2003-10-21 Arnaud Charlet <charlet@act-europe.fr>

	* 3psoccon.ads, 3veacodu.adb, 3vexpect.adb, 3vsoccon.ads,
	3vsocthi.adb, 3vsocthi.ads, 3vtrasym.adb, 3zsoccon.ads,
	3zsocthi.adb, 3zsocthi.ads, 50system.ads, 51system.ads,
	55system.ads, 56osinte.adb, 56osinte.ads, 56taprop.adb,
	56taspri.ads, 56tpopsp.adb, 57system.ads, 58system.ads,
	59system.ads, 5aml-tgt.adb, 5bml-tgt.adb, 5csystem.ads,
	5dsystem.ads, 5fosinte.adb, 5gml-tgt.adb, 5hml-tgt.adb,
	5isystem.ads, 5lparame.adb, 5msystem.ads, 5psystem.ads,
	5sml-tgt.adb, 5sosprim.adb, 5stpopsp.adb, 5tsystem.ads,
	5usystem.ads, 5vml-tgt.adb, 5vsymbol.adb, 5vtraent.adb,
	5vtraent.ads, 5wml-tgt.adb, 5xparame.ads, 5xsystem.ads,
	5xvxwork.ads, 5yparame.ads, 5ytiitho.adb, 5zinit.adb,
	5zml-tgt.adb, 5zparame.ads, 5ztaspri.ads, 5ztfsetr.adb,
	5zthrini.adb, 5ztiitho.adb, 5ztpopsp.adb, 7stfsetr.adb,
	7straces.adb, 7strafor.adb, 7strafor.ads, 7stratas.adb,
	a-excach.adb, a-exexda.adb, a-exexpr.adb, a-exextr.adb,
	a-exstat.adb, a-strsup.adb, a-strsup.ads, a-stwisu.adb,
	a-stwisu.ads, bld.adb, bld.ads, bld-io.adb,
	bld-io.ads, clean.adb, clean.ads, ctrl_c.c,
	erroutc.adb, erroutc.ads, errutil.adb, errutil.ads,
	err_vars.ads, final.c, g-arrspl.adb, g-arrspl.ads,
	g-boubuf.adb, g-boubuf.ads, g-boumai.ads, g-bubsor.adb,
	g-bubsor.ads, g-comver.adb, g-comver.ads, g-ctrl_c.ads,
	g-dynhta.adb, g-dynhta.ads, g-eacodu.adb, g-excact.adb,
	g-excact.ads, g-heasor.adb, g-heasor.ads, g-memdum.adb,
	g-memdum.ads, gnatclean.adb, gnatsym.adb, g-pehage.adb,
	g-pehage.ads, g-perhas.ads, gpr2make.adb, gpr2make.ads,
	gprcmd.adb, gprep.adb, gprep.ads, g-semaph.adb,
	g-semaph.ads, g-string.adb, g-string.ads, g-strspl.ads,
	g-wistsp.ads, i-vthrea.adb, i-vthrea.ads, i-vxwoio.adb,
	i-vxwoio.ads, Makefile.generic, Makefile.prolog, Makefile.rtl,
	prep.adb, prep.ads, prepcomp.adb, prepcomp.ads,
	prj-err.adb, prj-err.ads, s-boarop.ads, s-carsi8.adb,
	s-carsi8.ads, s-carun8.adb, s-carun8.ads, s-casi16.adb,
	s-casi16.ads, s-casi32.adb, s-casi32.ads, s-casi64.adb,
	s-casi64.ads, s-casuti.adb, s-casuti.ads, s-caun16.adb,
	s-caun16.ads, s-caun32.adb, s-caun32.ads, s-caun64.adb,
	s-caun64.ads, scng.adb, scng.ads, s-exnint.adb,
	s-exnllf.adb, s-exnlli.adb, s-expint.adb, s-explli.adb,
	s-geveop.adb, s-geveop.ads, s-hibaen.ads, s-htable.adb,
	s-htable.ads, sinput-c.adb, sinput-c.ads, s-memcop.ads,
	socket.c, s-purexc.ads, s-scaval.adb, s-stopoo.adb,
	s-strcom.adb, s-strcom.ads, s-strxdr.adb, s-rident.ads,
	s-thread.adb, s-thread.ads, s-tpae65.adb, s-tpae65.ads,
	s-tporft.adb, s-traent.adb, s-traent.ads, styleg.adb,
	styleg.ads, styleg-c.adb, styleg-c.ads, s-veboop.adb,
	s-veboop.ads, s-vector.ads, symbols.adb, symbols.ads,
	tb-alvms.c, tb-alvxw.c, tempdir.adb, tempdir.ads,
	vms_conv.ads, vms_conv.adb, vms_data.ads,
	vxaddr2line.adb: Files added. Merge with ACT tree.

	* 4dintnam.ads, 4mintnam.ads, 4uintnam.ads, 52system.ads,
	5dosinte.ads, 5etpopse.adb, 5mosinte.ads, 5qosinte.adb,
	5qosinte.ads, 5qstache.adb, 5qtaprop.adb, 5qtaspri.ads,
	5stpopse.adb, 5uintman.adb, 5uosinte.ads, adafinal.c,
	g-enblsp.adb, io-aux.c, scn-nlit.adb, scn-slit.adb,
	s-exnflt.ads, s-exngen.adb, s-exngen.ads, s-exnlfl.ads,
	s-exnlin.ads, s-exnsfl.ads, s-exnsin.ads, s-exnssi.ads,
	s-expflt.ads, s-expgen.adb, s-expgen.ads, s-explfl.ads,
	s-explin.ads, s-expllf.ads, s-expsfl.ads, s-expsin.ads,
	s-expssi.ads, style.adb: Files removed. Merge with ACT tree.

