--- _hdtoa.c.orig 2004-06-03 15:22:08.000000000 -0700
+++ _hdtoa.c 2004-08-28 17:10:21.000000000 -0700
@@ -32,6 +32,9 @@
#include <limits.h>
#include <math.h>
#include <stdlib.h>
+#ifdef LDBL_HEAD_TAIL_PAIR
+#include <alloca.h>
+#endif /* LDBL_HEAD_TAIL_PAIR */
#include "fpmath.h"
#include "gdtoaimp.h"
@@ -301,16 +304,31 @@
int pos;
int shift; /* for subnormals, # of shifts required to normalize */
int sigfigs; /* number of significant hex figures in result */
+#ifdef LDBL_HEAD_TAIL_PAIR
+ uint32_t bits[4];
+ int i;
+#endif /* LDBL_HEAD_TAIL_PAIR */
u.e = e;
*sign = u.bits.sign;
+#ifdef LDBL_HEAD_TAIL_PAIR
+ switch (__fpclassifyd(u.d[0])) {
+#else /* LDBL_HEAD_TAIL_PAIR */
switch (fpclassify(e)) {
+#endif /* LDBL_HEAD_TAIL_PAIR */
case FP_NORMAL:
+#ifdef LDBL_HEAD_TAIL_PAIR
sigfigs = (LDBL_MANT_DIG + 3) / 4;
impnbit = 1 << ((LDBL_MANT_DIG - 1) % 4);
*decpt = u.bits.exp - LDBL_BIAS + 1 -
((LDBL_MANT_DIG - 1) % 4);
+#else /* LDBL_HEAD_TAIL_PAIR */
+ sigfigs = (LDBL_MANT_DIG + 3) / 4;
+ impnbit = 1 << ((LDBL_MANT_DIG - 1) % 4);
+ *decpt = u.bits.exp - LDBL_BIAS + 1 -
+ ((LDBL_MANT_DIG - 1) % 4);
+#endif /* LDBL_HEAD_TAIL_PAIR */
break;
case FP_ZERO:
*decpt = 1;
@@ -328,13 +346,26 @@
/* Don't trust the normalization bit to be off. */
u.bits.manh &= ~(~0ULL << (LDBL_MANH_SIZE - 1));
#endif
+#ifndef LDBL_HEAD_TAIL_PAIR
if (u.bits.manh != 0) {
+#endif /* LDBL_HEAD_TAIL_PAIR */
#if LDBL_MANH_SIZE > 32
pos = log2_64(u.bits.manh);
#else
pos = log2_32(u.bits.manh);
#endif
shift = LDBL_MANH_SIZE - LDBL_NBIT_ADJ - pos;
+#ifdef LDBL_HEAD_TAIL_PAIR
+ sigfigs = (3 + LDBL_MANT_DIG - LDBL_NBIT_ADJ - shift) / 4;
+ // we use DBL_MIN_EXP below because the head double is
+ // subnormal (and the tail double is zero)
+ *decpt = DBL_MIN_EXP + LDBL_NBIT_ADJ;
+ pos = (LDBL_MANT_DIG + 3) % 4;
+ if (pos < shift)
+ *decpt -= pos + ((shift - pos + 3) & ~(4 - 1));
+ else
+ *decpt -= shift;
+#else /* LDBL_HEAD_TAIL_PAIR */
} else {
#if LDBL_MANL_SIZE > 32
pos = log2_64(u.bits.manl);
@@ -345,8 +376,9 @@
LDBL_NBIT_ADJ - pos;
}
sigfigs = (3 + LDBL_MANT_DIG - LDBL_NBIT_ADJ - shift) / 4;
- *decpt = LDBL_MIN_EXP + LDBL_NBIT_ADJ -
+ *decpt = DBL_MIN_EXP + LDBL_NBIT_ADJ -
((shift + 3) & ~(4 - 1));
+#endif /* LDBL_HEAD_TAIL_PAIR */
impnbit = 0;
break;
case FP_INFINITE:
@@ -381,6 +413,19 @@
*/
for (s = s0 + bufsize - 1; s > s0 + sigfigs - 1; s--)
*s = 0;
+#ifdef LDBL_HEAD_TAIL_PAIR
+ _ldbl2array32dd(u, bits);
+ i = 0;
+ pos = 8;
+ for (; s > s0; s--) {
+ *s = bits[i] & 0xf;
+ bits[i] >>= 4;
+ if (--pos <= 0) {
+ i++;
+ pos = 8;
+ }
+ }
+#else /* LDBL_HEAD_TAIL_PAIR */
for (; s > s0 + sigfigs - (LDBL_MANL_SIZE / 4) - 1 && s > s0; s--) {
*s = u.bits.manl & 0xf;
u.bits.manl >>= 4;
@@ -389,6 +434,7 @@
*s = u.bits.manh & 0xf;
u.bits.manh >>= 4;
}
+#endif /* LDBL_HEAD_TAIL_PAIR */
/*
* At this point, we have snarfed all the bits in the
@@ -398,7 +444,11 @@
* in manl instead for small subnormals. We also tack on the
* implicit normalization bit if appropriate.
*/
+#ifdef LDBL_HEAD_TAIL_PAIR
+ *s = bits[i] | impnbit;
+#else /* LDBL_HEAD_TAIL_PAIR */
*s = u.bits.manh | u.bits.manl | impnbit;
+#endif /* LDBL_HEAD_TAIL_PAIR */
/* If ndigits < 0, we are expected to auto-size the precision. */
if (ndigits < 0) {