Fix nearbyintf rounding.

(cherry-picked from commit 6cbeae4719aeb3edb6143fe5dd6d2a5ab45c0248)

diff --git a/ChangeLog b/ChangeLog
index 6d01b56ba4db4359c9b95f0f09aada3297d3ecab..fea77729f28af923404dee5f3d5bfb39c7dd4449 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.

diff --git a/NEWS b/NEWS
index b92705d8a3fb6b66b698dc23bffb7392f92f92ff..2b097a35de46b14848a6c1d6bb3fd8d5e8da3c7f 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -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
 

diff --git a/math/libm-test.inc b/math/libm-test.inc
index 2c739fa6500f8027b6907a3f19a32d996b1c580d..025a8eaae95e3e3a7728cf0dc9801c1fd5779326 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -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);
 }
 

diff --git a/sysdeps/ieee754/flt-32/s_nearbyintf.c b/sysdeps/ieee754/flt-32/s_nearbyintf.c
index 04ef9ab20c3bbb714b905a5a1b3159982b3e5201..a6d602bb4da56c0405aa2755e3609c6471981f3e 100644 (file)
--- a/sysdeps/ieee754/flt-32/s_nearbyintf.c
+++ b/sysdeps/ieee754/flt-32/s_nearbyintf.c
@@ -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];