blob: 45f58c65a2c225b07638ae5c26b66c546c6d9128 [file] [log] [blame]
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="Asciidoctor 1.5.8">
<meta name="author" content="Khronos&#174; OpenCL Working Group">
<title>The OpenCL&#8482; Extension Specification</title>
<style>
/*! normalize.css v2.1.2 | MIT License | git.io/normalize */
/* ========================================================================== HTML5 display definitions ========================================================================== */
/** Correct `block` display not defined in IE 8/9. */
article, aside, details, figcaption, figure, footer, header, hgroup, main, nav, section, summary { display: block; }
/** Correct `inline-block` display not defined in IE 8/9. */
audio, canvas, video { display: inline-block; }
/** Prevent modern browsers from displaying `audio` without controls. Remove excess height in iOS 5 devices. */
audio:not([controls]) { display: none; height: 0; }
/** Address `[hidden]` styling not present in IE 8/9. Hide the `template` element in IE, Safari, and Firefox < 22. */
[hidden], template { display: none; }
script { display: none !important; }
/* ========================================================================== Base ========================================================================== */
/** 1. Set default font family to sans-serif. 2. Prevent iOS text size adjust after orientation change, without disabling user zoom. */
html { font-family: sans-serif; /* 1 */ -ms-text-size-adjust: 100%; /* 2 */ -webkit-text-size-adjust: 100%; /* 2 */ }
/** Remove default margin. */
body { margin: 0; }
/* ========================================================================== Links ========================================================================== */
/** Remove the gray background color from active links in IE 10. */
a { background: transparent; }
/** Address `outline` inconsistency between Chrome and other browsers. */
a:focus { outline: thin dotted; }
/** Improve readability when focused and also mouse hovered in all browsers. */
a:active, a:hover { outline: 0; }
/* ========================================================================== Typography ========================================================================== */
/** Address variable `h1` font-size and margin within `section` and `article` contexts in Firefox 4+, Safari 5, and Chrome. */
h1 { font-size: 2em; margin: 0.67em 0; }
/** Address styling not present in IE 8/9, Safari 5, and Chrome. */
abbr[title] { border-bottom: 1px dotted; }
/** Address style set to `bolder` in Firefox 4+, Safari 5, and Chrome. */
b, strong { font-weight: bold; }
/** Address styling not present in Safari 5 and Chrome. */
dfn { font-style: italic; }
/** Address differences between Firefox and other browsers. */
hr { -moz-box-sizing: content-box; box-sizing: content-box; height: 0; }
/** Address styling not present in IE 8/9. */
mark { background: #ff0; color: #000; }
/** Correct font family set oddly in Safari 5 and Chrome. */
code, kbd, pre, samp { font-family: monospace, serif; font-size: 1em; }
/** Improve readability of pre-formatted text in all browsers. */
pre { white-space: pre-wrap; }
/** Set consistent quote types. */
q { quotes: "\201C" "\201D" "\2018" "\2019"; }
/** Address inconsistent and variable font size in all browsers. */
small { font-size: 80%; }
/** Prevent `sub` and `sup` affecting `line-height` in all browsers. */
sub, sup { font-size: 75%; line-height: 0; position: relative; vertical-align: baseline; }
sup { top: -0.5em; }
sub { bottom: -0.25em; }
/* ========================================================================== Embedded content ========================================================================== */
/** Remove border when inside `a` element in IE 8/9. */
img { border: 0; }
/** Correct overflow displayed oddly in IE 9. */
svg:not(:root) { overflow: hidden; }
/* ========================================================================== Figures ========================================================================== */
/** Address margin not present in IE 8/9 and Safari 5. */
figure { margin: 0; }
/* ========================================================================== Forms ========================================================================== */
/** Define consistent border, margin, and padding. */
fieldset { border: 1px solid #c0c0c0; margin: 0 2px; padding: 0.35em 0.625em 0.75em; }
/** 1. Correct `color` not being inherited in IE 8/9. 2. Remove padding so people aren't caught out if they zero out fieldsets. */
legend { border: 0; /* 1 */ padding: 0; /* 2 */ }
/** 1. Correct font family not being inherited in all browsers. 2. Correct font size not being inherited in all browsers. 3. Address margins set differently in Firefox 4+, Safari 5, and Chrome. */
button, input, select, textarea { font-family: inherit; /* 1 */ font-size: 100%; /* 2 */ margin: 0; /* 3 */ }
/** Address Firefox 4+ setting `line-height` on `input` using `!important` in the UA stylesheet. */
button, input { line-height: normal; }
/** Address inconsistent `text-transform` inheritance for `button` and `select`. All other form control elements do not inherit `text-transform` values. Correct `button` style inheritance in Chrome, Safari 5+, and IE 8+. Correct `select` style inheritance in Firefox 4+ and Opera. */
button, select { text-transform: none; }
/** 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio` and `video` controls. 2. Correct inability to style clickable `input` types in iOS. 3. Improve usability and consistency of cursor style between image-type `input` and others. */
button, html input[type="button"], input[type="reset"], input[type="submit"] { -webkit-appearance: button; /* 2 */ cursor: pointer; /* 3 */ }
/** Re-set default cursor for disabled elements. */
button[disabled], html input[disabled] { cursor: default; }
/** 1. Address box sizing set to `content-box` in IE 8/9. 2. Remove excess padding in IE 8/9. */
input[type="checkbox"], input[type="radio"] { box-sizing: border-box; /* 1 */ padding: 0; /* 2 */ }
/** 1. Address `appearance` set to `searchfield` in Safari 5 and Chrome. 2. Address `box-sizing` set to `border-box` in Safari 5 and Chrome (include `-moz` to future-proof). */
input[type="search"] { -webkit-appearance: textfield; /* 1 */ -moz-box-sizing: content-box; -webkit-box-sizing: content-box; /* 2 */ box-sizing: content-box; }
/** Remove inner padding and search cancel button in Safari 5 and Chrome on OS X. */
input[type="search"]::-webkit-search-cancel-button, input[type="search"]::-webkit-search-decoration { -webkit-appearance: none; }
/** Remove inner padding and border in Firefox 4+. */
button::-moz-focus-inner, input::-moz-focus-inner { border: 0; padding: 0; }
/** 1. Remove default vertical scrollbar in IE 8/9. 2. Improve readability and alignment in all browsers. */
textarea { overflow: auto; /* 1 */ vertical-align: top; /* 2 */ }
/* ========================================================================== Tables ========================================================================== */
/** Remove most spacing between table cells. */
table { border-collapse: collapse; border-spacing: 0; }
meta.foundation-mq-small { font-family: "only screen and (min-width: 768px)"; width: 768px; }
meta.foundation-mq-medium { font-family: "only screen and (min-width:1280px)"; width: 1280px; }
