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[unix-history] / usr / src / lib / libc / vax / stdio / doprnt.c
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2ce81398 1#ifdef LIBC_SCCS
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2 .data
3_sccsid:
95f51977 4 .asciz "@(#)doprnt.c 5.4 (Berkeley) 3/9/86"
64377ad2 5 .text
2ce81398 6#endif LIBC_SCCS
64377ad2 7
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8 # C library -- conversions
9
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10#include "DEFS.h"
11
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12.globl __doprnt
13.globl __flsbuf
14
15#define vbit 1
16#define flags r10
17#define ndfnd 0
18#define prec 1
19#define zfill 2
20#define minsgn 3
21#define plssgn 4
22#define numsgn 5
23#define caps 6
24#define blank 7
25#define gflag 8
26#define dpflag 9
27#define width r9
28#define ndigit r8
29#define llafx r7
30#define lrafx r6
31#define fdesc -4(fp)
32#define exp -8(fp)
33#define sexp -12(fp)
34#define nchar -16(fp)
35#define sign -17(fp)
36 .set ch.zer,'0 # cpp doesn't like single appostrophes
37
38 .align 2
39strtab: # translate table for detecting null and percent
40 .byte 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
41 .byte 16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
42 .byte ' ,'!,'",'#,'$, 0,'&,'','(,'),'*,'+,',,'-,'.,'/
43 .byte '0,'1,'2,'3,'4,'5,'6,'7,'8,'9,':,';,'<,'=,'>,'?
44 .byte '@,'A,'B,'C,'D,'E,'F,'G,'H,'I,'J,'K,'L,'M,'N,'O
45 .byte 'P,'Q,'R,'S,'T,'U,'V,'W,'X,'Y,'Z,'[,'\,'],'^,'_
46 .byte '`,'a,'b,'c,'d,'e,'f,'g,'h,'i,'j,'k,'l,'m,'n,'o
47 .byte 'p,'q,'r,'s,'t,'u,'v,'w,'x,'y,'z,'{,'|,'},'~,127
48 .byte 128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143
49 .byte 144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159
50 .byte 160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175
51 .byte 176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191
52 .byte 192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207
53 .byte 208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223
54 .byte 224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239
55 .byte 240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255
56
ff35c7a1 57ENTRY(_doprnt, R6|R7|R8|R9|R10|R11)
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58 jbr doit
59
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60strfoo:
61 clrl r4 # fix interrupt race
62 jbr strok # and try again
4e447cd1 63strout2: # enter here to force out r2; r0,r1 must be set
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64 # do some tricks with line buffering (_IOLBF) first
65 movl fdesc,r3
66 jbc $7,16(r3),0f # not line buffered (unbuffered)
67 addl3 12(r3),8(r3),r4 # fdesc->_base+fdesc->_bufsiz
68 cmpl 4(r3),r4 # buffer full?
69 jgeq 0f # yes
70 cmpl r2,$10 # c == '\n'?
71 jeql 0f # yes
72 movb r2,*4(r3) # line buffered and not buffer full
73 incl 4(r3) # and not newline
74 clrl (r3) # just stuff it and fix _cnt
75 incl nchar # count the char
76 jbr strout # skip __flsbuf
770: pushr $3 # save input descriptor
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78 pushl fdesc # FILE
79 pushl r2 # the char
80 calls $2,__flsbuf # please empty the buffer and handle 1 char
81 tstl r0 # successful?
82 jgeq strm1 # yes
83 jbcs $31,nchar,strm1 # turn on sign bit of nchar to signify error
84strm1:
85 incl nchar # count the char
86 popr $3 # get input descriptor back
87strout: # enter via bsb with (r0,r1)=input descriptor
88 movab strtab,r3 # table address
89 movq *fdesc,r4 # output descriptor
90 jbs $31,r4,strfoo # negative count is a no no
91strok:
92 addl2 r0,nchar # we intend to move this many chars
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93/******* Start bogus movtuc workaround *****/
94 clrl r2
95 tstl r0
96 bleq movdon
97movlp:
98 tstl r4
99 bleq movdon
100 movzbl (r1)+,r3
101 tstb strtab[r3]
102 bneq 1f
103 mnegl $1,r2
104 decl r1
105 brb movdon
1061:
107 movb r3,(r5)+
108 decl r4
109 sobgtr r0,movlp
110 /******* End bogus movtuc workaround ***
4e447cd1 111 movtuc r0,(r1),$0,(r3),r4,(r5)
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112 movpsl r2 /* squirrel away condition codes */
113 /******* End equally bogus movtuc ****/
114movdon: movq r4,*fdesc /* update output descriptor */
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115 subl2 r0,nchar # some chars not moved
116 jbs $vbit,r2,stresc # terminated by escape?
