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authorRoland McGrath <roland@gnu.org>2006-03-16 23:17:32 +0000
committerRoland McGrath <roland@gnu.org>2006-03-16 23:17:32 +0000
commit830fce0415390c4a7326fe91ad678fd987a1c53f (patch)
tree839393ec850233231d49b8cc3cfd02aece5aa675 /sysdeps/ieee754/ldbl-128ibm/s_llroundl.c
parent27c0e0d8630de8efbbd633ffb425c85515a5e89d (diff)
downloadglibc-830fce0415390c4a7326fe91ad678fd987a1c53f.tar.gz
[BZ #2466]
* math/gen-libm-test.pl (parse_args): Take function name for pretty output as an argument. (generate_testfile): Pass it the name given in the START macro. [BZ #2466] * math/libm-test.inc (llrint_test, llround_test): Fix last change to protect large-precision cases with [LDBL_MANT_DIG > 100]. (llrint_test_tonearest, llrint_test_towardzero): Likewise. (llrint_test_downward, llrint_test_upward): Likewise. 2006-03-15 Steven Munroe <sjmunroe@us.ibm.com> Alan Modra <amodra@bigpond.net.au> [BZ #2466] * math/libm-test.inc (llrint_test, llround_test) [TEST_LDOUBLE]: Add new test values. (llrint_test_tonearest, llrint_test_towardzero, llrint_test_downward, llrint_test_upward): New functions. (main): Call them. * sysdeps/ieee754/ldbl-128ibm/s_llrintl.c (__llrintl): Handle rounding that spans doubles in IBM long double format. * sysdeps/ieee754/ldbl-128ibm/s_llroundl.c (__llroundl): Likewise. * sysdeps/powerpc/powerpc64/fpu/s_llrintl.S: Removed. * sysdeps/powerpc/powerpc64/fpu/s_llroundl.S: Removed. * sysdeps/powerpc/powerpc64/fpu/s_lrintl.S: Removed. * sysdeps/powerpc/powerpc64/fpu/s_lroundl.S: Removed. 2006-03-16 Roland McGrath <roland@redhat.com>
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_llroundl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_llroundl.c158
1 files changed, 80 insertions, 78 deletions
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);