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
[];
43 * Build any floating-point literal here.
44 * Also build any bignum literal here.
47 /* LITTLENUM_TYPE generic_buffer [6]; */ /* JF this is a hack */
48 /* Seems atof_machine can backscan through generic_bignum and hit whatever
49 happens to be loaded before it in memory. And its way too complicated
50 for me to fix right. Thus a hack. JF: Just make generic_bignum bigger,
51 and never write into the early words, thus they'll always be zero.
52 I hate Dean's floating-point code. Bleh.
54 LITTLENUM_TYPE generic_bignum
[SIZE_OF_LARGE_NUMBER
+6];
55 FLONUM_TYPE generic_floating_point_number
=
57 & generic_bignum
[6], /* low (JF: Was 0) */
58 & generic_bignum
[SIZE_OF_LARGE_NUMBER
+6 - 1], /* high JF: (added +6) */
63 /* If nonzero, we've been asked to assemble nan, +inf or -inf */
64 int generic_floating_point_magic
;
66 floating_constant(expressionP
)
67 expressionS
*expressionP
;
69 /* input_line_pointer->*/
70 /* floating-point constant. */
73 error_code
= atof_generic
74 (& input_line_pointer
, ".", EXP_CHARS
,
75 & generic_floating_point_number
);
79 if (error_code
== ERROR_EXPONENT_OVERFLOW
)
81 as_bad("bad floating-point constant: exponent overflow, probably assembling junk");
85 as_bad("bad floating-point constant: unknown error code=%d.", error_code
);
88 expressionP
->X_seg
= SEG_BIG
;
89 /* input_line_pointer->just after constant, */
90 /* which may point to whitespace. */
91 expressionP
->X_add_number
=-1;
97 integer_constant(radix
, expressionP
)
99 expressionS
*expressionP
;
101 register char * digit_2
; /*->2nd digit of number. */
104 register valueT number
; /* offset or (absolute) value */
105 register short int digit
; /* value of next digit in current radix */
106 register short int maxdig
= 0; /* highest permitted digit value. */
107 register int too_many_digits
= 0; /* if we see >= this number of */
108 register char *name
; /* points to name of symbol */
109 register symbolS
* symbolP
; /* points to symbol */
111 int small
; /* true if fits in 32 bits. */
112 extern char hex_value
[]; /* in hex_value.c */
114 /* may be bignum, or may fit in 32 bits. */
116 * most numbers fit into 32 bits, and we want this case to be fast.
117 * so we pretend it will fit into 32 bits. if, after making up a 32
118 * bit number, we realise that we have scanned more digits than
119 * comfortably fit into 32 bits, we re-scan the digits coding
120 * them into a bignum. for decimal and octal numbers we are conservative: some
121 * numbers may be assumed bignums when in fact they do fit into 32 bits.
122 * numbers of any radix can have excess leading zeros: we strive
123 * to recognise this and cast them back into 32 bits.
124 * we must check that the bignum really is more than 32
125 * bits, and change it back to a 32-bit number if it fits.
126 * the number we are looking for is expected to be positive, but
127 * if it fits into 32 bits as an unsigned number, we let it be a 32-bit
128 * number. the cavalier approach is for speed in ordinary cases.
136 too_many_digits
= 33;
140 too_many_digits
= 11;
150 too_many_digits
= 11;
152 c
= *input_line_pointer
;
153 input_line_pointer
++;
154 digit_2
= input_line_pointer
;
155 for (number
=0; (digit
=hex_value
[c
])<maxdig
; c
= * input_line_pointer
++)
157 number
= number
* radix
+ digit
;
159 /* c contains character after number. */
160 /* input_line_pointer->char after c. */
161 small
= input_line_pointer
- digit_2
< too_many_digits
;
165 * we saw a lot of digits. manufacture a bignum the hard way.