	* 1ic.ads, 31soccon.ads, 31soliop.ads, 3asoccon.ads,
	3bsoccon.ads, 3gsoccon.ads, 3hsoccon.ads, 3ssoccon.ads,
	3ssoliop.ads, 3wsoccon.ads, 3wsocthi.adb, 3wsocthi.ads,
	3wsoliop.ads, 41intnam.ads, 42intnam.ads, 4aintnam.ads,
	4cintnam.ads, 4gintnam.ads, 4hexcpol.adb, 4hintnam.ads,
	4lintnam.ads, 4nintnam.ads, 4ointnam.ads, 4onumaux.ads,
	4pintnam.ads, 4sintnam.ads, 4vcaldel.adb, 4vcalend.adb,
	4vintnam.ads, 4wexcpol.adb, 4wintnam.ads, 4zintnam.ads,
	51osinte.adb, 51osinte.ads, 52osinte.adb, 52osinte.ads,
	53osinte.ads, 54osinte.ads, 5aosinte.adb, 5aosinte.ads,
	5asystem.ads, 5ataprop.adb, 5atasinf.ads, 5ataspri.ads,
	5atpopsp.adb, 5avxwork.ads, 5bosinte.adb, 5bosinte.ads,
	5bsystem.ads, 5cosinte.ads, 5esystem.ads, 5fintman.adb,
	5fosinte.ads, 5fsystem.ads, 5ftaprop.adb, 5ftasinf.ads,
	5ginterr.adb, 5gintman.adb, 5gmastop.adb, 5gosinte.ads,
	5gproinf.ads, 5gsystem.ads, 5gtaprop.adb, 5gtasinf.ads,
	5gtpgetc.adb, 5hosinte.adb, 5hosinte.ads, 5hsystem.ads,
	5htaprop.adb, 5htaspri.ads, 5htraceb.adb, 5iosinte.adb,
	5itaprop.adb, 5itaspri.ads, 5ksystem.ads, 5kvxwork.ads,
	5lintman.adb, 5lml-tgt.adb, 5losinte.ads, 5lsystem.ads,
	5mvxwork.ads, 5ninmaop.adb, 5nintman.adb, 5nosinte.ads,
	5ntaprop.adb, 5ntaspri.ads, 5ointerr.adb, 5omastop.adb,
	5oosinte.adb, 5oosinte.ads, 5oosprim.adb, 5oparame.adb,
	5osystem.ads, 5otaprop.adb, 5otaspri.ads, 5posinte.ads,
	5posprim.adb, 5pvxwork.ads, 5sintman.adb, 5sosinte.adb,
	5sosinte.ads, 5ssystem.ads, 5staprop.adb, 5stasinf.ads,
	5staspri.ads, 5svxwork.ads, 5tosinte.ads, 5vasthan.adb,
	5vinmaop.adb, 5vinterr.adb, 5vintman.adb, 5vintman.ads,
	5vmastop.adb, 5vosinte.adb, 5vosinte.ads, 5vosprim.adb,
	5vsystem.ads, 5vtaprop.adb, 5vtaspri.ads, 5vtpopde.adb,
	5vtpopde.ads, 5wgloloc.adb, 5wintman.adb, 5wmemory.adb,
	5wosprim.adb, 5wsystem.ads, 5wtaprop.adb, 5wtaspri.ads,
	5ysystem.ads, 5zinterr.adb, 5zintman.adb, 5zosinte.adb,
	5zosinte.ads, 5zosprim.adb, 5zsystem.ads, 5ztaprop.adb,
	6vcpp.adb, 6vcstrea.adb, 6vinterf.ads, 7sinmaop.adb,
	7sintman.adb, 7sosinte.adb, 7sosprim.adb, 7staprop.adb,
	7staspri.ads, 7stpopsp.adb, 7straceb.adb, 9drpc.adb,
	a-caldel.adb, a-caldel.ads, a-charac.ads, a-colien.ads,
	a-comlin.adb, adaint.c, adaint.h, ada-tree.def,
	a-diocst.adb, a-diocst.ads, a-direio.adb, a-except.adb,
	a-except.ads, a-excpol.adb, a-exctra.adb, a-exctra.ads,
	a-filico.adb, a-interr.adb, a-intsig.adb, a-intsig.ads,
	ali.adb, ali.ads, ali-util.adb, ali-util.ads,
	a-ngcefu.adb, a-ngcoty.adb, a-ngelfu.adb, a-nudira.adb,
	a-nudira.ads, a-nuflra.adb, a-nuflra.ads, a-reatim.adb,
	a-reatim.ads, a-retide.ads, a-sequio.adb, a-siocst.adb,
	a-siocst.ads, a-ssicst.adb, a-ssicst.ads, a-strbou.adb,
	a-strbou.ads, a-strfix.adb, a-strmap.adb, a-strsea.ads,
	a-strunb.adb, a-strunb.ads, a-ststio.adb, a-stunau.adb,
	a-stunau.ads, a-stwibo.adb, a-stwibo.ads, a-stwifi.adb,
	a-stwima.adb, a-stwiun.adb, a-stwiun.ads, a-tags.adb,
	a-tags.ads, a-tasatt.adb, a-taside.adb, a-teioed.adb,
	a-textio.adb, a-textio.ads, a-tienau.adb, a-tifiio.adb,
	a-tiflau.adb, a-tiflio.adb, a-tigeau.adb, a-tigeau.ads,
	a-tiinau.adb, a-timoau.adb, a-tiocst.adb, a-tiocst.ads,
	atree.adb, atree.ads, a-witeio.adb, a-witeio.ads,
	a-wtcstr.adb, a-wtcstr.ads, a-wtdeio.adb, a-wtedit.adb,
	a-wtenau.adb, a-wtflau.adb, a-wtinau.adb, a-wtmoau.adb,
	bcheck.adb, binde.adb, bindgen.adb, bindusg.adb,
	checks.adb, checks.ads, cio.c, comperr.adb,
	comperr.ads, csets.adb, cstand.adb, cstreams.c,
	debug_a.adb, debug_a.ads, debug.adb, decl.c,
