1 /* expr.c -operands, expressions-
2 Copyright (C) 1987, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GAS is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 * This is really a branch office of as-read.c. I split it out to clearly
22 * distinguish the world of expressions from the world of statements.
23 * (It also gives smaller files to re-compile.)
24 * Here, "operand"s are of expressions, not instructions.
34 static void clean_up_expression PARAMS ((expressionS * expressionP));
35 extern const char EXP_CHARS[], FLT_CHARS[];
38 * Build any floating-point literal here.
39 * Also build any bignum literal here.
42 /* Seems atof_machine can backscan through generic_bignum and hit whatever
43 happens to be loaded before it in memory. And its way too complicated
44 for me to fix right. Thus a hack. JF: Just make generic_bignum bigger,
45 and never write into the early words, thus they'll always be zero.
46 I hate Dean's floating-point code. Bleh. */
47 LITTLENUM_TYPE generic_bignum[SIZE_OF_LARGE_NUMBER + 6];
48 FLONUM_TYPE generic_floating_point_number =
50 &generic_bignum[6], /* low (JF: Was 0) */
51 &generic_bignum[SIZE_OF_LARGE_NUMBER + 6 - 1], /* high JF: (added +6) */
56 /* If nonzero, we've been asked to assemble nan, +inf or -inf */
57 int generic_floating_point_magic;
59 floating_constant (expressionP)
60 expressionS *expressionP;
62 /* input_line_pointer->*/
63 /* floating-point constant. */
66 error_code = atof_generic
67 (&input_line_pointer, ".", EXP_CHARS,
68 &generic_floating_point_number);
72 if (error_code == ERROR_EXPONENT_OVERFLOW)
74 as_bad ("bad floating-point constant: exponent overflow, probably assembling junk");
78 as_bad ("bad floating-point constant: unknown error code=%d.", error_code);
81 expressionP->X_seg = big_section;
82 /* input_line_pointer->just after constant, */
83 /* which may point to whitespace. */
84 expressionP->X_add_number = -1;
89 integer_constant (radix, expressionP)
91 expressionS *expressionP;
93 register char *digit_2; /*->2nd digit of number. */
96 register valueT number; /* offset or (absolute) value */
97 register short int digit; /* value of next digit in current radix */
98 register short int maxdig = 0;/* highest permitted digit value. */
99 register int too_many_digits = 0; /* if we see >= this number of */
100 register char *name; /* points to name of symbol */
101 register symbolS *symbolP; /* points to symbol */
103 int small; /* true if fits in 32 bits. */
104 extern const char hex_value[]; /* in hex_value.c */
106 /* may be bignum, or may fit in 32 bits. */
108 * most numbers fit into 32 bits, and we want this case to be fast.
109 * so we pretend it will fit into 32 bits. if, after making up a 32
110 * bit number, we realise that we have scanned more digits than
111 * comfortably fit into 32 bits, we re-scan the digits coding
112 * them into a bignum. for decimal and octal numbers we are conservative: some
113 * numbers may be assumed bignums when in fact they do fit into 32 bits.
114 * numbers of any radix can have excess leading zeros: we strive
115 * to recognise this and cast them back into 32 bits.
116 * we must check that the bignum really is more than 32
117 * bits, and change it back to a 32-bit number if it fits.
118 * the number we are looking for is expected to be positive, but
119 * if it fits into 32 bits as an unsigned number, we let it be a 32-bit
120 * number. the cavalier approach is for speed in ordinary cases.
128 too_many_digits = 33;
132 too_many_digits = 11;
142 too_many_digits = 11;
144 c = *input_line_pointer;
145 input_line_pointer++;
146 digit_2 = input_line_pointer;
147 for (number = 0; (digit = hex_value[c]) < maxdig; c = *input_line_pointer++)
149 number = number * radix + digit;
151 /* c contains character after number. */
152 /* input_line_pointer->char after c. */
153 small = input_line_pointer - digit_2 < too_many_digits;
157 * we saw a lot of digits. manufacture a bignum the hard way.