167 LITTLENUM_TYPE
* leader
; /*->high order littlenum of the bignum. */
168 LITTLENUM_TYPE
* pointer
; /*->littlenum we are frobbing now. */
171 leader
= generic_bignum
;
172 generic_bignum
[0] = 0;
173 generic_bignum
[1] = 0;
174 /* we could just use digit_2, but lets be mnemonic. */
175 input_line_pointer
= --digit_2
; /*->1st digit. */
176 c
= *input_line_pointer
++;
177 for (; (carry
= hex_value
[c
]) < maxdig
; c
= *input_line_pointer
++)
179 for (pointer
= generic_bignum
;
185 work
= carry
+ radix
* * pointer
;
186 *pointer
= work
& LITTLENUM_MASK
;
187 carry
= work
>> LITTLENUM_NUMBER_OF_BITS
;
191 if (leader
< generic_bignum
+ SIZE_OF_LARGE_NUMBER
- 1)
192 { /* room to grow a longer bignum. */
197 /* again, c is char after number, */
198 /* input_line_pointer->after c. */
199 know(sizeof (int) * 8 == 32);
200 know(LITTLENUM_NUMBER_OF_BITS
== 16);
201 /* hence the constant "2" in the next line. */
202 if (leader
< generic_bignum
+ 2)
203 { /* will fit into 32 bits. */
205 ((generic_bignum
[1] & LITTLENUM_MASK
) << LITTLENUM_NUMBER_OF_BITS
)
206 | (generic_bignum
[0] & LITTLENUM_MASK
);
211 number
= leader
- generic_bignum
+ 1; /* number of littlenums in the bignum. */
216 * here with number, in correct radix. c is the next char.
217 * note that unlike un*x, we allow "011f" "0x9f" to
218 * both mean the same as the (conventional) "9f". this is simply easier
219 * than checking for strict canonical form. syntax sux!
224 #ifdef LOCAL_LABELS_FB
227 * backward ref to local label.
228 * because it is backward, expect it to be defined.
231 * construct a local label.
233 name
= fb_label_name((int) number
, 0);
235 /* seen before, or symbol is defined: ok */
236 symbolP
= symbol_find(name
);
237 if ((symbolP
!= NULL
) && (S_IS_DEFINED(symbolP
))) {
239 /* local labels are never absolute. don't waste time checking absoluteness. */
240 know(SEG_NORMAL(S_GET_SEGMENT(symbolP
)));
242 expressionP
->X_add_symbol
= symbolP
;
243 expressionP
->X_seg
= S_GET_SEGMENT(symbolP
);
245 } else { /* either not seen or not defined. */
246 as_bad("backw. ref to unknown label \"%d:\", 0 assumed.", number
);
247 expressionP
->X_seg
= SEG_ABSOLUTE
;
250 expressionP
->X_add_number
= 0;
256 * forward reference. expect symbol to be undefined or
257 * unknown. undefined: seen it before. unknown: never seen
259 * construct a local label name, then an undefined symbol.
260 * don't create a xseg frag for it: caller may do that.
261 * just return it as never seen before.
263 name
= fb_label_name((int) number
, 1);
264 symbolP
= symbol_find_or_make(name
);
265 /* we have no need to check symbol properties. */
266 #ifndef many_segments
267 /* since "know" puts its arg into a "string", we
268 can't have newlines in the argument. */
269 know(S_GET_SEGMENT(symbolP
) == SEG_UNKNOWN
|| S_GET_SEGMENT(symbolP
) == SEG_TEXT
|| S_GET_SEGMENT(symbolP
) == SEG_DATA
);
271 expressionP
->X_add_symbol
= symbolP
;
272 expressionP
->X_seg
= SEG_UNKNOWN
;
273 expressionP
->X_subtract_symbol
= NULL
;
274 expressionP
->X_add_number
= 0;
279 #endif /* LOCAL_LABELS_FB */
281 #ifdef LOCAL_LABELS_DOLLAR
285 /* if the dollar label is *currently* defined, then this is just another
286 reference to it. If it is not *currently* defined, then this is a
287 fresh instantiation of that number, so create it. */
289 if (dollar_label_defined(number
)) {
290 name
= dollar_label_name(number
, 0);
291 symbolP
= symbol_find(name
);
292 know(symbolP
!= NULL
);
294 name
= dollar_label_name(number
, 1);
295 symbolP
= symbol_find_or_make(name
);
298 expressionP
->X_add_symbol
= symbolP
;
299 expressionP
->X_add_number
= 0;
300 expressionP
->X_seg
= S_GET_SEGMENT(symbolP
);
305 #endif /* LOCAL_LABELS_DOLLAR */
308 expressionP
->X_add_number
= number
;
309 expressionP
->X_seg
= SEG_ABSOLUTE
;
310 input_line_pointer
--; /* restore following character. */
312 } /* really just a number */
314 } /* switch on char following the number */
317 } else { /* not a small number */
318 expressionP
->X_add_number
= number
;
319 expressionP
->X_seg
= SEG_BIG
;
320 input_line_pointer
--; /*->char following number. */
322 } /* integer_constant() */
326 * Summary of operand().