117 sobgeq r0,strmore # no; but out buffer might be full
118stresc:
119 rsb
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120strmore:
121 movzbl (r1)+,r2 # one char
122 tstb strtab[r2] # translate
123 jneq strout2 # bad guy in disguise (outbuf is full)
124 incl r0 # fix the length
125 decl r1 # and the addr
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126 movl $1<vbit,r2 # fake condition codes
127 rsb
128
129errdone:
130 jbcs $31,nchar,prdone # set error bit
131prdone:
132 movl nchar,r0
133 ret
134
afa32ae8 135doit:
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136 movab -256(sp),sp # work space
137 movl 4(ap),r11 # addr of format string
138 movl 12(ap),fdesc # output FILE ptr
139 movl 8(ap),ap # addr of first arg
140 clrl nchar # number of chars transferred
141loop:
142 movzwl $65535,r0 # pseudo length
3fd6f19e 143 movl r11,r1 # fmt addr
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144 # comet sucks.
145 movq *fdesc,r4
146 subl3 r1,r5,r2
147 jlss lp1
148 cmpl r0,r2
149 jleq lp1
150 movl r2,r0
151lp1:
152 #
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153 bsbw strout # copy to output, stop at null or percent
154 movl r1,r11 # new fmt
155 jbc $vbit,r2,loop # if no escape, then very long fmt
156 tstb (r11)+ # escape; null or percent?
157 jeql prdone # null means end of fmt
158
159 movl sp,r5 # reset output buffer pointer
160 clrq r9 # width; flags
161 clrq r6 # lrafx,llafx
162longorunsg: # we can ignore both of these distinctions
163short:
164L4a:
165 movzbl (r11)+,r0 # so capital letters can tail merge
166L4: caseb r0,$' ,$'x-' # format char
167L5:
168 .word space-L5 # space
169 .word fmtbad-L5 # !
170 .word fmtbad-L5 # "
171 .word sharp-L5 # #
172 .word fmtbad-L5 # $
173 .word fmtbad-L5 # %
174 .word fmtbad-L5 # &
175 .word fmtbad-L5 # '
176 .word fmtbad-L5 # (
177 .word fmtbad-L5 # )
178 .word indir-L5 # *
179 .word plus-L5 # +
180 .word fmtbad-L5 # ,
181 .word minus-L5 # -
182 .word dot-L5 # .
183 .word fmtbad-L5 # /
184 .word gnum0-L5 # 0
185 .word gnum-L5 # 1
186 .word gnum-L5 # 2
187 .word gnum-L5 # 3
188 .word gnum-L5 # 4
189 .word gnum-L5 # 5
190 .word gnum-L5 # 6
191 .word gnum-L5 # 7
192 .word gnum-L5 # 8
193 .word gnum-L5 # 9
194 .word fmtbad-L5 # :
195 .word fmtbad-L5 # ;
196 .word fmtbad-L5 # <
197 .word fmtbad-L5 # =
198 .word fmtbad-L5 # >
199 .word fmtbad-L5 # ?
