1 /* expr.c -operands, expressions-
2 Copyright (C) 1987, 1990, 1991, 1992 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.
35 static void clean_up_expression(expressionS *expressionP);
37 static void clean_up_expression(); /* Internal. */
38 #endif /* not __STDC__ */
39 extern const char EXP_CHARS[]; /* JF hide MD floating pt stuff all the same place */
40 extern const char FLT_CHARS[];
42 #ifdef LOCAL_LABELS_DOLLAR
43 extern int local_label_defined[];
47 * Build any floating-point literal here.
48 * Also build any bignum literal here.
51 /* LITTLENUM_TYPE generic_buffer [6]; */ /* JF this is a hack */
52 /* Seems atof_machine can backscan through generic_bignum and hit whatever
53 happens to be loaded before it in memory. And its way too complicated
54 for me to fix right. Thus a hack. JF: Just make generic_bignum bigger,
55 and never write into the early words, thus they'll always be zero.
56 I hate Dean's floating-point code. Bleh.
58 LITTLENUM_TYPE generic_bignum [SIZE_OF_LARGE_NUMBER+6];
59 FLONUM_TYPE generic_floating_point_number =
61 & generic_bignum [6], /* low (JF: Was 0) */
62 & generic_bignum [SIZE_OF_LARGE_NUMBER+6 - 1], /* high JF: (added +6) */
67 /* If nonzero, we've been asked to assemble nan, +inf or -inf */
68 int generic_floating_point_magic;
70 floating_constant(expressionP)
71 expressionS *expressionP;
73 /* input_line_pointer->*/
74 /* floating-point constant. */
77 error_code = atof_generic
78 (& input_line_pointer, ".", EXP_CHARS,
79 & generic_floating_point_number);
83 if (error_code == ERROR_EXPONENT_OVERFLOW)
85 as_bad("bad floating-point constant: exponent overflow, probably assembling junk");
89 as_bad("bad floating-point constant: unknown error code=%d.", error_code);
92 expressionP->X_seg = SEG_BIG;
93 /* input_line_pointer->just after constant, */
94 /* which may point to whitespace. */
95 expressionP->X_add_number =-1;
101 integer_constant(radix, expressionP)
103 expressionS *expressionP;
107 register char * digit_2; /*->2nd digit of number. */
110 register valueT number; /* offset or (absolute) value */
111 register short int digit; /* value of next digit in current radix */
112 register short int maxdig = 0; /* highest permitted digit value. */
113 register int too_many_digits = 0; /* if we see >= this number of */
114 register char *name; /* points to name of symbol */
115 register symbolS * symbolP; /* points to symbol */
117 int small; /* true if fits in 32 bits. */
118 extern char hex_value[]; /* in hex_value.c */
120 /* may be bignum, or may fit in 32 bits. */
122 * most numbers fit into 32 bits, and we want this case to be fast.
123 * so we pretend it will fit into 32 bits. if, after making up a 32
124 * bit number, we realise that we have scanned more digits than
125 * comfortably fit into 32 bits, we re-scan the digits coding
126 * them into a bignum. for decimal and octal numbers we are conservative: some
127 * numbers may be assumed bignums when in fact they do fit into 32 bits.
128 * numbers of any radix can have excess leading zeros: we strive
129 * to recognise this and cast them back into 32 bits.
130 * we must check that the bignum really is more than 32
131 * bits, and change it back to a 32-bit number if it fits.
132 * the number we are looking for is expected to be positive, but
133 * if it fits into 32 bits as an unsigned number, we let it be a 32-bit
134 * number. the cavalier approach is for speed in ordinary cases.
142 too_many_digits = 33;
146 too_many_digits = 11;
156 too_many_digits = 11;
158 c = *input_line_pointer;
159 input_line_pointer++;
160 digit_2 = input_line_pointer;
161 for (number=0; (digit=hex_value[c])<maxdig; c = * input_line_pointer ++)
163 number = number * radix + digit;
165 /* c contains character after number. */
166 /* input_line_pointer->char after c. */
167 small = input_line_pointer - digit_2 < too_many_digits;
171 * we saw a lot of digits. manufacture a bignum the hard way.