328 * in: Input_line_pointer points to 1st char of operand, which may
331 * out: A expressionS. X_seg determines how to understand the rest of the
333 * The operand may have been empty: in this case X_seg == SEG_ABSENT.
334 * Input_line_pointer->(next non-blank) char after operand.
341 operand (expressionP
)
342 register expressionS
* expressionP
;
345 register symbolS
* symbolP
; /* points to symbol */
346 register char *name
; /* points to name of symbol */
347 /* invented for humans only, hope */
348 /* optimising compiler flushes it! */
349 register short int radix
; /* 2, 8, 10 or 16, 0 when floating */
350 /* 0 means we saw start of a floating- */
351 /* point constant. */
353 /* digits, assume it is a bignum. */
358 SKIP_WHITESPACE(); /* leading whitespace is part of operand. */
359 c
= * input_line_pointer
++; /* input_line_pointer->past char in c. */
365 integer_constant(2, expressionP
);
368 integer_constant(8, expressionP
);
371 integer_constant(16, expressionP
);
383 input_line_pointer
--;
385 integer_constant(10, expressionP
);
389 /* non-decimal radix */
392 c
= *input_line_pointer
;
397 if (c
&& strchr(FLT_CHARS
,c
))
399 input_line_pointer
++;
400 floating_constant(expressionP
);
406 /* The string was only zero */
407 expressionP
->X_add_symbol
= 0;
408 expressionP
->X_add_number
= 0;
409 expressionP
->X_seg
= SEG_ABSOLUTE
;
416 input_line_pointer
++;
417 integer_constant(16, expressionP
);
421 input_line_pointer
++;
422 integer_constant(2, expressionP
);
433 integer_constant(8, expressionP
);
437 /* if it says '0f' and the line ends or it doesn't look like
438 a floating point #, its a local label ref. dtrt */
439 /* likewise for the b's. xoxorich. */
440 if ((c
== 'f' || c
== 'b' || c
== 'b')
441 && (!*input_line_pointer
||
442 (!strchr("+-.0123456789",*input_line_pointer
) &&
443 !strchr(EXP_CHARS
,*input_line_pointer
))))
445 input_line_pointer
-= 2;
446 integer_constant(10, expressionP
);
459 input_line_pointer
++;
460 floating_constant(expressionP
);
466 /* didn't begin with digit & not a name */
468 (void)expression(expressionP
);
469 /* Expression() will pass trailing whitespace */
470 if (* input_line_pointer
++ != ')')
472 as_bad("Missing ')' assumed");
473 input_line_pointer
--;
475 /* here with input_line_pointer->char after "(...)" */
477 return expressionP
->X_seg
;
482 * Warning: to conform to other people's assemblers NO ESCAPEMENT is permitted
483 * for a single quote. The next character, parity errors and all, is taken
484 * as the value of the operand. VERY KINKY.
486 expressionP
->X_add_number
= * input_line_pointer
++;
487 expressionP
->X_seg
= SEG_ABSOLUTE
;
495 /* unary operator: hope for SEG_ABSOLUTE */
496 switch(operand (expressionP
)) {
498 /* input_line_pointer -> char after operand */
501 expressionP
-> X_add_number
= - expressionP
-> X_add_number
;
503 * Notice: '-' may overflow: no warning is given. This is compatible
504 * with other people's assemblers. Sigh.