200 .word fmtbad-L5 # @
201 .word fmtbad-L5 # A
202 .word fmtbad-L5 # B
203 .word fmtbad-L5 # C
204 .word decimal-L5 # D
205 .word capital-L5 # E
206 .word fmtbad-L5 # F
207 .word capital-L5 # G
208 .word fmtbad-L5 # H
209 .word fmtbad-L5 # I
210 .word fmtbad-L5 # J
211 .word fmtbad-L5 # K
212 .word fmtbad-L5 # L
213 .word fmtbad-L5 # M
214 .word fmtbad-L5 # N
215 .word octal-L5 # O
216 .word fmtbad-L5 # P
217 .word fmtbad-L5 # Q
218 .word fmtbad-L5 # R
219 .word fmtbad-L5 # S
220 .word fmtbad-L5 # T
221 .word unsigned-L5 # U
222 .word fmtbad-L5 # V
223 .word fmtbad-L5 # W
6773a72e 224 .word capital-L5 # X
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225 .word fmtbad-L5 # Y
226 .word fmtbad-L5 # Z
227 .word fmtbad-L5 # [
228 .word fmtbad-L5 # \
229 .word fmtbad-L5 # ]
230 .word fmtbad-L5 # ^
231 .word fmtbad-L5 # _
232 .word fmtbad-L5 # `
233 .word fmtbad-L5 # a
234 .word fmtbad-L5 # b
235 .word charac-L5 # c
236 .word decimal-L5 # d
237 .word scien-L5 # e
238 .word float-L5 # f
239 .word general-L5 # g
240 .word short-L5 # h
241 .word fmtbad-L5 # i
242 .word fmtbad-L5 # j
243 .word fmtbad-L5 # k
244 .word longorunsg-L5 # l
245 .word fmtbad-L5 # m
246 .word fmtbad-L5 # n
247 .word octal-L5 # o
248 .word fmtbad-L5 # p
249 .word fmtbad-L5 # q
250 .word fmtbad-L5 # r
251 .word string-L5 # s
252 .word fmtbad-L5 # t
253 .word unsigned-L5 # u
254 .word fmtbad-L5 # v
255 .word fmtbad-L5 # w
256 .word hex-L5 # x
257fmtbad:
258 movb r0,(r5)+ # print the unfound character
259 jeql errdone # dumb users who end the format with a %
260 jbr prbuf
261capital:
262 bisl2 $1<caps,flags # note that it was capitalized
263 xorb2 $'a^'A,r0 # make it small
264 jbr L4 # and try again
265
266string:
267 movl ndigit,r0
268 jbs $prec,flags,L20 # max length was specified
269 mnegl $1,r0 # default max length
270L20: movl (ap)+,r2 # addr first byte
271 locc $0,r0,(r2) # find the zero at the end
272 movl r1,r5 # addr last byte +1
273 movl r2,r1 # addr first byte
274 jbr prstr
275
276htab: .byte '0,'1,'2,'3,'4,'5,'6,'7,'8,'9,'a,'b,'c,'d,'e,'f
277Htab: .byte '0,'1,'2,'3,'4,'5,'6,'7,'8,'9,'A,'B,'C,'D,'E,'F
278
279octal:
280 movl $30,r2 # init position
281 movl $3,r3 # field width
282 movab htab,llafx # translate table
283 jbr L10
284
285hex:
286 movl $28,r2 # init position
287 movl $4,r3 # field width
288 movab htab,llafx # translate table
289 jbc $caps,flags,L10
290 movab Htab,llafx
291L10: mnegl r3,r6 # increment
292 clrl r1
293 addl2 $4,r5 # room for left affix (2) and slop [forced sign?]
294 movl (ap)+,r0 # fetch arg
295L11: extzv r2,r3,r0,r1 # pull out a digit
296 movb (llafx)[r1],(r5)+ # convert to character
297L12: acbl $0,r6,r2,L11 # continue until done
298 clrq r6 # lrafx, llafx
299 clrb (r5) # flag end
300 skpc $'0,$11,4(sp) # skip over leading zeroes
301 jbc $numsgn,flags,prn3 # easy if no left affix
302 tstl -4(ap) # original value
303 jeql prn3 # no affix on 0, for some reason
304 cmpl r3,$4 # were we doing hex or octal?