meta.foundation-mq-large { font-family: "only screen and (min-width:1440px)"; width: 1440px; }
*, *:before, *:after { -moz-box-sizing: border-box; -webkit-box-sizing: border-box; box-sizing: border-box; }
html, body { font-size: 100%; }
body { background: white; color: #222222; padding: 0; margin: 0; font-family: "Helvetica Neue", "Helvetica", Helvetica, Arial, sans-serif; font-weight: normal; font-style: normal; line-height: 1; position: relative; cursor: auto; }
a:hover { cursor: pointer; }
img, object, embed { max-width: 100%; height: auto; }
object, embed { height: 100%; }
img { -ms-interpolation-mode: bicubic; }
#map_canvas img, #map_canvas embed, #map_canvas object, .map_canvas img, .map_canvas embed, .map_canvas object { max-width: none !important; }
.left { float: left !important; }
.right { float: right !important; }
.text-left { text-align: left !important; }
.text-right { text-align: right !important; }
.text-center { text-align: center !important; }
.text-justify { text-align: justify !important; }
.hide { display: none; }
.antialiased { -webkit-font-smoothing: antialiased; }
img { display: inline-block; vertical-align: middle; }
textarea { height: auto; min-height: 50px; }
select { width: 100%; }
object, svg { display: inline-block; vertical-align: middle; }
.center { margin-left: auto; margin-right: auto; }
.spread { width: 100%; }
p.lead, .paragraph.lead > p, #preamble > .sectionbody > .paragraph:first-of-type p { font-size: 1.21875em; line-height: 1.6; }
.subheader, .admonitionblock td.content > .title, .audioblock > .title, .exampleblock > .title, .imageblock > .title, .listingblock > .title, .literalblock > .title, .stemblock > .title, .openblock > .title, .paragraph > .title, .quoteblock > .title, table.tableblock > .title, .verseblock > .title, .videoblock > .title, .dlist > .title, .olist > .title, .ulist > .title, .qlist > .title, .hdlist > .title { line-height: 1.4; color: black; font-weight: 300; margin-top: 0.2em; margin-bottom: 0.5em; }
/* Typography resets */
div, dl, dt, dd, ul, ol, li, h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6, pre, form, p, blockquote, th, td { margin: 0; padding: 0; direction: ltr; }
/* Default Link Styles */
a { color: #0068b0; text-decoration: none; line-height: inherit; }
a:hover, a:focus { color: #333333; }
a img { border: none; }
/* Default paragraph styles */
p { font-family: Noto, sans-serif; font-weight: normal; font-size: 1em; line-height: 1.6; margin-bottom: 0.75em; text-rendering: optimizeLegibility; }
p aside { font-size: 0.875em; line-height: 1.35; font-style: italic; }
/* Default header styles */
h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 { font-family: Noto, sans-serif; font-weight: normal; font-style: normal; color: black; text-rendering: optimizeLegibility; margin-top: 0.5em; margin-bottom: 0.5em; line-height: 1.2125em; }
h1 small, h2 small, h3 small, #toctitle small, .sidebarblock > .content > .title small, h4 small, h5 small, h6 small { font-size: 60%; color: #4d4d4d; line-height: 0; }
h1 { font-size: 2.125em; }
h2 { font-size: 1.6875em; }
h3, #toctitle, .sidebarblock > .content > .title { font-size: 1.375em; }
h4 { font-size: 1.125em; }
h5 { font-size: 1.125em; }
h6 { font-size: 1em; }
hr { border: solid #dddddd; border-width: 1px 0 0; clear: both; margin: 1.25em 0 1.1875em; height: 0; }
/* Helpful Typography Defaults */
em, i { font-style: italic; line-height: inherit; }
strong, b { font-weight: bold; line-height: inherit; }
small { font-size: 60%; line-height: inherit; }
code { font-family: Consolas, "Liberation Mono", Courier, monospace; font-weight: normal; color: #264357; }
/* Lists */
ul, ol, dl { font-size: 1em; line-height: 1.6; margin-bottom: 0.75em; list-style-position: outside; font-family: Noto, sans-serif; }
ul, ol { margin-left: 1.5em; }
ul.no-bullet, ol.no-bullet { margin-left: 1.5em; }
/* Unordered Lists */
ul li ul, ul li ol { margin-left: 1.25em; margin-bottom: 0; font-size: 1em; /* Override nested font-size change */ }
ul.square li ul, ul.circle li ul, ul.disc li ul { list-style: inherit; }
ul.square { list-style-type: square; }
ul.circle { list-style-type: circle; }
ul.disc { list-style-type: disc; }
ul.no-bullet { list-style: none; }
/* Ordered Lists */
ol li ul, ol li ol { margin-left: 1.25em; margin-bottom: 0; }
/* Definition Lists */
dl dt { margin-bottom: 0.3em; font-weight: bold; }
dl dd { margin-bottom: 0.75em; }
/* Abbreviations */
abbr, acronym { text-transform: uppercase; font-size: 90%; color: black; border-bottom: 1px dotted #dddddd; cursor: help; }
abbr { text-transform: none; }
/* Blockquotes */
blockquote { margin: 0 0 0.75em; padding: 0.5625em 1.25em 0 1.1875em; border-left: 1px solid #dddddd; }
blockquote cite { display: block; font-size: 0.8125em; color: #5e93b8; }
blockquote cite:before { content: "\2014 \0020"; }
blockquote cite a, blockquote cite a:visited { color: #5e93b8; }
blockquote, blockquote p { line-height: 1.6; color: #333333; }
/* Microformats */
.vcard { display: inline-block; margin: 0 0 1.25em 0; border: 1px solid #dddddd; padding: 0.625em 0.75em; }
.vcard li { margin: 0; display: block; }
.vcard .fn { font-weight: bold; font-size: 0.9375em; }
.vevent .summary { font-weight: bold; }
.vevent abbr { cursor: auto; text-decoration: none; font-weight: bold; border: none; padding: 0 0.0625em; }
@media only screen and (min-width: 768px) { h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 { line-height: 1.4; }
h1 { font-size: 2.75em; }
h2 { font-size: 2.3125em; }
h3, #toctitle, .sidebarblock > .content > .title { font-size: 1.6875em; }
h4 { font-size: 1.4375em; } }
/* Tables */
table { background: white; margin-bottom: 1.25em; border: solid 1px #d8d8ce; }
table thead, table tfoot { background: -webkit-linear-gradient(top, #add386, #90b66a); font-weight: bold; }
table thead tr th, table thead tr td, table tfoot tr th, table tfoot tr td { padding: 0.5em 0.625em 0.625em; font-size: inherit; color: white; text-align: left; }
table tr th, table tr td { padding: 0.5625em 0.625em; font-size: inherit; color: #6d6e71; }
table tr.even, table tr.alt, table tr:nth-of-type(even) { background: #edf2f2; }
table thead tr th, table tfoot tr th, table tbody tr td, table tr td, table tfoot tr td { display: table-cell; line-height: 1.4; }
body { -moz-osx-font-smoothing: grayscale; -webkit-font-smoothing: antialiased; tab-size: 4; }
h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 { line-height: 1.4; }
a:hover, a:focus { text-decoration: underline; }
.clearfix:before, .clearfix:after, .float-group:before, .float-group:after { content: " "; display: table; }
.clearfix:after, .float-group:after { clear: both; }
*:not(pre) > code { font-size: inherit; font-style: normal !important; letter-spacing: 0; padding: 0; background-color: white; -webkit-border-radius: 0; border-radius: 0; line-height: inherit; word-wrap: break-word; }
*:not(pre) > code.nobreak { word-wrap: normal; }
*:not(pre) > code.nowrap { white-space: nowrap; }
pre, pre > code { line-height: 1.6; color: #264357; font-family: Consolas, "Liberation Mono", Courier, monospace; font-weight: normal; }
em em { font-style: normal; }
strong strong { font-weight: normal; }
.keyseq { color: #333333; }