509 expressionP
-> X_add_number
= ~ expressionP
-> X_add_number
;
518 if(c
=='-') { /* JF I hope this hack works */
519 expressionP
->X_subtract_symbol
=expressionP
->X_add_symbol
;
520 expressionP
->X_add_symbol
=0;
521 expressionP
->X_seg
=SEG_DIFFERENCE
;
524 default: /* unary on non-absolute is unsuported */
525 as_warn("Unary operator %c ignored because bad operand follows", c
);
527 /* Expression undisturbed from operand(). */
536 if( !is_part_of_name(*input_line_pointer
))
538 extern struct obstack frags
;
541 JF: '.' is pseudo symbol with value of current location in current
544 symbolP
= symbol_new("L0\001",
546 (valueT
)(obstack_next_free(&frags
)-frag_now
->fr_literal
),
549 expressionP
->X_add_number
=0;
550 expressionP
->X_add_symbol
=symbolP
;
551 expressionP
->X_seg
= now_seg
;
563 /* can't imagine any other kind of operand */
564 expressionP
->X_seg
= SEG_ABSENT
;
565 input_line_pointer
--;
566 md_operand (expressionP
);
570 if (is_name_beginner(c
)) /* here if did not begin with a digit */
573 * Identifier begins here.
574 * This is kludged for speed, so code is repeated.
577 name
= -- input_line_pointer
;
578 c
= get_symbol_end();
579 symbolP
= symbol_find_or_make(name
);
581 * If we have an absolute symbol or a reg, then we know its value now.
583 expressionP
->X_seg
= S_GET_SEGMENT(symbolP
);
584 switch (expressionP
->X_seg
)
588 expressionP
->X_add_number
= S_GET_VALUE(symbolP
);
592 expressionP
->X_add_number
= 0;
593 expressionP
->X_add_symbol
= symbolP
;
595 * input_line_pointer
= c
;
596 expressionP
->X_subtract_symbol
= NULL
;
600 as_bad("Bad expression");
601 expressionP
->X_add_number
= 0;
602 expressionP
->X_seg
= SEG_ABSOLUTE
;
615 * It is more 'efficient' to clean up the expressionS when they are created.
616 * Doing it here saves lines of code.
618 clean_up_expression (expressionP
);
619 SKIP_WHITESPACE(); /*->1st char after operand. */
620 know(* input_line_pointer
!= ' ');
621 return (expressionP
->X_seg
);
625 /* Internal. Simplify a struct expression for use by expr() */
628 * In: address of a expressionS.
629 * The X_seg field of the expressionS may only take certain values.
630 * Now, we permit SEG_PASS1 to make code smaller & faster.
631 * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT.
632 * Out: expressionS may have been modified:
633 * 'foo-foo' symbol references cancelled to 0,
634 * which changes X_seg from SEG_DIFFERENCE to SEG_ABSOLUTE;
635 * Unused fields zeroed to help expr().
639 clean_up_expression (expressionP
)
640 register expressionS
* expressionP
;
642 switch (expressionP
->X_seg
)
646 expressionP
->X_add_symbol
= NULL
;
647 expressionP
->X_subtract_symbol
= NULL
;
648 expressionP
->X_add_number
= 0;
653 expressionP
->X_subtract_symbol
= NULL
;
654 expressionP
->X_add_symbol
= NULL
;
658 expressionP
->X_subtract_symbol
= NULL
;
663 * It does not hurt to 'cancel' NULL==NULL
664 * when comparing symbols for 'eq'ness.
665 * It is faster to re-cancel them to NULL
666 * than to check for this special case.
668 if (expressionP
->X_subtract_symbol
== expressionP
->X_add_symbol
669 || (expressionP
->X_subtract_symbol
670 && expressionP
->X_add_symbol
671 && expressionP
->X_subtract_symbol
->sy_frag
==expressionP
->X_add_symbol
->sy_frag
672 && S_GET_VALUE(expressionP
->X_subtract_symbol
) == S_GET_VALUE(expressionP
->X_add_symbol
))) {
673 expressionP
->X_subtract_symbol
= NULL
;
674 expressionP
->X_add_symbol
= NULL
;
675 expressionP
->X_seg
= SEG_ABSOLUTE
;
680 expressionP
->X_add_symbol
= NULL
;
681 expressionP
->X_subtract_symbol
= NULL
;
685 if (SEG_NORMAL(expressionP
->X_seg
)) {
686 expressionP
->X_subtract_symbol
= NULL
;
689 BAD_CASE (expressionP
->X_seg
);
693 } /* clean_up_expression() */
698 * Internal. Made a function because this code is used in 2 places.
699 * Generate error or correct X_?????_symbol of expressionS.
703 * symbol_1 += symbol_2 ... well ... sort of.