305 jneq L12a # octal
306 movb $'x,r0
307 jbc $caps,flags,L12b
308 movb $'X,r0
309L12b: movb r0,-(r1)
310 movl $2,llafx # leading 0x for hex is an affix
311L12a: movb $'0,-(r1) # leading zero for octal is a digit, not an affix
312 jbr prn3 # omit sign (plus, blank) massaging
313
314unsigned:
315lunsigned:
316 bicl2 $1<plssgn|1<blank,flags # omit sign (plus, blank) massaging
317 extzv $1,$31,(ap),r0 # right shift logical 1 bit
318 cvtlp r0,$10,(sp) # convert [n/2] to packed
319 movp $10,(sp),8(sp) # copy packed
320 addp4 $10,8(sp),$10,(sp) # 2*[n/2] in packed, at (sp)
321 blbc (ap)+,L14 # n was even
322 addp4 $1,pone,$10,(sp) # n was odd
323 jbr L14
324
325patdec: # editpc pattern for decimal printing
326 .byte 0xAA # eo$float 10
327 .byte 0x01 # eo$end_float
328 .byte 0 # eo$end
329
330decimal:
331 cvtlp (ap)+,$10,(sp) # 10 digits max
332 jgeq L14
333 incl llafx # minus sign is a left affix
334L14: editpc $10,(sp),patdec,8(sp) # ascii at 8(sp); r5=end+1
335 skpc $' ,$11,8(sp) # skip leading blanks; r1=first
336
337prnum: # r1=addr first byte, r5=addr last byte +1, llafx=size of signs
338 # -1(r1) vacant, for forced sign
339 tstl llafx
340 jneq prn3 # already some left affix, dont fuss
341 jbc $plssgn,flags,prn2
342 movb $'+,-(r1) # needs a plus sign
343 jbr prn4
344prn2: jbc $blank,flags,prn3
345 movb $' ,-(r1) # needs a blank sign
346prn4: incl llafx
347prn3: jbs $prec,flags,prn1
348 movl $1,ndigit # default precision is 1
349prn1: subl3 r1,r5,lrafx # raw width
350 subl2 llafx,lrafx # number of digits
351 subl2 lrafx,ndigit # number of leading zeroes needed
352 jleq prstr # none
353 addl2 llafx,r1 # where current digits start
354 pushl r1 # movcx gobbles registers
355 # check bounds on users who say %.300d
356 movab 32(r5)[ndigit],r2
357 subl2 fp,r2
358 jlss prn5
359 subl2 r2,ndigit
360prn5:
361 #
362 movc3 lrafx,(r1),(r1)[ndigit] # make room in middle
363 movc5 $0,(r1),$ch.zer,ndigit,*(sp) # '0 fill
364 subl3 llafx,(sp)+,r1 # first byte addr
365 addl3 lrafx,r3,r5 # last byte addr +1
366
367prstr: # r1=addr first byte; r5=addr last byte +1
368 # width=minimum width; llafx=len. left affix
369 # ndigit=<avail>
370 subl3 r1,r5,ndigit # raw width
371 subl3 ndigit,width,r0 # pad length
372 jleq padlno # in particular, no left padding
373 jbs $minsgn,flags,padlno
374 # extension for %0 flag causing left zero padding to field width
375 jbs $zfill,flags,padlz
376 # this bsbb needed even if %0 flag extension is removed
377 bsbb padb # blank pad on left
378 jbr padnlz
379padlz:
380 movl llafx,r0
381 jleq padnlx # left zero pad requires left affix first
382 subl2 r0,ndigit # part of total length will be transferred
383 subl2 r0,width # and will account for part of minimum width
384 bsbw strout # left affix
385padnlx:
386 subl3 ndigit,width,r0 # pad length
387 bsbb padz # zero pad on left
388padnlz:
389 # end of extension for left zero padding
390padlno: # remaining: root, possible right padding
391 subl2 ndigit,width # root reduces minimum width
392 movl ndigit,r0 # root length
393p1: bsbw strout # transfer to output buffer
394p3: jbc $vbit,r2,padnpct # percent sign (or null byte via %c) ?
395 decl r0 # yes; adjust count
396 movzbl (r1)+,r2 # fetch byte
397 movq *fdesc,r4 # output buffer descriptor
398 sobgeq r4,p2 # room at the out [inn] ?
399 bsbw strout2 # no; force it, then try rest
400 jbr p3 # here we go 'round the mullberry bush, ...
401p2: movb r2,(r5)+ # hand-deposit the percent or null
402 incl nchar # count it
403 movq r4,*fdesc # store output descriptor
404 jbr p1 # what an expensive hiccup!
