diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/fpu/s_llroundl.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/fpu/s_llroundl.S | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_llroundl.S b/sysdeps/powerpc/powerpc64/fpu/s_llroundl.S deleted file mode 100644 index 29eca11093..0000000000 --- a/sysdeps/powerpc/powerpc64/fpu/s_llroundl.S +++ /dev/null @@ -1,167 +0,0 @@ -/* llroundl function. - 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, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include <sysdep.h> -#include <math_ldbl_opt.h> - - .section ".toc","aw" -.LC0: /* 0.0 */ - .tc FD_00000000_0[TC],0x0000000000000000 -.LC1: /* 0.5 */ - .tc FD_3fe00000_0[TC],0x3fe0000000000000 -.LC2: /* 2**52 */ - .tc FD_43300000_0[TC],0x4330000000000000 -.LC3: /* 2**63 */ - .tc FD_43E00000_0[TC],0x43e0000000000000 - .section ".text" - -/* long long [r3] llround (long double x [fp1,fp2]) - IEEE 1003.1 llroundl function. IEEE specifies "round to the nearest - integer value, rounding halfway cases away from zero, regardless of - the current rounding mode." However PowerPC Architecture defines - "round to Nearest" as "Choose the best approximation. In case of a - tie, choose the one that is even (least significant bit o).". - So we can't use the PowerPC "round to Nearest" mode. Instead we set - "round toward Zero" mode and round by adding +-0.5 before rounding - toward zero. The "Floating Convert To Integer Doubleword with round - toward zero" instruction handles the conversion including the - overflow cases and signalling "Invalid Operation". - - 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 rounded - to represent a normal rounding 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 rounding. - - For long double there is 4 cases: - 1) |x| < 2**52, all the integer bits are in the high double. - Round and convert the high double to long long. - 2) 2**52 <= |x|< 2**63, Still fits but need bits from both doubles. - Round the low double, convert both, then sum the long long values. - 3) |x| == 2**63, Looks like an overflow but may not be due to rounding - of the high double. - See the description following lable L2. - 4) |x| > 2**63, This will overflow the 64-bit signed integer. - Treat like case #1. The fctidz instruction will generate the - appropriate and signal "invalid operation". - - */ - -ENTRY (__llroundl) - mffs fp7 /* Save current FPU rounding mode. */ - fabs fp0,fp1 - lfd fp13,.LC2@toc(2) /* 2**52 */ - lfd fp12,.LC3@toc(2) /* 2**63 */ - lfd fp11,.LC0@toc(2) /* 0.0 */ - lfd fp10,.LC1@toc(2) /* 0.5 */ - fabs fp9,fp2 - fcmpu cr7,fp0,fp13 /* if (fabs(x) > TWO52) */ - fcmpu cr6,fp1,fp11 /* if (x > 0.0) */ - bnl- cr7,.L2 - mtfsfi 7,1 /* Set rounding mode toward 0. */ - ble- cr6,.L1 - fadd fp9,fp1,fp10 /* x+= 0.5; */ - b .L0 -.L1: - fsub fp9,fp1,fp10 /* x-= 0.5; */ -.L0: - fctid fp0,fp9 - stfd fp0,-16(r1) - mtfsf 0x01,fp7 /* restore previous rounding mode. */ - nop /* Insure the following load is in a different dispatch group */ - nop /* to avoid pipe stall on POWER4&5. */ - nop - ld r3,-16(r1) - blr - -/* 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 = trunc(x_high/TWO52); - x0 = x_high - tau; - x1 = x_low + tau; - r1 = round(x1); - y_high = x0 + r1; - y_low = x0 - y_high + r1; - return y; */ -.L2: - fcmpu cr7,fp0,fp12 /* if (|x_high| > TWO63) */ - fcmpu cr0,fp9,fp11 /* || (|x_low| == 0.0) */ - fmr fp9,fp1 - fcmpu cr5,fp2,fp11 /* if (x_low > 0.0) */ - bgt- cr7,.L0 /* return llround(x); */ - mtfsfi 7,1 /* Set rounding mode toward 0. */ - fdiv fp8,fp1,fp13 /* x_high/TWO52 */ - - bng- cr6,.L6 /* if (x > 0.0) */ - fctidz fp0,fp8 - fcfid fp8,fp0 /* tau = trunc(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,fp10 /* r1 = x1 + 0.5; */ - b .L9 -.L6: /* if (x < 0.0) */ - fctidz fp0,fp8 - fcfid fp8,fp0 /* tau = trunc(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,fp10 /* r1 = x1 - 0.5; */ -.L9: - fctid. fp11,fp3 - fctid fp12,fp5 - stfd fp11,-16(r1) - stfd fp12,-8(r1) - mtfsf 0x01,fp7 /* restore previous rounding mode. */ - nop /* Insure the following load is in a different dispatch group */ - nop /* to avoid pipe stall on POWER4&5. */ - nop - ld r3,-16(r1) - bunlr cr1 /* if not overflow, return. */ - ld r0,-8(r1) - addo. r3,r3,r0 - bnslr cr0 - fmr fp9,fp12 - bng cr6,.L0 - fneg fp9,fp12 - b .L0 -END (__llroundl) - -strong_alias (__llroundl, __lroundl) -long_double_symbol (libm, __llroundl, llroundl) -long_double_symbol (libm, __lroundl, lroundl) |