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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-03-14 07:35:43 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-03-14 12:54:47 -0500
commit374f7f61214967bb4e2257695aeeeecc2a77f369 (patch)
tree5fdfc34f3a435a8df5823508a51e5bb3e726a300
parent4655c291d1808c35b7c54236ae62be7a3aaa0a2d (diff)
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PowerPC: remove wrong ceill implementation for PowerPC64
The ceill assembly implementation (sysdeps/powerpc/powerpc64/fpu/s_ceill.S) returns wrong results for some inputs where first double is a exact integer and the precision is determined by second long double. Checking on implementation comments and history, I am very confident the assembly implementation was based on a version before commit 5c68d401698a58cf7da150d9cce769fa6679ba5f that fixes BZ#2423 (Errors in long double (ldbl-128ibm) rounding functions in glibc-2.4). By just removing the implementation and make the build select sysdeps/ieee754/ldbl-128ibm/s_ceill.c instead fixes the failing math. Fixes BZ#16701.
-rw-r--r--ChangeLog7
-rw-r--r--NEWS2
-rw-r--r--math/libm-test.inc9
-rw-r--r--sysdeps/powerpc/powerpc64/fpu/s_ceill.S132
4 files changed, 17 insertions, 133 deletions
diff --git a/ChangeLog b/ChangeLog
index 59f3bb3..5db859e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
2014-03-14 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+ [BZ #16701]
+ * sysdeps/powerpc/powerpc64/fpu/s_ceill.S: Remove wrong
+ implementation.
+ * math/libm-test.inc (ceil_test_data): Add more tests.
+
+2014-03-14 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+
* math/libm-test.inc (trunc_test_data): Add more tests related to
BZ#16414.
diff --git a/NEWS b/NEWS
index e8e7f80..16a17c8 100644
--- a/NEWS
+++ b/NEWS
@@ -11,7 +11,7 @@ Version 2.20
15347, 15804, 15894, 16447, 16532, 16545, 16574, 16600, 16609, 16610,
16611, 16613, 16623, 16632, 16639, 16642, 16670, 16674, 16677, 16683,
- 16689, 16695.
+ 16689, 16695, 16701.
* The am33 port, which had not worked for several years, has been removed
from ports.
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 10e7806..c151b7d 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -6106,6 +6106,15 @@ static const struct test_f_f_data ceil_test_data[] =
TEST_f_f (ceil, -72057594037927936.75L, -72057594037927936.0L),
TEST_f_f (ceil, -72057594037927937.5L, -72057594037927937.0L),
+ /* Check cases where first double is a exact integer higher than 2^52 and
+ the precision is determined by second long double for IBM long double. */
+ TEST_f_f (ceil, 34503599627370498.515625L, 34503599627370499.0L),
+ TEST_f_f (ceil, -34503599627370498.515625L, -34503599627370498.0L),
+# if LDBL_MANT_DIG >= 106
+ TEST_f_f (ceil, 1192568192774434123539907640624.484375L, 1192568192774434123539907640625.0L),
+ TEST_f_f (ceil, -1192568192774434123539907640624.484375L, -1192568192774434123539907640624.0L),
+# endif
+
TEST_f_f (ceil, 10141204801825835211973625643007.5L, 10141204801825835211973625643008.0L),
TEST_f_f (ceil, 10141204801825835211973625643008.25L, 10141204801825835211973625643009.0L),
TEST_f_f (ceil, 10141204801825835211973625643008.5L, 10141204801825835211973625643009.0L),
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_ceill.S b/sysdeps/powerpc/powerpc64/fpu/s_ceill.S
deleted file mode 100644
index 42a73af..0000000
--- a/sysdeps/powerpc/powerpc64/fpu/s_ceill.S
+++ /dev/null
@@ -1,132 +0,0 @@
-/* s_ceill.S IBM extended format long double version.
- Copyright (C) 2004-2014 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
- .section ".toc","aw"
-.LC0: /* 2**52 */
- .tc FD_43300000_0[TC],0x4330000000000000
-
- .section ".text"
-
-/* long double [fp1,fp2] ceill (long double x [fp1,fp2])
- IEEE 1003.1 ceil function.
-
- PowerPC64 long double uses the IBM extended format which is
- represented two 64-floating point double values. The values are
- non-overlapping giving an effective precision of 106 bits. The first
- double contains the high order bits of mantissa and is always ceiled
- to represent a normal ceiling of long double to double. Since the
- long double value is sum of the high and low values, the low double
- normally has the opposite sign to compensate for the this ceiling.
