Fix rintf rounding.

This commit is contained in:
Joseph Myers 2012-02-22 13:01:20 +00:00
parent ff3b3d8278
commit fe45ce09f3
4 changed files with 93 additions and 14 deletions

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@ -1,3 +1,14 @@
2012-02-22 Joseph Myers <joseph@codesourcery.com>
[BZ #2548]
* sysdeps/ieee754/flt-32/s_rintf.c (__rintf): Do not manipulate
bits before adding and subtracting TWO23[sx].
* math/libm-test.inc (rint_test): Add more tests.
(rint_test_tonearest): Likewise.
(rint_test_towardzero): Likewise.
(rint_test_downward): Likewise.
(rint_test_upward: Likewise.
2012-02-22 Joseph Myers <joseph@codesourcery.com>
[BZ #10110]

4
NEWS
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@ -9,8 +9,8 @@ Version 2.16
* The following bugs are resolved with this release:
174, 350, 411, 3335, 4026, 4596, 4822, 5077, 5805, 5993, 6884, 6907, 9739,
9902, 10110, 10140, 10210, 11174, 11322, 11494, 12047, 13058, 13525,
174, 350, 411, 2548, 3335, 4026, 4596, 4822, 5077, 5805, 5993, 6884, 6907,
9739, 9902, 10110, 10140, 10210, 11174, 11322, 11494, 12047, 13058, 13525,
13526, 13527, 13528, 13529, 13530, 13531, 13532, 13533, 13547, 13551,
13552, 13553, 13555, 13559, 13583, 13618, 13695, 13704