173 LITTLENUM_TYPE * leader; /*->high order littlenum of the bignum. */
174 LITTLENUM_TYPE * pointer; /*->littlenum we are frobbing now. */
177 leader = generic_bignum;
178 generic_bignum [0] = 0;
179 generic_bignum [1] = 0;
180 /* we could just use digit_2, but lets be mnemonic. */
181 input_line_pointer = -- digit_2; /*->1st digit. */
182 c = *input_line_pointer ++;
183 for (; (carry = hex_value [c]) < maxdig; c = * input_line_pointer ++)
185 for (pointer = generic_bignum;
191 work = carry + radix * * pointer;
192 * pointer = work & LITTLENUM_MASK;
193 carry = work >> LITTLENUM_NUMBER_OF_BITS;
197 if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1)
198 { /* room to grow a longer bignum. */
203 /* again, c is char after number, */
204 /* input_line_pointer->after c. */
205 know(sizeof (int) * 8 == 32);
206 know(LITTLENUM_NUMBER_OF_BITS == 16);
207 /* hence the constant "2" in the next line. */
208 if (leader < generic_bignum + 2)
209 { /* will fit into 32 bits. */
211 ((generic_bignum [1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS)
212 | (generic_bignum [0] & LITTLENUM_MASK);
217 number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */
223 * here with number, in correct radix. c is the next char.
224 * note that unlike un*x, we allow "011f" "0x9f" to
225 * both mean the same as the (conventional) "9f". this is simply easier
226 * than checking for strict canonical form. syntax sux!
231 #ifdef local_labels_fb
234 #ifdef local_labels_dollar
235 || (c=='$' && local_label_defined[number])
240 * backward ref to local label.
241 * because it is backward, expect it to be defined.
244 * construct a local label.
246 name = local_label_name ((int)number, 0);
247 if (((symbolP = symbol_find(name)) != NULL) /* seen before */
248 && (S_IS_DEFINED(symbolP))) /* symbol is defined: ok */
249 { /* expected path: symbol defined. */
250 /* local labels are never absolute. don't waste time checking absoluteness. */
251 know(SEG_NORMAL(S_GET_SEGMENT(symbolP)));
253 expressionP->X_add_symbol = symbolP;
254 expressionP->X_add_number = 0;
255 expressionP->X_seg = S_GET_SEGMENT(symbolP);
258 { /* either not seen or not defined. */
259 as_bad("backw. ref to unknown label \"%d:\", 0 assumed.",
261 expressionP->X_add_number = 0;
262 expressionP->X_seg = SEG_ABSOLUTE;
268 #ifdef local_labels_fb
271 #ifdef local_labels_dollar
272 || (c=='$' && !local_label_defined[number])
277 * forward reference. expect symbol to be undefined or
278 * unknown. undefined: seen it before. unknown: never seen
280 * construct a local label name, then an undefined symbol.
281 * don't create a xseg frag for it: caller may do that.
282 * just return it as never seen before.
284 name = local_label_name((int)number, 1);
285 symbolP = symbol_find_or_make(name);
286 /* we have no need to check symbol properties. */
287 #ifndef many_segments
288 /* since "know" puts its arg into a "string", we
289 can't have newlines in the argument. */
290 know(S_GET_SEGMENT(symbolP) == SEG_UNKNOWN || S_GET_SEGMENT(symbolP) == SEG_TEXT || S_GET_SEGMENT(symbolP) == SEG_DATA);
292 expressionP->X_add_symbol = symbolP;
293 expressionP->X_seg = SEG_UNKNOWN;
294 expressionP->X_subtract_symbol = NULL;
295 expressionP->X_add_number = 0;
298 { /* really a number, not a local label. */
299 expressionP->X_add_number = number;
300 expressionP->X_seg = SEG_ABSOLUTE;
301 input_line_pointer --; /* restore following character. */
306 { /* really a number. */
307 expressionP->X_add_number = number;
308 expressionP->X_seg = SEG_ABSOLUTE;
309 input_line_pointer --; /* restore following character. */
310 } /* if (number<10) */
314 expressionP->X_add_number = number;
315 expressionP->X_seg = SEG_BIG;
316 input_line_pointer --; /*->char following number. */
322 * Summary of operand().
