You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
179 lines
6.7 KiB
179 lines
6.7 KiB
Backport of this upstream commit (with libm-test.inc adjustments): |
|
|
|
commit 374f7f61214967bb4e2257695aeeeecc2a77f369 |
|
Author: Adhemerval Zanella <azanella@linux.vnet.ibm.com> |
|
Date: Fri Mar 14 07:35:43 2014 -0500 |
|
|
|
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. |
|
|
|
Index: b/math/libm-test.inc |
|
=================================================================== |
|
--- a/math/libm-test.inc |
|
+++ b/math/libm-test.inc |
|
@@ -2241,6 +2241,15 @@ ceil_test (void) |
|
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); |
|
Index: b/sysdeps/powerpc/powerpc64/fpu/s_ceill.S |
|
=================================================================== |
|
--- 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, 2006 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 mantisa 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 lable .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)
|
|
|