summaryrefslogtreecommitdiff
path: root/lib/libc/gdtoa/gdtoa.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/libc/gdtoa/gdtoa.c')
-rw-r--r--lib/libc/gdtoa/gdtoa.c192
1 files changed, 98 insertions, 94 deletions
diff --git a/lib/libc/gdtoa/gdtoa.c b/lib/libc/gdtoa/gdtoa.c
index 33c5adf4c48..fd11de56001 100644
--- a/lib/libc/gdtoa/gdtoa.c
+++ b/lib/libc/gdtoa/gdtoa.c
@@ -125,6 +125,7 @@ gdtoa
the returned string. If not null, *rve is set to point
to the end of the return value. If d is +-Infinity or NaN,
then *decpt is set to 9999.
+ be = exponent: value = (integer represented by bits) * (2 to the power of be).
mode:
0 ==> shortest string that yields d when read in
@@ -159,8 +160,9 @@ gdtoa
int rdir, s2, s5, spec_case, try_quick;
Long L;
Bigint *b, *b1, *delta, *mlo, *mhi, *mhi1, *S;
- double d, d2, ds, eps;
+ double d2, ds;
char *s, *s0;
+ U d, eps;
#ifndef MULTIPLE_THREADS
if (dtoa_result) {
@@ -201,21 +203,21 @@ gdtoa
return nrv_alloc("0", rve, 1);
}
- dval(d) = b2d(b, &i);
+ dval(&d) = b2d(b, &i);
i = be + bbits - 1;
- word0(d) &= Frac_mask1;
- word0(d) |= Exp_11;
+ word0(&d) &= Frac_mask1;
+ word0(&d) |= Exp_11;
#ifdef IBM
- if ( (j = 11 - hi0bits(word0(d) & Frac_mask)) !=0)
- dval(d) /= 1 << j;
+ if ( (j = 11 - hi0bits(word0(&d) & Frac_mask)) !=0)
+ dval(&d) /= 1 << j;
#endif
/* log(x) ~=~ log(1.5) + (x-1.5)/1.5
* log10(x) = log(x) / log(10)
* ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
- * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
+ * log10(&d) = (i-Bias)*log(2)/log(10) + log10(d2)
*
- * This suggests computing an approximation k to log10(d) by
+ * This suggests computing an approximation k to log10(&d) by
*
* k = (i - Bias)*0.301029995663981
* + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
@@ -235,7 +237,7 @@ gdtoa
i <<= 2;
i += j;
#endif
- ds = (dval(d)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
+ ds = (dval(&d)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
/* correct assumption about exponent range */
if ((j = i) < 0)
@@ -250,13 +252,13 @@ gdtoa
#ifdef IBM
j = be + bbits - 1;
if ( (j1 = j & 3) !=0)
- dval(d) *= 1 << j1;
- word0(d) += j << Exp_shift - 2 & Exp_mask;
+ dval(&d) *= 1 << j1;
+ word0(&d) += j << Exp_shift - 2 & Exp_mask;
#else
- word0(d) += (be + bbits - 1) << Exp_shift;
+ word0(&d) += (be + bbits - 1) << Exp_shift;
#endif
if (k >= 0 && k <= Ten_pmax) {
- if (dval(d) < tens[k])
+ if (dval(&d) < tens[k])
k--;
k_check = 0;
}
@@ -286,11 +288,14 @@ gdtoa
mode -= 4;
try_quick = 0;
}
+ else if (i >= -4 - Emin || i < Emin)
+ try_quick = 0;
leftright = 1;
+ ilim = ilim1 = -1; /* Values for cases 0 and 1; done here to */
+ /* silence erroneous "gcc -Wall" warning. */
switch(mode) {
case 0:
case 1:
- ilim = ilim1 = -1;
i = (int)(nbits * .30103) + 3;
ndigits = 0;
break;
@@ -334,10 +339,10 @@ gdtoa
/* Try to get by with floating-point arithmetic. */
i = 0;
- d2 = dval(d);
+ d2 = dval(&d);
#ifdef IBM
- if ( (j = 11 - hi0bits(word0(d) & Frac_mask)) !=0)
- dval(d) /= 1 << j;
+ if ( (j = 11 - hi0bits(word0(&d) & Frac_mask)) !=0)
+ dval(&d) /= 1 << j;
#endif
k0 = k;
ilim0 = ilim;
@@ -348,7 +353,7 @@ gdtoa
if (j & Bletch) {
/* prevent overflows */
j &= Bletch - 1;
- dval(d) /= bigtens[n_bigtens-1];
+ dval(&d) /= bigtens[n_bigtens-1];
ieps++;
}
for(; j; j >>= 1, i++)
@@ -360,30 +365,30 @@ gdtoa
else {
ds = 1.;
if ( (j1 = -k) !=0) {
- dval(d) *= tens[j1 & 0xf];
+ dval(&d) *= tens[j1 & 0xf];
for(j = j1 >> 4; j; j >>= 1, i++)
if (j & 1) {
ieps++;
- dval(d) *= bigtens[i];
+ dval(&d) *= bigtens[i];
}
}
}
- if (k_check && dval(d) < 1. && ilim > 0) {
+ if (k_check && dval(&d) < 1. && ilim > 0) {
if (ilim1 <= 0)
goto fast_failed;
ilim = ilim1;
k--;
- dval(d) *= 10.;
+ dval(&d) *= 10.;
ieps++;
}
- dval(eps) = ieps*dval(d) + 7.;
- word0(eps) -= (P-1)*Exp_msk1;
+ dval(&eps) = ieps*dval(&d) + 7.;
+ word0(&eps) -= (P-1)*Exp_msk1;
if (ilim == 0) {
S = mhi = 0;
- dval(d) -= 5.;
- if (dval(d) > dval(eps))
+ dval(&d) -= 5.;
+ if (dval(&d) > dval(&eps))
goto one_digit;
- if (dval(d) < -dval(eps))
+ if (dval(&d) < -dval(&eps))
goto no_digits;
goto fast_failed;
}
@@ -392,38 +397,38 @@ gdtoa
/* Use Steele & White method of only
* generating digits needed.