405padnpct:
406 movl width,r0 # size of pad
407 jleq loop
408 bsbb padb
409 jbr loop
410
411padz:
412 movb $'0,r2
413 jbr pad
414padb:
415 movb $' ,r2
416pad:
417 subl2 r0,width # pad width decreases minimum width
418 pushl r1 # save non-pad addr
419 movl r0,llafx # remember width of pad
420 subl2 r0,sp # allocate
421 movc5 $0,(r0),r2,llafx,(sp) # create pad string
422 movl llafx,r0 # length
423 movl sp,r1 # addr
424 bsbw strout
425 addl2 llafx,sp # deallocate
426 movl (sp)+,r1 # recover non-pad addr
427 rsb
428
429pone: .byte 0x1C # packed 1
430
431charac:
432 movl (ap)+,r0 # word containing the char
433 movb r0,(r5)+ # one byte, that's all
434
435prbuf:
436 movl sp,r1 # addr first byte
437 jbr prstr
438
439space: bisl2 $1<blank,flags # constant width e fmt, no plus sign
440 jbr L4a
441sharp: bisl2 $1<numsgn,flags # 'self identifying', please
442 jbr L4a
443plus: bisl2 $1<plssgn,flags # always print sign for floats
444 jbr L4a
445minus: bisl2 $1<minsgn,flags # left justification, please
446 jbr L4a
447gnum0: jbs $ndfnd,flags,gnum
448 jbs $prec,flags,gnump # ignore when reading precision
449 bisl2 $1<zfill,flags # leading zero fill, please
450gnum: jbs $prec,flags,gnump
451 moval (width)[width],width # width *= 5;
452 movaw -ch.zer(r0)[width],width # width = 2*witdh + r0 - '0';
453 jbr gnumd
454gnump: moval (ndigit)[ndigit],ndigit # ndigit *= 5;
455 movaw -ch.zer(r0)[ndigit],ndigit # ndigit = 2*ndigit + r0 - '0';
456gnumd: bisl2 $1<ndfnd,flags # digit seen
457 jbr L4a
458dot: clrl ndigit # start on the precision
459 bisl2 $1<prec,flags
460 bicl2 $1<ndfnd,flags
461 jbr L4a
462indir:
463 jbs $prec,flags,in1
464 movl (ap)+,width # width specified by parameter
465 jgeq gnumd
466 xorl2 $1<minsgn,flags # parameterized left adjustment
467 mnegl width,width
468 jbr gnumd
469in1:
470 movl (ap)+,ndigit # precision specified by paratmeter
471 jgeq gnumd
472 mnegl ndigit,ndigit
473 jbr gnumd
474
475float:
476 jbs $prec,flags,float1
477 movl $6,ndigit # default # digits to right of decpt.
478float1: bsbw fltcvt
479 addl3 exp,ndigit,r7
480 movl r7,r6 # for later "underflow" checking
481 bgeq fxplrd
482 clrl r7 # poor programmer planning
483fxplrd: cmpl r7,$31 # expressible in packed decimal?
484 bleq fnarro # yes
485 movl $31,r7
486fnarro: subl3 $17,r7,r0 # where to round
487 ashp r0,$17,(sp),$5,r7,16(sp) # do it
488 bvc fnovfl
489 # band-aid for microcode error (spurious overflow)
490 # clrl r0 # assume even length result
491 # jlbc r7,fleven # right
492 # movl $4,r0 # odd length result
493 #fleven: cmpv r0,$4,16(sp),$0 # top digit zero iff true overflow
494 # bneq fnovfl
495 # end band-aid
496 aobleq $0,r6,fnovfl # if "underflow" then jump
497 movl r7,r0
498 incl exp
499 incl r7
500 ashp r0,$1,pone,$0,r7,16(sp)
501 ashl $-1,r7,r0 # displ to last byte
502 bisb2 sign,16(sp)[r0] # insert sign
503fnovfl:
504 movab 16(sp),r1 # packed source
505 movl r7,r6 # packed length
506 pushab prnum # goto prnum after fall-through call to fedit
507
508
509 # enter via bsb
510 # r1=addr of packed source
511 # 16(r1) used to unpack source
512 # 48(r1) used to construct pattern to unpack source
513 # 48(r1) used to hold result
514 # r6=length of packed source (destroyed)
515 # exp=# digits to left of decimal point (destroyed)
516 # ndigit=# digits to right of decimal point (destroyed)
517 # sign=1 if negative, 0 otherwise
518 # stack will be used for work space for pattern and unpacked source
519 # exits with
520 # r1=addr of punctuated result
521 # r5=addr of last byte +1
522 # llafx=1 if minus sign inserted, 0 otherwise
523fedit:
524 pushab 48(r1) # save result addr
525 movab 48(r1),r3 # pattern addr
526 movb $0x03,(r3)+ # eo$set_signif
527 movc5 $0,(r1),$0x91,r6,(r3) # eo$move 1
528 clrb (r3) # eo$end
529 editpc r6,(r1),48(r1),16(r1) # unpack 'em all
530 subl3 r6,r5,r1 # addr unpacked source
531 movl (sp),r3 # punctuated output placed here
532 clrl llafx
533 jlbc sign,f1
534 movb $'-,(r3)+ # negative
535 incl llafx
536f1: movl exp,r0
537 jgtr f2
538 movb $'0,(r3)+ # must have digit before decimal point
539 jbr f3
540f2: cmpl r0,r6 # limit on packed length
541 jleq f4
542 movl r6,r0
543f4: subl2 r0,r6 # eat some digits
544 subl2 r0,exp # from the exponent
545 movc3 r0,(r1),(r3) # (most of the) digits to left of decimal point
546 movl exp,r0 # need any more?
