy
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copy_decn(&a_tmp, a);
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copy_decn(&b_tmp, b);
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@ -448,7 +460,7 @@ static void _incr_exp(dec80* acc, int16_t exponent){
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static void sub_mag(dec80* acc, const dec80* x){
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int8_t i;
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uint8_t carry = 0;
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dec80 tmp;
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static __xdata dec80 tmp;
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copy_decn(&tmp, x);
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//normalize
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remove_leading_zeros(acc);
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@ -478,7 +490,7 @@ static void sub_mag(dec80* acc, const dec80* x){
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}
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void add_decn(dec80* acc, const dec80* x){
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dec80 tmp;
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static __xdata dec80 tmp;
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int8_t rel;
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uint8_t carry = 0;
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int8_t i;
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@ -599,8 +611,8 @@ void add_decn(dec80* acc, const dec80* x){
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}
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void mult_decn(dec80* acc, const dec80* x){
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dec80 tmp; //copy of x
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dec80 acc_tmp; //holds sum
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static __xdata dec80 tmp; //copy of x
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static __xdata dec80 acc_tmp; //holds sum
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int8_t i, j;
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uint8_t carry = 0;
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uint8_t is_neg;
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@ -631,7 +643,7 @@ void mult_decn(dec80* acc, const dec80* x){
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carry = digit100 / 100;
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assert(carry < 100);
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}
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#ifdef DEBUG_MULT
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#ifdef DEBUG_MULT_ALL
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printf("\n%d:", i);
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printf("\n acc:");
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for (j = 0; j < DEC80_NUM_LSU; j++){
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@ -644,6 +656,8 @@ void mult_decn(dec80* acc, const dec80* x){
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else
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printf(" ");
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}
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#endif
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#ifdef DEBUG_MULT
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printf("\n acc_tmp:");
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for (j = 0; j < DEC80_NUM_LSU; j++){
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printf(" %3d", acc_tmp.lsu[j]);
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@ -681,14 +695,16 @@ void mult_decn(dec80* acc, const dec80* x){
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}
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void div_decn(dec80* acc, const dec80* x){
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dec80 tmp; //copy of x, holds current 1/x estimate
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dec80 acc_copy; //holds copy of original acc
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static __xdata dec80 tmp; //copy of x, holds current 1/x estimate
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static __xdata dec80 acc_copy; //holds copy of original acc
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uint8_t i;
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//check divide by zero
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#ifdef EXTRA_CHECKS
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if (decn_is_zero(x)){
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set_dec80_NaN(acc);
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return;
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}
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#endif
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//store copy of acc for final multiply by 1/x
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copy_decn(&acc_copy, acc);
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//get initial estimate for 1/x, by negating exponent, and setting signif. to 1
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@ -702,24 +718,24 @@ void div_decn(dec80* acc, const dec80* x){
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for (i = 0; i < 20; i++){ //just fix number of iterations for now
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#ifdef DEBUG_DIV
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extern char Buf[80];
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dec80_to_str(buf, &tmp);
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printf("%2d: %s\n", i, buf);
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dec80_to_str(Buf, &tmp);
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printf("%2d: %s\n", i, Buf);
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#endif
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mult_decn(acc, x);
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#ifdef DEBUG_DIV
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dec80_to_str(buf, acc);
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printf(" %20s: %s\n", "recip*x", buf);
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dec80_to_str(Buf, acc);
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printf(" %20s: %s\n", "recip*x", Buf);
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#endif
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negate_decn(acc);
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add_decn(acc, &DECN_1);
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#ifdef DEBUG_DIV
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dec80_to_str(buf, acc);
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printf(" %20s: %s\n", "(1-recip*x)", buf);
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dec80_to_str(Buf, acc);
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printf(" %20s: %s\n", "(1-recip*x)", Buf);
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#endif
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mult_decn(acc, &tmp);
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#ifdef DEBUG_DIV
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dec80_to_str(buf, acc);
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printf(" %20s: %s\n", "recip * (1-recip*x)", buf);
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dec80_to_str(Buf, acc);
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printf(" %20s: %s\n", "recip * (1-recip*x)", Buf);
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#endif
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add_decn(acc, &tmp);
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//new_est(acc) = recip + (1 - recip*x)*recip, where tmp is current recip estimate
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@ -737,7 +753,7 @@ void dec80_to_str(char* buf, const dec80* x){
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int16_t exponent = 0;
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uint8_t trailing_zeros = 0;
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uint8_t use_sci = 0;
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dec80 tmp;
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static __xdata dec80 tmp;
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//copy and normalize
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copy_decn(&tmp, x);
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