diff options
Diffstat (limited to 'gas')
| -rw-r--r-- | gas/config/atof-ns32k.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/gas/config/atof-ns32k.c b/gas/config/atof-ns32k.c new file mode 100644 index 0000000..6091b74 --- /dev/null +++ b/gas/config/atof-ns32k.c @@ -0,0 +1,436 @@ +/* atof_ns32k.c - turn a Flonum into a ns32k floating point number + Copyright (C) 1987 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* this is atof-m68k.c hacked for ns32k */ + +#include "as.h" + +extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */ + +extern char EXP_CHARS[]; + /* Precision in LittleNums. */ +#define MAX_PRECISION (4) +#define F_PRECISION (2) +#define D_PRECISION (4) + + /* Length in LittleNums of guard bits. */ +#define GUARD (2) + +int /* Number of chars in flonum type 'letter'. */ +atof_sizeof (letter) + char letter; +{ + int return_value; + + /* + * Permitting uppercase letters is probably a bad idea. + * Please use only lower-cased letters in case the upper-cased + * ones become unsupported! + */ + switch (letter) + { + case 'f': + return_value = F_PRECISION; + break; + + case 'd': + return_value = D_PRECISION; + break; + + default: + return_value = 0; + break; + } + return (return_value); +} + +static unsigned long int mask [] = { + 0x00000000, + 0x00000001, + 0x00000003, + 0x00000007, + 0x0000000f, + 0x0000001f, + 0x0000003f, + 0x0000007f, + 0x000000ff, + 0x000001ff, + 0x000003ff, + 0x000007ff, + 0x00000fff, + 0x00001fff, + 0x00003fff, + 0x00007fff, + 0x0000ffff, + 0x0001ffff, + 0x0003ffff, + 0x0007ffff, + 0x000fffff, + 0x001fffff, + 0x003fffff, + 0x007fffff, + 0x00ffffff, + 0x01ffffff, + 0x03ffffff, + 0x07ffffff, + 0x0fffffff, + 0x1fffffff, + 0x3fffffff, + 0x7fffffff, + 0xffffffff + }; + +static int bits_left_in_littlenum; +static int littlenums_left; +static LITTLENUM_TYPE * littlenum_pointer; + +static int +next_bits (number_of_bits) + int number_of_bits; +{ + int return_value; + + if(!littlenums_left) + return 0; + if (number_of_bits >= bits_left_in_littlenum) + { + return_value = mask [bits_left_in_littlenum] & *littlenum_pointer; + number_of_bits -= bits_left_in_littlenum; + return_value <<= number_of_bits; + if(littlenums_left) { + bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits; + littlenum_pointer --; + --littlenums_left; + return_value |= (*littlenum_pointer>>bits_left_in_littlenum) & mask[number_of_bits]; + } + } + else + { + bits_left_in_littlenum -= number_of_bits; + return_value = mask [number_of_bits] & (*littlenum_pointer>>bits_left_in_littlenum); + } + return (return_value); +} + +static void +make_invalid_floating_point_number (words) + LITTLENUM_TYPE * words; +{ + words[0]= ((unsigned)-1)>>1; /* Zero the leftmost bit */ + words[1]= -1; + words[2]= -1; + words[3]= -1; +} + +/***********************************************************************\ +* * +* Warning: this returns 16-bit LITTLENUMs, because that is * +* what the VAX thinks in. It is up to the caller to figure * +* out any alignment problems and to conspire for the bytes/word * +* to be emitted in the right order. Bigendians beware! * +* * +\***********************************************************************/ + +char * /* Return pointer past text consumed. */ +atof_ns32k (str, what_kind, words) + char * str; /* Text to convert to binary. */ + char what_kind; /* 'd', 'f', 'g', 'h' */ + LITTLENUM_TYPE * words; /* Build the binary here. */ +{ + FLONUM_TYPE f; + LITTLENUM_TYPE bits [MAX_PRECISION + MAX_PRECISION + GUARD]; + /* Extra bits for zeroed low-order bits. */ + /* The 1st MAX_PRECISION are zeroed, */ + /* the last contain flonum bits. */ + char * return_value; + int precision; /* Number of 16-bit words in the format. */ + long int exponent_bits; + + long int exponent_1; + long int exponent_2; + long int exponent_3; + long int exponent_4; + int exponent_skippage; + LITTLENUM_TYPE word1; + LITTLENUM_TYPE * lp; + + return_value = str; + f.low = bits + MAX_PRECISION; + f.high = NULL; + f.leader = NULL; + f.exponent = NULL; + f.sign = '\0'; + + /* Use more LittleNums than seems */ + /* necessary: the highest flonum may have */ + /* 15 leading 0 bits, so could be useless. */ + + bzero (bits, sizeof(LITTLENUM_TYPE) * MAX_PRECISION); + + switch(what_kind) { + case 'f': + precision = F_PRECISION; + exponent_bits = 8; + break; + + case 'd': + precision = D_PRECISION; + exponent_bits = 11; + break; + + default: + make_invalid_floating_point_number (words); + return NULL; + } + + f.high = f.low + precision - 1 + GUARD; + + if (atof_generic (& return_value, ".", EXP_CHARS, & f)) { + as_warn("Error converting floating point number (Exponent overflow?)"); + make_invalid_floating_point_number (words); + return NULL; + } + + if (f.low > f.leader) { + /* 0.0e0 seen. */ + bzero (words, sizeof(LITTLENUM_TYPE) * precision); + return return_value; + } + + if(f.sign!='+' && f.sign!='-') { + make_invalid_floating_point_number(words); + return NULL; + } + + + /* + * All vaxen floating_point formats (so far) have: + * Bit 15 is sign bit. + * Bits 14:n are excess-whatever exponent. + * Bits n-1:0 (if any) are most significant bits of fraction. + * Bits 15:0 of the next word are the next most significant bits. + * And so on for each other word. + * + * So we need: number of bits of exponent, number of bits of + * mantissa. + */ + bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS; + littlenum_pointer = f.leader; + littlenums_left = 1 + f.leader-f.low; + /* Seek (and forget) 1st significant bit */ + for (exponent_skippage = 0;! next_bits(1); exponent_skippage ++) + ; + exponent_1 = f.exponent + f.leader + 1 - f.low; + /* Radix LITTLENUM_RADIX, point just higher than f.leader. */ + exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS; + /* Radix 2. */ + exponent_3 = exponent_2 - exponent_skippage; + /* Forget leading zeros, forget 1st bit. */ + exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2); + /* Offset exponent. */ + + if (exponent_4 & ~ mask [exponent_bits]) { + /* + * Exponent overflow. Lose immediately. + */ + + /* + * We leave return_value alone: admit we read the + * number, but return a floating exception + * because we can't encode the number. + */ + + as_warn("Exponent overflow in floating-point number"); + make_invalid_floating_point_number (words); + return return_value; + } + lp = words; + + /* Word 1. Sign, exponent and perhaps high bits. */ + /* Assume 2's complement integers. */ + word1 = ((exponent_4 & mask [exponent_bits]) << (15 - exponent_bits)) | + ((f.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits); + * lp ++ = word1; + + /* The rest of the words are just mantissa bits. */ + for (; lp < words + precision; lp++) + * lp = next_bits (LITTLENUM_NUMBER_OF_BITS); + + if (next_bits (1)) { + unsigned long int carry; + /* + * Since the NEXT bit is a 1, round UP the mantissa. + * The cunning design of these hidden-1 floats permits + * us to let the mantissa overflow into the exponent, and + * it 'does the right thing'. However, we lose if the + * highest-order bit of the lowest-order word flips. + * Is that clear? + */ + + +/* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2) + Please allow at least 1 more bit in carry than is in a LITTLENUM. + We need that extra bit to hold a carry during a LITTLENUM carry + propagation. Another extra bit (kept 0) will assure us that we + don't get a sticky sign bit after shifting right, and that + permits us to propagate the carry without any masking of bits. +#endif */ + for (carry = 1, lp --; carry && (lp >= words); lp --) { + carry = * lp + carry; + * lp = carry; + carry >>= LITTLENUM_NUMBER_OF_BITS; + } + if ( (word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)) ) { + /* We leave return_value alone: admit we read the + * number, but return a floating exception + * because we can't encode the number. + */ + make_invalid_floating_point_number (words); + return return_value; + } + } + return (return_value); +} + +/* This is really identical to atof_ns32k except for some details */ + +gen_to_words(words,precision,exponent_bits) +LITTLENUM_TYPE *words; +long int exponent_bits; +{ + int return_value=0; + + long int exponent_1; + long int exponent_2; + long int exponent_3; + long int exponent_4; + int exponent_skippage; + LITTLENUM_TYPE word1; + LITTLENUM_TYPE * lp; + + if (generic_floating_point_number.low > generic_floating_point_number.leader) { + /* 0.0e0 seen. */ + bzero (words, sizeof(LITTLENUM_TYPE) * precision); + return return_value; + } + + /* + * All vaxen floating_point formats (so far) have: + * Bit 15 is sign bit. + * Bits 14:n are excess-whatever exponent. + * Bits n-1:0 (if any) are most significant bits of fraction. + * Bits 15:0 of the next word are the next most significant bits. + * And so on for each other word. + * + * So we need: number of bits of exponent, number of bits of + * mantissa. + */ + bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS; + littlenum_pointer = generic_floating_point_number.leader; + littlenums_left = 1+generic_floating_point_number.leader - generic_floating_point_number.low; + /* Seek (and forget) 1st significant bit */ + for (exponent_skippage = 0;! next_bits(1); exponent_skippage ++) + ; + exponent_1 = generic_floating_point_number.exponent + generic_floating_point_number.leader + 1 - + generic_floating_point_number.low; + /* Radix LITTLENUM_RADIX, point just higher than generic_floating_point_number.leader. */ + exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS; + /* Radix 2. */ + exponent_3 = exponent_2 - exponent_skippage; + /* Forget leading zeros, forget 1st bit. */ + exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2); + /* Offset exponent. */ + + if (exponent_4 & ~ mask [exponent_bits]) { + /* + * Exponent overflow. Lose immediately. + */ + + /* + * We leave return_value alone: admit we read the + * number, but return a floating exception + * because we can't encode the number. + */ + + make_invalid_floating_point_number (words); + return return_value; + } + lp = words; + + /* Word 1. Sign, exponent and perhaps high bits. */ + /* Assume 2's complement integers. */ + word1 = ((exponent_4 & mask [exponent_bits]) << (15 - exponent_bits)) | + ((generic_floating_point_number.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits); + * lp ++ = word1; + + /* The rest of the words are just mantissa bits. */ + for (; lp < words + precision; lp++) + * lp = next_bits (LITTLENUM_NUMBER_OF_BITS); + + if (next_bits (1)) { + unsigned long int carry; + /* + * Since the NEXT bit is a 1, round UP the mantissa. + * The cunning design of these hidden-1 floats permits + * us to let the mantissa overflow into the exponent, and + * it 'does the right thing'. However, we lose if the + * highest-order bit of the lowest-order word flips. + * Is that clear? + */ + + +/* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2) + Please allow at least 1 more bit in carry than is in a LITTLENUM. + We need that extra bit to hold a carry during a LITTLENUM carry + propagation. Another extra bit (kept 0) will assure us that we + don't get a sticky sign bit after shifting right, and that + permits us to propagate the carry without any masking of bits. +#endif */ + for (carry = 1, lp --; carry && (lp >= words); lp --) { + carry = * lp + carry; + * lp = carry; + carry >>= LITTLENUM_NUMBER_OF_BITS; + } + if ( (word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)) ) { + /* We leave return_value alone: admit we read the + * number, but return a floating exception + * because we can't encode the number. + */ + make_invalid_floating_point_number (words); + return return_value; + } + } + return (return_value); +} + +/* This routine is a real kludge. Someone really should do it better, but + I'm too lazy, and I don't understand this stuff all too well anyway + (JF) + */ +void int_to_gen(x) +long x; +{ + char buf[20]; + char *bufp; + + sprintf(buf,"%ld",x); + bufp= &buf[0]; + if(atof_generic(&bufp,".", EXP_CHARS, &generic_floating_point_number)) + as_warn("Error converting number to floating point (Exponent overflow?)"); +} |