Fix rintf rounding.

(cherry-picked from commit fe45ce09f366f2260aef528d37ae35070b3a2a36)

diff --git a/ChangeLog b/ChangeLog
index fea77729f28af923404dee5f3d5bfb39c7dd4449..86b074bdd5b620c4359504671188ca52cc3bc5b1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,17 @@
        manipulate bits before adding and subtracting TWO23[sx].
        * math/libm-test.inc (nearbyint_test): Add more tests.
 
+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.
+
 2012-02-21  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 2b097a35de46b14848a6c1d6bb3fd8d5e8da3c7f..a342ba8b14b81a380add7965bd54577dbcd1f40d 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -9,7 +9,7 @@ Version 2.15.1
 
 * The following bugs are resolved with this release:
 
-  411, 2547, 11365, 13731, 13732, 13748
+  411, 2547, 2548, 11365, 13731, 13732, 13748
 
 Version 2.15
 

diff --git a/math/libm-test.inc b/math/libm-test.inc
index 025a8eaae95e3e3a7728cf0dc9801c1fd5779326..475857d8c2eccac061e813823fae412778ee4033 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -5061,6 +5061,22 @@ 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);
@@ -5161,6 +5177,22 @@ 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);
@@ -5231,6 +5263,22 @@ 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);
@@ -5301,6 +5349,22 @@ 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);
@@ -5371,6 +5435,22 @@ 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);

diff --git a/sysdeps/ieee754/flt-32/s_rintf.c b/sysdeps/ieee754/flt-32/s_rintf.c
index 9ea9b6fc4f9b7ab55898c95c1d87ec71e4ce4333..9ba6b57d94753aa8253367e21d146b7c61c9ba29 100644 (file)
--- a/sysdeps/ieee754/flt-32/s_rintf.c
+++ b/sysdeps/ieee754/flt-32/s_rintf.c
@@ -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];
 }