diff options
Diffstat (limited to 'kernel/arch/parisc/math-emu/fcnvxf.c')
| -rw-r--r-- | kernel/arch/parisc/math-emu/fcnvxf.c | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/kernel/arch/parisc/math-emu/fcnvxf.c b/kernel/arch/parisc/math-emu/fcnvxf.c new file mode 100644 index 000000000..05c7fadb3 --- /dev/null +++ b/kernel/arch/parisc/math-emu/fcnvxf.c @@ -0,0 +1,386 @@ +/* + * Linux/PA-RISC Project (http://www.parisc-linux.org/) + * + * Floating-point emulation code + * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +/* + * BEGIN_DESC + * + * File: + * @(#) pa/spmath/fcnvxf.c $Revision: 1.1 $ + * + * Purpose: + * Single Fixed-point to Single Floating-point + * Single Fixed-point to Double Floating-point + * Double Fixed-point to Single Floating-point + * Double Fixed-point to Double Floating-point + * + * External Interfaces: + * dbl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status) + * dbl_to_sgl_fcnvxf(srcptr,nullptr,dstptr,status) + * sgl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status) + * sgl_to_sgl_fcnvxf(srcptr,nullptr,dstptr,status) + * + * Internal Interfaces: + * + * Theory: + * <<please update with a overview of the operation of this file>> + * + * END_DESC +*/ + + +#include "float.h" +#include "sgl_float.h" +#include "dbl_float.h" +#include "cnv_float.h" + +/* + * Convert single fixed-point to single floating-point format + */ + +int +sgl_to_sgl_fcnvxf( + int *srcptr, + unsigned int *nullptr, + sgl_floating_point *dstptr, + unsigned int *status) +{ + register int src, dst_exponent; + register unsigned int result = 0; + + src = *srcptr; + /* + * set sign bit of result and get magnitude of source + */ + if (src < 0) { + Sgl_setone_sign(result); + Int_negate(src); + } + else { + Sgl_setzero_sign(result); + /* Check for zero */ + if (src == 0) { + Sgl_setzero(result); + *dstptr = result; + return(NOEXCEPTION); + } + } + /* + * Generate exponent and normalized mantissa + */ + dst_exponent = 16; /* initialize for normalization */ + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + */ + Find_ms_one_bit(src,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent >= 0) src <<= dst_exponent; + else src = 1 << 30; + Sgl_set_mantissa(result, src >> (SGL_EXP_LENGTH-1)); + Sgl_set_exponent(result, 30+SGL_BIAS - dst_exponent); + + /* check for inexact */ + if (Int_isinexact_to_sgl(src)) { + switch (Rounding_mode()) { + case ROUNDPLUS: + if (Sgl_iszero_sign(result)) + Sgl_increment(result); + break; + case ROUNDMINUS: + if (Sgl_isone_sign(result)) + Sgl_increment(result); + break; + case ROUNDNEAREST: + Sgl_roundnearest_from_int(src,result); + } + if (Is_inexacttrap_enabled()) { + *dstptr = result; + return(INEXACTEXCEPTION); + } + else Set_inexactflag(); + } + *dstptr = result; + return(NOEXCEPTION); +} + +/* + * Single Fixed-point to Double Floating-point + */ + +int +sgl_to_dbl_fcnvxf( + int *srcptr, + unsigned int *nullptr, + dbl_floating_point *dstptr, + unsigned int *status) +{ + register int src, dst_exponent; + register unsigned int resultp1 = 0, resultp2 = 0; + + src = *srcptr; + /* + * set sign bit of result and get magnitude of source + */ + if (src < 0) { + Dbl_setone_sign(resultp1); + Int_negate(src); + } + else { + Dbl_setzero_sign(resultp1); + /* Check for zero */ + if (src == 0) { + Dbl_setzero(resultp1,resultp2); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); + } + } + /* + * Generate exponent and normalized mantissa + */ + dst_exponent = 16; /* initialize for normalization */ + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + */ + Find_ms_one_bit(src,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent >= 0) src <<= dst_exponent; + else src = 1 << 30; + Dbl_set_mantissap1(resultp1, src >> DBL_EXP_LENGTH - 1); + Dbl_set_mantissap2(resultp2, src << (33-DBL_EXP_LENGTH)); + Dbl_set_exponent(resultp1, (30+DBL_BIAS) - dst_exponent); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); +} + +/* + * Double Fixed-point to Single Floating-point + */ + +int +dbl_to_sgl_fcnvxf( + dbl_integer *srcptr, + unsigned int *nullptr, + sgl_floating_point *dstptr, + unsigned int *status) +{ + int dst_exponent, srcp1; + unsigned int result = 0, srcp2; + + Dint_copyfromptr(srcptr,srcp1,srcp2); + /* + * set sign bit of result and get magnitude of