547 jleq f3
548 movc5 $0,(r1),$'0,r0,(r3) # '0 fill
549f3: movl ndigit,r0 # # digits to right of decimal point
550 jgtr f5
551 jbs $numsgn,flags,f5 # no decimal point unless forced
552 jbcs $dpflag,flags,f6 # no decimal point
553f5: movb $'.,(r3)+ # the decimal point
554f6: mnegl exp,r0 # "leading" zeroes to right of decimal point
555 jleq f9
556 cmpl r0,ndigit # cant exceed this many
557 jleq fa
558 movl ndigit,r0
559fa: subl2 r0,ndigit
560 movc5 $0,(r1),$'0,r0,(r3)
561f9: movl ndigit,r0
562 cmpl r0,r6 # limit on packed length
563 jleq f7
564 movl r6,r0
565f7: subl2 r0,ndigit # eat some digits from the fraction
566 movc3 r0,(r1),(r3) # (most of the) digits to right of decimal point
567 movl ndigit,r0 # need any more?
568 jleq f8
569 # check bounds on users who say %.300f
570 movab 32(r3)[r0],r2
571 subl2 fp,r2
572 jlss fb
573 subl2 r2,r0 # truncate, willy-nilly
574 movl r0,ndigit # and no more digits later, either
575fb:
576 #
577 subl2 r0,ndigit # eat some digits from the fraction
578 movc5 $0,(r1),$'0,r0,(r3) # '0 fill
579f8: movl r3,r5 # addr last byte +1
580 popr $1<1 # [movl (sp)+,r1] addr first byte
581 rsb
582
583patexp: .byte 0x03 # eo$set_signif
584 .byte 0x44,'e # eo$insert 'e
585 .byte 0x42,'+ # eo$load_plus '+
586 .byte 0x04 # eo$store_sign
587 .byte 0x92 # eo$move 2
588 .byte 0 # eo$end
589
590scien:
591 incl ndigit
592 jbs $prec,flags,L23
593 movl $7,ndigit
594L23: bsbw fltcvt # get packed digits
595 movl ndigit,r7
596 cmpl r7,$31 # expressible in packed decimal?
597 jleq snarro # yes
598 movl $31,r7
599snarro: subl3 $17,r7,r0 # rounding position
600 ashp r0,$17,(sp),$5,r7,16(sp) # shift and round
601 bvc snovfl
602 # band-aid for microcode error (spurious overflow)
603 # clrl r0 # assume even length result
604 # jlbc ndigit,sceven # right
605 # movl $4,r0 # odd length result
606 #sceven: cmpv r0,$4,16(sp),$0 # top digit zero iff true overflow
607 # bneq snovfl
608 # end band-aid
609 incl exp # rounding overflowed to 100...