kbd { font-family: Consolas, "Liberation Mono", Courier, monospace; display: inline-block; color: black; font-size: 0.65em; line-height: 1.45; background-color: #f7f7f7; border: 1px solid #ccc; -webkit-border-radius: 3px; border-radius: 3px; -webkit-box-shadow: 0 1px 0 rgba(0, 0, 0, 0.2), 0 0 0 0.1em white inset; box-shadow: 0 1px 0 rgba(0, 0, 0, 0.2), 0 0 0 0.1em white inset; margin: 0 0.15em; padding: 0.2em 0.5em; vertical-align: middle; position: relative; top: -0.1em; white-space: nowrap; }
.keyseq kbd:first-child { margin-left: 0; }
.keyseq kbd:last-child { margin-right: 0; }
.menuseq, .menuref { color: #000; }
.menuseq b:not(.caret), .menuref { font-weight: inherit; }
.menuseq { word-spacing: -0.02em; }
.menuseq b.caret { font-size: 1.25em; line-height: 0.8; }
.menuseq i.caret { font-weight: bold; text-align: center; width: 0.45em; }
b.button:before, b.button:after { position: relative; top: -1px; font-weight: normal; }
b.button:before { content: "["; padding: 0 3px 0 2px; }
b.button:after { content: "]"; padding: 0 2px 0 3px; }
#header, #content, #footnotes, #footer { width: 100%; margin-left: auto; margin-right: auto; margin-top: 0; margin-bottom: 0; max-width: 62.5em; *zoom: 1; position: relative; padding-left: 1.5em; padding-right: 1.5em; }
#header:before, #header:after, #content:before, #content:after, #footnotes:before, #footnotes:after, #footer:before, #footer:after { content: " "; display: table; }
#header:after, #content:after, #footnotes:after, #footer:after { clear: both; }
#content { margin-top: 1.25em; }
#content:before { content: none; }
#header > h1:first-child { color: black; margin-top: 2.25rem; margin-bottom: 0; }
#header > h1:first-child + #toc { margin-top: 8px; border-top: 1px solid #dddddd; }
#header > h1:only-child, body.toc2 #header > h1:nth-last-child(2) { border-bottom: 1px solid #dddddd; padding-bottom: 8px; }
#header .details { border-bottom: 1px solid #dddddd; line-height: 1.45; padding-top: 0.25em; padding-bottom: 0.25em; padding-left: 0.25em; color: #5e93b8; display: -ms-flexbox; display: -webkit-flex; display: flex; -ms-flex-flow: row wrap; -webkit-flex-flow: row wrap; flex-flow: row wrap; }
#header .details span:first-child { margin-left: -0.125em; }
#header .details span.email a { color: #333333; }
#header .details br { display: none; }
#header .details br + span:before { content: "\00a0\2013\00a0"; }
#header .details br + span.author:before { content: "\00a0\22c5\00a0"; color: #333333; }
#header .details br + span#revremark:before { content: "\00a0|\00a0"; }
#header #revnumber { text-transform: capitalize; }
#header #revnumber:after { content: "\00a0"; }
#content > h1:first-child:not([class]) { color: black; border-bottom: 1px solid #dddddd; padding-bottom: 8px; margin-top: 0; padding-top: 1rem; margin-bottom: 1.25rem; }
#toc { border-bottom: 0 solid #dddddd; padding-bottom: 0.5em; }
#toc > ul { margin-left: 0.125em; }
#toc ul.sectlevel0 > li > a { font-style: italic; }
#toc ul.sectlevel0 ul.sectlevel1 { margin: 0.5em 0; }
#toc ul { font-family: Noto, sans-serif; list-style-type: none; }
#toc li { line-height: 1.3334; margin-top: 0.3334em; }
#toc a { text-decoration: none; }
#toc a:active { text-decoration: underline; }
#toctitle { color: black; font-size: 1.2em; }
@media only screen and (min-width: 768px) { #toctitle { font-size: 1.375em; }
body.toc2 { padding-left: 15em; padding-right: 0; }
#toc.toc2 { margin-top: 0 !important; background-color: white; position: fixed; width: 15em; left: 0; top: 0; border-right: 1px solid #dddddd; border-top-width: 0 !important; border-bottom-width: 0 !important; z-index: 1000; padding: 1.25em 1em; height: 100%; overflow: auto; }
#toc.toc2 #toctitle { margin-top: 0; margin-bottom: 0.8rem; font-size: 1.2em; }
#toc.toc2 > ul { font-size: 0.9em; margin-bottom: 0; }
#toc.toc2 ul ul { margin-left: 0; padding-left: 1em; }
#toc.toc2 ul.sectlevel0 ul.sectlevel1 { padding-left: 0; margin-top: 0.5em; margin-bottom: 0.5em; }
body.toc2.toc-right { padding-left: 0; padding-right: 15em; }
body.toc2.toc-right #toc.toc2 { border-right-width: 0; border-left: 1px solid #dddddd; left: auto; right: 0; } }
@media only screen and (min-width: 1280px) { body.toc2 { padding-left: 20em; padding-right: 0; }
#toc.toc2 { width: 20em; }
#toc.toc2 #toctitle { font-size: 1.375em; }
#toc.toc2 > ul { font-size: 0.95em; }
#toc.toc2 ul ul { padding-left: 1.25em; }
body.toc2.toc-right { padding-left: 0; padding-right: 20em; } }
#content #toc { border-style: solid; border-width: 1px; border-color: #e6e6e6; margin-bottom: 1.25em; padding: 1.25em; background: white; -webkit-border-radius: 0; border-radius: 0; }
#content #toc > :first-child { margin-top: 0; }
#content #toc > :last-child { margin-bottom: 0; }
#footer { max-width: 100%; background-color: none; padding: 1.25em; }
#footer-text { color: black; line-height: 1.44; }
#content { margin-bottom: 0.625em; }
.sect1 { padding-bottom: 0.625em; }
@media only screen and (min-width: 768px) { #content { margin-bottom: 1.25em; }
.sect1 { padding-bottom: 1.25em; } }
.sect1:last-child { padding-bottom: 0; }
.sect1 + .sect1 { border-top: 0 solid #dddddd; }
#content h1 > a.anchor, h2 > a.anchor, h3 > a.anchor, #toctitle > a.anchor, .sidebarblock > .content > .title > a.anchor, h4 > a.anchor, h5 > a.anchor, h6 > a.anchor { position: absolute; z-index: 1001; width: 1.5ex; margin-left: -1.5ex; display: block; text-decoration: none !important; visibility: hidden; text-align: center; font-weight: normal; }
#content h1 > a.anchor:before, h2 > a.anchor:before, h3 > a.anchor:before, #toctitle > a.anchor:before, .sidebarblock > .content > .title > a.anchor:before, h4 > a.anchor:before, h5 > a.anchor:before, h6 > a.anchor:before { content: "\00A7"; font-size: 0.85em; display: block; padding-top: 0.1em; }
#content h1:hover > a.anchor, #content h1 > a.anchor:hover, h2:hover > a.anchor, h2 > a.anchor:hover, h3:hover > a.anchor, #toctitle:hover > a.anchor, .sidebarblock > .content > .title:hover > a.anchor, h3 > a.anchor:hover, #toctitle > a.anchor:hover, .sidebarblock > .content > .title > a.anchor:hover, h4:hover > a.anchor, h4 > a.anchor:hover, h5:hover > a.anchor, h5 > a.anchor:hover, h6:hover > a.anchor, h6 > a.anchor:hover { visibility: visible; }
#content h1 > a.link, h2 > a.link, h3 > a.link, #toctitle > a.link, .sidebarblock > .content > .title > a.link, h4 > a.link, h5 > a.link, h6 > a.link { color: black; text-decoration: none; }
#content h1 > a.link:hover, h2 > a.link:hover, h3 > a.link:hover, #toctitle > a.link:hover, .sidebarblock > .content > .title > a.link:hover, h4 > a.link:hover, h5 > a.link:hover, h6 > a.link:hover { color: black; }
.audioblock, .imageblock, .literalblock, .listingblock, .stemblock, .videoblock { margin-bottom: 1.25em; }
.admonitionblock td.content > .title, .audioblock > .title, .exampleblock > .title, .imageblock > .title, .listingblock > .title, .literalblock > .title, .stemblock > .title, .openblock > .title, .paragraph > .title, .quoteblock > .title, table.tableblock > .title, .verseblock > .title, .videoblock > .title, .dlist > .title, .olist > .title, .ulist > .title, .qlist > .title, .hdlist > .title { text-rendering: optimizeLegibility; text-align: left; }
table.tableblock > caption.title { white-space: nowrap; overflow: visible; max-width: 0; }
.paragraph.lead > p, #preamble > .sectionbody > .paragraph:first-of-type p { color: black; }
table.tableblock #preamble > .sectionbody > .paragraph:first-of-type p { font-size: inherit; }
.admonitionblock > table { border-collapse: separate; border: 0; background: none; width: 100%; }
