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Diffstat (limited to 'binutils-2.24/gas/flonum-mult.c')
| -rw-r--r-- | binutils-2.24/gas/flonum-mult.c | 188 |
1 files changed, 0 insertions, 188 deletions
diff --git a/binutils-2.24/gas/flonum-mult.c b/binutils-2.24/gas/flonum-mult.c deleted file mode 100644 index e5f32fca..00000000 --- a/binutils-2.24/gas/flonum-mult.c +++ /dev/null @@ -1,188 +0,0 @@ -/* flonum_mult.c - multiply two flonums - Copyright 1987, 1990, 1991, 1992, 1995, 2000, 2002, 2003, 2007 - Free Software Foundation, Inc. - - This file is part of GAS, the GNU Assembler. - - GAS 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 3, or (at your option) - any later version. - - GAS 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 GAS; see the file COPYING. If not, write to the Free - Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA - 02110-1301, USA. */ - -#include "ansidecl.h" -#include "flonum.h" - -/* plan for a . b => p(roduct) - - +-------+-------+-/ /-+-------+-------+ - | a | a | ... | a | a | - | A | A-1 | | 1 | 0 | - +-------+-------+-/ /-+-------+-------+ - - +-------+-------+-/ /-+-------+-------+ - | b | b | ... | b | b | - | B | B-1 | | 1 | 0 | - +-------+-------+-/ /-+-------+-------+ - - +-------+-------+-/ /-+-------+-/ /-+-------+-------+ - | p | p | ... | p | ... | p | p | - | A+B+1| A+B | | N | | 1 | 0 | - +-------+-------+-/ /-+-------+-/ /-+-------+-------+ - - /^\ - (carry) a .b ... | ... a .b a .b - A B | 0 1 0 0 - | - ... | ... a .b - | 1 0 - | - | ... - | - | - | - | ___ - | \ - +----- P = > a .b - N /__ i j - - N = 0 ... A+B - - for all i,j where i+j=N - [i,j integers > 0] - - a[], b[], p[] may not intersect. - Zero length factors signify 0 significant bits: treat as 0.0. - 0.0 factors do the right thing. - Zero length product OK. - - I chose the ForTran accent "foo[bar]" instead of the C accent "*garply" - because I felt the ForTran way was more intuitive. The C way would - probably yield better code on most C compilers. Dean Elsner. - (C style also gives deeper insight [to me] ... oh well ...) */ - -void -flonum_multip (const FLONUM_TYPE *a, const FLONUM_TYPE *b, - FLONUM_TYPE *product) -{ - int size_of_a; /* 0 origin */ - int size_of_b; /* 0 origin */ - int size_of_product; /* 0 origin */ - int size_of_sum; /* 0 origin */ - int extra_product_positions; /* 1 origin */ - unsigned long work; - unsigned long carry; - long exponent; - LITTLENUM_TYPE *q; - long significant; /* TRUE when we emit a non-0 littlenum */ - /* ForTran accent follows. */ - int P; /* Scan product low-order -> high. */ - int N; /* As in sum above. */ - int A; /* Which [] of a? */ - int B; /* Which [] of b? */ - - if ((a->sign != '-' && a->sign != '+') - || (b->sign != '-' && b->sign != '+')) - { - /* Got to fail somehow. Any suggestions? */ - product->sign = 0; - return; - } - product->sign = (a->sign == b->sign) ? '+' : '-'; - size_of_a = a->leader - a->low; - size_of_b = b->leader - b->low; - exponent = a->exponent + b->exponent; - size_of_product = product->high - product->low; - size_of_sum = size_of_a + size_of_b; - extra_product_positions = size_of_product - size_of_sum; - if (extra_product_positions < 0) - { - P = extra_product_positions; /* P < 0 */ - exponent -= extra_product_positions; /* Increases exponent. */ - } - else - { - P = 0; - } - carry = 0; - significant = 0; - for (N = 0; N <= size_of_sum; N++) - { - work = carry; - carry = 0; - for (A = 0; A <= N; A++) - { - B = N - A; - if (A <= size_of_a && B <= size_of_b && B >= 0) - { -#ifdef TRACE - printf ("a:low[%d.]=%04x b:low[%d.]=%04x work_before=%08x\n", - A, a->low[A], B, b->low[B], work); -#endif - /* Watch out for sign extension! Without the casts, on - the DEC Alpha, the multiplication result is *signed* - int, which gets sign-extended to convert to the - unsigned long! */ - work += (unsigned long) a->low[A] * (unsigned long) b->low[B]; - carry += work >> LITTLENUM_NUMBER_OF_BITS; - work &= LITTLENUM_MASK; -#ifdef TRACE - printf ("work=%08x carry=%04x\n", work, carry); -#endif - } - } - significant |= work; - if (significant || P < 0) - { - if (P >= 0) - { - product->low[P] = work; -#ifdef TRACE - printf ("P=%d. work[p]:=%04x\n", P, work); -#endif - } - P++; - } - else - { - extra_product_positions++; - exponent++; - } - } - /* [P]-> position # size_of_sum + 1. - This is where 'carry' should go. */ -#ifdef TRACE - printf ("final carry =%04x\n", carry); -#endif - if (carry) - { - if (extra_product_positions > 0) - product->low[P] = carry; - else - { - /* No room at high order for carry littlenum. */ - /* Shift right 1 to make room for most significant littlenum. */ - exponent++; - P--; - for (q = product->low + P; q >= product->low; q--) - { - work = *q; - *q = carry; - carry = work; - } - } - } - else - P--; - product->leader = product->low + P; - product->exponent = exponent; -} |