2023-06-09 01:41:37 +03:00
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
< html >
< head >
< title > Mathematics Template< / title >
< link href = "../docs-assets/Breadcrumbs.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< meta name = "viewport" content = "width=device-width initial-scale=1" >
< meta http-equiv = "Content-Type" content = "text/html; charset=utf-8" >
< meta http-equiv = "Content-Language" content = "en-gb" >
< link href = "../docs-assets/Contents.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< link href = "../docs-assets/Progress.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< link href = "../docs-assets/Navigation.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< link href = "../docs-assets/Fonts.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< link href = "../docs-assets/Base.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< script >
MathJax = {
tex: {
inlineMath: '$', '$'], ['\\(', '\\)'
},
svg: {
fontCache: 'global'
}
};
< / script >
< script type = "text/javascript" id = "MathJax-script" async
src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js">
< / script >
< link href = "../docs-assets/Colours.css" rel = "stylesheet" rev = "stylesheet" type = "text/css" >
< / head >
< body class = "commentary-font" >
< nav role = "navigation" >
< h1 > < a href = "../index.html" >
< img src = "../docs-assets/Inform.png" height = 72" >
< / a > < / h1 >
< ul > < li > < a href = "../index.html" > home< / a > < / li >
< / ul > < h2 > Compiler< / h2 > < ul >
< li > < a href = "../structure.html" > structure< / a > < / li >
< li > < a href = "../inbuildn.html" > inbuild< / a > < / li >
< li > < a href = "../inform7n.html" > inform7< / a > < / li >
< li > < a href = "../intern.html" > inter< / a > < / li >
< li > < a href = "../services.html" > services< / a > < / li >
< li > < a href = "../secrets.html" > secrets< / a > < / li >
< / ul > < h2 > Other Tools< / h2 > < ul >
< li > < a href = "../inblorbn.html" > inblorb< / a > < / li >
< li > < a href = "../indocn.html" > indoc< / a > < / li >
< li > < a href = "../inform6.html" > inform6< / a > < / li >
< li > < a href = "../inpolicyn.html" > inpolicy< / a > < / li >
< li > < a href = "../inrtpsn.html" > inrtps< / a > < / li >
< / ul > < h2 > Resources< / h2 > < ul >
< li > < a href = "../extensions.html" > extensions< / a > < / li >
< li > < a href = "../kits.html" > kits< / a > < / li >
< / ul > < h2 > Repository< / h2 > < ul >
< li > < a href = "https://github.com/ganelson/inform" > < img src = "../docs-assets/github.png" height = 18 > github< / a > < / li >
< / ul > < h2 > Related Projects< / h2 > < ul >
< li > < a href = "../../../inweb/index.html" > inweb< / a > < / li >
< li > < a href = "../../../intest/index.html" > intest< / a > < / li >
< / ul >
< / nav >
< main role = "main" >
<!-- Weave of 'Mathematics Template' generated by Inweb -->
< div class = "breadcrumbs" >
< ul class = "crumbs" > < li > < a href = "../index.html" > Home< / a > < / li > < li > < a href = "../extensions.html" > Kits< / a > < / li > < li > < a href = "index.html" > Architecture16Kit< / a > < / li > < li > < b > Mathematics Template< / b > < / li > < / ul > < / div >
< p class = "purpose" > Mathematical functions.< / p >
< ul class = "toc" > < li > < a href = "S-mth.html#SP1" > § 1. Unsigned integer comparison< / a > < / li > < li > < a href = "S-mth.html#SP2" > § 2. Integer roots< / a > < / li > < li > < a href = "S-mth.html#SP3" > § 3. Real number support< / a > < / li > < / ul > < hr class = "tocbar" >
< p class = "commentary firstcommentary" > < a id = "SP1" class = "paragraph-anchor" > < / a > < b > § 1. Unsigned integer comparison. < / b > Comparison of integers is normally signed, that is, treating the word as
a twos-complement signed number, so that < span class = "extract" > < span class = "extract-syntax" > $FFFF< / span > < / span > is less than < span class = "extract" > < span class = "extract-syntax" > 0< / span > < / span > , for
instance. If we want to construe words as being unsigned integers, or as
addresses, we need to compare them with the following routine, which returns
1 if \(x> y\), 0 if \(x=y\) and \(-1\) if \(x< y\).