159 LITTLENUM_TYPE *leader; /*->high order littlenum of the bignum. */
160 LITTLENUM_TYPE *pointer; /*->littlenum we are frobbing now. */
163 leader = generic_bignum;
164 generic_bignum[0] = 0;
165 generic_bignum[1] = 0;
166 /* we could just use digit_2, but lets be mnemonic. */
167 input_line_pointer = --digit_2; /*->1st digit. */
168 c = *input_line_pointer++;
169 for (; (carry = hex_value[c]) < maxdig; c = *input_line_pointer++)
171 for (pointer = generic_bignum;
177 work = carry + radix * *pointer;
178 *pointer = work & LITTLENUM_MASK;
179 carry = work >> LITTLENUM_NUMBER_OF_BITS;
183 if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1)
184 { /* room to grow a longer bignum. */
189 /* again, c is char after number, */
190 /* input_line_pointer->after c. */
191 know (sizeof (int) * 8 == 32);
192 know (LITTLENUM_NUMBER_OF_BITS == 16);
193 /* hence the constant "2" in the next line. */
194 if (leader < generic_bignum + 2)
195 { /* will fit into 32 bits. */
197 ((generic_bignum[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS)
198 | (generic_bignum[0] & LITTLENUM_MASK);
203 number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */
209 * here with number, in correct radix. c is the next char.
210 * note that unlike un*x, we allow "011f" "0x9f" to
211 * both mean the same as the (conventional) "9f". this is simply easier
212 * than checking for strict canonical form. syntax sux!
218 #ifdef LOCAL_LABELS_FB
222 * backward ref to local label.
223 * because it is backward, expect it to be defined.
225 /* Construct a local label. */
226 name = fb_label_name ((int) number, 0);
228 /* seen before, or symbol is defined: ok */
229 symbolP = symbol_find (name);
230 if ((symbolP != NULL) && (S_IS_DEFINED (symbolP)))
233 /* local labels are never absolute. don't waste time
234 checking absoluteness. */
235 know (SEG_NORMAL (S_GET_SEGMENT (symbolP)));
237 expressionP->X_add_symbol = symbolP;
238 expressionP->X_seg = S_GET_SEGMENT (symbolP);
242 { /* either not seen or not defined. */
243 as_bad ("backw. ref to unknown label \"%d:\", 0 assumed.", number);
244 expressionP->X_seg = absolute_section;
247 expressionP->X_add_number = 0;
254 * forward reference. expect symbol to be undefined or
255 * unknown. undefined: seen it before. unknown: never seen
257 * construct a local label name, then an undefined symbol.
258 * don't create a xseg frag for it: caller may do that.
259 * just return it as never seen before.
261 name = fb_label_name ((int) number, 1);
262 symbolP = symbol_find_or_make (name);
263 /* we have no need to check symbol properties. */
264 #ifndef many_segments
265 /* since "know" puts its arg into a "string", we
266 can't have newlines in the argument. */
267 know (S_GET_SEGMENT (symbolP) == undefined_section || S_GET_SEGMENT (symbolP) == text_section || S_GET_SEGMENT (symbolP) == data_section);
269 expressionP->X_add_symbol = symbolP;
270 expressionP->X_seg = undefined_section;
271 expressionP->X_subtract_symbol = NULL;
272 expressionP->X_add_number = 0;
277 #endif /* LOCAL_LABELS_FB */
279 #ifdef LOCAL_LABELS_DOLLAR
284 /* If the dollar label is *currently* defined, then this is just
285 another reference to it. If it is not *currently* defined,
286 then this is a fresh instantiation of that number, so create
289 if (dollar_label_defined (number))
291 name = dollar_label_name (number, 0);
292 symbolP = symbol_find (name);
293 know (symbolP != NULL);
297 name = dollar_label_name (number, 1);
298 symbolP = symbol_find_or_make (name);
301 expressionP->X_add_symbol = symbolP;
302 expressionP->X_add_number = 0;
303 expressionP->X_seg = S_GET_SEGMENT (symbolP);
308 #endif /* LOCAL_LABELS_DOLLAR */
312 expressionP->X_add_number = number;
313 expressionP->X_seg = absolute_section;
314 input_line_pointer--; /* restore following character. */
316 } /* really just a number */
318 } /* switch on char following the number */
323 { /* not a small number */
324 expressionP->X_add_number = number;
325 expressionP->X_seg = big_section;
326 input_line_pointer--; /*->char following number. */
328 } /* integer_constant() */
332 * Summary of operand().