.admonitionblock > table td.icon { text-align: center; width: 80px; }
.admonitionblock > table td.icon img { max-width: initial; }
.admonitionblock > table td.icon .title { font-weight: bold; font-family: Noto, sans-serif; text-transform: uppercase; }
.admonitionblock > table td.content { padding-left: 1.125em; padding-right: 1.25em; border-left: 1px solid #dddddd; color: #5e93b8; }
.admonitionblock > table td.content > :last-child > :last-child { margin-bottom: 0; }
.exampleblock > .content { border-style: solid; border-width: 1px; border-color: #e6e6e6; margin-bottom: 1.25em; padding: 1.25em; background: white; -webkit-border-radius: 0; border-radius: 0; }
.exampleblock > .content > :first-child { margin-top: 0; }
.exampleblock > .content > :last-child { margin-bottom: 0; }
.sidebarblock { border-style: solid; border-width: 1px; border-color: #e6e6e6; margin-bottom: 1.25em; padding: 1.25em; background: white; -webkit-border-radius: 0; border-radius: 0; }
.sidebarblock > :first-child { margin-top: 0; }
.sidebarblock > :last-child { margin-bottom: 0; }
.sidebarblock > .content > .title { color: black; margin-top: 0; }
.exampleblock > .content > :last-child > :last-child, .exampleblock > .content .olist > ol > li:last-child > :last-child, .exampleblock > .content .ulist > ul > li:last-child > :last-child, .exampleblock > .content .qlist > ol > li:last-child > :last-child, .sidebarblock > .content > :last-child > :last-child, .sidebarblock > .content .olist > ol > li:last-child > :last-child, .sidebarblock > .content .ulist > ul > li:last-child > :last-child, .sidebarblock > .content .qlist > ol > li:last-child > :last-child { margin-bottom: 0; }
.literalblock pre, .listingblock pre:not(.highlight), .listingblock pre[class="highlight"], .listingblock pre[class^="highlight "], .listingblock pre.CodeRay, .listingblock pre.prettyprint { background: #eeeeee; }
.sidebarblock .literalblock pre, .sidebarblock .listingblock pre:not(.highlight), .sidebarblock .listingblock pre[class="highlight"], .sidebarblock .listingblock pre[class^="highlight "], .sidebarblock .listingblock pre.CodeRay, .sidebarblock .listingblock pre.prettyprint { background: #f2f1f1; }
.literalblock pre, .literalblock pre[class], .listingblock pre, .listingblock pre[class] { border: 1px hidden #666666; -webkit-border-radius: 0; border-radius: 0; word-wrap: break-word; padding: 1.25em 1.5625em 1.125em 1.5625em; font-size: 0.8125em; }
.literalblock pre.nowrap, .literalblock pre[class].nowrap, .listingblock pre.nowrap, .listingblock pre[class].nowrap { overflow-x: auto; white-space: pre; word-wrap: normal; }
@media only screen and (min-width: 768px) { .literalblock pre, .literalblock pre[class], .listingblock pre, .listingblock pre[class] { font-size: 0.90625em; } }
@media only screen and (min-width: 1280px) { .literalblock pre, .literalblock pre[class], .listingblock pre, .listingblock pre[class] { font-size: 1em; } }
.literalblock.output pre { color: #eeeeee; background-color: #264357; }
.listingblock pre.highlightjs { padding: 0; }
.listingblock pre.highlightjs > code { padding: 1.25em 1.5625em 1.125em 1.5625em; -webkit-border-radius: 0; border-radius: 0; }
.listingblock > .content { position: relative; }
.listingblock code[data-lang]:before { display: none; content: attr(data-lang); position: absolute; font-size: 0.75em; top: 0.425rem; right: 0.5rem; line-height: 1; text-transform: uppercase; color: #999; }
.listingblock:hover code[data-lang]:before { display: block; }
.listingblock.terminal pre .command:before { content: attr(data-prompt); padding-right: 0.5em; color: #999; }
.listingblock.terminal pre .command:not([data-prompt]):before { content: "$"; }
table.pyhltable { border-collapse: separate; border: 0; margin-bottom: 0; background: none; }
table.pyhltable td { vertical-align: top; padding-top: 0; padding-bottom: 0; line-height: 1.6; }
table.pyhltable td.code { padding-left: .75em; padding-right: 0; }
pre.pygments .lineno, table.pyhltable td:not(.code) { color: #999; padding-left: 0; padding-right: .5em; border-right: 1px solid #dddddd; }
pre.pygments .lineno { display: inline-block; margin-right: .25em; }
table.pyhltable .linenodiv { background: none !important; padding-right: 0 !important; }
.quoteblock { margin: 0 1em 0.75em 1.5em; display: table; }
.quoteblock > .title { margin-left: -1.5em; margin-bottom: 0.75em; }
.quoteblock blockquote, .quoteblock blockquote p { color: #333333; font-size: 1.15rem; line-height: 1.75; word-spacing: 0.1em; letter-spacing: 0; font-style: italic; text-align: justify; }
.quoteblock blockquote { margin: 0; padding: 0; border: 0; }
.quoteblock blockquote:before { content: "\201c"; float: left; font-size: 2.75em; font-weight: bold; line-height: 0.6em; margin-left: -0.6em; color: black; text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1); }
.quoteblock blockquote > .paragraph:last-child p { margin-bottom: 0; }
.quoteblock .attribution { margin-top: 0.5em; margin-right: 0.5ex; text-align: right; }
.quoteblock .quoteblock { margin-left: 0; margin-right: 0; padding: 0.5em 0; border-left: 3px solid #5e93b8; }
.quoteblock .quoteblock blockquote { padding: 0 0 0 0.75em; }
.quoteblock .quoteblock blockquote:before { display: none; }
.verseblock { margin: 0 1em 0.75em 1em; }
.verseblock pre { font-family: "Open Sans", "DejaVu Sans", sans; font-size: 1.15rem; color: #333333; font-weight: 300; text-rendering: optimizeLegibility; }
.verseblock pre strong { font-weight: 400; }
.verseblock .attribution { margin-top: 1.25rem; margin-left: 0.5ex; }
.quoteblock .attribution, .verseblock .attribution { font-size: 0.8125em; line-height: 1.45; font-style: italic; }
.quoteblock .attribution br, .verseblock .attribution br { display: none; }
.quoteblock .attribution cite, .verseblock .attribution cite { display: block; letter-spacing: -0.025em; color: #5e93b8; }
.quoteblock.abstract { margin: 0 0 0.75em 0; display: block; }
.quoteblock.abstract blockquote, .quoteblock.abstract blockquote p { text-align: left; word-spacing: 0; }
.quoteblock.abstract blockquote:before, .quoteblock.abstract blockquote p:first-of-type:before { display: none; }
table.tableblock { max-width: 100%; border-collapse: separate; }
table.tableblock td > .paragraph:last-child p > p:last-child, table.tableblock th > p:last-child, table.tableblock td > p:last-child { margin-bottom: 0; }
table.tableblock, th.tableblock, td.tableblock { border: 0 solid #d8d8ce; }
table.grid-all > thead > tr > .tableblock, table.grid-all > tbody > tr > .tableblock { border-width: 0 1px 1px 0; }
table.grid-all > tfoot > tr > .tableblock { border-width: 1px 1px 0 0; }
table.grid-cols > * > tr > .tableblock { border-width: 0 1px 0 0; }
table.grid-rows > thead > tr > .tableblock, table.grid-rows > tbody > tr > .tableblock { border-width: 0 0 1px 0; }
table.grid-rows > tfoot > tr > .tableblock { border-width: 1px 0 0 0; }
table.grid-all > * > tr > .tableblock:last-child, table.grid-cols > * > tr > .tableblock:last-child { border-right-width: 0; }
table.grid-all > tbody > tr:last-child > .tableblock, table.grid-all > thead:last-child > tr > .tableblock, table.grid-rows > tbody > tr:last-child > .tableblock, table.grid-rows > thead:last-child > tr > .tableblock { border-bottom-width: 0; }
table.frame-all { border-width: 1px; }
table.frame-sides { border-width: 0 1px; }
table.frame-topbot { border-width: 1px 0; }