610 subl3 $1,r7,r0
611 ashp r0,$1,pone,$0,r7,16(sp)
612 ashl $-1,r7,r0 # displ to last byte
613 bisb2 sign,16(sp)[r0] # insert sign
614snovfl:
615 jbs $gflag,flags,gfmt # %g format
616 movab 16(sp),r1
617 bsbb eedit
618eexp:
619 movl r1,r6 # save fwa from destruction by cvtlp
620 subl3 $1,sexp,r0 # 1P exponent
621 cvtlp r0,$2,(sp) # packed
622 editpc $2,(sp),patexp,(r5)
623 movl r6,r1 # fwa
624 jbc $caps,flags,prnum
625 xorb2 $'e^'E,-4(r5)
626 jbr prnum
627
628eedit:
629 movl r7,r6 # packed length
630 decl ndigit # 1 digit before decimal point
631 movl exp,sexp # save from destruction
632 movl $1,exp # and pretend
633 jbr fedit
634
635gfmt:
636 addl3 $3,exp,r0 # exp is 1 more than e
637 jlss gfmte # (e+1)+3<0, e+4<=-1, e<=-5
638 subl2 $3,r0 # exp [==(e+1)]
639 cmpl r0,ndigit
640 jgtr gfmte # e+1>n, e>=n
641gfmtf:
642 movl r7,r6
643 subl2 r0,ndigit # n-e-1
644 movab 16(sp),r1
645 bsbw fedit
646g1: jbs $numsgn,flags,g2
647 jbs $dpflag,flags,g2 # dont strip if no decimal point
648g3: cmpb -(r5),$'0 # strip trailing zeroes
649 jeql g3
650 cmpb (r5),$'. # and trailing decimal point
651 jeql g2
652 incl r5
653g2: jbc $gflag,flags,eexp
654 jbr prnum
655gfmte:
656 movab 16(sp),r1 # packed source
657 bsbw eedit
658 jbsc $gflag,flags,g1 # gflag now means "use %f" [hence no exponent]
659
660general:
661 jbs $prec,flags,gn1
662 movl $6,ndigit # default precision is 6 significant digits
663gn1: tstl ndigit # cannot allow precision of 0
664 jgtr gn2
665 movl $1,ndigit # change 0 to 1, willy-nilly
666gn2: jbcs $gflag,flags,L23
667 jbr L23 # safety net
668
669 # convert double-floating at (ap) to 17-digit packed at (sp),
670 # set 'sign' and 'exp', advance ap.
671fltcvt:
672 clrb sign
673 movd (ap)+,r5
674 jeql fzero
675 bgtr fpos
676 mnegd r5,r5
677 incb sign
678fpos:
679 extzv $7,$8,r5,r2 # exponent of 2
680 movab -0200(r2),r2 # unbias
681 mull2 $59,r2 # 59/196: 3rd convergent continued frac of log10(2)
682 jlss eneg
683 movab 196(r2),r2
684eneg:
685 movab -98(r2),r2
686 divl2 $196,r2
687 bsbw expten
688 cmpd r0,r5
689 bgtr ceil
690 incl r2
691ceil: movl r2,exp
692 mnegl r2,r2
693 cmpl r2,$29 # 10^(29+9) is all we can handle
694 bleq getman
695 muld2 ten16,r5
696 subl2 $16,r2
697getman: addl2 $9,r2 # -ceil(log10(x)) + 9
861952dc 698 jsb expten
4e447cd1
BJ
699 emodd r0,r4,r5,r0,r5 # (r0+r4)*r5; r0=int, r5=frac
700fz1: cvtlp r0,$9,16(sp) # leading 9 digits
701 ashp $8,$9,16(sp),$0,$17,4(sp) # as top 9 of 17
702 emodd ten8,$0,r5,r0,r5
703 cvtlp r0,$8,16(sp) # trailing 8 digits
704 # if precision >= 17, must round here
705 movl ndigit,r7 # so figure out what precision is
706 pushab scien
707 cmpl (sp)+,(sp)
708 jleq gm1 # who called us?
