aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/ieee754
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_llrintl.c168
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_llroundl.c158
2 files changed, 177 insertions, 149 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
index bacf1bee0d..7228489098 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
@@ -22,6 +22,7 @@
when it's coded in C. */
#include <math.h>
+#include <fenv_libc.h>
#include <math_ldbl_opt.h>
#include <float.h>
#include <ieee754.h>
@@ -36,89 +37,114 @@ __llrintl (x)
long double x;
#endif
{
- static const double TWO52 = 4503599627370496.0L;
- union ibm_extended_long_double u;
- long long result = __LONG_LONG_MAX__;
+ double xh, xl;
+ long long res, hi, lo;
+ int save_round;
- u.d = x;
+ ldbl_unpack (x, &xh, &xl);
- if (fabs (u.dd[0]) < TWO52)
+ /* Limit the range of values handled by the conversion to long long.
+ We do this because we aren't sure whether that conversion properly
+ raises FE_INVALID. */
+ if (__builtin_expect
+ ((__builtin_fabs (xh) <= -(double) (-__LONG_LONG_MAX__ - 1)), 1)
+#if !defined (FE_INVALID)
+ || 1
+#endif
+ )
{
- double high = u.dd[0];
- if (high > 0.0)
- {
- high += TWO52;
- high -= TWO52;
- if (high == -0.0) high = 0.0;
- }
- else if (high < 0.0)
+ save_round = fegetround ();
+
+ if (__builtin_expect ((xh == -(double) (-__LONG_LONG_MAX__ - 1)), 0))
{
- high -= TWO52;
- high += TWO52;
- if (high == 0.0) high = -0.0;
+ /* When XH is 9223372036854775808.0, converting to long long will
+ overflow, resulting in an invalid operation. However, XL might
+ be negative and of sufficient magnitude that the overall long
+ double is in fact in range. Avoid raising an exception. In any
+ case we need to convert this value specially, because
+ the converted value is not exactly represented as a double
+ thus subtracting HI from XH suffers rounding error. */
+ hi = __LONG_LONG_MAX__;
+ xh = 1.0;
}
- result = high;
- }
- else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
- {
- double high, low, tau;
- long long lowint;
- /* In this case we have to round the low double and handle any
- adjustment to the high double that may be caused by rounding
- (up). This is complicated by the fact that the high double
- may already be rounded and the low double may have the
- opposite sign to compensate. */
- if (u.dd[0] > 0.0)
+ else
{
- if (u.dd[1] > 0.0)
- {
- /* If the high/low doubles are the same sign then simply
- round the low double. */
- high = u.dd[0];
- low = u.dd[1];
- }
- else if (u.dd[1] < 0.0)
- {
- /* Else the high double is pre rounded and we need to
- adjust for that. */
-
- tau = nextafter (u.dd[0], 0.0);
- tau = (u.dd[0] - tau) * 2.0;
- high = u.dd[0] - tau;
- low = u.dd[1] + tau;
- }
- low += TWO52;
- low -= TWO52;
+ hi = (long long) xh;
+ xh -= hi;
}
- else if (u.dd[0] < 0.0)
+ ldbl_canonicalize (&xh, &xl);
+
+ lo = (long long) xh;
+
+ /* Peg at max/min values, assuming that the above conversions do so.
+ Strictly speaking, we can return anything for values that overflow,
+ but this is more useful. */
+ res = hi + lo;
+
+ /* This is just sign(hi) == sign(lo) && sign(res) != sign(hi). */
+ if (__builtin_expect (((~(hi ^ lo) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ xh -= lo;
+ ldbl_canonicalize (&xh, &xl);
+
+ hi = res;
+ switch (save_round)
{
- if (u.dd[1] < 0.0)
- {
- /* If the high/low doubles are the same sign then simply
- round the low double. */
- high = u.dd[0];
- low = u.dd[1];
- }
- else if (u.dd[1] > 0.0)
- {
- /* Else the high double is pre rounded and we need to
- adjust for that. */
- tau = nextafter (u.dd[0], 0.0);
- tau = (u.dd[0] - tau) * 2.0;
- high = u.dd[0] - tau;
- low = u.dd[1] + tau;
- }
- low = TWO52 - low;
- low = -(low - TWO52);
+ case FE_TONEAREST:
+ if (fabs (xh) < 0.5
+ || (fabs (xh) == 0.5
+ && ((xh > 0.0 && xl < 0.0)
+ || (xh < 0.0 && xl > 0.0)
+ || (xl == 0.0 && (res & 1) == 0))))
+ return res;
+
+ if (xh < 0.0)
+ res -= 1;
+ else
+ res += 1;
+ break;
+
+ case FE_TOWARDZERO:
+ if (res > 0 && (xh < 0.0 || (xh == 0.0 && xl < 0.0)))
+ res -= 1;
+ else if (res < 0 && (xh > 0.0 || (xh == 0.0 && xl > 0.0)))
+ res += 1;
+ return res;
+ break;
+
+ case FE_UPWARD:
+ if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+ res += 1;
+ break;
+
+ case FE_DOWNWARD:
+ if (xh < 0.0 || (xh == 0.0 && xl < 0.0))
+ res -= 1;
+ break;
}
- lowint = low;
- result = high;
- result += lowint;
+
+ if (__builtin_expect (((~(hi ^ (res - hi)) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ return res;
}
else
- result = u.dd[0];
+ {
+ if (xh > 0.0)
+ hi = __LONG_LONG_MAX__;
+ else if (xh < 0.0)
+ hi = -__LONG_LONG_MAX__ - 1;
+ else
+ /* Nan */
+ hi = 0;
+ }
- return result;
+overflow:
+#ifdef FE_INVALID
+ feraiseexcept (FE_INVALID);
+#endif
+ return hi;
}
long_double_symbol (libm, __llrintl, llrintl);
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_llroundl.c b/sysdeps/ieee754/ldbl-128ibm/s_llroundl.c
index 567e7ecc07..103529d5a1 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_llroundl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_llroundl.c
@@ -22,12 +22,11 @@
when it's coded in C. */
#include <math.h>
-#include <fenv.h>
+#include <fenv_libc.h>
#include <math_ldbl_opt.h>
#include <float.h>
#include <ieee754.h>
-
#ifdef __STDC__
long long
__llroundl (long double x)
@@ -37,92 +36,95 @@ __llroundl (x)
long double x;
#endif
{
- static const double TWO52 = 4503599627370496.0;
- static const double HALF = 0.5;
- int mode = fegetround();
- union ibm_extended_long_double u;
- long long result = __LONG_LONG_MAX__;
-
- u.d = x;
-
- if (fabs (u.dd[0]) < TWO52)
- {
- fesetround(FE_TOWARDZERO);
- if (u.dd[0] > 0.0)
+ double xh, xl;
+ long long res, hi, lo;
+
+ ldbl_unpack (x, &xh, &xl);
+
+ /* Limit the range of values handled by the conversion to long long.