707 expr_part (symbol_1_PP
, symbol_2_P
)
708 symbolS
** symbol_1_PP
;
709 symbolS
* symbol_2_P
;
712 #ifndef MANY_SEGMENTS
713 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
)));
714 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
)));
718 if (!S_IS_DEFINED(* symbol_1_PP
))
722 return_value
= SEG_PASS1
;
723 * symbol_1_PP
= NULL
;
727 know(!S_IS_DEFINED(* symbol_1_PP
));
728 return_value
= SEG_UNKNOWN
;
735 if (!S_IS_DEFINED(symbol_2_P
))
737 * symbol_1_PP
= NULL
;
738 return_value
= SEG_PASS1
;
742 /* {seg1} - {seg2} */
743 as_bad("Expression too complex, 2 symbolS forgotten: \"%s\" \"%s\"",
744 S_GET_NAME(* symbol_1_PP
), S_GET_NAME(symbol_2_P
));
745 * symbol_1_PP
= NULL
;
746 return_value
= SEG_ABSOLUTE
;
751 return_value
= S_GET_SEGMENT(* symbol_1_PP
);
756 { /* (* symbol_1_PP) == NULL */
759 * symbol_1_PP
= symbol_2_P
;
760 return_value
= S_GET_SEGMENT(symbol_2_P
);
764 * symbol_1_PP
= NULL
;
765 return_value
= SEG_ABSOLUTE
;
768 #ifndef MANY_SEGMENTS
769 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
);
771 know((*symbol_1_PP
) == NULL
|| (S_GET_SEGMENT(*symbol_1_PP
) == return_value
));
772 return (return_value
);
775 /* Expression parser. */
778 * We allow an empty expression, and just assume (absolute,0) silently.
779 * Unary operators and parenthetical expressions are treated as operands.
780 * As usual, Q==quantity==operand, O==operator, X==expression mnemonics.
782 * We used to do a aho/ullman shift-reduce parser, but the logic got so
783 * warped that I flushed it and wrote a recursive-descent parser instead.
784 * Now things are stable, would anybody like to write a fast parser?
785 * Most expressions are either register (which does not even reach here)
786 * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common.
787 * So I guess it doesn't really matter how inefficient more complex expressions
790 * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK.
791 * Also, we have consumed any leading or trailing spaces (operand does that)
792 * and done all intervening operators.
797 O_illegal
, /* (0) what we get for illegal op */
799 O_multiply
, /* (1) * */
800 O_divide
, /* (2) / */
801 O_modulus
, /* (3) % */
802 O_left_shift
, /* (4) < */
803 O_right_shift
, /* (5) > */
804 O_bit_inclusive_or
, /* (6) | */
805 O_bit_or_not
, /* (7) ! */
806 O_bit_exclusive_or
, /* (8) ^ */
807 O_bit_and
, /* (9) & */
809 O_subtract
/* (11) - */
815 static const operatorT op_encoding
[256] = { /* maps ASCII->operators */
817 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
818 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
820 __
, O_bit_or_not
, __
, __
, __
, O_modulus
, O_bit_and
, __
,
821 __
, __
, O_multiply
, O_add
, __
, O_subtract
, __
, O_divide
,
822 __
, __
, __
, __
, __
, __
, __
, __
,
823 __
, __
, __
, __
, O_left_shift
, __
, O_right_shift
, __
,
824 __
, __
, __
, __
, __
, __
, __
, __
,
825 __
, __
, __
, __
, __
, __
, __
, __
,
826 __
, __
, __
, __
, __
, __
, __
, __
,
827 __
, __
, __
, __
, __
, __
, O_bit_exclusive_or
, __
,
828 __
, __
, __
, __
, __
, __
, __
, __
,
829 __
, __
, __
, __
, __
, __
, __
, __
,
830 __
, __
, __
, __
, __
, __