*/
- dval(eps) = ds*0.5/tens[ilim-1] - dval(eps);
+ dval(&eps) = ds*0.5/tens[ilim-1] - dval(&eps);
for(i = 0;;) {
- L = (Long)(dval(d)/ds);
- dval(d) -= L*ds;
+ L = (Long)(dval(&d)/ds);
+ dval(&d) -= L*ds;
*s++ = '0' + (int)L;
- if (dval(d) < dval(eps)) {
- if (dval(d))
+ if (dval(&d) < dval(&eps)) {
+ if (dval(&d))
inex = STRTOG_Inexlo;
goto ret1;
}
- if (ds - dval(d) < dval(eps))
+ if (ds - dval(&d) < dval(&eps))
goto bump_up;
if (++i >= ilim)
break;
- dval(eps) *= 10.;
- dval(d) *= 10.;
+ dval(&eps) *= 10.;
+ dval(&d) *= 10.;
}
}
else {
#endif
/* Generate ilim digits, then fix them up. */
- dval(eps) *= tens[ilim-1];
- for(i = 1;; i++, dval(d) *= 10.) {
- if ( (L = (Long)(dval(d)/ds)) !=0)
- dval(d) -= L*ds;
+ dval(&eps) *= tens[ilim-1];
+ for(i = 1;; i++, dval(&d) *= 10.) {
+ if ( (L = (Long)(dval(&d)/ds)) !=0)
+ dval(&d) -= L*ds;
*s++ = '0' + (int)L;
if (i == ilim) {
ds *= 0.5;
- if (dval(d) > ds + dval(eps))
+ if (dval(&d) > ds + dval(&eps))
goto bump_up;
- else if (dval(d) < ds - dval(eps)) {
- if (dval(d))
+ else if (dval(&d) < ds - dval(&eps)) {
+ if (dval(&d))
inex = STRTOG_Inexlo;
goto clear_trailing0;
}
@@ -435,7 +440,7 @@ gdtoa
#endif
fast_failed:
s = s0;
- dval(d) = d2;
+ dval(&d) = d2;
k = k0;
ilim = ilim0;
}
@@ -447,22 +452,22 @@ gdtoa
ds = tens[k];
if (ndigits < 0 && ilim <= 0) {
S = mhi = 0;
- if (ilim < 0 || dval(d) <= 5*ds)
+ if (ilim < 0 || dval(&d) <= 5*ds)
goto no_digits;
goto one_digit;
}
- for(i = 1;; i++, dval(d) *= 10.) {
- L = dval(d) / ds;
- dval(d) -= L*ds;
+ for(i = 1;; i++, dval(&d) *= 10.) {
+ L = dval(&d) / ds;
+ dval(&d) -= L*ds;
#ifdef Check_FLT_ROUNDS
/* If FLT_ROUNDS == 2, L will usually be high by 1 */
- if (dval(d) < 0) {
+ if (dval(&d) < 0) {
L--;
- dval(d) += ds;
+ dval(&d) += ds;
}
#endif
*s++ = '0' + (int)L;
- if (dval(d) == 0.)