334 * in: Input_line_pointer points to 1st char of operand, which may
337 * out: A expressionS. X_seg determines how to understand the rest of the
339 * The operand may have been empty: in this case X_seg == SEG_ABSENT.
340 * Input_line_pointer->(next non-blank) char after operand.
347 operand (expressionP)
348 register expressionS *expressionP;
351 register symbolS *symbolP; /* points to symbol */
352 register char *name; /* points to name of symbol */
353 /* invented for humans only, hope */
354 /* optimising compiler flushes it! */
355 register short int radix; /* 2, 8, 10 or 16, 0 when floating */
356 /* 0 means we saw start of a floating- */
357 /* point constant. */
359 /* digits, assume it is a bignum. */
361 SKIP_WHITESPACE (); /* leading whitespace is part of operand. */
362 c = *input_line_pointer++; /* input_line_pointer->past char in c. */
368 integer_constant (2, expressionP);
371 integer_constant (8, expressionP);
374 integer_constant (16, expressionP);
386 input_line_pointer--;
388 integer_constant (10, expressionP);
392 /* non-decimal radix */
395 c = *input_line_pointer;
400 if (c && strchr (FLT_CHARS, c))
402 input_line_pointer++;
403 floating_constant (expressionP);
407 /* The string was only zero */
408 expressionP->X_add_symbol = 0;
409 expressionP->X_add_number = 0;
410 expressionP->X_seg = absolute_section;
417 input_line_pointer++;
418 integer_constant (16, expressionP);
422 #ifdef LOCAL_LABELS_FB
423 if (!*input_line_pointer
424 || (!strchr ("+-.0123456789", *input_line_pointer)
425 && !strchr (EXP_CHARS, *input_line_pointer)))
427 input_line_pointer--;
428 integer_constant (10, expressionP);
433 input_line_pointer++;
434 integer_constant (2, expressionP);
445 integer_constant (8, expressionP);
449 #ifdef LOCAL_LABELS_FB
450 /* if it says '0f' and the line ends or it doesn't look like
451 a floating point #, its a local label ref. dtrt */
452 /* likewise for the b's. xoxorich. */
454 && (!*input_line_pointer ||
455 (!strchr ("+-.0123456789", *input_line_pointer) &&
456 !strchr (EXP_CHARS, *input_line_pointer))))
458 input_line_pointer -= 1;
459 integer_constant (10, expressionP);
473 input_line_pointer++;
474 floating_constant (expressionP);
475 expressionP->X_add_number = -(isupper (c) ? tolower (c) : c);
478 #ifdef LOCAL_LABELS_DOLLAR
480 integer_constant (10, expressionP);
487 /* didn't begin with digit & not a name */
489 (void) expression (expressionP);
490 /* Expression() will pass trailing whitespace */
491 if (*input_line_pointer++ != ')')
493 as_bad ("Missing ')' assumed");
494 input_line_pointer--;
496 /* here with input_line_pointer->char after "(...)" */
498 return expressionP->X_seg;
502 /* Warning: to conform to other people's assemblers NO ESCAPEMENT is
503 permitted for a single quote. The next character, parity errors and
504 all, is taken as the value of the operand. VERY KINKY. */
505 expressionP->X_add_number = *input_line_pointer++;
506 expressionP->X_seg = absolute_section;
510 operand (expressionP);
516 /* unary operator: hope for SEG_ABSOLUTE */
517 segT opseg = operand (expressionP);
518 if (opseg == absolute_section)
520 /* input_line_pointer -> char after operand */
523 expressionP->X_add_number = -expressionP->X_add_number;
524 /* Notice: '-' may overflow: no warning is given. This is
525 compatible with other people's assemblers. Sigh. */
529 expressionP->X_add_number = ~expressionP->X_add_number;
532 else if (opseg == text_section
533 || opseg == data_section
534 || opseg == bss_section
535 || opseg == pass1_section
536 || opseg == undefined_section)
540 expressionP->X_subtract_symbol = expressionP->X_add_symbol;
541 expressionP->X_add_symbol = 0;
542 expressionP->X_seg = diff_section;
545 as_warn ("Unary operator %c ignored because bad operand follows",
549 as_warn ("Unary operator %c ignored because bad operand follows", c);
554 if (!is_part_of_name (*input_line_pointer))
557 extern struct obstack frags;
559 /* JF: '.' is pseudo symbol with value of current location
560 in current segment. */
561 #ifdef DOT_LABEL_PREFIX
566 symbolP = symbol_new (fake,
568 (valueT) (obstack_next_free (&frags) - frag_now->fr_literal),
571 expressionP->X_add_number = 0;
572 expressionP->X_add_symbol = symbolP;
573 expressionP->X_seg = now_seg;
587 /* can't imagine any other kind of operand */
588 expressionP->X_seg = absent_section;
589 input_line_pointer--;
590 md_operand (expressionP);
594 if (is_end_of_line[c])
596 if (is_name_beginner (c)) /* here if did not begin with a digit */
599 * Identifier begins here.