	einfo.adb, einfo.ads, errout.adb, errout.ads,
	eval_fat.adb, eval_fat.ads, exp_aggr.adb, expander.adb,
	expander.ads, exp_attr.adb, exp_ch11.adb, exp_ch13.adb,
	exp_ch2.adb, exp_ch3.adb, exp_ch3.ads, exp_ch4.adb,
	exp_ch5.adb, exp_ch6.adb, exp_ch7.adb, exp_ch7.ads,
	exp_ch8.adb, exp_ch9.adb, exp_code.adb, exp_dbug.adb,
	exp_dbug.ads, exp_disp.adb, exp_dist.adb, expect.c,
	exp_fixd.adb, exp_imgv.adb, exp_intr.adb, exp_pakd.adb,
	exp_prag.adb, exp_strm.adb, exp_strm.ads, exp_tss.adb,
	exp_tss.ads, exp_util.adb, exp_util.ads, exp_vfpt.adb,
	fe.h, fmap.adb, fmap.ads, fname.adb,
	fname.ads, fname-uf.adb, fname-uf.ads, freeze.adb,
	freeze.ads, frontend.adb, g-awk.adb, g-awk.ads,
	g-busora.adb, g-busora.ads, g-busorg.adb, g-busorg.ads,
	g-casuti.adb, g-casuti.ads, g-catiio.adb, g-catiio.ads,
	g-cgi.adb, g-cgi.ads, g-cgicoo.adb, g-cgicoo.ads,
	g-cgideb.adb, g-cgideb.ads, g-comlin.adb, g-comlin.ads,
	g-crc32.adb, g-crc32.ads, g-debpoo.adb, g-debpoo.ads,
	g-debuti.adb, g-debuti.ads, g-diopit.adb, g-diopit.ads,
	g-dirope.adb, g-dirope.ads, g-dyntab.adb, g-dyntab.ads,
	g-except.ads, g-exctra.adb, g-exctra.ads, g-expect.adb,
	g-expect.ads, g-hesora.adb, g-hesora.ads, g-hesorg.adb,
	g-hesorg.ads, g-htable.adb, g-htable.ads, gigi.h,
	g-io.adb, g-io.ads, g-io_aux.adb, g-io_aux.ads,
	g-locfil.adb, g-locfil.ads, g-md5.adb, g-md5.ads,
	gmem.c, gnat1drv.adb, gnatbind.adb, gnatchop.adb,
	gnatcmd.adb, gnatfind.adb, gnatkr.adb, gnatlbr.adb,
	gnatlink.adb, gnatls.adb, gnatmake.adb, gnatmem.adb,
	gnatname.adb, gnatprep.adb, gnatprep.ads, gnatpsta.adb,
	gnatxref.adb, g-os_lib.adb, g-os_lib.ads, g-regexp.adb,
	g-regexp.ads, g-regist.adb, g-regist.ads, g-regpat.adb,
	g-regpat.ads, g-soccon.ads, g-socket.adb, g-socket.ads,
	g-socthi.adb, g-socthi.ads, g-soliop.ads, g-souinf.ads,
	g-speche.adb, g-speche.ads, g-spipat.adb, g-spipat.ads,
	g-spitbo.adb, g-spitbo.ads, g-sptabo.ads, g-sptain.ads,
	g-sptavs.ads, g-table.adb, g-table.ads, g-tasloc.adb,
	g-tasloc.ads, g-thread.adb, g-thread.ads, g-traceb.adb,
	g-traceb.ads, g-trasym.adb, g-trasym.ads, hostparm.ads,
	i-c.ads, i-cobol.adb, i-cpp.adb, i-cstrea.ads,
	i-cstrin.adb, i-cstrin.ads, impunit.adb, init.c,
	inline.adb, interfac.ads, i-pacdec.ads, itypes.adb,
	itypes.ads, i-vxwork.ads, lang.opt, lang-specs.h,
	layout.adb, lib.adb, lib.ads, lib-list.adb,
	lib-load.adb, lib-load.ads, lib-sort.adb, lib-util.adb,
	lib-writ.adb, lib-writ.ads, lib-xref.adb, lib-xref.ads,
	link.c, live.adb, make.adb, make.ads,
	Makefile.adalib, Makefile.in, Make-lang.in, makeusg.adb,
	mdll.adb, mdll-fil.adb, mdll-fil.ads, mdll-utl.adb,
	mdll-utl.ads, memroot.adb, memroot.ads, memtrack.adb,
	misc.c, mkdir.c, mlib.adb, mlib.ads,
	mlib-fil.adb, mlib-fil.ads, mlib-prj.adb, mlib-prj.ads,
	mlib-tgt.adb, mlib-tgt.ads, mlib-utl.adb, mlib-utl.ads,
	namet.adb, namet.ads, namet.h, nlists.ads,
	nlists.h, nmake.adt, opt.adb, opt.ads,
	osint.adb, osint.ads, osint-b.adb, osint-c.adb,
	par.adb, par-ch10.adb, par-ch11.adb, par-ch2.adb,
	par-ch3.adb, par-ch4.adb, par-ch5.adb, par-ch6.adb,
	par-ch9.adb, par-endh.adb, par-labl.adb, par-load.adb,
	par-prag.adb, par-sync.adb, par-tchk.adb, par-util.adb,
	prj.adb, prj.ads, prj-attr.adb, prj-attr.ads,
	prj-com.adb, prj-com.ads, prj-dect.adb, prj-dect.ads,
	prj-env.adb, prj-env.ads, prj-ext.adb, prj-ext.ads,
	prj-makr.adb, prj-makr.ads, prj-nmsc.adb, prj-nmsc.ads,
	prj-pars.adb, prj-pars.ads, prj-part.adb, prj-part.ads,
	prj-pp.adb, prj-pp.ads, prj-proc.adb, prj-proc.ads,
	prj-strt.adb, prj-strt.ads, prj-tree.adb, prj-tree.ads,