th.halign-left, td.halign-left { text-align: left; }
th.halign-right, td.halign-right { text-align: right; }
th.halign-center, td.halign-center { text-align: center; }
th.valign-top, td.valign-top { vertical-align: top; }
th.valign-bottom, td.valign-bottom { vertical-align: bottom; }
th.valign-middle, td.valign-middle { vertical-align: middle; }
table thead th, table tfoot th { font-weight: bold; }
tbody tr th { display: table-cell; line-height: 1.4; background: -webkit-linear-gradient(top, #add386, #90b66a); }
tbody tr th, tbody tr th p, tfoot tr th, tfoot tr th p { color: white; font-weight: bold; }
p.tableblock > code:only-child { background: none; padding: 0; }
p.tableblock { font-size: 1em; }
td > div.verse { white-space: pre; }
ol { margin-left: 1.75em; }
ul li ol { margin-left: 1.5em; }
dl dd { margin-left: 1.125em; }
dl dd:last-child, dl dd:last-child > :last-child { margin-bottom: 0; }
ol > li p, ul > li p, ul dd, ol dd, .olist .olist, .ulist .ulist, .ulist .olist, .olist .ulist { margin-bottom: 0.375em; }
ul.checklist, ul.none, ol.none, ul.no-bullet, ol.no-bullet, ol.unnumbered, ul.unstyled, ol.unstyled { list-style-type: none; }
ul.no-bullet, ol.no-bullet, ol.unnumbered { margin-left: 0.625em; }
ul.unstyled, ol.unstyled { margin-left: 0; }
ul.checklist { margin-left: 0.625em; }
ul.checklist li > p:first-child > .fa-square-o:first-child, ul.checklist li > p:first-child > .fa-check-square-o:first-child { width: 1.25em; font-size: 0.8em; position: relative; bottom: 0.125em; }
ul.checklist li > p:first-child > input[type="checkbox"]:first-child { margin-right: 0.25em; }
ul.inline { display: -ms-flexbox; display: -webkit-box; display: flex; -ms-flex-flow: row wrap; -webkit-flex-flow: row wrap; flex-flow: row wrap; list-style: none; margin: 0 0 0.375em -0.75em; }
ul.inline > li { margin-left: 0.75em; }
.unstyled dl dt { font-weight: normal; font-style: normal; }
ol.arabic { list-style-type: decimal; }
ol.decimal { list-style-type: decimal-leading-zero; }
ol.loweralpha { list-style-type: lower-alpha; }
ol.upperalpha { list-style-type: upper-alpha; }
ol.lowerroman { list-style-type: lower-roman; }
ol.upperroman { list-style-type: upper-roman; }
ol.lowergreek { list-style-type: lower-greek; }
.hdlist > table, .colist > table { border: 0; background: none; }
.hdlist > table > tbody > tr, .colist > table > tbody > tr { background: none; }
td.hdlist1, td.hdlist2 { vertical-align: top; padding: 0 0.625em; }
td.hdlist1 { font-weight: bold; padding-bottom: 0.75em; }
.literalblock + .colist, .listingblock + .colist { margin-top: -0.5em; }
.colist > table tr > td:first-of-type { padding: 0.4em 0.75em 0 0.75em; line-height: 1; vertical-align: top; }
.colist > table tr > td:first-of-type img { max-width: initial; }
.colist > table tr > td:last-of-type { padding: 0.25em 0; }
.thumb, .th { line-height: 0; display: inline-block; border: solid 4px white; -webkit-box-shadow: 0 0 0 1px #dddddd; box-shadow: 0 0 0 1px #dddddd; }
.imageblock.left, .imageblock[style*="float: left"] { margin: 0.25em 0.625em 1.25em 0; }
.imageblock.right, .imageblock[style*="float: right"] { margin: 0.25em 0 1.25em 0.625em; }
.imageblock > .title { margin-bottom: 0; }
.imageblock.thumb, .imageblock.th { border-width: 6px; }
.imageblock.thumb > .title, .imageblock.th > .title { padding: 0 0.125em; }
.image.left, .image.right { margin-top: 0.25em; margin-bottom: 0.25em; display: inline-block; line-height: 0; }
.image.left { margin-right: 0.625em; }
.image.right { margin-left: 0.625em; }
a.image { text-decoration: none; display: inline-block; }
a.image object { pointer-events: none; }
sup.footnote, sup.footnoteref { font-size: 0.875em; position: static; vertical-align: super; }
sup.footnote a, sup.footnoteref a { text-decoration: none; }
sup.footnote a:active, sup.footnoteref a:active { text-decoration: underline; }
#footnotes { padding-top: 0.75em; padding-bottom: 0.75em; margin-bottom: 0.625em; }
#footnotes hr { width: 20%; min-width: 6.25em; margin: -0.25em 0 0.75em 0; border-width: 1px 0 0 0; }
#footnotes .footnote { padding: 0 0.375em 0 0.225em; line-height: 1.3334; font-size: 0.875em; margin-left: 1.2em; margin-bottom: 0.2em; }
#footnotes .footnote a:first-of-type { font-weight: bold; text-decoration: none; margin-left: -1.05em; }
#footnotes .footnote:last-of-type { margin-bottom: 0; }
#content #footnotes { margin-top: -0.625em; margin-bottom: 0; padding: 0.75em 0; }
.gist .file-data > table { border: 0; background: #fff; width: 100%; margin-bottom: 0; }
.gist .file-data > table td.line-data { width: 99%; }
div.unbreakable { page-break-inside: avoid; }
.big { font-size: larger; }
.small { font-size: smaller; }
.underline { text-decoration: underline; }
.overline { text-decoration: overline; }
.line-through { text-decoration: line-through; }
.aqua { color: #00bfbf; }
.aqua-background { background-color: #00fafa; }
.black { color: black; }
.black-background { background-color: black; }
.blue { color: #0000bf; }
.blue-background { background-color: #0000fa; }
.fuchsia { color: #bf00bf; }
.fuchsia-background { background-color: #fa00fa; }
.gray { color: #606060; }
.gray-background { background-color: #7d7d7d; }
.green { color: #006000; }
.green-background { background-color: #007d00; }
.lime { color: #00bf00; }
.lime-background { background-color: #00fa00; }
.maroon { color: #600000; }
.maroon-background { background-color: #7d0000; }
.navy { color: #000060; }
.navy-background { background-color: #00007d; }
.olive { color: #606000; }
.olive-background { background-color: #7d7d00; }
.purple { color: #600060; }
.purple-background { background-color: #7d007d; }
.red { color: #bf0000; }
.red-background { background-color: #fa0000; }
.silver { color: #909090; }
.silver-background { background-color: #bcbcbc; }
.teal { color: #006060; }
.teal-background { background-color: #007d7d; }
.white { color: #bfbfbf; }
.white-background { background-color: #fafafa; }
.yellow { color: #bfbf00; }
.yellow-background { background-color: #fafa00; }
span.icon > .fa { cursor: default; }
a span.icon > .fa { cursor: inherit; }
.admonitionblock td.icon [class^="fa icon-"] { font-size: 2.5em; text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5); cursor: default; }
.admonitionblock td.icon .icon-note:before { content: "\f05a"; color: #29475c; }
.admonitionblock td.icon .icon-tip:before { content: "\f0eb"; text-shadow: 1px 1px 2px rgba(155, 155, 0, 0.8); color: #111; }
.admonitionblock td.icon .icon-warning:before { content: "\f071"; color: #bf6900; }
.admonitionblock td.icon .icon-caution:before { content: "\f06d"; color: #bf3400; }
.admonitionblock td.icon .icon-important:before { content: "\f06a"; color: #bf0000; }
.conum[data-value] { display: inline-block; color: #fff !important; background-color: black; -webkit-border-radius: 100px; border-radius: 100px; text-align: center; font-size: 0.75em; width: 1.67em; height: 1.67em; line-height: 1.67em; font-family: "Open Sans", "DejaVu Sans", sans-serif; font-style: normal; font-weight: bold; }
.conum[data-value] * { color: #fff !important; }
.conum[data-value] + b { display: none; }
.conum[data-value]:after { content: attr(data-value); }
pre .conum[data-value] { position: relative; top: -0.125em; }
b.conum * { color: inherit !important; }
.conum:not([data-value]):empty { display: none; }
h1, h2, h3, #toctitle, .sidebarblock > .content > .title, h4, h5, h6 { border-bottom: 1px solid #dddddd; }