, __
, __
,
831 __
, __
, __
, __
, O_bit_inclusive_or
, __
, __
, __
,
833 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
834 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
835 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
836 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
837 __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
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846 * 0 operand, (expression)
851 static const operator_rankT
852 op_rank
[] = { 0, 3, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1 };
854 /* Return resultP->X_seg. */
855 segT
expr(rank
, resultP
)
856 register operator_rankT rank
; /* Larger # is higher rank. */
857 register expressionS
*resultP
; /* Deliver result here. */
860 register operatorT op_left
;
861 register char c_left
; /* 1st operator character. */
862 register operatorT op_right
;
863 register char c_right
;
866 (void)operand (resultP
);
867 know(* input_line_pointer
!= ' '); /* Operand() gobbles spaces. */
868 c_left
= * input_line_pointer
; /* Potential operator character. */
869 op_left
= op_encoding
[c_left
];
870 while (op_left
!= O_illegal
&& op_rank
[(int) op_left
] > rank
)
872 input_line_pointer
++; /*->after 1st character of operator. */
873 /* Operators "<<" and ">>" have 2 characters. */
874 if (* input_line_pointer
== c_left
&& (c_left
== '<' || c_left
== '>'))
876 input_line_pointer
++;
877 } /*->after operator. */
878 if (SEG_ABSENT
== expr (op_rank
[(int) op_left
], &right
))
880 as_warn("Missing operand value assumed absolute 0.");
881 resultP
->X_add_number
= 0;
882 resultP
->X_subtract_symbol
= NULL
;
883 resultP
->X_add_symbol
= NULL
;
884 resultP
->X_seg
= SEG_ABSOLUTE
;
886 know(* input_line_pointer
!= ' ');
887 c_right
= * input_line_pointer
;
888 op_right
= op_encoding
[c_right
];
889 if (* input_line_pointer
== c_right
&& (c_right
== '<' || c_right
== '>'))
891 input_line_pointer
++;
892 } /*->after operator. */
893 know((int) op_right
== 0 || op_rank
[(int) op_right
] <= op_rank
[(int) op_left
]);
894 /* input_line_pointer->after right-hand quantity. */
895 /* left-hand quantity in resultP */
896 /* right-hand quantity in right. */
897 /* operator in op_left. */
898 if (resultP
->X_seg
== SEG_PASS1
|| right
. X_seg
== SEG_PASS1
)
900 resultP
->X_seg
= SEG_PASS1
;
904 if (resultP
->X_seg
== SEG_BIG
)
906 as_warn("Left operand of %c is a %s. Integer 0 assumed.",
907 c_left
, resultP
->X_add_number
> 0 ? "bignum" : "float");
908 resultP
->X_seg
= SEG_ABSOLUTE
;
909 resultP
->X_add_symbol
= 0;
910 resultP
->X_subtract_symbol
= 0;
911 resultP
->X_add_number
= 0;
913 if (right
. X_seg
== SEG_BIG
)
915 as_warn("Right operand of %c is a %s. Integer 0 assumed.",
916 c_left
, right
. X_add_number
> 0 ? "bignum" : "float");
917 right
. X_seg
= SEG_ABSOLUTE
;
918 right
. X_add_symbol
= 0;
919 right
. X_subtract_symbol
= 0;
920 right
. X_add_number
= 0;
922 if (op_left
== O_subtract
)
925 * Convert - into + by exchanging symbolS and negating number.
926 * I know -infinity can't be negated in 2's complement:
927 * but then it can't be subtracted either. This trick
928 * does not cause any further inaccuracy.