+ if (dval(&d) == 0.)
break;
if (i == ilim) {
if (rdir) {
@@ -471,8 +476,13 @@ gdtoa
inex = STRTOG_Inexlo;
goto ret1;
}
- dval(d) += dval(d);
- if (dval(d) > ds || dval(d) == ds && L & 1) {
+ dval(&d) += dval(&d);
+#ifdef ROUND_BIASED
+ if (dval(&d) >= ds)
+#else
+ if (dval(&d) > ds || (dval(&d) == ds && L & 1))
+#endif
+ {
bump_up:
inex = STRTOG_Inexhi;
while(*--s == '9')
@@ -499,13 +509,15 @@ gdtoa
m5 = b5;
mhi = mlo = 0;
if (leftright) {
- if (mode < 2) {
- i = nbits - bbits;
- if (be - i++ < fpi->emin)
- /* denormal */
- i = be - fpi->emin + 1;
+ i = nbits - bbits;
+ if (be - i++ < fpi->emin && mode != 3 && mode != 5) {
+ /* denormal */
+ i = be - fpi->emin + 1;
+ if (mode >= 2 && ilim > 0 && ilim < i)
+ goto small_ilim;
}
- else {
+ else if (mode >= 2) {
+ small_ilim:
j = ilim - 1;
if (m5 >= j)
m5 -= j;
@@ -547,13 +559,13 @@ gdtoa
b = pow5mult(b, j);
if (b == NULL)
return (NULL);
- }
+ }
}
else {
b = pow5mult(b, b5);
if (b == NULL)
return (NULL);
- }
+ }
}
S = i2b(1);
if (S == NULL)
@@ -562,7 +574,7 @@ gdtoa
S = pow5mult(S, s5);
if (S == NULL)
return (NULL);
- }
+ }
/* Check for special case that d is a normalized power of 2. */
@@ -583,35 +595,18 @@ gdtoa
* and for all and pass them and a shift to quorem, so it
* can do shifts and ors to compute the numerator for q.
*/
-#ifdef Pack_32
- if ( (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f) !=0)
- i = 32 - i;
-#else
- if ( (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf) !=0)
- i = 16 - i;
-#endif
- if (i > 4) {
- i -= 4;
- b2 += i;
- m2 += i;
- s2 += i;
- }
- else if (i < 4) {
- i += 28;
- b2 += i;
- m2 += i;
- s2 += i;
- }
- if (b2 > 0) {
+ i = ((s5 ? hi0bits(S->x[S->wds-1]) : ULbits - 1) - s2 - 4) & kmask;
+ m2 += i;
+ if ((b2 += i) > 0) {
b = lshift(b, b2);
if (b == NULL)
return (NULL);
- }
- if (s2 > 0) {
+ }
+ if ((s2 += i) > 0) {
S = lshift(S, s2);
if (S == NULL)
return (NULL);
- }
+ }
if (k_check) {
if (cmp(b,S) < 0) {
k--;
@@ -622,15 +617,15 @@ gdtoa
mhi = multadd(mhi, 10, 0);
if (mhi == NULL)
return (NULL);
- }
+ }
ilim = ilim1;
}
}
if (ilim <= 0 && mode > 2) {
- S = multadd(S, 5, 0);
+ S = multadd(S,5,0);
if (S == NULL)
return (NULL);
- if (ilim < 0 || cmp(b, S) <= 0) {
+ if (ilim < 0 || cmp(b,S) <= 0) {
/* no digits, fcvt style */
no_digits:
k = -1 - ndigits;
@@ -648,7 +643,7 @@ gdtoa
mhi = lshift(mhi, m2);
if (mhi == NULL)
return (NULL);
- }
+ }
/* Compute mlo -- check for special case
* that d is a normalized power of 2.
@@ -692,11 +687,11 @@ gdtoa
goto ret;
}
#endif
- if (j < 0 || j == 0 && !mode
+ if (j < 0 || (j == 0 && !mode
#ifndef ROUND_BIASED
&& !(bits[0] & 1)
#endif
- ) {
+ )) {
if (rdir && (b->wds > 1 || b->x[0])) {
if (rdir == 2) {
inex = STRTOG_Inexlo;
@@ -725,7 +720,11 @@ gdtoa
if (b == NULL)
return (NULL);
j1 = cmp(b, S);
- if ((j1 > 0 || j1 == 0 && dig & 1)
+#ifdef ROUND_BIASED
+ if (j1 >= 0 /*)*/
+#else
+ if ((j1 > 0 || (j1 == 0 && dig & 1))
+#endif
&& dig++ == '9')
goto round_9_up;
inex = STRTOG_Inexhi;
@@ -757,7 +756,7 @@ gdtoa
mlo = mhi = multadd(mhi, 10, 0);
if (mlo == NULL)
return (NULL);
- }
+ }
else {
mlo = multadd(mlo, 10, 0);
if (mlo == NULL)
@@ -781,7 +780,7 @@ gdtoa
/* Round off last digit */
if (rdir) {
- if (rdir == 2 || b->wds <= 1 && !b->x[0])
+ if (rdir == 2 || (b->wds <= 1 && !b->x[0]))
goto chopzeros;
goto roundoff;
}
@@ -789,7 +788,12 @@ gdtoa
if (b == NULL)
return (NULL);
j = cmp(b, S);
- if (j > 0 || j == 0 && dig & 1) {
+#ifdef ROUND_BIASED
+ if (j >= 0)
+#else
+ if (j > 0 || (j == 0 && dig & 1))
+#endif
+ {
roundoff:
inex = STRTOG_Inexhi;
while(*--s == '9')
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-22 20:37:14 +0000