324 * in: Input_line_pointer points to 1st char of operand, which may
327 * out: A expressionS. X_seg determines how to understand the rest of the
329 * The operand may have been empty: in this case X_seg == SEG_ABSENT.
330 * Input_line_pointer->(next non-blank) char after operand.
337 operand (expressionP)
338 register expressionS * expressionP;
341 register symbolS * symbolP; /* points to symbol */
342 register char *name; /* points to name of symbol */
343 /* invented for humans only, hope */
344 /* optimising compiler flushes it! */
345 register short int radix; /* 2, 8, 10 or 16, 0 when floating */
346 /* 0 means we saw start of a floating- */
347 /* point constant. */
349 /* digits, assume it is a bignum. */
354 SKIP_WHITESPACE(); /* leading whitespace is part of operand. */
355 c = * input_line_pointer ++; /* input_line_pointer->past char in c. */
361 integer_constant(2, expressionP);
364 integer_constant(8, expressionP);
367 integer_constant(16, expressionP);
379 input_line_pointer--;
381 integer_constant(10, expressionP);
385 /* non-decimal radix */
388 c = *input_line_pointer;
393 /* The string was only zero */
394 expressionP->X_add_symbol = 0;
395 expressionP->X_add_number = 0;
396 expressionP->X_seg = SEG_ABSOLUTE;
401 input_line_pointer++;
402 integer_constant(16, expressionP);
406 input_line_pointer++;
407 integer_constant(2, expressionP);
417 integer_constant(8, expressionP);
421 /* if it says '0f' and the line ends or it doesn't look like
422 a floating point #, its a local label ref. dtrt */
423 /* likewise for the b's. xoxorich. */
424 if ((c == 'f' || c == 'b' || c == 'b')
425 && (!*input_line_pointer ||
426 (!strchr("+-.0123456789",*input_line_pointer) &&
427 !strchr(EXP_CHARS,*input_line_pointer))))
429 input_line_pointer -= 2;
430 integer_constant(10, expressionP);
443 input_line_pointer++;
444 floating_constant(expressionP);
450 /* didn't begin with digit & not a name */
452 (void)expression(expressionP);
453 /* Expression() will pass trailing whitespace */
454 if (* input_line_pointer ++ != ')')
456 as_bad("Missing ')' assumed");
457 input_line_pointer --;
459 /* here with input_line_pointer->char after "(...)" */
466 * Warning: to conform to other people's assemblers NO ESCAPEMENT is permitted
467 * for a single quote. The next character, parity errors and all, is taken
468 * as the value of the operand. VERY KINKY.
470 expressionP->X_add_number = * input_line_pointer ++;
471 expressionP->X_seg = SEG_ABSOLUTE;
479 /* unary operator: hope for SEG_ABSOLUTE */
480 switch(operand (expressionP)) {
482 /* input_line_pointer -> char after operand */
485 expressionP -> X_add_number = - expressionP -> X_add_number;
487 * Notice: '-' may overflow: no warning is given. This is compatible
488 * with other people's assemblers. Sigh.
493 expressionP -> X_add_number = ~ expressionP -> X_add_number;
502 if(c=='-') { /* JF I hope this hack works */
503 expressionP->X_subtract_symbol=expressionP->X_add_symbol;
504 expressionP->X_add_symbol=0;
505 expressionP->X_seg=SEG_DIFFERENCE;
508 default: /* unary on non-absolute is unsuported */
509 as_warn("Unary operator %c ignored because bad operand follows", c);
511 /* Expression undisturbed from operand(). */
520 if( !is_part_of_name(*input_line_pointer))
522 extern struct obstack frags;
525 JF: '.' is pseudo symbol with value of current location in current
528 symbolP = symbol_new("L0\001",
530 (valueT)(obstack_next_free(&frags)-frag_now->fr_literal),
533 expressionP->X_add_number=0;
534 expressionP->X_add_symbol=symbolP;
535 expressionP->X_seg = now_seg;
547 /* can't imagine any other kind of operand */
548 expressionP->X_seg = SEG_ABSENT;
549 input_line_pointer --;
550 md_operand (expressionP);
554 if (is_name_beginner(c)) /* here if did not begin with a digit */
557 * Identifier begins here.