600 * This is kludged for speed, so code is repeated.
603 name = --input_line_pointer;
604 c = get_symbol_end ();
605 symbolP = symbol_find_or_make (name);
606 /* If we have an absolute symbol or a reg, then we know its value
608 expressionP->X_seg = S_GET_SEGMENT (symbolP);
609 if (expressionP->X_seg == absolute_section
610 || expressionP->X_seg == reg_section)
611 expressionP->X_add_number = S_GET_VALUE (symbolP);
614 expressionP->X_add_number = 0;
615 expressionP->X_add_symbol = symbolP;
617 *input_line_pointer = c;
618 expressionP->X_subtract_symbol = NULL;
622 as_bad ("Bad expression");
623 expressionP->X_add_number = 0;
624 expressionP->X_seg = absolute_section;
629 * It is more 'efficient' to clean up the expressionS when they are created.
630 * Doing it here saves lines of code.
632 clean_up_expression (expressionP);
633 SKIP_WHITESPACE (); /*->1st char after operand. */
634 know (*input_line_pointer != ' ');
635 return (expressionP->X_seg);
639 /* Internal. Simplify a struct expression for use by expr() */
642 * In: address of a expressionS.
643 * The X_seg field of the expressionS may only take certain values.
644 * Now, we permit SEG_PASS1 to make code smaller & faster.
645 * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT.
646 * Out: expressionS may have been modified:
647 * 'foo-foo' symbol references cancelled to 0,
648 * which changes X_seg from SEG_DIFFERENCE to SEG_ABSOLUTE;
649 * Unused fields zeroed to help expr().
653 clean_up_expression (expressionP)
654 register expressionS *expressionP;
656 segT s = expressionP->X_seg;
657 if (s == absent_section
658 || s == pass1_section)
660 expressionP->X_add_symbol = NULL;
661 expressionP->X_subtract_symbol = NULL;
662 expressionP->X_add_number = 0;
664 else if (s == big_section
665 || s == absolute_section)
667 expressionP->X_subtract_symbol = NULL;
668 expressionP->X_add_symbol = NULL;
670 else if (s == undefined_section)
671 expressionP->X_subtract_symbol = NULL;
672 else if (s == diff_section)
675 * It does not hurt to 'cancel' NULL==NULL
676 * when comparing symbols for 'eq'ness.
677 * It is faster to re-cancel them to NULL
678 * than to check for this special case.
680 if (expressionP->X_subtract_symbol == expressionP->X_add_symbol
681 || (expressionP->X_subtract_symbol
682 && expressionP->X_add_symbol
683 && (expressionP->X_subtract_symbol->sy_frag
684 == expressionP->X_add_symbol->sy_frag)
685 && (S_GET_VALUE (expressionP->X_subtract_symbol)
686 == S_GET_VALUE (expressionP->X_add_symbol))))
688 expressionP->X_subtract_symbol = NULL;
689 expressionP->X_add_symbol = NULL;
690 expressionP->X_seg = absolute_section;
693 else if (s == reg_section)
695 expressionP->X_add_symbol = NULL;
696 expressionP->X_subtract_symbol = NULL;
700 if (SEG_NORMAL (expressionP->X_seg))
702 expressionP->X_subtract_symbol = NULL;
706 BAD_CASE (expressionP->X_seg);
714 * Internal. Made a function because this code is used in 2 places.