-
- For long double there are two cases:
- 1) |x| < 2**52, all the integer bits are in the high double.
- ceil the high double and set the low double to -0.0.
- 2) |x| >= 2**52, ceiling involves both doubles.
- See the comment before label .L2 for details.
- */
-
-ENTRY (__ceill)
- mffs fp11 /* Save current FPU rounding mode. */
- lfd fp13,.LC0@toc(2)
- fabs fp0,fp1
- fabs fp9,fp2
- fsub fp12,fp13,fp13 /* generate 0.0 */
- fcmpu cr7,fp0,fp13 /* if (fabs(x) > TWO52) */
- fcmpu cr6,fp1,fp12 /* if (x > 0.0) */
- bnl- cr7,.L2
- mtfsfi 7,2 /* Set rounding mode toward +inf. */
- fneg fp2,fp12
- ble- cr6,.L1
- fadd fp1,fp1,fp13 /* x+= TWO52; */
- fsub fp1,fp1,fp13 /* x-= TWO52; */
- fabs fp1,fp1 /* if (x == 0.0) */
-.L0:
- mtfsf 0x01,fp11 /* restore previous rounding mode. */
- blr /* x = 0.0; */
-.L1:
- bge- cr6,.L0 /* if (x < 0.0) */
- fsub fp1,fp1,fp13 /* x-= TWO52; */
- fadd fp1,fp1,fp13 /* x+= TWO52; */
- fcmpu cr5,fp1,fp12 /* if (x > 0.0) */
- mtfsf 0x01,fp11 /* restore previous rounding mode. */
- fnabs fp1,fp1 /* if (x == 0.0) */
- blr /* x = -0.0; */
-
-/* The high double is > TWO52 so we need to round the low double and
- perhaps the high double. In this case we have to round the low
- double and handle any adjustment to the high double that may be
- caused by rounding (up). This is complicated by the fact that the
- high double may already be rounded and the low double may have the
- opposite sign to compensate.This gets a bit tricky so we use the
- following algorithm:
-
- tau = floor(x_high/TWO52);
- x0 = x_high - tau;
- x1 = x_low + tau;
- r1 = rint(x1);
- y_high = x0 + r1;
- y_low = x0 - y_high + r1;
- return y; */
-.L2:
- fcmpu cr7,fp9,fp13 /* if (|x_low| > TWO52) */
- fcmpu cr0,fp9,fp12 /* || (|x_low| == 0.0) */
- fcmpu cr5,fp2,fp12 /* if (x_low > 0.0) */
- bgelr- cr7 /* return x; */
- beqlr- cr0
- mtfsfi 7,2 /* Set rounding mode toward +inf. */
- fdiv fp8,fp1,fp13 /* x_high/TWO52 */
-
- bng- cr6,.L6 /* if (x > 0.0) */
- fctidz fp0,fp8
- fcfid fp8,fp0 /* tau = floor(x_high/TWO52); */
- bng cr5,.L4 /* if (x_low > 0.0) */
- fmr fp3,fp1
- fmr fp4,fp2
- b .L5
-.L4: /* if (x_low < 0.0) */
- fsub fp3,fp1,fp8 /* x0 = x_high - tau; */
- fadd fp4,fp2,fp8 /* x1 = x_low + tau; */
-.L5:
- fadd fp5,fp4,fp13 /* r1 = r1 + TWO52; */
- fsub fp5,fp5,fp13 /* r1 = r1 - TWO52; */
- b .L9
-.L6: /* if (x < 0.0) */
- fctidz fp0,fp8
- fcfid fp8,fp0 /* tau = floor(x_high/TWO52); */
- bnl cr5,.L7 /* if (x_low < 0.0) */
- fmr fp3,fp1
- fmr fp4,fp2
- b .L8
-.L7: /* if (x_low > 0.0) */
- fsub fp3,fp1,fp8 /* x0 = x_high - tau; */
- fadd fp4,fp2,fp8 /* x1 = x_low + tau; */
-.L8:
- fsub fp5,fp4,fp13 /* r1-= TWO52; */
- fadd fp5,fp5,fp13 /* r1+= TWO52; */
-.L9:
- mtfsf 0x01,fp11 /* restore previous rounding mode. */
- fadd fp1,fp3,fp5 /* y_high = x0 + r1; */
- fsub fp2,fp3,fp1 /* y_low = x0 - y_high + r1; */
- fadd fp2,fp2,fp5
- blr
-END (__ceill)
-
-long_double_symbol (libm, __ceill, ceill)