558 * This is kludged for speed, so code is repeated.
561 name = -- input_line_pointer;
562 c = get_symbol_end();
563 symbolP = symbol_find_or_make(name);
565 * If we have an absolute symbol or a reg, then we know its value now.
567 expressionP->X_seg = S_GET_SEGMENT(symbolP);
568 switch (expressionP->X_seg)
572 expressionP->X_add_number = S_GET_VALUE(symbolP);
576 expressionP->X_add_number = 0;
577 expressionP->X_add_symbol = symbolP;
579 * input_line_pointer = c;
580 expressionP->X_subtract_symbol = NULL;
584 as_bad("Bad expression");
585 expressionP->X_add_number = 0;
586 expressionP->X_seg = SEG_ABSOLUTE;
599 * It is more 'efficient' to clean up the expressionS when they are created.
600 * Doing it here saves lines of code.
602 clean_up_expression (expressionP);
603 SKIP_WHITESPACE(); /*->1st char after operand. */
604 know(* input_line_pointer != ' ');
605 return (expressionP->X_seg);
609 /* Internal. Simplify a struct expression for use by expr() */
612 * In: address of a expressionS.
613 * The X_seg field of the expressionS may only take certain values.
614 * Now, we permit SEG_PASS1 to make code smaller & faster.
615 * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT.
616 * Out: expressionS may have been modified:
617 * 'foo-foo' symbol references cancelled to 0,
618 * which changes X_seg from SEG_DIFFERENCE to SEG_ABSOLUTE;
619 * Unused fields zeroed to help expr().
623 clean_up_expression (expressionP)
624 register expressionS * expressionP;
626 switch (expressionP->X_seg)
630 expressionP->X_add_symbol = NULL;
631 expressionP->X_subtract_symbol = NULL;
632 expressionP->X_add_number = 0;
637 expressionP->X_subtract_symbol = NULL;
638 expressionP->X_add_symbol = NULL;
642 expressionP->X_subtract_symbol = NULL;
647 * It does not hurt to 'cancel' NULL==NULL
648 * when comparing symbols for 'eq'ness.
649 * It is faster to re-cancel them to NULL
650 * than to check for this special case.
652 if (expressionP->X_subtract_symbol == expressionP->X_add_symbol
653 || (expressionP->X_subtract_symbol
654 && expressionP->X_add_symbol
655 && expressionP->X_subtract_symbol->sy_frag==expressionP->X_add_symbol->sy_frag
656 && S_GET_VALUE(expressionP->X_subtract_symbol) == S_GET_VALUE(expressionP->X_add_symbol))) {
657 expressionP->X_subtract_symbol = NULL;
658 expressionP->X_add_symbol = NULL;
659 expressionP->X_seg = SEG_ABSOLUTE;
664 expressionP->X_add_symbol = NULL;
665 expressionP->X_subtract_symbol = NULL;
669 if (SEG_NORMAL(expressionP->X_seg)) {
670 expressionP->X_subtract_symbol = NULL;
673 BAD_CASE (expressionP->X_seg);
677 } /* clean_up_expression() */
682 * Internal. Made a function because this code is used in 2 places.
683 * Generate error or correct X_?????_symbol of expressionS.
687 * symbol_1 += symbol_2 ... well ... sort of.