715 * Generate error or correct X_?????_symbol of expressionS.
719 * symbol_1 += symbol_2 ... well ... sort of.
723 expr_part (symbol_1_PP, symbol_2_P)
724 symbolS **symbol_1_PP;
728 #ifndef MANY_SEGMENTS
730 int test = ((*symbol_1_PP) == NULL
731 || (S_GET_SEGMENT (*symbol_1_PP) == text_section)
732 || (S_GET_SEGMENT (*symbol_1_PP) == data_section)
733 || (S_GET_SEGMENT (*symbol_1_PP) == bss_section)
734 || (!S_IS_DEFINED (*symbol_1_PP)));
736 test = (symbol_2_P == NULL
737 || (S_GET_SEGMENT (symbol_2_P) == text_section)
738 || (S_GET_SEGMENT (symbol_2_P) == data_section)
739 || (S_GET_SEGMENT (symbol_2_P) == bss_section)
740 || (!S_IS_DEFINED (symbol_2_P)));
746 if (!S_IS_DEFINED (*symbol_1_PP))
750 return_value = pass1_section;
755 know (!S_IS_DEFINED (*symbol_1_PP));
756 return_value = undefined_section;
763 if (!S_IS_DEFINED (symbol_2_P))
766 return_value = pass1_section;
770 /* {seg1} - {seg2} */
771 as_bad ("Expression too complex, 2 symbolS forgotten: \"%s\" \"%s\"",
772 S_GET_NAME (*symbol_1_PP), S_GET_NAME (symbol_2_P));
774 return_value = absolute_section;
779 return_value = S_GET_SEGMENT (*symbol_1_PP);
784 { /* (* symbol_1_PP) == NULL */
787 *symbol_1_PP = symbol_2_P;
788 return_value = S_GET_SEGMENT (symbol_2_P);
793 return_value = absolute_section;
796 #ifndef MANY_SEGMENTS
798 test = (return_value == absolute_section
799 || return_value == text_section
800 || return_value == data_section
801 || return_value == bss_section
802 || return_value == undefined_section
803 || return_value == pass1_section);
807 know ((*symbol_1_PP) == NULL
808 || (S_GET_SEGMENT (*symbol_1_PP) == return_value));
809 return (return_value);
812 /* Expression parser. */
815 * We allow an empty expression, and just assume (absolute,0) silently.
816 * Unary operators and parenthetical expressions are treated as operands.
817 * As usual, Q==quantity==operand, O==operator, X==expression mnemonics.
819 * We used to do a aho/ullman shift-reduce parser, but the logic got so
820 * warped that I flushed it and wrote a recursive-descent parser instead.
821 * Now things are stable, would anybody like to write a fast parser?
822 * Most expressions are either register (which does not even reach here)
823 * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common.
824 * So I guess it doesn't really matter how inefficient more complex expressions
827 * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK.
828 * Also, we have consumed any leading or trailing spaces (operand does that)
829 * and done all intervening operators.
