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/* s_ceill.S IBM extended format long double version.
Copyright (C) 2004-2013 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)
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