691 expr_part (symbol_1_PP, symbol_2_P)
692 symbolS ** symbol_1_PP;
693 symbolS * symbol_2_P;
696 #ifndef MANY_SEGMENTS
697 know((* symbol_1_PP) == NULL || (S_GET_SEGMENT(*symbol_1_PP) == SEG_TEXT) || (S_GET_SEGMENT(*symbol_1_PP) == SEG_DATA) || (S_GET_SEGMENT(*symbol_1_PP) == SEG_BSS) || (!S_IS_DEFINED(* symbol_1_PP)));
698 know(symbol_2_P == NULL || (S_GET_SEGMENT(symbol_2_P) == SEG_TEXT) || (S_GET_SEGMENT(symbol_2_P) == SEG_DATA) || (S_GET_SEGMENT(symbol_2_P) == SEG_BSS) || (!S_IS_DEFINED(symbol_2_P)));
702 if (!S_IS_DEFINED(* symbol_1_PP))
706 return_value = SEG_PASS1;
707 * symbol_1_PP = NULL;
711 know(!S_IS_DEFINED(* symbol_1_PP));
712 return_value = SEG_UNKNOWN;
719 if (!S_IS_DEFINED(symbol_2_P))
721 * symbol_1_PP = NULL;
722 return_value = SEG_PASS1;
726 /* {seg1} - {seg2} */
727 as_bad("Expression too complex, 2 symbolS forgotten: \"%s\" \"%s\"",
728 S_GET_NAME(* symbol_1_PP), S_GET_NAME(symbol_2_P));
729 * symbol_1_PP = NULL;
730 return_value = SEG_ABSOLUTE;
735 return_value = S_GET_SEGMENT(* symbol_1_PP);
740 { /* (* symbol_1_PP) == NULL */
743 * symbol_1_PP = symbol_2_P;
744 return_value = S_GET_SEGMENT(symbol_2_P);
748 * symbol_1_PP = NULL;
749 return_value = SEG_ABSOLUTE;
752 #ifndef MANY_SEGMENTS
753 know(return_value == SEG_ABSOLUTE || return_value == SEG_TEXT || return_value == SEG_DATA || return_value == SEG_BSS || return_value == SEG_UNKNOWN || return_value == SEG_PASS1);
755 know((*symbol_1_PP) == NULL || (S_GET_SEGMENT(*symbol_1_PP) == return_value));
756 return (return_value);
759 /* Expression parser. */
762 * We allow an empty expression, and just assume (absolute,0) silently.
763 * Unary operators and parenthetical expressions are treated as operands.
764 * As usual, Q==quantity==operand, O==operator, X==expression mnemonics.
766 * We used to do a aho/ullman shift-reduce parser, but the logic got so
767 * warped that I flushed it and wrote a recursive-descent parser instead.
768 * Now things are stable, would anybody like to write a fast parser?
769 * Most expressions are either register (which does not even reach here)
770 * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common.
771 * So I guess it doesn't really matter how inefficient more complex expressions
774 * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK.
775 * Also, we have consumed any leading or trailing spaces (operand does that)
776 * and done all intervening operators.
781 O_illegal, /* (0) what we get for illegal op */
783 O_multiply, /* (1) * */
784 O_divide, /* (2) / */
785 O_modulus, /* (3) % */
786 O_left_shift, /* (4) < */
787 O_right_shift, /* (5) > */
788 O_bit_inclusive_or, /* (6) | */
789 O_bit_or_not, /* (7) ! */
790 O_bit_exclusive_or, /* (8) ^ */
791 O_bit_and, /* (9) & */
793 O_subtract /* (11) - */
799 static const operatorT op_encoding [256] = { /* maps ASCII->operators */
801 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
802 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
804 __, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __,
805 __, __, O_multiply, O_add, __, O_subtract, __, O_divide,
806 __, __, __, __, __, __, __, __,
807 __, __, __, __, O_left_shift, __, O_right_shift, __,
808 __, __, __, __, __, __, __, __,
809 __, __, __, __, __, __, __, __,
810 __, __, __, __, __, __, __, __,
811 __, __, __, __, __, __, O_bit_exclusive_or, __,