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@ -5037,6 +5037,22 @@ rint_test (void)
TEST_f_f (rint, 262142.75, 262143.0);
TEST_f_f (rint, 524286.75, 524287.0);
TEST_f_f (rint, 524288.75, 524289.0);
TEST_f_f (rint, 1048576.75, 1048577.0);
TEST_f_f (rint, 2097152.75, 2097153.0);
TEST_f_f (rint, -1048576.75, -1048577.0);
TEST_f_f (rint, -2097152.75, -2097153.0);
#ifndef TEST_FLOAT
TEST_f_f (rint, 70368744177664.75, 70368744177665.0);
TEST_f_f (rint, 140737488355328.75, 140737488355329.0);
TEST_f_f (rint, 281474976710656.75, 281474976710657.0);
TEST_f_f (rint, 562949953421312.75, 562949953421313.0);
TEST_f_f (rint, 1125899906842624.75, 1125899906842625.0);
TEST_f_f (rint, -70368744177664.75, -70368744177665.0);
TEST_f_f (rint, -140737488355328.75, -140737488355329.0);
TEST_f_f (rint, -281474976710656.75, -281474976710657.0);
TEST_f_f (rint, -562949953421312.75, -562949953421313.0);
TEST_f_f (rint, -1125899906842624.75, -1125899906842625.0);
#endif
#ifdef TEST_LDOUBLE
/* The result can only be represented in long double. */
TEST_f_f (rint, 4503599627370495.5L, 4503599627370496.0L);
@ -5137,6 +5153,22 @@ rint_test_tonearest (void)
TEST_f_f (rint, -0.1, -0.0);
TEST_f_f (rint, -0.25, -0.0);
TEST_f_f (rint, -0.625, -1.0);
TEST_f_f (rint, 1048576.75, 1048577.0);
TEST_f_f (rint, 2097152.75, 2097153.0);
TEST_f_f (rint, -1048576.75, -1048577.0);
TEST_f_f (rint, -2097152.75, -2097153.0);
#ifndef TEST_FLOAT
TEST_f_f (rint, 70368744177664.75, 70368744177665.0);
TEST_f_f (rint, 140737488355328.75, 140737488355329.0);
TEST_f_f (rint, 281474976710656.75, 281474976710657.0);
TEST_f_f (rint, 562949953421312.75, 562949953421313.0);
TEST_f_f (rint, 1125899906842624.75, 1125899906842625.0);
TEST_f_f (rint, -70368744177664.75, -70368744177665.0);
TEST_f_f (rint, -140737488355328.75, -140737488355329.0);
TEST_f_f (rint, -281474976710656.75, -281474976710657.0);
TEST_f_f (rint, -562949953421312.75, -562949953421313.0);
TEST_f_f (rint, -1125899906842624.75, -1125899906842625.0);
#endif
#ifdef TEST_LDOUBLE
/* The result can only be represented in long double. */
TEST_f_f (rint, 4503599627370495.5L, 4503599627370496.0L);
@ -5207,6 +5239,22 @@ rint_test_towardzero (void)
TEST_f_f (rint, -0.1, -0.0);
TEST_f_f (rint, -0.25, -0.0);
TEST_f_f (rint, -0.625, -0.0);
TEST_f_f (rint, 1048576.75, 1048576.0);
TEST_f_f (rint, 2097152.75, 2097152.0);
TEST_f_f (rint, -1048576.75, -1048576.0);
TEST_f_f (rint, -2097152.75, -2097152.0);
#ifndef TEST_FLOAT
TEST_f_f (rint, 70368744177664.75, 70368744177664.0);
TEST_f_f (rint, 140737488355328.75, 140737488355328.0);
TEST_f_f (rint, 281474976710656.75, 281474976710656.0);
TEST_f_f (rint, 562949953421312.75, 562949953421312.0);
TEST_f_f (rint, 1125899906842624.75, 1125899906842624.0);
TEST_f_f (rint, -70368744177664.75, -70368744177664.0);
TEST_f_f (rint, -140737488355328.75, -140737488355328.0);
TEST_f_f (rint, -281474976710656.75, -281474976710656.0);
TEST_f_f (rint, -562949953421312.75, -562949953421312.0);
TEST_f_f (rint, -1125899906842624.75, -1125899906842624.0);
#endif
#ifdef TEST_LDOUBLE
/* The result can only be represented in long double. */
TEST_f_f (rint, 4503599627370495.5L, 4503599627370495.0L);
@ -5277,6 +5325,22 @@ rint_test_downward (void)
TEST_f_f (rint, -0.1, -1.0);
TEST_f_f (rint, -0.25, -1.0);
TEST_f_f (rint, -0.625, -1.0);
TEST_f_f (rint, 1048576.75, 1048576.0);
TEST_f_f (rint, 2097152.75, 2097152.0);
TEST_f_f (rint, -1048576.75, -1048577.0);
TEST_f_f (rint, -2097152.75, -2097153.0);
#ifndef TEST_FLOAT
TEST_f_f (rint, 70368744177664.75, 70368744177664.0);
TEST_f_f (rint, 140737488355328.75, 140737488355328.0);
TEST_f_f (rint, 281474976710656.75, 281474976710656.0);
TEST_f_f (rint, 562949953421312.75, 562949953421312.0);
TEST_f_f (rint, 1125899906842624.75, 1125899906842624.0);
TEST_f_f (rint, -70368744177664.75, -70368744177665.0);
TEST_f_f (rint, -140737488355328.75, -140737488355329.0);
TEST_f_f (rint, -281474976710656.75, -281474976710657.0);
TEST_f_f (rint, -562949953421312.75, -562949953421313.0);
TEST_f_f (rint, -1125899906842624.75, -1125899906842625.0);
#endif
#ifdef TEST_LDOUBLE
/* The result can only be represented in long double. */
TEST_f_f (rint, 4503599627370495.5L, 4503599627370495.0L);
@ -5347,6 +5411,22 @@ rint_test_upward (void)
TEST_f_f (rint, -0.1, -0.0);
TEST_f_f (rint, -0.25, -0.0);
TEST_f_f (rint, -0.625, -0.0);
TEST_f_f (rint, 1048576.75, 1048577.0);
TEST_f_f (rint, 2097152.75, 2097153.0);
TEST_f_f (rint, -1048576.75, -1048576.0);
TEST_f_f (rint, -2097152.75, -2097152.0);
#ifndef TEST_FLOAT
TEST_f_f (rint, 70368744177664.75, 70368744177665.0);
TEST_f_f (rint, 140737488355328.75, 140737488355329.0);
TEST_f_f (rint, 281474976710656.75, 281474976710657.0);
TEST_f_f (rint, 562949953421312.75, 562949953421313.0);
TEST_f_f (rint, 1125899906842624.75, 1125899906842625.0);
TEST_f_f (rint, -70368744177664.75, -70368744177664.0);
TEST_f_f (rint, -140737488355328.75, -140737488355328.0);
TEST_f_f (rint, -281474976710656.75, -281474976710656.0);
TEST_f_f (rint, -562949953421312.75, -562949953421312.0);
TEST_f_f (rint, -1125899906842624.75, -1125899906842624.0);
#endif
#ifdef TEST_LDOUBLE
/* The result can only be represented in long double. */
TEST_f_f (rint, 4503599627370495.5L, 4503599627370496.0L);

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@ -26,34 +26,22 @@ float
__rintf(float x)
{
int32_t i0,j0,sx;
u_int32_t i,i1;
float w,t;
GET_FLOAT_WORD(i0,x);
sx = (i0>>31)&1;
j0 = ((i0>>23)&0xff)-0x7f;
if(j0<23) {
if(j0<0) {
if((i0&0x7fffffff)==0) return x;
i1 = (i0&0x07fffff);
i0 &= 0xfff00000;
i0 |= ((i1|-i1)>>9)&0x400000;
SET_FLOAT_WORD(x,i0);
w = TWO23[sx]+x;
t = w-TWO23[sx];
GET_FLOAT_WORD(i0,t);
SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
return t;
} else {
i = (0x007fffff)>>j0;
if((i0&i)==0) return x; /* x is integral */
i>>=1;
if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>j0);
}
} else {
if(j0==0x80) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
SET_FLOAT_WORD(x,i0);
w = TWO23[sx]+x;
return w-TWO23[sx];
}