834 O_illegal, /* (0) what we get for illegal op */
836 O_multiply, /* (1) * */
837 O_divide, /* (2) / */
838 O_modulus, /* (3) % */
839 O_left_shift, /* (4) < */
840 O_right_shift, /* (5) > */
841 O_bit_inclusive_or, /* (6) | */
842 O_bit_or_not, /* (7) ! */
843 O_bit_exclusive_or, /* (8) ^ */
844 O_bit_and, /* (9) & */
846 O_subtract /* (11) - */
854 static const operatorT op_encoding[256] =
855 { /* maps ASCII->operators */
857 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
858 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
860 __, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __,
861 __, __, O_multiply, O_add, __, O_subtract, __, O_divide,
862 __, __, __, __, __, __, __, __,
863 __, __, __, __, O_left_shift, __, O_right_shift, __,
864 __, __, __, __, __, __, __, __,
865 __, __, __, __, __, __, __, __,
866 __, __, __, __, __, __, __, __,
867 __, __, __, __, __, __, O_bit_exclusive_or, __,
868 __, __, __, __, __, __, __, __,
869 __, __, __, __, __, __, __, __,
870 __, __, __, __, __, __, __, __,
871 __, __, __, __, O_bit_inclusive_or, __, __, __,
873 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
874 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
875 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
876 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
877 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
878 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
879 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
880 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __
886 * 0 operand, (expression)
891 static const operator_rankT
893 {0, 3, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1};
895 /* Return resultP->X_seg. */
898 register operator_rankT rank; /* Larger # is higher rank. */
899 register expressionS *resultP; /* Deliver result here. */
902 register operatorT op_left;
903 register char c_left; /* 1st operator character. */
904 register operatorT op_right;
905 register char c_right;
908 (void) operand (resultP);
909 know (*input_line_pointer != ' '); /* Operand() gobbles spaces. */
910 c_left = *input_line_pointer; /* Potential operator character. */
911 op_left = op_encoding[c_left];
912 while (op_left != O_illegal && op_rank[(int) op_left] > rank)
914 input_line_pointer++; /*->after 1st character of operator. */
915 /* Operators "<<" and ">>" have 2 characters. */
916 if (*input_line_pointer == c_left && (c_left == '<' || c_left == '>'))
918 input_line_pointer++;
919 } /*->after operator. */
920 if (absent_section == expr (op_rank[(int) op_left], &right))
922 as_warn ("Missing operand value assumed absolute 0.");
923 resultP->X_add_number = 0;
924 resultP->X_subtract_symbol = NULL;
925 resultP->X_add_symbol = NULL;
926 resultP->X_seg = absolute_section;
928 know (*input_line_pointer != ' ');
929 c_right = *input_line_pointer;
930 op_right = op_encoding[c_right];
931 if (*input_line_pointer == c_right && (c_right == '<' || c_right == '>'))
933 input_line_pointer++;
934 } /*->after operator. */
935 know ((int) op_right == 0 || op_rank[(int) op_right] <= op_rank[(int) op_left]);
936 /* input_line_pointer->after right-hand quantity. */
937 /* left-hand quantity in resultP */
938 /* right-hand quantity in right. */
939 /* operator in op_left. */
940 if (resultP->X_seg == pass1_section || right.X_seg == pass1_section)
942 resultP->X_seg = pass1_section;
946 if (resultP->X_seg == big_section)
948 as_warn ("Left operand of %c is a %s. Integer 0 assumed.",
949 c_left, resultP->X_add_number > 0 ? "bignum" : "float");
950 resultP->X_seg = absolute_section;
951 resultP->X_add_symbol = 0;
952 resultP->X_subtract_symbol = 0;
953 resultP->X_add_number = 0;
955 if (right.X_seg == big_section)
957 as_warn ("Right operand of %c is a %s. Integer 0 assumed.",
958 c_left, right.X_add_number > 0 ? "bignum" : "float");
959 right.X_seg = absolute_section;
960 right.X_add_symbol = 0;
961 right.X_subtract_symbol = 0;
962 right.X_add_number = 0;
964 if (op_left == O_subtract)
967 * Convert - into + by exchanging symbolS and negating number.
968 * I know -infinity can't be negated in 2's complement:
969 * but then it can't be subtracted either. This trick
970 * does not cause any further inaccuracy.
