^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Linux/PA-RISC Project (http://www.parisc-linux.org/)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Floating-point emulation code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * BEGIN_DESC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * File:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * @(#) pa/spmath/dfadd.c $Revision: 1.1 $
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Purpose:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Double_add: add two double precision values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * External Interfaces:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * dbl_fadd(leftptr, rightptr, dstptr, status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Internal Interfaces:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * Theory:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * <<please update with a overview of the operation of this file>>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * END_DESC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include "float.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include "dbl_float.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * Double_add: add two double precision values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) dbl_fadd(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) dbl_floating_point *leftptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) dbl_floating_point *rightptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) dbl_floating_point *dstptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) unsigned int *status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) register unsigned int signless_upper_left, signless_upper_right, save;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) register unsigned int leftp1, leftp2, rightp1, rightp2, extent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) register unsigned int resultp1 = 0, resultp2 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) register int result_exponent, right_exponent, diff_exponent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) register int sign_save, jumpsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) register boolean inexact = FALSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) register boolean underflowtrap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) /* Create local copies of the numbers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) Dbl_copyfromptr(leftptr,leftp1,leftp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Dbl_copyfromptr(rightptr,rightp1,rightp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /* A zero "save" helps discover equal operands (for later), *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * and is used in swapping operands (if needed). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) Dbl_xortointp1(leftp1,rightp1,/*to*/save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * check first operand for NaN's or infinity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if ((result_exponent = Dbl_exponent(leftp1)) == DBL_INFINITY_EXPONENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (Dbl_iszero_mantissa(leftp1,leftp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (Dbl_isnotnan(rightp1,rightp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (Dbl_isinfinity(rightp1,rightp2) && save!=0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * invalid since operands are opposite signed infinity's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) Set_invalidflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) Dbl_makequietnan(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * return infinity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) Dbl_copytoptr(leftp1,leftp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * is NaN; signaling or quiet?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (Dbl_isone_signaling(leftp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) /* trap if INVALIDTRAP enabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /* make NaN quiet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) Set_invalidflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) Dbl_set_quiet(leftp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * is second operand a signaling NaN?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) else if (Dbl_is_signalingnan(rightp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /* trap if INVALIDTRAP enabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /* make NaN quiet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) Set_invalidflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) Dbl_set_quiet(rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) Dbl_copytoptr(rightp1,rightp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * return quiet NaN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) Dbl_copytoptr(leftp1,leftp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) } /* End left NaN or Infinity processing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * check second operand for NaN's or infinity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) if (Dbl_isinfinity_exponent(rightp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (Dbl_iszero_mantissa(rightp1,rightp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /* return infinity */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) Dbl_copytoptr(rightp1,rightp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * is NaN; signaling or quiet?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) if (Dbl_isone_signaling(rightp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /* trap if INVALIDTRAP enabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /* make NaN quiet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) Set_invalidflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) Dbl_set_quiet(rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * return quiet NaN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) Dbl_copytoptr(rightp1,rightp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) } /* End right NaN or Infinity processing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /* Invariant: Must be dealing with finite numbers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) /* Compare operands by removing the sign */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) Dbl_copytoint_exponentmantissap1(leftp1,signless_upper_left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) Dbl_copytoint_exponentmantissap1(rightp1,signless_upper_right);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) /* sign difference selects add or sub operation. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if(Dbl_ismagnitudeless(leftp2,rightp2,signless_upper_left,signless_upper_right))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) /* Set the left operand to the larger one by XOR swap *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * First finish the first word using "save" */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) Dbl_xorfromintp1(save,rightp1,/*to*/rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) Dbl_xorfromintp1(save,leftp1,/*to*/leftp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) Dbl_swap_lower(leftp2,rightp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) result_exponent = Dbl_exponent(leftp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /* Invariant: left is not smaller than right. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if((right_exponent = Dbl_exponent(rightp1)) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) /* Denormalized operands. First look for zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) if(Dbl_iszero_mantissa(rightp1,rightp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /* right is zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if(Dbl_iszero_exponentmantissa(leftp1,leftp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) /* Both operands are zeros */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) if(Is_rounding_mode(ROUNDMINUS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) Dbl_or_signs(leftp1,/*with*/rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) Dbl_and_signs(leftp1,/*with*/rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) /* Left is not a zero and must be the result. Trapped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) * underflows are signaled if left is denormalized. Result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) * is always exact. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) if( (result_exponent == 0) && Is_underflowtrap_enabled() )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) /* need to normalize results mantissa */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) sign_save = Dbl_signextendedsign(leftp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) Dbl_leftshiftby1(leftp1,leftp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) Dbl_normalize(leftp1,leftp2,result_exponent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) Dbl_set_sign(leftp1,/*using*/sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) Dbl_setwrapped_exponent(leftp1,result_exponent,unfl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) Dbl_copytoptr(leftp1,leftp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /* inexact = FALSE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) return(UNDERFLOWEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) Dbl_copytoptr(leftp1,leftp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) /* Neither are zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) Dbl_clear_sign(rightp1); /* Exponent is already cleared */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if(result_exponent == 0 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) /* Both operands are denormalized. The result must be exact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) * and is simply calculated. A sum could become normalized and a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * difference could cancel to a true zero. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) if( (/*signed*/int) save < 0 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) Dbl_subtract(leftp1,leftp2,/*minus*/rightp1,rightp2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) /*into*/resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) if(Dbl_iszero_mantissa(resultp1,resultp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) if(Is_rounding_mode(ROUNDMINUS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) Dbl_setone_sign(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) Dbl_setzero_sign(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) Dbl_addition(leftp1,leftp2,rightp1,rightp2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) /*into*/resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) if(Dbl_isone_hidden(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) if(Is_underflowtrap_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) /* need to normalize result */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) sign_save = Dbl_signextendedsign(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) Dbl_leftshiftby1(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) Dbl_normalize(resultp1,resultp2,result_exponent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) Dbl_set_sign(resultp1,/*using*/sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) Dbl_setwrapped_exponent(resultp1,result_exponent,unfl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) /* inexact = FALSE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) return(UNDERFLOWEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) right_exponent = 1; /* Set exponent to reflect different bias
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * with denomalized numbers. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) Dbl_clear_signexponent_set_hidden(rightp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) Dbl_clear_exponent_set_hidden(leftp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) diff_exponent = result_exponent - right_exponent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * Special case alignment of operands that would force alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) * beyond the extent of the extension. A further optimization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * could special case this but only reduces the path length for this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) * infrequent case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) if(diff_exponent > DBL_THRESHOLD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) diff_exponent = DBL_THRESHOLD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) /* Align right operand by shifting to right */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) Dbl_right_align(/*operand*/rightp1,rightp2,/*shifted by*/diff_exponent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) /*and lower to*/extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) /* Treat sum and difference of the operands separately. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) if( (/*signed*/int) save < 0 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * Difference of the two operands. Their can be no overflow. A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * borrow can occur out of the hidden bit and force a post
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * normalization phase.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) Dbl_subtract_withextension(leftp1,leftp2,/*minus*/rightp1,rightp2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) /*with*/extent,/*into*/resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) if(Dbl_iszero_hidden(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) /* Handle normalization */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) /* A straight forward algorithm would now shift the result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * and extension left until the hidden bit becomes one. Not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * all of the extension bits need participate in the shift.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * Only the two most significant bits (round and guard) are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * needed. If only a single shift is needed then the guard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * bit becomes a significant low order bit and the extension
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * must participate in the rounding. If more than a single
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * shift is needed, then all bits to the right of the guard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * bit are zeros, and the guard bit may or may not be zero. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) sign_save = Dbl_signextendedsign(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) Dbl_leftshiftby1_withextent(resultp1,resultp2,extent,resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) /* Need to check for a zero result. The sign and exponent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * fields have already been zeroed. The more efficient test
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * of the full object can be used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) if(Dbl_iszero(resultp1,resultp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) /* Must have been "x-x" or "x+(-x)". */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) if(Is_rounding_mode(ROUNDMINUS)) Dbl_setone_sign(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) result_exponent--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) /* Look to see if normalization is finished. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if(Dbl_isone_hidden(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) if(result_exponent==0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) /* Denormalized, exponent should be zero. Left operand *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * was normalized, so extent (guard, round) was zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) goto underflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /* No further normalization is needed. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) Dbl_set_sign(resultp1,/*using*/sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) Ext_leftshiftby1(extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) goto round;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) /* Check for denormalized, exponent should be zero. Left *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * operand was normalized, so extent (guard, round) was zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) if(!(underflowtrap = Is_underflowtrap_enabled()) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) result_exponent==0) goto underflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) /* Shift extension to complete one bit of normalization and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) * update exponent. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) Ext_leftshiftby1(extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) /* Discover first one bit to determine shift amount. Use a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * modified binary search. We have already shifted the result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * one position right and still not found a one so the remainder