+ We do this because we aren't sure whether that conversion properly
+ raises FE_INVALID. */
+ if (__builtin_expect
+ ((__builtin_fabs (xh) <= -(double) (-__LONG_LONG_MAX__ - 1)), 1)
+#if !defined (FE_INVALID)
+ || 1
+#endif
+ )
+ {
+ if (__builtin_expect ((xh == -(double) (-__LONG_LONG_MAX__ - 1)), 0))
{
- u.dd[0] += HALF;
- u.dd[0] += TWO52;
- u.dd[0] -= TWO52;
+ /* When XH is 9223372036854775808.0, converting to long long will
+ overflow, resulting in an invalid operation. However, XL might
+ be negative and of sufficient magnitude that the overall long
+ double is in fact in range. Avoid raising an exception. In any
+ case we need to convert this value specially, because
+ the converted value is not exactly represented as a double
+ thus subtracting HI from XH suffers rounding error. */
+ hi = __LONG_LONG_MAX__;
+ xh = 1.0;
}
- else if (u.dd[0] < 0.0)
+ else
{
- u.dd[0] = TWO52 - (u.dd[0] - HALF);
- u.dd[0] = -(u.dd[0] - TWO52);
+ hi = (long long) xh;
+ xh -= hi;
}
- fesetround(mode);
- result = u.dd[0];
- }
- else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
- {
- double high, low;
- long long lowint;
- /* In this case we have to round the low double and handle any
- adjustment to the high double that may be caused by rounding
- (up). This is complicated by the fact that the high double
- may already be rounded and the low double may have the
- opposite sign to compensate. */
- if (u.dd[0] > 0.0)
+ ldbl_canonicalize (&xh, &xl);
+
+ lo = (long long) xh;
+
+ /* Peg at max/min values, assuming that the above conversions do so.
+ Strictly speaking, we can return anything for values that overflow,
+ but this is more useful. */
+ res = hi + lo;
+
+ /* This is just sign(hi) == sign(lo) && sign(res) != sign(hi). */
+ if (__builtin_expect (((~(hi ^ lo) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ xh -= lo;
+ ldbl_canonicalize (&xh, &xl);
+
+ hi = res;
+ if (xh > 0.5)
+ {
+ res += 1;
+ }
+ else if (xh == 0.5)
{
- if (u.dd[1] > 0.0)
- {
- /* If the high/low doubles are the same sign then simply
- round the low double. */
- high = u.dd[0];
- low = u.dd[1];
- }
- else if (u.dd[1] < 0.0)
- {
- /* Else the high double is pre rounded and we need to
- adjust for that. */
- high = nextafter (u.dd[0], 0.0);
- low = u.dd[1] + (u.dd[0] - high);
- }
- fesetround(FE_TOWARDZERO);
- low += HALF;
- low += TWO52;
- low -= TWO52;
+ if (xl > 0.0 || (xl == 0.0 && res >= 0))
+ res += 1;
}
- else if (u.dd[0] < 0.0)
+ else if (-xh > 0.5)
{
- if (u.dd[1] < 0.0)
- {
- /* If the high/low doubles are the same sign then simply
- round the low double. */
- high = u.dd[0];
- low = u.dd[1];
- }
- else if (u.dd[1] > 0.0)
- {
- /* Else the high double is pre rounded and we need to
- adjust for that. */
- high = nextafter (u.dd[0], 0.0);
- low = u.dd[1] + (u.dd[0] - high);
- }
- fesetround(FE_TOWARDZERO);
- low -= HALF;
- low = TWO52 - low;
- low = -(low - TWO52);
+ res -= 1;
}
- fesetround(mode);
- lowint = low;
- result = high;
- result += lowint;
+ else if (-xh == 0.5)
+ {
+ if (xl < 0.0 || (xl == 0.0 && res <= 0))
+ res -= 1;
+ }
+
+ if (__builtin_expect (((~(hi ^ (res - hi)) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ return res;
}
else
- {
- result = u.dd[0];
- }
- return result;
+ {
+ if (xh > 0.0)
+ hi = __LONG_LONG_MAX__;
+ else if (xh < 0.0)
+ hi = -__LONG_LONG_MAX__ - 1;
+ else
+ /* Nan */
+ hi = 0;
+ }
+
+overflow:
+#ifdef FE_INVALID
+ feraiseexcept (FE_INVALID);
+#endif
+ return hi;
}
long_double_symbol (libm, __llroundl, llroundl);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 12:35:37 +0000