973 register symbolS *symbolP;
975 right.X_add_number = -right.X_add_number;
976 symbolP = right.X_add_symbol;
977 right.X_add_symbol = right.X_subtract_symbol;
978 right.X_subtract_symbol = symbolP;
981 right.X_seg = diff_section;
986 if (op_left == O_add)
990 #ifndef MANY_SEGMENTS
992 know (resultP->X_seg == data_section || resultP->X_seg == text_section || resultP->X_seg == bss_section || resultP->X_seg == undefined_section || resultP->X_seg == diff_section || resultP->X_seg == absolute_section || resultP->X_seg == pass1_section || resultP->X_seg == reg_section);
994 know (right.X_seg == data_section || right.X_seg == text_section || right.X_seg == bss_section || right.X_seg == undefined_section || right.X_seg == diff_section || right.X_seg == absolute_section || right.X_seg == pass1_section);
997 clean_up_expression (&right);
998 clean_up_expression (resultP);
1000 seg1 = expr_part (&resultP->X_add_symbol, right.X_add_symbol);
1001 seg2 = expr_part (&resultP->X_subtract_symbol, right.X_subtract_symbol);
1002 if (seg1 == pass1_section || seg2 == pass1_section)
1005 resultP->X_seg = pass1_section;
1007 else if (seg2 == absolute_section)
1008 resultP->X_seg = seg1;
1009 else if (seg1 != undefined_section
1010 && seg1 != absolute_section
1011 && seg2 != undefined_section
1014 know (seg2 != absolute_section);
1015 know (resultP->X_subtract_symbol);
1016 #ifndef MANY_SEGMENTS
1018 know (seg1 == text_section || seg1 == data_section || seg1 == bss_section);
1019 know (seg2 == text_section || seg2 == data_section || seg2 == bss_section);
1022 know (resultP->X_add_symbol);
1023 know (resultP->X_subtract_symbol);
1024 as_bad ("Expression too complex: forgetting %s - %s",
1025 S_GET_NAME (resultP->X_add_symbol),
1026 S_GET_NAME (resultP->X_subtract_symbol));
1027 resultP->X_seg = absolute_section;
1028 /* Clean_up_expression() will do the rest. */
1031 resultP->X_seg = diff_section;
1033 resultP->X_add_number += right.X_add_number;
1034 clean_up_expression (resultP);
1038 if (resultP->X_seg == undefined_section || right.X_seg == undefined_section)
1040 resultP->X_seg = pass1_section;
1045 resultP->X_subtract_symbol = NULL;
1046 resultP->X_add_symbol = NULL;
1047 /* Will be absolute_section. */
1048 if (resultP->X_seg != absolute_section || right.X_seg != absolute_section)
1050 as_bad ("Relocation error. Absolute 0 assumed.");
1051 resultP->X_seg = absolute_section;
1052 resultP->X_add_number = 0;
1058 case O_bit_inclusive_or:
1059 resultP->X_add_number |= right.X_add_number;
1063 if (right.X_add_number)
1065 resultP->X_add_number %= right.X_add_number;
1069 as_warn ("Division by 0. 0 assumed.");
1070 resultP->X_add_number = 0;
1075 resultP->X_add_number &= right.X_add_number;
1079 resultP->X_add_number *= right.X_add_number;
1083 if (right.X_add_number)
1085 resultP->X_add_number /= right.X_add_number;
1089 as_warn ("Division by 0. 0 assumed.");
1090 resultP->X_add_number = 0;
1095 resultP->X_add_number <<= right.X_add_number;
1099 resultP->X_add_number >>= right.X_add_number;
1102 case O_bit_exclusive_or:
1103 resultP->X_add_number ^= right.X_add_number;
1107 resultP->X_add_number |= ~right.X_add_number;
1113 } /* switch(operator) */
1115 } /* If we have to force need_pass_2. */
1116 } /* If operator was +. */
1117 } /* If we didn't set need_pass_2. */
1119 } /* While next operator is >= this rank. */
1120 return (resultP->X_seg);
1126 * This lives here because it belongs equally in expr.c & read.c.
1127 * Expr.c is just a branch office read.c anyway, and putting it
1128 * here lessens the crowd at read.c.
1130 * Assume input_line_pointer is at start of symbol name.
1131 * Advance input_line_pointer past symbol name.
1132 * Turn that character into a '\0', returning its former value.
1133 * This allows a string compare (RMS wants symbol names to be strings)
1134 * of the symbol name.
1135 * There will always be a char following symbol name, because all good
1136 * lines end in end-of-line.
1143 while (is_part_of_name (c = *input_line_pointer++))
1145 *--input_line_pointer = 0;
1151 get_single_number ()
1155 return exp.X_add_number;