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * of the extension must be zero and simplifies rounding. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) /* Scan bytes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) while(Dbl_iszero_hiddenhigh7mantissa(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) Dbl_leftshiftby8(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) if((result_exponent -= 8) <= 0 && !underflowtrap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) goto underflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) /* Now narrow it down to the nibble */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) if(Dbl_iszero_hiddenhigh3mantissa(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) /* The lower nibble contains the normalizing one */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) Dbl_leftshiftby4(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if((result_exponent -= 4) <= 0 && !underflowtrap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) goto underflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) /* Select case were first bit is set (already normalized)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) * otherwise select the proper shift. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) if((jumpsize = Dbl_hiddenhigh3mantissa(resultp1)) > 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) /* Already normalized */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) if(result_exponent <= 0) goto underflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) Dbl_set_sign(resultp1,/*using*/sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) Dbl_set_exponent(resultp1,/*using*/result_exponent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) Dbl_sethigh4bits(resultp1,/*using*/sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) switch(jumpsize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) case 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) Dbl_leftshiftby3(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) result_exponent -= 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) case 2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) case 3:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) Dbl_leftshiftby2(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) result_exponent -= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) case 4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) case 5:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) case 6:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) case 7:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) Dbl_leftshiftby1(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) result_exponent -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if(result_exponent > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) Dbl_set_exponent(resultp1,/*using*/result_exponent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) return(NOEXCEPTION); /* Sign bit is already set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) /* Fixup potential underflows */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) underflow:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) if(Is_underflowtrap_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) Dbl_set_sign(resultp1,sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) Dbl_setwrapped_exponent(resultp1,result_exponent,unfl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) /* inexact = FALSE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) return(UNDERFLOWEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * Since we cannot get an inexact denormalized result,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * we can now return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) Dbl_fix_overshift(resultp1,resultp2,(1-result_exponent),extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) Dbl_clear_signexponent(resultp1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) Dbl_set_sign(resultp1,sign_save);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) } /* end if(hidden...)... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) /* Fall through and round */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) } /* end if(save < 0)... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) /* Add magnitudes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) Dbl_addition(leftp1,leftp2,rightp1,rightp2,/*to*/resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) if(Dbl_isone_hiddenoverflow(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) /* Prenormalization required. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) Dbl_rightshiftby1_withextent(resultp2,extent,extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) Dbl_arithrightshiftby1(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) result_exponent++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) } /* end if hiddenoverflow... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) } /* end else ...add magnitudes... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) /* Round the result. If the extension is all zeros,then the result is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * exact. Otherwise round in the correct direction. No underflow is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) * possible. If a postnormalization is necessary, then the mantissa is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * all zeros so no shift is needed. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) round:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) if(Ext_isnotzero(extent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) inexact = TRUE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) switch(Rounding_mode())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) case ROUNDNEAREST: /* The default. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) if(Ext_isone_sign(extent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) /* at least 1/2 ulp */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) if(Ext_isnotzero_lower(extent) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) Dbl_isone_lowmantissap2(resultp2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) /* either exactly half way and odd or more than 1/2ulp */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) Dbl_increment(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) case ROUNDPLUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) if(Dbl_iszero_sign(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) /* Round up positive results */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) Dbl_increment(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) case ROUNDMINUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) if(Dbl_isone_sign(resultp1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) /* Round down negative results */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) Dbl_increment(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) case ROUNDZERO:;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) /* truncate is simple */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) } /* end switch... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) if(Dbl_isone_hiddenoverflow(resultp1)) result_exponent++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) if(result_exponent == DBL_INFINITY_EXPONENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) /* Overflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) if(Is_overflowtrap_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) Dbl_setwrapped_exponent(resultp1,result_exponent,ovfl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) if (inexact)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) if (Is_inexacttrap_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) return(OVERFLOWEXCEPTION | INEXACTEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) else Set_inexactflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) return(OVERFLOWEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) inexact = TRUE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) Set_overflowflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) Dbl_setoverflow(resultp1,resultp2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) else Dbl_set_exponent(resultp1,result_exponent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) Dbl_copytoptr(resultp1,resultp2,dstptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) if(inexact)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) if(Is_inexacttrap_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) return(INEXACTEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) else Set_inexactflag();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) return(NOEXCEPTION);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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