	prj-util.adb, prj-util.ads, raise.c, raise.h,
	repinfo.adb, repinfo.h, restrict.adb, restrict.ads,
	rident.ads, rtsfind.adb, rtsfind.ads, s-addima.ads,
	s-arit64.adb, s-assert.adb, s-assert.ads, s-atacco.adb,
	s-atacco.ads, s-auxdec.adb, s-auxdec.ads, s-bitops.adb,
	scans.ads, scn.adb, scn.ads, s-crc32.adb,
	s-crc32.ads, s-direio.adb, sem.adb, sem.ads,
	sem_aggr.adb, sem_attr.adb, sem_attr.ads, sem_case.adb,
	sem_case.ads, sem_cat.adb, sem_cat.ads, sem_ch10.adb,
	sem_ch11.adb, sem_ch12.adb, sem_ch12.ads, sem_ch13.adb,
	sem_ch13.ads, sem_ch3.adb, sem_ch3.ads, sem_ch4.adb,
	sem_ch5.adb, sem_ch5.ads, sem_ch6.adb, sem_ch6.ads,
	sem_ch7.adb, sem_ch7.ads, sem_ch8.adb, sem_ch8.ads,
	sem_ch9.adb, sem_disp.adb, sem_disp.ads, sem_dist.adb,
	sem_elab.adb, sem_eval.adb, sem_eval.ads, sem_intr.adb,
	sem_maps.adb, sem_mech.adb, sem_prag.adb, sem_prag.ads,
	sem_res.adb, sem_res.ads, sem_type.adb, sem_type.ads,
	sem_util.adb, sem_util.ads, sem_warn.adb, s-errrep.adb,
	s-errrep.ads, s-exctab.adb, s-exctab.ads, s-exnint.ads,
	s-exnllf.ads, s-exnlli.ads, s-expint.ads, s-explli.ads,
	s-expuns.ads, s-fatflt.ads, s-fatgen.adb, s-fatgen.ads,
	s-fatlfl.ads, s-fatllf.ads, s-fatsfl.ads, s-fileio.adb,
	s-fileio.ads, s-finimp.adb, s-finimp.ads, s-finroo.adb,
	s-finroo.ads, sfn_scan.adb, s-gloloc.adb, s-gloloc.ads,
	s-imgdec.adb, s-imgenu.adb, s-imgrea.adb, s-imgwch.adb,
	sinfo.adb, sinfo.ads, s-inmaop.ads, sinput.adb,
	sinput.ads, sinput-d.adb, sinput-l.adb, sinput-l.ads,
	sinput-p.adb, sinput-p.ads, s-interr.adb, s-interr.ads,
	s-intman.ads, s-maccod.ads, s-mastop.adb, s-mastop.ads,
	s-memory.adb, s-memory.ads, snames.adb, snames.ads,
	snames.h, s-osprim.ads, s-parame.ads, s-parint.ads,
	s-pooloc.adb, s-pooloc.ads, s-poosiz.adb, sprint.adb,
	s-proinf.ads, s-scaval.ads, s-secsta.adb, s-secsta.ads,
	s-sequio.adb, s-shasto.adb, s-shasto.ads, s-soflin.ads,
	s-stache.adb, s-stache.ads, s-stalib.adb, s-stalib.ads,
	s-stoele.ads, s-stopoo.ads, s-stratt.adb, s-stratt.ads,
	s-strops.adb, s-strops.ads, s-taasde.adb, s-taasde.ads,
	s-tadeca.adb, s-tadeca.ads, s-tadert.adb, s-tadert.ads,
	s-taenca.adb, s-taenca.ads, s-taprob.adb, s-taprob.ads,
	s-taprop.ads, s-tarest.adb, s-tarest.ads, s-tasdeb.adb,
	s-tasdeb.ads, s-tasinf.adb, s-tasinf.ads, s-tasini.adb,
	s-tasini.ads, s-taskin.adb, s-taskin.ads, s-tasque.adb,
	s-tasque.ads, s-tasren.adb, s-tasren.ads, s-tasres.ads,
	s-tassta.adb, s-tassta.ads, s-tasuti.adb, s-tasuti.ads,
	s-tataat.adb, s-tataat.ads, s-tpinop.adb, s-tpinop.ads,
	s-tpoben.adb, s-tpoben.ads, s-tpobop.adb, s-tpobop.ads,
	s-tposen.adb, s-tposen.ads, s-traceb.adb, s-traceb.ads,
	stringt.adb, stringt.ads, stringt.h, style.ads,
	stylesw.adb, stylesw.ads, s-unstyp.ads, s-vaflop.ads,
	s-valrea.adb, s-valuti.adb, s-vercon.adb, s-vmexta.adb,
	s-wchcnv.ads, s-wchcon.ads, s-widcha.adb, switch.adb,
	switch.ads, switch-b.adb, switch-c.adb, switch-m.adb,
	s-wwdcha.adb, s-wwdwch.adb, sysdep.c, system.ads,
	table.adb, table.ads, targparm.adb, targparm.ads,
	targtyps.c, tbuild.adb, tbuild.ads, tracebak.c,
	trans.c, tree_io.adb, treepr.adb, treeprs.adt,
	ttypes.ads, types.ads, types.h, uintp.adb,
	uintp.ads, uintp.h, uname.adb, urealp.adb,
	urealp.ads, urealp.h, usage.adb, utils2.c,
	utils.c, validsw.adb, validsw.ads, widechar.adb,
	xeinfo.adb, xnmake.adb, xref_lib.adb, xref_lib.ads,
	xr_tabls.adb, xr_tabls.ads, xtreeprs.adb, xsnames.adb,
	einfo.h, sinfo.h, treeprs.ads, nmake.ads, nmake.adb,
	gnatvsn.ads: Merge with ACT tree.

