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libm: fix invalid result of function remquo/remquof

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Currently we will get the wrong result as follows:
remquof(0x7bb33336, 0x63000000) = -671088640, 0x00000000
remquo(0xbff0000000000003, 0x3ff0000000000003) = 1, 0x8000000000000000
remquo(0x9120000000000001, 0x0000000000000005) = -1288490188, 0x0000000000000004
while the correct one should be:
remquof(0x7bb33336, 0x63000000) = 1476395008, 0x00000000
remquo(0xbff0000000000003, 0x3ff0000000000003) = -1, 0x8000000000000000
remquo(0x9120000000000001, 0x0000000000000005) = -1288490189, 0x0000000000000001

Fixed in this patch.

Change-Id: I540b348cd10a539f3b39b1753945c893c4c7ec46
Signed-off-by: Jingwei Zhang <jingwei.zhang@intel.com>
Signed-off-by: Jin Wei <wei.a.jin@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
This commit is contained in:
Jack Ren 2011-11-19 15:52:08 +08:00
parent b88f810d58
commit bd0383acf8
2 changed files with 8 additions and 6 deletions
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9
libm/src/s_remquo.c
View File

@ -49,7 +49,7 @@ remquo(double x, double y, int *quo)
goto fixup; /* |x|<|y| return x or x-y */
}
if(lx==ly) {
*quo = 1;
*quo = (sxy ? -1 : 1);
return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/
}
}
@ -112,7 +112,8 @@ remquo(double x, double y, int *quo)
/* convert back to floating value and restore the sign */
if((hx|lx)==0) { /* return sign(x)*0 */
*quo = (sxy ? -q : q);
q &= 0x7fffffff;
*quo = (sxy ? -q : q);
return Zero[(u_int32_t)sx>>31];
}
while(hx<0x00100000) { /* normalize x */
@ -127,9 +128,9 @@ remquo(double x, double y, int *quo)
lx = (lx>>n)|((u_int32_t)hx<<(32-n));
hx >>= n;
} else if (n<=31) {
lx = (hx<<(32-n))|(lx>>n); hx = sx;
lx = (hx<<(32-n))|(lx>>n); hx = 0;
} else {
lx = hx>>(n-32); hx = sx;
lx = hx>>(n-32); hx = 0;
}
}
fixup:

5
libm/src/s_remquof.c
View File

@ -46,7 +46,7 @@ remquof(float x, float y, int *quo)
q = 0;
goto fixup; /* |x|<|y| return x or x-y */
} else if(hx==hy) {
*quo = 1;
*quo = (sxy ? -1 : 1);
return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/
}
@ -88,7 +88,8 @@ remquof(float x, float y, int *quo)
/* convert back to floating value and restore the sign */
if(hx==0) { /* return sign(x)*0 */
*quo = (sxy ? -q : q);
q &= 0x7fffffff;
*quo = (sxy ? -q : q);
return Zero[(u_int32_t)sx>>31];
}
while(hx<0x00800000) { /* normalize x */