812 __, __, __, __, __, __, __, __,
813 __, __, __, __, __, __, __, __,
814 __, __, __, __, __, __, __, __,
815 __, __, __, __, O_bit_inclusive_or, __, __, __,
817 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
818 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
819 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
820 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
821 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
822 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
823 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
824 __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __
830 * 0 operand, (expression)
835 static const operator_rankT
836 op_rank [] = { 0, 3, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1 };
838 /* Return resultP->X_seg. */
839 segT expr(rank, resultP)
840 register operator_rankT rank; /* Larger # is higher rank. */
841 register expressionS *resultP; /* Deliver result here. */
844 register operatorT op_left;
845 register char c_left; /* 1st operator character. */
846 register operatorT op_right;
847 register char c_right;
850 (void)operand (resultP);
851 know(* input_line_pointer != ' '); /* Operand() gobbles spaces. */
852 c_left = * input_line_pointer; /* Potential operator character. */
853 op_left = op_encoding [c_left];
854 while (op_left != O_illegal && op_rank [(int) op_left] > rank)
856 input_line_pointer ++; /*->after 1st character of operator. */
857 /* Operators "<<" and ">>" have 2 characters. */
858 if (* input_line_pointer == c_left && (c_left == '<' || c_left == '>'))
860 input_line_pointer ++;
861 } /*->after operator. */
862 if (SEG_ABSENT == expr (op_rank[(int) op_left], &right))
864 as_warn("Missing operand value assumed absolute 0.");
865 resultP->X_add_number = 0;
866 resultP->X_subtract_symbol = NULL;
867 resultP->X_add_symbol = NULL;
868 resultP->X_seg = SEG_ABSOLUTE;
870 know(* input_line_pointer != ' ');
871 c_right = * input_line_pointer;
872 op_right = op_encoding [c_right];
873 if (* input_line_pointer == c_right && (c_right == '<' || c_right == '>'))
875 input_line_pointer ++;
876 } /*->after operator. */
877 know((int) op_right == 0 || op_rank [(int) op_right] <= op_rank[(int) op_left]);
878 /* input_line_pointer->after right-hand quantity. */
879 /* left-hand quantity in resultP */
880 /* right-hand quantity in right. */
881 /* operator in op_left. */
882 if (resultP->X_seg == SEG_PASS1 || right . X_seg == SEG_PASS1)
884 resultP->X_seg = SEG_PASS1;
888 if (resultP->X_seg == SEG_BIG)
890 as_warn("Left operand of %c is a %s. Integer 0 assumed.",
891 c_left, resultP->X_add_number > 0 ? "bignum" : "float");
892 resultP->X_seg = SEG_ABSOLUTE;
893 resultP->X_add_symbol = 0;
894 resultP->X_subtract_symbol = 0;
895 resultP->X_add_number = 0;
897 if (right . X_seg == SEG_BIG)
899 as_warn("Right operand of %c is a %s. Integer 0 assumed.",
900 c_left, right . X_add_number > 0 ? "bignum" : "float");
901 right . X_seg = SEG_ABSOLUTE;
902 right . X_add_symbol = 0;
903 right . X_subtract_symbol = 0;
904 right . X_add_number = 0;
906 if (op_left == O_subtract)
909 * Convert - into + by exchanging symbolS and negating number.
910 * I know -infinity can't be negated in 2's complement:
911 * but then it can't be subtracted either. This trick
912 * does not cause any further inaccuracy.