	* gnatvsn.adb: Rewritten in a simpler and more efficient way.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@72751 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 545 insertions, 10 deletions

diff --git a/gcc/ada/a-tifiio.adb b/gcc/ada/a-tifiio.adb
index a1b3badd96b..52f8e706458 100644
--- a/gcc/ada/a-tifiio.adb
+++ b/gcc/ada/a-tifiio.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-1999 Free Software Foundation, Inc.          --
+--          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -31,19 +31,284 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
+--  Fixed point I/O
+--  ---------------
+
+--  The following documents implementation details of the fixed point
+--  input/output routines in the GNAT run time. The first part describes
+--  general properties of fixed point types as defined by the Ada 95 standard,
+--  including the Information Systems Annex.
+
+--  Subsequently these are reduced to implementation constraints and the impact
+--  of these constraints on a few possible approaches to I/O are given.
+--  Based on this analysis, a specific implementation is selected for use in
+--  the GNAT run time. Finally, the chosen algorithm is analyzed numerically in
+--  order to provide user-level documentation on limits for range and precision
+--  of fixed point types as well as accuracy of input/output conversions.
+
+--  -------------------------------------------
+--  - General Properties of Fixed Point Types -
+--  -------------------------------------------
+
+--  Operations on fixed point values, other than input and output, are not
+--  important for the purposes of this document. Only the set of values that a
+--  fixed point type can represent and the input and output operations are
+--  significant.
+
+--  Values
+--  ------
+
+--  Set set of values of a fixed point type comprise the integral
+--  multiples of a number called the small of the type. The small can
+--  either be a power of ten, a power of two or (if the implementation
+--  allows) an arbitrary strictly positive real value.
+
+--  Implementations need to support fixed-point types with a precision
+--  of at least 24 bits, and (in order to comply with the Information
+--  Systems Annex) decimal types need to support at least digits 18.
+--  For the rest, however, no requirements exist for the minimal small
+--  and range that need to be supported.
+
+--  Operations
+--  ----------
+
+--  'Image and 'Wide_Image (see RM 3.5(34))
+
+--          These attributes return a decimal real literal best approximating
+--          the value (rounded away from zero if halfway between) with a
+--          single leading character that is either a minus sign or a space,
+--          one or more digits before the decimal point (with no redundant
+--          leading zeros), a decimal point, and N digits after the decimal
+--          point. For a subtype S, the value of N is S'Aft, the smallest
+--          positive integer such that (10**N)*S'Delta is greater or equal to
+--          one, see RM 3.5.10(5).
+
+--          For an arbitrary small, this means large number arithmetic needs
+--          to be performed.
+
+--  Put (see RM A.10.9(22-26))
+
+--          The requirements for Put add no extra constraints over the image
+--          attributes, although it would be nice to be able to output more
+--          than S'Aft digits after the decimal point for values of subtype S.
+
+--  'Value and 'Wide_Value attribute (RM 3.5(40-55))
+
+--          Since the input can be given in any base in the range 2..16,
+--          accurate conversion to a fixed point number may require
+--          arbitrary precision arithmetic if there is no limit on the
+--          magnitude of the small of the fixed point type.
+
+--  Get (see RM A.10.9(12-21))
+
+--          The requirements for Get are identical to those of the Value
+--          attribute.
+
+--  ------------------------------
+--  - Implementation Constraints -
+--  ------------------------------
+
+--  The requirements listed above for the input/output operations lead to
+--  significant complexity, if no constraints are put on supported smalls.
+
+--  Implementation Strategies
+--  -------------------------
+
+--  * Float arithmetic
+--  * Arbitrary-precision integer arithmetic
+--  * Fixed-precision integer arithmetic
+
+--  Although it seems convenient to convert fixed point numbers to floating-
+--  point and then print them, this leads to a number of restrictions.
+--  The first one is precision. The widest floating-point type generally
+--  available has 53 bits of mantissa. This means that Fine_Delta cannot
+--  be less than 2.0**(-53).
+
+--  In GNAT, Fine_Delta is 2.0**(-63), and Duration for example is a
+--  64-bit type. It would still be possible to use multi-precision
+--  floating-point to perform calculations using longer mantissas,
+--  but this is a much harder approach.
+
+--  The base conversions needed for input and output of (non-decimal)
+--  fixed point types can be seen as pairs of integer multiplications
+--  and divisions.
+
+--  Arbitrary-precision integer arithmetic would be suitable for the job
+--  at hand, but has the draw-back that it is very heavy implementation-wise.
+--  Especially in embedded systems, where fixed point types are often used,
+--  it may not be desirable to require large amounts of storage and time
+--  for fixed I/O operations.
+
+--  Fixed-precision integer arithmetic has the advantage of simplicity and
+--  speed. For the most common fixed point types this would be a perfect
+--  solution. The downside however may be a too limited set of acceptable
+--  fixed point types.
+
+--  Extra Precision
+--  ---------------
+
+--  Using a scaled divide which truncates and returns a remainder R,
+--  another E trailing digits can be calculated by computing the value
+--  (R * (10.0**E)) / Z using another scaled divide. This procedure
+--  can be repeated to compute an arbitrary number of digits in linear
+--  time and storage. The last scaled divide should be rounded, with
+--  a possible carry propagating to the more significant digits, to
+--  ensure correct rounding of the unit in the last place.
+
+--  An extension of this technique is to limit the value of Q to 9 decimal
+--  digits, since 32-bit integers can be much more efficient than 64-bit
+--  integers to output.
