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Fix nearbyintf rounding.

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(cherry-picked from commit 6cbeae4719)
This commit is contained in:
Joseph Myers 2012-02-22 13:03:40 +00:00 committed by Carlos O'Donell
parent 21902de70d
commit e02cc8de8c
4 changed files with 32 additions and 13 deletions
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8
ChangeLog
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@ -1,3 +1,11 @@
2012-02-22 Joseph Myers <joseph@codesourcery.com>
[BZ #2547]
[BZ #11365]
* sysdeps/ieee754/flt-32/s_nearbyintf.c (__nearbyintf): Do not
manipulate bits before adding and subtracting TWO23[sx].
* math/libm-test.inc (nearbyint_test): Add more tests.
2012-02-21 David S. Miller <davem@davemloft.net>
* sysdeps/sparc/sparc32/fpu/libm-test-ulps: More jn test ULP updates.

2
NEWS
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@ -9,7 +9,7 @@ Version 2.15.1
* The following bugs are resolved with this release:
411, 13731, 13732, 13748
411, 2547, 11365, 13731, 13732, 13748
Version 2.15

23
math/libm-test.inc
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@ -4633,6 +4633,29 @@ nearbyint_test (void)
TEST_f_f (nearbyint, 524286.75, 524287.0);
TEST_f_f (nearbyint, 524288.75, 524289.0);
TEST_f_f (nearbyint, 1048576.75, 1048577.0);
TEST_f_f (nearbyint, 2097152.75, 2097153.0);
TEST_f_f (nearbyint, 2492472.75, 2492473.0);
TEST_f_f (nearbyint, 2886220.75, 2886221.0);
TEST_f_f (nearbyint, 3058792.75, 3058793.0);
TEST_f_f (nearbyint, -1048576.75, -1048577.0);
TEST_f_f (nearbyint, -2097152.75, -2097153.0);
TEST_f_f (nearbyint, -2492472.75, -2492473.0);
TEST_f_f (nearbyint, -2886220.75, -2886221.0);
TEST_f_f (nearbyint, -3058792.75, -3058793.0);
#ifndef TEST_FLOAT
TEST_f_f (nearbyint, 70368744177664.75, 70368744177665.0);
TEST_f_f (nearbyint, 140737488355328.75, 140737488355329.0);
TEST_f_f (nearbyint, 281474976710656.75, 281474976710657.0);
TEST_f_f (nearbyint, 562949953421312.75, 562949953421313.0);
TEST_f_f (nearbyint, 1125899906842624.75, 1125899906842625.0);
TEST_f_f (nearbyint, -70368744177664.75, -70368744177665.0);
TEST_f_f (nearbyint, -140737488355328.75, -140737488355329.0);
TEST_f_f (nearbyint, -281474976710656.75, -281474976710657.0);
TEST_f_f (nearbyint, -562949953421312.75, -562949953421313.0);
TEST_f_f (nearbyint, -1125899906842624.75, -1125899906842625.0);
#endif
END (nearbyint);
}

12
sysdeps/ieee754/flt-32/s_nearbyintf.c
View File

@ -30,18 +30,12 @@ __nearbyintf(float x)
{
fenv_t env;
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);
libc_feholdexceptf (&env);
w = TWO23[sx]+x;
t = w-TWO23[sx];
@ -49,17 +43,11 @@ __nearbyintf(float x)
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(__builtin_expect(j0==0x80, 0)) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
SET_FLOAT_WORD(x,i0);
libc_feholdexceptf (&env);
w = TWO23[sx]+x;
t = w-TWO23[sx];