915 register symbolS * symbolP;
917 right . X_add_number = - right . X_add_number;
918 symbolP = right . X_add_symbol;
919 right . X_add_symbol = right . X_subtract_symbol;
920 right . X_subtract_symbol = symbolP;
923 right . X_seg = SEG_DIFFERENCE;
928 if (op_left == O_add)
932 #ifndef MANY_SEGMENTS
933 know(resultP->X_seg == SEG_DATA || resultP->X_seg == SEG_TEXT || resultP->X_seg == SEG_BSS || resultP->X_seg == SEG_UNKNOWN || resultP->X_seg == SEG_DIFFERENCE || resultP->X_seg == SEG_ABSOLUTE || resultP->X_seg == SEG_PASS1);
934 know(right.X_seg == SEG_DATA || right.X_seg == SEG_TEXT || right.X_seg == SEG_BSS || right.X_seg == SEG_UNKNOWN || right.X_seg == SEG_DIFFERENCE || right.X_seg == SEG_ABSOLUTE || right.X_seg == SEG_PASS1);
936 clean_up_expression (& right);
937 clean_up_expression (resultP);
939 seg1 = expr_part (& resultP->X_add_symbol, right . X_add_symbol);
940 seg2 = expr_part (& resultP->X_subtract_symbol, right . X_subtract_symbol);
941 if (seg1 == SEG_PASS1 || seg2 == SEG_PASS1) {
943 resultP->X_seg = SEG_PASS1;
944 } else if (seg2 == SEG_ABSOLUTE)
945 resultP->X_seg = seg1;
946 else if (seg1 != SEG_UNKNOWN
947 && seg1 != SEG_ABSOLUTE
948 && seg2 != SEG_UNKNOWN
950 know(seg2 != SEG_ABSOLUTE);
951 know(resultP->X_subtract_symbol);
952 #ifndef MANY_SEGMENTS
953 know(seg1 == SEG_TEXT || seg1 == SEG_DATA || seg1== SEG_BSS);
954 know(seg2 == SEG_TEXT || seg2 == SEG_DATA || seg2== SEG_BSS);
956 know(resultP->X_add_symbol);
957 know(resultP->X_subtract_symbol);
958 as_bad("Expression too complex: forgetting %s - %s",
959 S_GET_NAME(resultP->X_add_symbol),
960 S_GET_NAME(resultP->X_subtract_symbol));
961 resultP->X_seg = SEG_ABSOLUTE;
962 /* Clean_up_expression() will do the rest. */
964 resultP->X_seg = SEG_DIFFERENCE;
966 resultP->X_add_number += right . X_add_number;
967 clean_up_expression (resultP);
971 if (resultP->X_seg == SEG_UNKNOWN || right . X_seg == SEG_UNKNOWN)
973 resultP->X_seg = SEG_PASS1;
978 resultP->X_subtract_symbol = NULL;
979 resultP->X_add_symbol = NULL;
980 /* Will be SEG_ABSOLUTE. */
981 if (resultP->X_seg != SEG_ABSOLUTE || right . X_seg != SEG_ABSOLUTE)
983 as_bad("Relocation error. Absolute 0 assumed.");
984 resultP->X_seg = SEG_ABSOLUTE;
985 resultP->X_add_number = 0;
991 case O_bit_inclusive_or:
992 resultP->X_add_number |= right . X_add_number;
996 if (right . X_add_number)
998 resultP->X_add_number %= right . X_add_number;
1002 as_warn("Division by 0. 0 assumed.");
1003 resultP->X_add_number = 0;
1008 resultP->X_add_number &= right . X_add_number;
1012 resultP->X_add_number *= right . X_add_number;
1016 if (right . X_add_number)
1018 resultP->X_add_number /= right . X_add_number;
1022 as_warn("Division by 0. 0 assumed.");
1023 resultP->X_add_number = 0;
1028 resultP->X_add_number <<= right . X_add_number;
1032 resultP->X_add_number >>= right . X_add_number;
1035 case O_bit_exclusive_or:
1036 resultP->X_add_number ^= right . X_add_number;
1040 resultP->X_add_number |= ~ right . X_add_number;
1046 } /* switch(operator) */
1048 } /* If we have to force need_pass_2. */
1049 } /* If operator was +. */
1050 } /* If we didn't set need_pass_2. */
1052 } /* While next operator is >= this rank. */
1053 return (resultP->X_seg);
1059 * This lives here because it belongs equally in expr.c & read.c.
1060 * Expr.c is just a branch office read.c anyway, and putting it
1061 * here lessens the crowd at read.c.
1063 * Assume input_line_pointer is at start of symbol name.
1064 * Advance input_line_pointer past symbol name.
1065 * Turn that character into a '\0', returning its former value.
1066 * This allows a string compare (RMS wants symbol names to be strings)
1067 * of the symbol name.
1068 * There will always be a char following symbol name, because all good
1069 * lines end in end-of-line.
1076 while (is_part_of_name(c = * input_line_pointer ++))
1078 * -- input_line_pointer = 0;
1083 unsigned int get_single_number()
1087 return exp.X_add_number;