+
+with Interfaces;                        use Interfaces;
+with System.Arith_64;                   use System.Arith_64;
+with System.Img_Real;                   use System.Img_Real;
+with Ada.Text_IO;                       use Ada.Text_IO;
 with Ada.Text_IO.Float_Aux;
+with Ada.Text_IO.Generic_Aux;
 
 package body Ada.Text_IO.Fixed_IO is
 
-   --  Note: we use the floating-point I/O routines for input/output of
-   --  ordinary fixed-point. This works fine for fixed-point declarations
-   --  whose mantissa is no longer than the mantissa of Long_Long_Float,
-   --  and we simply consider that we have only partial support for fixed-
-   --  point types with larger mantissas (this situation will not arise on
-   --  the x86, but it will rise on machines only supporting IEEE long).
+   --  Note: we still use the floating-point I/O routines for input of
+   --  ordinary fixed-point and output using exponent format. This will
+   --  result in inaccuracies for fixed point types with a small that is
+   --  not a power of two, and for types that require more precision than
+   --  is available in Long_Long_Float.
 
    package Aux renames Ada.Text_IO.Float_Aux;
 
+   Extra_Layout_Space : constant Field := 5 + Num'Fore;
+   --  Extra space that may be needed for output of sign, decimal point,
+   --  exponent indication and mandatory decimals after and before the
+   --  decimal point. A string with length
+
+   --    Fore + Aft + Exp + Extra_Layout_Space
+
+   --  is always long enough for formatting any fixed point number.
+
+   --  Implementation of Put routines
+
+   --  The following section describes a specific implementation choice for
+   --  performing base conversions needed for output of values of a fixed
+   --  point type T with small T'Small. The goal is to be able to output
+   --  all values of types with a precision of 64 bits and a delta of at
+   --  least 2.0**(-63), as these are current GNAT limitations already.
+
+   --  The chosen algorithm uses fixed precision integer arithmetic for
+   --  reasons of simplicity and efficiency. It is important to understand
+   --  in what ways the most simple and accurate approach to fixed point I/O
+   --  is limiting, before considering more complicated schemes.
+
+   --  Without loss of generality assume T has a range (-2.0**63) * T'Small
+   --  .. (2.0**63 - 1) * T'Small, and is output with Aft digits after the
+   --  decimal point and T'Fore - 1 before. If T'Small is integer, or
+   --  1.0 / T'Small is integer, let S = T'Small and E = 0. For other T'Small,
+   --  let S and E be integers such that S / 10**E best approximates T'Small
+   --  and S is in the range 10**17 .. 10**18 - 1. The extra decimal scaling
+   --  factor 10**E can be trivially handled during final output, by adjusting
+   --  the decimal point or exponent.
+
+   --  Convert a value X * S of type T to a 64-bit integer value Q equal
+   --  to 10.0**D * (X * S) rounded to the nearest integer.
+   --  This conversion is a scaled integer divide of the form
+
+   --     Q := (X * Y) / Z,
+
+   --  where all variables are 64-bit signed integers using 2's complement,
+   --  and both the multiplication and division are done using full
+   --  intermediate precision. The final decimal value to be output is
+
+   --     Q * 10**(E-D)
+
+   --  This value can be written to the output file or to the result string
+   --  according to the format described in RM A.3.10. The details of this
+   --  operation are omitted here.
+
+   --  A 64-bit value can contain all integers with 18 decimal digits, but
+   --  not all with 19 decimal digits. If the total number of requested output
+   --  digits (Fore - 1) + Aft is greater than 18, for purposes of the
+   --  conversion Aft is adjusted to 18 - (Fore - 1). In that case, or
+   --  when Fore > 19, trailing zeros can complete the output after writing
+   --  the first 18 significant digits, or the technique described in the
+   --  next section can be used.
+
+   --  The final expression for D is
+
+   --     D :=  Integer'Max (-18, Integer'Min (Aft, 18 - (Fore - 1)));
+
+   --  For Y and Z the following expressions can be derived:
+
+   --     Q / (10.0**D) = X * S
+
+   --     Q = X * S * (10.0**D) = (X * Y) / Z
+
+   --     S * 10.0**D = Y / Z;
+
+   --  If S is an integer greater than or equal to one, then Fore must be at
+   --  least 20 in order to print T'First, which is at most -2.0**63.
+   --  This means D < 0, so use
+
+   --    (1)   Y = -S and Z = -10**(-D).
+
+   --  If 1.0 / S is an integer greater than one, use
+
+   --    (2)   Y = -10**D and Z = -(1.0 / S), for D >= 0
+
+   --  or
+
+   --    (3)   Y = 1 and Z = (1.0 / S) * 10**(-D), for D < 0
+
+   --  Negative values are used for nominator Y and denominator Z, so that S
+   --  can have a maximum value of 2.0**63 and a minimum of 2.0**(-63).
+   --  For Z in -1 .. -9, Fore will still be 20, and D will be negative, as
+   --  (-2.0**63) / -9 is greater than 10**18. In these cases there is room
+   --  in the denominator for the extra decimal scaling required, so case (3)
+   --  will not overflow.
+
+   pragma Assert (System.Fine_Delta >= 2.0**(-63));
+   pragma Assert (Num'Small in 2.0**(-63) .. 2.0**63);
+   pragma Assert (Num'Fore <= 37);
+   --  These assertions need to be relaxed to allow for a Small of
+   --  2.0**(-64) at least, since there is an ACATS test for this ???
+
+   Max_Digits : constant := 18;
+   --  Maximum number of decimal digits that can be represented in a
+   --  64-bit signed number, see above
+
+   --  The constants E0 .. E5 implement a binary search for the appropriate
+   --  power of ten to scale the small so that it has one digit before the
+   --  decimal point.