< / p >
< pre class = "displayed-code all-displayed-code code-font" >
< span class = "plain-syntax" > [ < / span > < span class = "identifier-syntax" > UnsignedCompare< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > x< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > y< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > u< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > v< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > if< / span > < span class = "plain-syntax" > (< / span > < span class = "identifier-syntax" > x< / span > < span class = "plain-syntax" > == < / span > < span class = "identifier-syntax" > y< / span > < span class = "plain-syntax" > ) < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > if< / span > < span class = "plain-syntax" > (< / span > < span class = "identifier-syntax" > x< / span > < span class = "plain-syntax" > < < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > & & < / span > < span class = "identifier-syntax" > y< / span > < span class = "plain-syntax" > > = < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > ) < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "constant-syntax" > 1< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > if< / span > < span class = "plain-syntax" > (< / span > < span class = "identifier-syntax" > x< / span > < span class = "plain-syntax" > > = < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > & & < / span > < span class = "identifier-syntax" > y< / span > < span class = "plain-syntax" > < < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > ) < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > -1;< / span >
< span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > u< / span > < span class = "plain-syntax" > = < / span > < span class = "identifier-syntax" > x< / span > < span class = "plain-syntax" > & ~< / span > < span class = "identifier-syntax" > WORD_HIGHBIT< / span > < span class = "plain-syntax" > ; < / span > < span class = "identifier-syntax" > v< / span > < span class = "plain-syntax" > = < / span > < span class = "identifier-syntax" > y< / span > < span class = "plain-syntax" > & ~< / span > < span class = "identifier-syntax" > WORD_HIGHBIT< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > if< / span > < span class = "plain-syntax" > (< / span > < span class = "identifier-syntax" > u< / span > < span class = "plain-syntax" > > < / span > < span class = "identifier-syntax" > v< / span > < span class = "plain-syntax" > ) < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "constant-syntax" > 1< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > -1;< / span >
< span class = "plain-syntax" > ];< / span >
< / pre >
< p class = "commentary firstcommentary" > < a id = "SP2" class = "paragraph-anchor" > < / a > < b > § 2. Integer roots. < / b > We are unable to provide VM support for taking square or cube roots rapidly:
< / p >
< pre class = "displayed-code all-displayed-code code-font" >
< span class = "plain-syntax" > [ < / span > < span class = "identifier-syntax" > VM_SquareRoot< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > num< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > ];< / span >
< span class = "plain-syntax" > [ < / span > < span class = "identifier-syntax" > VM_CubeRoot< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > num< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "constant-syntax" > 0< / span > < span class = "plain-syntax" > ;< / span >
< span class = "plain-syntax" > ];< / span >
< / pre >
< p class = "commentary firstcommentary" > < a id = "SP3" class = "paragraph-anchor" > < / a > < b > § 3. Real number support. < / b > These need to exist, but are likely never to be used.
< / p >
< pre class = "displayed-code all-displayed-code code-font" >
< span class = "plain-syntax" > [ < / span > < span class = "identifier-syntax" > REAL_NUMBER_TY_Say< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > real< / span > < span class = "plain-syntax" > ; < / span > < span class = "reserved-syntax" > print< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > real< / span > < span class = "plain-syntax" > ; ];< / span >
< span class = "plain-syntax" > [ < / span > < span class = "identifier-syntax" > REAL_NUMBER_TY_Compare< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > r1< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > r2< / span > < span class = "plain-syntax" > ; < / span > < span class = "reserved-syntax" > return< / span > < span class = "plain-syntax" > < / span > < span class = "identifier-syntax" > UnsignedCompare< / span > < span class = "plain-syntax" > (< / span > < span class = "identifier-syntax" > r1< / span > < span class = "plain-syntax" > , < / span > < span class = "identifier-syntax" > r2< / span > < span class = "plain-syntax" > ); ];< / span >
< / pre >
< nav role = "progress" > < div class = "progresscontainer" >
2023-06-10 11:36:17 +03:00
< ul class = "progressbar" > < li class = "progressprev" > < a href = "S-stt.html" > ❮ < / a > < / li > < li class = "progresssection" > < a href = "S-cpb.html" > cpb< / a > < / li > < li class = "progresssection" > < a href = "S-str.html" > str< / a > < / li > < li class = "progresssection" > < a href = "S-stt.html" > stt< / a > < / li > < li class = "progresscurrent" > mth< / li > < li class = "progresssection" > < a href = "S-cs.html" > cs< / a > < / li > < li class = "progresssection" > < a href = "S-io.html" > io< / a > < / li > < li class = "progresssection" > < a href = "S-fio.html" > fio< / a > < / li > < li class = "progresssection" > < a href = "S-vnr.html" > vnr< / a > < / li > < li class = "progressnext" > < a href = "S-cs.html" > ❯ < / a > < / li > < / ul > < / div >
2023-06-09 01:41:37 +03:00
< / nav > <!-- End of weave -->
< / main >
< / body >
< / html >