.sect1 { padding-bottom: 0; }
#toctitle { color: #00406F; font-weight: normal; margin-top: 1.5em; }
.sidebarblock { border-color: #aaa; }
code { -webkit-border-radius: 4px; border-radius: 4px; }
p.tableblock.header { color: #6d6e71; }
.literalblock pre, .listingblock pre { background: #eeeeee; }
</style>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style>
/* Stylesheet for CodeRay to match GitHub theme | MIT License | http://foundation.zurb.com */
/*pre.CodeRay {background-color:#f7f7f8;}*/
.CodeRay .line-numbers{border-right:1px solid #d8d8d8;padding:0 0.5em 0 .25em}
.CodeRay span.line-numbers{display:inline-block;margin-right:.5em;color:rgba(0,0,0,.3)}
.CodeRay .line-numbers strong{color:rgba(0,0,0,.4)}
table.CodeRay{border-collapse:separate;border-spacing:0;margin-bottom:0;border:0;background:none}
table.CodeRay td{vertical-align: top;line-height:1.45}
table.CodeRay td.line-numbers{text-align:right}
table.CodeRay td.line-numbers>pre{padding:0;color:rgba(0,0,0,.3)}
table.CodeRay td.code{padding:0 0 0 .5em}
table.CodeRay td.code>pre{padding:0}
.CodeRay .debug{color:#fff !important;background:#000080 !important}
.CodeRay .annotation{color:#007}
.CodeRay .attribute-name{color:#000080}
.CodeRay .attribute-value{color:#700}
.CodeRay .binary{color:#509}
.CodeRay .comment{color:#998;font-style:italic}
.CodeRay .char{color:#04d}
.CodeRay .char .content{color:#04d}
.CodeRay .char .delimiter{color:#039}
.CodeRay .class{color:#458;font-weight:bold}
.CodeRay .complex{color:#a08}
.CodeRay .constant,.CodeRay .predefined-constant{color:#008080}
.CodeRay .color{color:#099}
.CodeRay .class-variable{color:#369}
.CodeRay .decorator{color:#b0b}
.CodeRay .definition{color:#099}
.CodeRay .delimiter{color:#000}
.CodeRay .doc{color:#970}
.CodeRay .doctype{color:#34b}
.CodeRay .doc-string{color:#d42}
.CodeRay .escape{color:#666}
.CodeRay .entity{color:#800}
.CodeRay .error{color:#808}
.CodeRay .exception{color:inherit}
.CodeRay .filename{color:#099}
.CodeRay .function{color:#900;font-weight:bold}
.CodeRay .global-variable{color:#008080}
.CodeRay .hex{color:#058}
.CodeRay .integer,.CodeRay .float{color:#099}
.CodeRay .include{color:#555}
.CodeRay .inline{color:#000}
.CodeRay .inline .inline{background:#ccc}
.CodeRay .inline .inline .inline{background:#bbb}
.CodeRay .inline .inline-delimiter{color:#d14}
.CodeRay .inline-delimiter{color:#d14}
.CodeRay .important{color:#555;font-weight:bold}
.CodeRay .interpreted{color:#b2b}
.CodeRay .instance-variable{color:#008080}
.CodeRay .label{color:#970}
.CodeRay .local-variable{color:#963}
.CodeRay .octal{color:#40e}
.CodeRay .predefined{color:#369}
.CodeRay .preprocessor{color:#579}
.CodeRay .pseudo-class{color:#555}
.CodeRay .directive{font-weight:bold}
.CodeRay .type{font-weight:bold}
.CodeRay .predefined-type{color:inherit}
.CodeRay .reserved,.CodeRay .keyword {color:#000;font-weight:bold}
.CodeRay .key{color:#808}
.CodeRay .key .delimiter{color:#606}
.CodeRay .key .char{color:#80f}
.CodeRay .value{color:#088}
.CodeRay .regexp .delimiter{color:#808}
.CodeRay .regexp .content{color:#808}
.CodeRay .regexp .modifier{color:#808}
.CodeRay .regexp .char{color:#d14}
.CodeRay .regexp .function{color:#404;font-weight:bold}
.CodeRay .string{color:#d20}
.CodeRay .string .string .string{background:#ffd0d0}
.CodeRay .string .content{color:#d14}
.CodeRay .string .char{color:#d14}
.CodeRay .string .delimiter{color:#d14}
.CodeRay .shell{color:#d14}
.CodeRay .shell .delimiter{color:#d14}
.CodeRay .symbol{color:#990073}
.CodeRay .symbol .content{color:#a60}
.CodeRay .symbol .delimiter{color:#630}
.CodeRay .tag{color:#008080}
.CodeRay .tag-special{color:#d70}
.CodeRay .variable{color:#036}
.CodeRay .insert{background:#afa}
.CodeRay .delete{background:#faa}
.CodeRay .change{color:#aaf;background:#007}
.CodeRay .head{color:#f8f;background:#505}
.CodeRay .insert .insert{color:#080}
.CodeRay .delete .delete{color:#800}
.CodeRay .change .change{color:#66f}
.CodeRay .head .head{color:#f4f}
</style>
<link rel="stylesheet" href="../katex/katex.min.css">
<script src="../katex/katex.min.js"></script>
<script src="../katex/contrib/auto-render.min.js"></script>
<!-- Use KaTeX to render math once document is loaded, see
https://github.com/Khan/KaTeX/tree/master/contrib/auto-render -->
<script>
document.addEventListener("DOMContentLoaded", function () {
renderMathInElement(
document.body,
{
delimiters: [
{ left: "$$", right: "$$", display: true},
{ left: "\\[", right: "\\]", display: true},
{ left: "$", right: "$", display: false},
{ left: "\\(", right: "\\)", display: false}
]
}
);
});
</script></head>
<body class="book toc2 toc-left" style="max-width: 100;">
<div id="header">
<h1>The OpenCL<sup>&#8482;</sup> Extension Specification</h1>
<div class="details">
<span id="author" class="author">Khronos<sup>&#174;</sup> OpenCL Working Group</span><br>
<span id="revnumber">version v3.0.7,</span>
<span id="revdate">Fri, 23 Apr 2021 20:00:00 +0000</span>
<br><span id="revremark">from git branch: master commit: 133503b85911ca8fd6642721d440e89460d491a3</span>
</div>
<div id="toc" class="toc2">
<div id="toctitle">Table of Contents</div>
<ul class="sectlevel1">
<li><a href="#extensions-overview">1. Extensions Overview</a></li>
<li><a href="#cl_khr_icd-opencl">2. Installable Client Drivers</a></li>
<li><a href="#cl_khr_byte_addressable_store">3. Byte Addressable Stores</a></li>
<li><a href="#cl_khr_3d_image_writes">4. Writing to 3D Image Objects</a></li>
<li><a href="#cl_khr_fp16">5. Half Precision Floating-Point</a></li>
<li><a href="#cl_khr_fp64">6. Double Precision Floating-Point</a></li>
<li><a href="#cl_khr_int32_atomics">7. 32-bit Atomics</a></li>
<li><a href="#cl_khr_int64_atomics">8. 64-bit Atomics</a></li>
<li><a href="#cl_khr_select_fprounding_mode">9. Selecting the Rounding Mode <strong>(DEPRECATED)</strong></a></li>
<li><a href="#cl_khr_gl_sharing">10. Creating an OpenCL Context from an OpenGL Context or Share Group</a></li>
<li><a href="#cl_khr_gl_sharing__memobjs">11. Creating OpenCL Memory Objects from OpenGL Objects</a></li>
<li><a href="#cl_khr_gl_event">12. Creating OpenCL Event Objects from OpenGL Sync Objects</a></li>
<li><a href="#cl_khr_d3d10_sharing">13. Creating OpenCL Memory Objects from Direct3D 10 Buffers and Textures</a></li>
<li><a href="#cl_khr_d3d11_sharing">14. Creating OpenCL Memory Objects from Direct3D 11 Buffers and Textures</a></li>
<li><a href="#cl_khr_dx9_media_sharing">15. Creating OpenCL Memory Objects from DirectX 9 Media Surfaces</a></li>
<li><a href="#cl_khr_depth_images">16. Depth Images</a></li>
<li><a href="#cl_khr_gl_depth_images">17. Sharing OpenGL and OpenGL ES Depth and Depth-Stencil Images</a></li>
<li><a href="#cl_khr_gl_msaa_sharing">18. Creating OpenCL Memory Objects from OpenGL MSAA Textures</a></li>
<li><a href="#cl_khr_egl_event">19. Creating OpenCL Event Objects from EGL Sync Objects</a></li>
<li><a href="#cl_khr_egl_image">20. Creating OpenCL Memory Objects from EGL Images</a></li>
<li><a href="#cl_khr_image2d_from_buffer">21. Creating a 2D Image From A Buffer</a></li>
<li><a href="#cl_khr_initialize_memory">22. Local and Private Memory Initialization</a></li>
<li><a href="#cl_khr_terminate_context">23. Terminating OpenCL contexts</a></li>
<li><a href="#cl_khr_spir">24. Standard Portable Intermediate Representation Binaries</a></li>
<li><a href="#cl_khr_il_program">25. Intermediate Language Programs</a></li>