+
+   subtype Int is Integer;
+   E0 : constant Int := -20 * Boolean'Pos (Num'Small >= 1.0E1);
+   E1 : constant Int := E0 + 10 * Boolean'Pos (Num'Small * 10.0**E0 < 1.0E-10);
+   E2 : constant Int := E1 +  5 * Boolean'Pos (Num'Small * 10.0**E1 < 1.0E-5);
+   E3 : constant Int := E2 +  3 * Boolean'Pos (Num'Small * 10.0**E2 < 1.0E-3);
+   E4 : constant Int := E3 +  2 * Boolean'Pos (Num'Small * 10.0**E3 < 1.0E-1);
+   E5 : constant Int := E4 +  1 * Boolean'Pos (Num'Small * 10.0**E4 < 1.0E-0);
+
+   Scale : constant Integer := E5;
+
+   pragma Assert (Num'Small * 10.0**Scale >= 1.0
+                   and then Num'Small * 10.0**Scale < 10.0);
+
+   Exact : constant Boolean :=
+                Float'Floor (Num'Small) = Float'Ceiling (Num'Small)
+            or Float'Floor (1.0 / Num'Small) = Float'Ceiling (1.0 / Num'Small)
+            or Num'Small >= 10.0**Max_Digits;
+   --  True iff a numerator and denominator can be calculated such that
+   --  their ratio exactly represents the small of Num
+
+   --  Local Subprograms
+
+   procedure Put
+     (To   : out String;
+      Last : out Natural;
+      Item : Num;
+      Fore : Field;
+      Aft  : Field;
+      Exp  : Field);
+   --  Actual output function, used internally by all other Put routines
+
    ---------
    -- Get --
    ---------
@@ -100,8 +365,11 @@ package body Ada.Text_IO.Fixed_IO is
       Aft  : in Field := Default_Aft;
       Exp  : in Field := Default_Exp)
    is
+      S    : String (1 .. Fore + Aft + Exp + Extra_Layout_Space);
+      Last : Natural;
    begin
-      Aux.Put (File, Long_Long_Float (Item), Fore, Aft, Exp);
+      Put (S, Last, Item, Fore, Aft, Exp);
+      Generic_Aux.Put_Item (File, S (1 .. Last));
    end Put;
 
    procedure Put
@@ -110,8 +378,11 @@ package body Ada.Text_IO.Fixed_IO is
       Aft  : in Field := Default_Aft;
       Exp  : in Field := Default_Exp)
    is
+      S    : String (1 .. Fore + Aft + Exp + Extra_Layout_Space);
+      Last : Natural;
    begin
-      Aux.Put (Current_Out, Long_Long_Float (Item), Fore, Aft, Exp);
+      Put (S, Last, Item, Fore, Aft, Exp);
+      Generic_Aux.Put_Item (Text_IO.Current_Out, S (1 .. Last));
    end Put;
 
    procedure Put
@@ -120,8 +391,272 @@ package body Ada.Text_IO.Fixed_IO is
       Aft  : in Field := Default_Aft;
       Exp  : in Field := Default_Exp)
    is
+      Fore : constant Integer := To'Length
+                                - 1                      -- Decimal point
+                                - Field'Max (1, Aft)     -- Decimal part
+                                - Boolean'Pos (Exp /= 0) -- Exponent indicator
+                                - Exp;                   -- Exponent
+      Last : Natural;
+
    begin
-      Aux.Puts (To, Long_Long_Float (Item), Aft, Exp);
+      if Fore not in Field'Range then
+         raise Layout_Error;
+      end if;
+
+      Put (To, Last, Item, Fore, Aft, Exp);
+
+      if Last /= To'Last then
+         raise Layout_Error;
+      end if;
+   end Put;
+
+   procedure Put
+     (To   : out String;
+      Last : out Natural;
+      Item : Num;
+      Fore : Field;
+      Aft  : Field;
+      Exp  : Field)
+   is
+      subtype Digit is Int64 range 0 .. 9;
+      X     : constant Int64   := Int64'Integer_Value (Item);
+      A     : constant Field   := Field'Max (Aft, 1);
+      Neg   : constant Boolean := (Item < 0.0);
+      Pos   : Integer;  -- Next digit X has value X * 10.0**Pos;
+
+      Y, Z : Int64;
+      E : constant Integer := Boolean'Pos (not Exact)
+                                *  (Max_Digits - 1 + Scale);
+      D : constant Integer := Boolean'Pos (Exact)
+                                * Integer'Min (A, Max_Digits - (Num'Fore - 1))
+                            + Boolean'Pos (not Exact)
+                                * (Scale - 1);
+
+
+      procedure Put_Character (C : Character);
+      pragma Inline (Put_Character);
+      --  Add C to the output string To, updating Last
+
+      procedure Put_Digit (X : Digit);
+      --  Add digit X to the output string (going from left to right),
+      --  updating Last and Pos, and inserting the sign, leading zeroes
+      --  or a decimal point when necessary. After outputting the first
+      --  digit, Pos must not be changed outside Put_Digit anymore
+
+      procedure Put_Int64 (X : Int64; Scale : Integer);
+      --  Output the decimal number X * 10**Scale
+
+      procedure Put_Scaled
+        (X, Y, Z : Int64;
+         A       : Field;
+         E       : Integer);
+      --  Output the decimal number (X * Y / Z) * 10**E, producing A digits
+      --  after the decimal point and rounding the final digit. The value
+      --  X * Y / Z is computed with full precision, but must be in the
+      --  range of Int64.
+
+      -------------------
+      -- Put_Character --
+      -------------------
+
+      procedure Put_Character (C : Character) is
+      begin
+         Last := Last + 1;
+         To (Last) := C;
+      end Put_Character;
+
+      ---------------
+      -- Put_Digit --
+      ---------------
+
+      procedure Put_Digit (X : Digit) is
+         Digs : constant array (Digit) of Character := "0123456789";
+      begin
+         if Last = 0 then
+            if X /= 0 or Pos <= 0 then
+               --  Before outputting first digit, include leading space,
+               --  posible minus sign and, if the first digit is fractional,
+               --  decimal seperator and leading zeros.