709 addl2 exp,r7 # float; adjust for exponent
710gm1: cmpl r7,$17
711 jlss gm2
712 cmpd r5,$0d0.5 # must round here; check fraction
713 jlss gm2
714 bisb2 $0x10,8+4(sp) # increment l.s. digit
715gm2: # end of "round here" code
716 addp4 $8,16(sp),$17,4(sp) # combine leading and trailing
717 bisb2 sign,12(sp) # and insert sign
718 rsb
719fzero: clrl r0
720 movl $1,exp # 0.000e+00 and 0.000 rather than 0.000e-01 and .000
721 jbr fz1
722
723 .align 2
724lsb: .long 0x00010000 # lsb in the crazy floating-point format
725
726 # return 10^r2 as a double float in r0||r1 and 8 extra bits of precision in r4
727 # preserve r2, r5||r6
728expten:
729 movd $0d1.0,r0 # begin computing 10^exp10
730 clrl r4 # bit counter
731 movad ten1,r3 # table address
732 tstl r2
733 bgeq e10lp
734 mnegl r2,r2 # get absolute value
735 jbss $6,r2,e10lp # flag as negative
736e10lp: jbc r4,r2,el1 # want this power?
737 muld2 (r3),r0 # yes
738el1: addl2 $8,r3 # advance to next power
739 aobleq $5,r4,e10lp # through 10^32
740 jbcc $6,r2,el2 # correct for negative exponent
741 divd3 r0,$0d1.0,r0 # by taking reciprocal
742 cmpl $28,r2
743 jneq enm28
744 addl2 lsb,r1 # 10**-28 needs lsb incremented
745enm28: mnegl r2,r2 # original exponent of 10
746el2: addl3 $5*8,r2,r3 # negative bit positions are illegal?
747 jbc r3,xlsbh-5,eoklsb
748 subl2 lsb,r1 # lsb was too high
749eoklsb:
750 movzbl xprec[r2],r4 # 8 extra bits
751 rsb
752
753 # powers of ten
754 .align 2
755ten1: .word 0x4220,0,0,0
756ten2: .word 0x43c8,0,0,0
757ten4: .word 0x471c,0x4000,0,0
758ten8: .word 0x4dbe,0xbc20,0,0
759ten16: .word 0x5b0e,0x1bc9,0xbf04,0
760ten32: .word 0x759d,0xc5ad,0xa82b,0x70b6
761
762 # whether lsb is too high or not
763 .byte 1:0,1:0,1:0,1:0,1:1,1:0,1:1,1:0 # -40 thru -33
764 .byte 1:0,1:1,1:0,1:0,1:0,1:0,1:1,1:0 # -32 thru -25
765 .byte 1:0,1:0,1:1,1:1,1:1,1:1,1:0,1:0 # -24 thru -17
766 .byte 1:0,1:1,1:0,1:0,1:1,1:1,1:1,1:1 # -16 thru -9
767 .byte 1:1,1:1,1:1,1:0,1:0,1:0,1:0,1:1 # -8 thru -1
768xlsbh:
769 .byte 1:0,1:0,1:0,1:0,1:0,1:0,1:0,1:0 # 0 thru 7
770 .byte 1:0,1:0,1:0,1:0,1:0,1:0,1:0,1:0 # 8 thru 15
771 .byte 1:0,1:0,1:0,1:0,1:0,1:0,1:0,1:0 # 16 thru 23
772 .byte 1:0,1:1,1:1,1:0,1:1,1:1,1:1,1:1 # 24 thru 31
773 .byte 1:1,1:1,1:1,1:1,1:1,1:1,1:1 # 32 thru 38
774
775 # bytes of extra precision
776 .byte 0x56,0x76,0xd3,0x88,0xb5,0x62 # -38 thru -33
777 .byte 0xba,0xf5,0x32,0x3e,0x0e,0x48,0xdb,0x51 # -32 thru -25
778 .byte 0x53,0x27,0xb1,0xef,0xeb,0xa5,0x07,0x49 # -24 thru -17
779 .byte 0x5b,0xd9,0x0f,0x13,0xcd,0xff,0xbf,0x97 # -16 thru -9
780 .byte 0xfd,0xbc,0xb6,0x23,0x2c,0x3b,0x0a,0xcd # -8 thru -1
781xprec:
782 .byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 # 0 thru 7
783 .byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 # 8 thru 15
784 .byte 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 # 16 thru 23
785 .byte 0x00,0xa0,0xc8,0x3a,0x84,0xe4,0xdc,0x92 # 24 thru 31
786 .byte 0x9b,0x00,0xc0,0x58,0xae,0x18,0xef # 32 thru 38