<li><a href="#cl_khr_create_command_queue">26. Creating Command Queues with Properties</a></li>
<li><a href="#cl_khr_device_enqueue_local_arg_types">27. Device Enqueue Local Argument Types</a></li>
<li><a href="#cl_khr_subgroups">28. Subgroups</a></li>
<li><a href="#cl_khr_mipmap_image">29. Mipmaps</a></li>
<li><a href="#cl_khr_srgb_image_writes">30. sRGB Image Writes</a></li>
<li><a href="#cl_khr_priority_hints">31. Priority Hints</a></li>
<li><a href="#cl_khr_throttle_hints">32. Throttle Hints</a></li>
<li><a href="#cl_khr_subgroup_named_barrier">33. Named Barriers for Subgroups</a></li>
<li><a href="#cl_khr_extended_async_copies">34. Extended Async Copies (Provisional)</a></li>
<li><a href="#cl_khr_async_work_group_copy_fence">35. Async Work Group Copy Fence (Provisional)</a></li>
<li><a href="#cl_khr_device_uuid">36. Unique Device Identifiers</a></li>
<li><a href="#cl_khr_extended_versioning">37. Extended versioning</a></li>
<li><a href="#_extended_subgroup_functions">38. Extended Subgroup Functions</a></li>
<li><a href="#cl_khr_pci_bus_info">39. PCI Bus Information Query</a></li>
<li><a href="#cl_khr_extended_bit_ops">40. Extended Bit Operations</a></li>
<li><a href="#cl_khr_suggested_local_work_size">41. Suggested Local Work Size Query</a></li>
<li><a href="#spirv_extensions">42. Extensions to the OpenCL SPIR-V Environment</a></li>
<li><a href="#_extensions_promoted_to_core_features">Appendix A: Extensions Promoted to Core Features</a></li>
<li><a href="#_deprecated_extensions">Appendix B: Deprecated Extensions</a></li>
<li><a href="#_quick_reference">Appendix C: Quick Reference</a></li>
</ul>
</div>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph">
<p>Copyright 2008-2020 The Khronos Group.</p>
</div>
<div class="paragraph">
<p>This specification is protected by copyright laws and contains material proprietary
to the Khronos Group, Inc. Except as described by these terms, it or any components
may not be reproduced, republished, distributed, transmitted, displayed, broadcast
or otherwise exploited in any manner without the express prior written permission
of Khronos Group.</p>
</div>
<div class="paragraph">
<p>Khronos Group grants a conditional copyright license to use and reproduce the
unmodified specification for any purpose, without fee or royalty, EXCEPT no licenses
to any patent, trademark or other intellectual property rights are granted under
these terms. Parties desiring to implement the specification and make use of
Khronos trademarks in relation to that implementation, and receive reciprocal patent
license protection under the Khronos IP Policy must become Adopters and confirm the
implementation as conformant under the process defined by Khronos for this
specification; see <a href="https://www.khronos.org/adopters" class="bare">https://www.khronos.org/adopters</a>.</p>
</div>
<div class="paragraph">
<p>Khronos Group makes no, and expressly disclaims any, representations or warranties,
express or implied, regarding this specification, including, without limitation:
merchantability, fitness for a particular purpose, non-infringement of any
intellectual property, correctness, accuracy, completeness, timeliness, and
reliability. Under no circumstances will the Khronos Group, or any of its Promoters,
Contributors or Members, or their respective partners, officers, directors,
employees, agents or representatives be liable for any damages, whether direct,
indirect, special or consequential damages for lost revenues, lost profits, or
otherwise, arising from or in connection with these materials.</p>
</div>
<div class="paragraph">
<p>Vulkan and Khronos are registered trademarks, and OpenXR, SPIR, SPIR-V, SYCL, WebGL,
WebCL, OpenVX, OpenVG, EGL, COLLADA, glTF, NNEF, OpenKODE, OpenKCAM, StreamInput,
OpenWF, OpenSL ES, OpenMAX, OpenMAX AL, OpenMAX IL, OpenMAX DL, OpenML and DevU are
trademarks of the Khronos Group Inc. ASTC is a trademark of ARM Holdings PLC,
OpenCL is a trademark of Apple Inc. and OpenGL and OpenML are registered trademarks
and the OpenGL ES and OpenGL SC logos are trademarks of Silicon Graphics
International used under license by Khronos. All other product names, trademarks,
and/or company names are used solely for identification and belong to their
respective owners.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="extensions-overview"><a class="anchor" href="#extensions-overview"></a>1. Extensions Overview</h2>
<div class="sectionbody">
<div class="paragraph">
<p>This document describes the list of optional features supported by OpenCL.
Optional extensions are not required to be supported by a conformant OpenCL
implementation, but are expected to be widely available, and in some cases may define
functionality that is likely to be required in a future revision of the
OpenCL specification.</p>
</div>
<div class="paragraph">
<p>This document describes all extensions that have been approved by the OpenCL
working group.
It is a <em>unified</em> specification, meaning that the extensions described in this
document are not specific to a specific core OpenCL specification version.</p>
</div>
<div class="paragraph">
<p>OpenCL extensions approved by the OpenCL working group may be <em>promoted</em> to
core features in later revisions of OpenCL.
When this occurs, the feature described by the extension specification
is merged into the core OpenCL specification.
The extension will continue to be documented in this specification, both for
backwards compatibility and for devices that wish to support the feature
but that are unable to support the newer core OpenCL version.</p>
</div>
<div class="sect2">
<h3 id="naming-convention-for-optional-extensions"><a class="anchor" href="#naming-convention-for-optional-extensions"></a>1.1. Naming Convention for Optional Extensions</h3>
<div class="paragraph">
<p>OpenCL extensions approved by the OpenCL working group use the following
naming convention:</p>
</div>
<div class="ulist">
<ul>
<li>
<p>A unique <em>name string</em> of the form <code>"<strong>cl_khr_&lt;<em>name</em>&gt;</strong>"</code> is associated
with each extension.
If the extension is supported by an implementation, this string will be
present in the implementation&#8217;s <code>CL_PLATFORM_EXTENSIONS</code> string or
<code>CL_DEVICE_EXTENSIONS</code> string.</p>
</li>
<li>
<p>All API functions defined by the extension will have names of the form
<strong>cl&lt;<em>function_name</em>&gt;KHR</strong>.</p>
</li>
<li>
<p>All enumerants defined by the extension will have names of the form
<strong>CL_&lt;<em>enum_name</em>&gt;_KHR.</strong></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>Functions and enumerants defined by extensions that are promoted to
core features will have their <strong>KHR</strong> affix removed.
OpenCL implementations of such later revisions must also export the name
strings of promoted extensions in the <code>CL_PLATFORM_EXTENSIONS</code> or
<code>CL_DEVICE_EXTENSIONS</code> string, and support the <strong>KHR</strong>-affixed versions of
functions and enumerants as a transition aid.</p>
</div>
<div class="paragraph">
<p>Vendor extensions are strongly encouraged to follow a similar naming
convention:</p>
</div>
<div class="ulist">
<ul>
<li>
<p>A unique <em>name string</em> of the form <code>"<strong>cl_&lt;<em>vendor_name</em>&gt;_&lt;<em>name&gt;</em></strong>"</code>
is associated with each extension.