931 register symbolS
* symbolP
;
933 right
. X_add_number
= - right
. X_add_number
;
934 symbolP
= right
. X_add_symbol
;
935 right
. X_add_symbol
= right
. X_subtract_symbol
;
936 right
. X_subtract_symbol
= symbolP
;
939 right
. X_seg
= SEG_DIFFERENCE
;
944 if (op_left
== O_add
)
948 #ifndef MANY_SEGMENTS
949 know(resultP
->X_seg
== SEG_DATA
|| resultP
->X_seg
== SEG_TEXT
|| resultP
->X_seg
== SEG_BSS
|| resultP
->X_seg
==
950 SEG_UNKNOWN
|| resultP
->X_seg
== SEG_DIFFERENCE
|| resultP
->X_seg
== SEG_ABSOLUTE
|| resultP
->X_seg
== SEG_PASS1
951 || resultP
->X_seg
== SEG_REGISTER
);
952 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
);
954 clean_up_expression (& right
);
955 clean_up_expression (resultP
);
957 seg1
= expr_part (& resultP
->X_add_symbol
, right
. X_add_symbol
);
958 seg2
= expr_part (& resultP
->X_subtract_symbol
, right
. X_subtract_symbol
);
959 if (seg1
== SEG_PASS1
|| seg2
== SEG_PASS1
) {
961 resultP
->X_seg
= SEG_PASS1
;
962 } else if (seg2
== SEG_ABSOLUTE
)
963 resultP
->X_seg
= seg1
;
964 else if (seg1
!= SEG_UNKNOWN
965 && seg1
!= SEG_ABSOLUTE
966 && seg2
!= SEG_UNKNOWN
968 know(seg2
!= SEG_ABSOLUTE
);
969 know(resultP
->X_subtract_symbol
);
970 #ifndef MANY_SEGMENTS
971 know(seg1
== SEG_TEXT
|| seg1
== SEG_DATA
|| seg1
== SEG_BSS
);
972 know(seg2
== SEG_TEXT
|| seg2
== SEG_DATA
|| seg2
== SEG_BSS
);
974 know(resultP
->X_add_symbol
);
975 know(resultP
->X_subtract_symbol
);
976 as_bad("Expression too complex: forgetting %s - %s",
977 S_GET_NAME(resultP
->X_add_symbol
),
978 S_GET_NAME(resultP
->X_subtract_symbol
));
979 resultP
->X_seg
= SEG_ABSOLUTE
;
980 /* Clean_up_expression() will do the rest. */
982 resultP
->X_seg
= SEG_DIFFERENCE
;
984 resultP
->X_add_number
+= right
. X_add_number
;
985 clean_up_expression (resultP
);
989 if (resultP
->X_seg
== SEG_UNKNOWN
|| right
. X_seg
== SEG_UNKNOWN
)
991 resultP
->X_seg
= SEG_PASS1
;
996 resultP
->X_subtract_symbol
= NULL
;
997 resultP
->X_add_symbol
= NULL
;
998 /* Will be SEG_ABSOLUTE. */
999 if (resultP
->X_seg
!= SEG_ABSOLUTE
|| right
. X_seg
!= SEG_ABSOLUTE
)
1001 as_bad("Relocation error. Absolute 0 assumed.");
1002 resultP
->X_seg
= SEG_ABSOLUTE
;
1003 resultP
->X_add_number
= 0;
1009 case O_bit_inclusive_or
:
1010 resultP
->X_add_number
|= right
. X_add_number
;
1014 if (right
. X_add_number
)
1016 resultP
->X_add_number
%= right
. X_add_number
;
1020 as_warn("Division by 0. 0 assumed.");
1021 resultP
->X_add_number
= 0;
1026 resultP
->X_add_number
&= right
. X_add_number
;
1030 resultP
->X_add_number
*= right
. X_add_number
;
1034 if (right
. X_add_number
)
1036 resultP
->X_add_number
/= right
. X_add_number
;
1040 as_warn("Division by 0. 0 assumed.");
1041 resultP
->X_add_number
= 0;
1046 resultP
->X_add_number
<<= right
. X_add_number
;
1050 resultP
->X_add_number
>>= right
. X_add_number
;
1053 case O_bit_exclusive_or
:
1054 resultP
->X_add_number
^= right
. X_add_number
;
1058 resultP
->X_add_number
|= ~ right
. X_add_number
;
1064 } /* switch(operator) */
1066 } /* If we have to force need_pass_2. */
1067 } /* If operator was +. */
1068 } /* If we didn't set need_pass_2. */
1070 } /* While next operator is >= this rank. */
1071 return (resultP
->X_seg
);
1077 * This lives here because it belongs equally in expr.c & read.c.
1078 * Expr.c is just a branch office read.c anyway, and putting it
1079 * here lessens the crowd at read.c.
1081 * Assume input_line_pointer is at start of symbol name.
1082 * Advance input_line_pointer past symbol name.
1083 * Turn that character into a '\0', returning its former value.
1084 * This allows a string compare (RMS wants symbol names to be strings)
1085 * of the symbol name.
1086 * There will always be a char following symbol name, because all good
1087 * lines end in end-of-line.
1094 while (is_part_of_name(c
= * input_line_pointer
++))
1096 * -- input_line_pointer
= 0;
1101 unsigned int get_single_number()
1105 return exp
.X_add_number
;