source + */ + if (srcp1 < 0) { + Sgl_setone_sign(result); + Dint_negate(srcp1,srcp2); + } + else { + Sgl_setzero_sign(result); + /* Check for zero */ + if (srcp1 == 0 && srcp2 == 0) { + Sgl_setzero(result); + *dstptr = result; + return(NOEXCEPTION); + } + } + /* + * Generate exponent and normalized mantissa + */ + dst_exponent = 16; /* initialize for normalization */ + if (srcp1 == 0) { + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + */ + Find_ms_one_bit(srcp2,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent >= 0) { + srcp1 = srcp2 << dst_exponent; + srcp2 = 0; + } + else { + srcp1 = srcp2 >> 1; + srcp2 <<= 31; + } + /* + * since msb set is in second word, need to + * adjust bit position count + */ + dst_exponent += 32; + } + else { + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + * + */ + Find_ms_one_bit(srcp1,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent > 0) { + Variable_shift_double(srcp1,srcp2,(32-dst_exponent), + srcp1); + srcp2 <<= dst_exponent; + } + /* + * If dst_exponent = 0, we don't need to shift anything. + * If dst_exponent = -1, src = - 2**63 so we won't need to + * shift srcp2. + */ + else srcp1 >>= -(dst_exponent); + } + Sgl_set_mantissa(result, srcp1 >> SGL_EXP_LENGTH - 1); + Sgl_set_exponent(result, (62+SGL_BIAS) - dst_exponent); + + /* check for inexact */ + if (Dint_isinexact_to_sgl(srcp1,srcp2)) { + switch (Rounding_mode()) { + case ROUNDPLUS: + if (Sgl_iszero_sign(result)) + Sgl_increment(result); + break; + case ROUNDMINUS: + if (Sgl_isone_sign(result)) + Sgl_increment(result); + break; + case ROUNDNEAREST: + Sgl_roundnearest_from_dint(srcp1,srcp2,result); + } + if (Is_inexacttrap_enabled()) { + *dstptr = result; + return(INEXACTEXCEPTION); + } + else Set_inexactflag(); + } + *dstptr = result; + return(NOEXCEPTION); +} + +/* + * Double Fixed-point to Double Floating-point + */ + +int +dbl_to_dbl_fcnvxf( + dbl_integer *srcptr, + unsigned int *nullptr, + dbl_floating_point *dstptr, + unsigned int *status) +{ + register int srcp1, dst_exponent; + register unsigned int srcp2, resultp1 = 0, resultp2 = 0; + + Dint_copyfromptr(srcptr,srcp1,srcp2); + /* + * set sign bit of result and get magnitude of source + */ + if (srcp1 < 0) { + Dbl_setone_sign(resultp1); + Dint_negate(srcp1,srcp2); + } + else { + Dbl_setzero_sign(resultp1); + /* Check for zero */ + if (srcp1 == 0 && srcp2 ==0) { + Dbl_setzero(resultp1,resultp2); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); + } + } + /* + * Generate exponent and normalized mantissa + */ + dst_exponent = 16; /* initialize for normalization */ + if (srcp1 == 0) { + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + */ + Find_ms_one_bit(srcp2,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent >= 0) { + srcp1 = srcp2 << dst_exponent; + srcp2 = 0; + } + else { + srcp1 = srcp2 >> 1; + srcp2 <<= 31; + } + /* + * since msb set is in second word, need to + * adjust bit position count + */ + dst_exponent += 32; + } + else { + /* + * Check word for most significant bit set. Returns + * a value in dst_exponent indicating the bit position, + * between -1 and 30. + */ + Find_ms_one_bit(srcp1,dst_exponent); + /* left justify source, with msb at bit position 1 */ + if (dst_exponent > 0) { + Variable_shift_double(srcp1,srcp2,(32-dst_exponent), + srcp1); + srcp2 <<= dst_exponent; + } + /* + * If dst_exponent = 0, we don't need to shift anything. + * If dst_exponent = -1, src = - 2**63 so we won't need to + * shift srcp2. + */ + else srcp1 >>= -(dst_exponent); + } + Dbl_set_mantissap1(resultp1, srcp1 >> (DBL_EXP_LENGTH-1)); + Shiftdouble(srcp1,srcp2,DBL_EXP_LENGTH-1,resultp2); + Dbl_set_exponent(resultp1, (62+DBL_BIAS) - dst_exponent); + + /* check for inexact */ + if (Dint_isinexact_to_dbl(srcp2)) { + switch (Rounding_mode()) { + case ROUNDPLUS: + if (Dbl_iszero_sign(resultp1)) { + Dbl_increment(resultp1,resultp2); + } + break; + case ROUNDMINUS: + if (Dbl_isone_sign(resultp1)) { + Dbl_increment(resultp1,resultp2); + } + break; + case ROUNDNEAREST: + Dbl_roundnearest_from_dint(srcp2,resultp1, + resultp2); + } + if (Is_inexacttrap_enabled()) { + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(INEXACTEXCEPTION); + } + else Set_inexactflag(); + } + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); +} |