+
+               --  The Fore part has Pos + 1 + Boolean'Pos (Neg) characters,
+               --  if Pos >= 0 and otherwise has a single zero digit plus minus
+               --  sign if negative. Add leading space if necessary.
+
+               for J in Integer'Max (0, Pos) + 2 + Boolean'Pos (Neg) .. Fore
+               loop
+                  Put_Character (' ');
+               end loop;
+
+               --  Output minus sign, if number is negative
+
+               if Neg then
+                  Put_Character ('-');
+               end if;
+
+               --  If starting with fractional digit, output leading zeros
+
+               if Pos < 0 then
+                  Put_Character ('0');
+                  Put_Character ('.');
+
+                  for J in Pos .. -2 loop
+                     Put_Character ('0');
+                  end loop;
+               end if;
+
+               Put_Character (Digs (X));
+            end if;
+
+         else
+            --  This is not the first digit to be output, so the only
+            --  special handling is that for the decimal point
+
+            if Pos = -1 then
+               Put_Character ('.');
+            end if;
+
+            Put_Character (Digs (X));
+         end if;
+
+         Pos := Pos - 1;
+      end Put_Digit;
+
+      ---------------
+      -- Put_Int64 --
+      ---------------
+
+      procedure Put_Int64 (X : Int64; Scale : Integer) is
+      begin
+         if X = 0 then
+            return;
+         end if;
+
+         Pos := Scale;
+
+         if X not in -9 .. 9 then
+            Put_Int64 (X / 10, Scale + 1);
+         end if;
+
+         Put_Digit (abs (X rem 10));
+      end Put_Int64;
+
+      ----------------
+      -- Put_Scaled --
+      ----------------
+
+      procedure Put_Scaled
+        (X, Y, Z : Int64;
+         A       : Field;
+         E       : Integer)
+      is
+         N  : constant Natural := (A + Max_Digits - 1) / Max_Digits + 1;
+         pragma Debug (Put_Line ("N =" & N'Img));
+         Q  : array (1 .. N) of Int64 := (others => 0);
+
+         XX : Int64 := X;
+         YY : Int64 := Y;
+         AA : Field := A;
+
+      begin
+         for J in Q'Range loop
+            exit when XX = 0;
+
+            Scaled_Divide (XX, YY, Z, Q (J), XX, Round => AA = 0);
+
+            --  As the last block of digits is rounded, a carry may have to
+            --  be propagated to the more significant digits. Since the last
+            --  block may have less than Max_Digits, the test for this block
+            --  is specialized.
+
+            --  The absolute value of the left-most digit block may equal
+            --  10*Max_Digits, as no carry can be propagated from there.
+            --  The final output routines need to be prepared to handle
+            --  this specific case.
+
+            if (Q (J) = YY or -Q (J) = YY) and then J > Q'First then
+               if Q (J) < 0 then
+                  Q (J - 1) := Q (J - 1) + 1;
+               else
+                  Q (J - 1) := Q (J - 1) - 1;
+               end if;
+
+               Q (J) := 0;
+
+               Propagate_Carry :
+               for J in reverse Q'First + 1 .. Q'Last loop
+                  if Q (J) >= 10**Max_Digits then
+                     Q (J - 1) := Q (J - 1) + 1;
+                     Q (J) := Q (J) - 10**Max_Digits;
+
+                  elsif Q (J) <= -10**Max_Digits then
+                     Q (J - 1) := Q (J - 1) - 1;
+                     Q (J) := Q (J) + 10**Max_Digits;
+                  end if;
+               end loop Propagate_Carry;
+            end if;
+
+            YY := -10**Integer'Min (Max_Digits, AA);
+            AA := AA - Integer'Min (Max_Digits, AA);
+         end loop;
+
+         for J in Q'First .. Q'Last - 1 loop
+            Put_Int64 (Q (J), E - (J - Q'First) * Max_Digits);
+         end loop;
+
+         Put_Int64 (Q (Q'Last), E - A);
+      end Put_Scaled;
+
+   --  Start of processing for Put
+
+   begin
+      Last := To'First - 1;
+
+      if Exp /= 0 then
+
+         --  With the Exp format, it is not known how many output digits to
+         --  generate, as leading zeros must be ignored. Computing too many
+         --  digits and then truncating the output will not give the closest
+         --  output, it is necessary to round at the correct digit.
+
+         --  The general approach is as follows: as long as no digits have
+         --  been generated, compute the Aft next digits (without rounding).
+         --  Once a non-zero digit is generated, determine the exact number
+         --  of digits remaining and compute them with rounding.
+         --  Since a large number of iterations might be necessary in case
+         --  of Aft = 1, the following optimization would be desirable.
+         --  Count the number Z of leading zero bits in the integer
+         --  representation of X, and start with producing
+         --  Aft + Z * 1000 / 3322 digits in the first scaled division.
+
+         --  However, the floating-point routines are still used now ???
+
+         System.Img_Real.Set_Image_Real (Long_Long_Float (Item), To, Last,
+            Fore, Aft, Exp);
+         return;
+      end if;
+
+      if Exact then
+         Y := Int64'Min (Int64 (-Num'Small), -1) * 10**Integer'Max (0, D);
+         Z := Int64'Min (Int64 (-1.0 / Num'Small), -1)
+                                                 * 10**Integer'Max (0, -D);
+      else
+         Y := Int64 (-Num'Small * 10.0**E);
+         Z := -10**Max_Digits;
+      end if;
+
+      Put_Scaled (X, Y, Z, A - D, -D);
+
+      --  If only zero digits encountered, unit digit has not been output yet
+
+      if Last < To'First then
+         Pos := 0;
+      end if;
+
+      --  Always output digits up to the first one after the decimal point
+
+      while Pos >= -A loop
+         Put_Digit (0);
+      end loop;
    end Put;
 
 end Ada.Text_IO.Fixed_IO;