If the extension is supported by an implementation, this string will be
present in the implementation&#8217;s <code>CL_PLATFORM_EXTENSIONS</code> string or
<code>CL_DEVICE_EXTENSIONS</code> string.</p>
</li>
<li>
<p>All API functions defined by the vendor extension will have names of the
form <strong>cl&lt;<em>function_name</em>&gt;&lt;<em>vendor_name</em>&gt;</strong>.</p>
</li>
<li>
<p>All enumerants defined by the vendor extension will have names of the
form <strong>CL_&lt;<em>enum_name</em>&gt;_&lt;<em>vendor_name</em>&gt;.</strong></p>
</li>
</ul>
</div>
</div>
<div class="sect2">
<h3 id="compiler-directives-for-optional-extensions"><a class="anchor" href="#compiler-directives-for-optional-extensions"></a>1.2. Compiler Directives for Optional Extensions</h3>
<div class="paragraph">
<p>The <strong>#pragma OPENCL EXTENSION</strong> directive controls the behavior of the OpenCL
compiler with respect to extensions.
The <strong>#pragma OPENCL EXTENSION</strong> directive is defined as:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="preprocessor">#pragma</span> OPENCL EXTENSION &lt;extension_name&gt; : &lt;behavior&gt;
<span class="preprocessor">#pragma</span> OPENCL EXTENSION all : &lt;behavior&gt;</code></pre>
</div>
</div>
<div class="paragraph">
<p>where <em>extension_name</em> is the name of the extension.
The <em>extension_name</em> will have names of the form <strong>cl_khr_&lt;<em>name</em>&gt;</strong> for an
extension approved by the OpenCL working group and will have names of the
form <strong>cl_&lt;<em>vendor_name</em>&gt;_&lt;<em>name</em>&gt;</strong> for vendor extensions.
The token <strong>all</strong> means that the behavior applies to all extensions supported
by the compiler.
The <em>behavior</em> can be set to one of the following values given by the table
below.</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 25%;">
<col style="width: 75%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>behavior</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>enable</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Behave as specified by the extension <em>extension_name</em>.</p>
<p class="tableblock"> Report an error on the <strong><code>#pragma OPENCL EXTENSION</code></strong> if the
<em>extension_name</em> is not supported, or if <strong>all</strong> is specified.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>disable</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Behave (including issuing errors and warnings) as if the extension
<em>extension_name</em> is not part of the language definition.</p>
<p class="tableblock"> If <strong>all</strong> is specified, then behavior must revert back to that of the
non-extended core version of the language being compiled to.</p>
<p class="tableblock"> Warn on the <strong><code>#pragma OPENCL EXTENSION</code></strong> if the extension <em>extension_name</em>
is not supported.</p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
<p>The <strong><code>#pragma OPENCL EXTENSION</code></strong> directive is a simple, low-level mechanism
to set the behavior for each extension.
It does not define policies such as which combinations are appropriate;
those must be defined elsewhere.
The order of directives matter in setting the behavior for each extension.
Directives that occur later override those seen earlier.
The <strong>all</strong> variant sets the behavior for all extensions, overriding all
previously issued extension directives, but only if the <em>behavior</em> is set to
<strong>disable</strong>.</p>
</div>
<div class="paragraph">
<p>The initial state of the compiler is as if the directive</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="preprocessor">#pragma</span> OPENCL EXTENSION all : disable</code></pre>
</div>
</div>
<div class="paragraph">
<p>was issued, telling the compiler that all error and warning reporting must
be done according to this specification, ignoring any extensions.</p>
</div>
<div class="paragraph">
<p>Every extension which affects the OpenCL language semantics, syntax or adds
built-in functions to the language must create a preprocessor <code>#define</code> that
matches the extension name string.
This <code>#define</code> would be available in the language if and only if the
extension is supported on a given implementation.</p>
</div>
<div class="paragraph">
<p><strong>Example</strong>:</p>
</div>
<div class="paragraph">
<p>An extension which adds the extension string <code>"cl_khr_3d_image_writes"</code>
should also add a preprocessor <code>#define</code> called <strong><code>cl_khr_3d_image_writes</code></strong>.
A kernel can now use this preprocessor <code>#define</code> to do something like:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="preprocessor">#ifdef</span> cl_khr_3d_image_writes
<span class="comment">// do something using the extension</span>
<span class="preprocessor">#else</span>
<span class="comment">// do something else or #error!</span>
<span class="preprocessor">#endif</span></code></pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="getting-opencl-api-extension-function-pointers"><a class="anchor" href="#getting-opencl-api-extension-function-pointers"></a>1.3. Getting OpenCL API Extension Function Pointers</h3>
<div class="paragraph">
<p>The function
</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="directive">void</span>* clGetExtensionFunctionAddressForPlatform(cl_platform_id platform,
<span class="directive">const</span> <span class="predefined-type">char</span> *funcname)</code></pre>
</div>
</div>
<div class="paragraph">
<p>returns the address of the extension function named by <em>funcname</em> for a
given <em>platform</em> The pointer returned should be cast to a function pointer
type matching the extension function&#8217;s definition defined in the appropriate
extension specification and header file.
A return value of <code>NULL</code> indicates that the specified function does not
exist for the implementation or <em>platform</em> is not a valid platform.
A non-<code>NULL</code> return value for <strong>clGetExtensionFunctionAddressForPlatform</strong>
does not guarantee that an extension function is actually supported by the
platform.
The application must also make a corresponding query using
<strong>clGetPlatformInfo</strong>(platform, CL_PLATFORM_EXTENSIONS, &#8230;&#8203;) or
<strong>clGetDeviceInfo</strong>(device, CL_DEVICE_EXTENSIONS, &#8230;&#8203;) to determine if an
extension is supported by the OpenCL implementation.</p>
</div>
<div class="paragraph">
<p>Since there is no way to qualify the query with a
device, the function pointer returned must work for all implementations of
that extension on different devices for a platform.
The behavior of calling a device extension function on a device not
supporting that extension is undefined.</p>
</div>
<div class="paragraph">
<p><strong>clGetExtensionFunctionAddressForPlatform</strong> may not be be used to query for core
(non-extension) functions in OpenCL.
For extension functions that may be queried using
<strong>clGetExtensionFunctionAddressForPlatform</strong>, implementations may also choose to
export those functions statically from the object libraries
implementing those functions, however, portable applications cannot rely on
this behavior.</p>
</div>
<div class="paragraph">
<p>Function pointer typedefs must be declared for all extensions that add API
entrypoints.
These typedefs are a required part of the extension interface, to be
provided in an appropriate header (such as cl_ext.h if the extension is an
OpenCL extension, or cl_gl_ext.h if the extension is an OpenCL / OpenGL
sharing extension).</p>
</div>
<div class="paragraph">
<p>The following convention must be followed for all extensions affecting the
host API:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="preprocessor">#ifndef</span> extension_name
<span class="preprocessor">#define</span> extension_name <span class="integer">1</span>
<span class="comment">// all data typedefs, token #defines, prototypes, and</span>
<span class="comment">// function pointer typedefs for this extension</span>
<span class="comment">// function pointer typedefs must use the</span>
<span class="comment">// following naming convention</span>
<span class="keyword">typedef</span> return_type
(CL_API_CALL *clExtensionFunctionNameTAG_fn)(...);
<span class="preprocessor">#endif</span> <span class="comment">// _extension_name_</span></code></pre>
</div>
</div>
<div class="paragraph">
<p>where <code>TAG</code> can be <code>KHR</code>, <code>EXT</code> or <code>vendor-specific</code>.</p>
</div>
<div class="paragraph">
<p>Consider, for example, the <strong>cl_khr_gl_sharing</strong> extension.
This extension would add the following to cl_gl_ext.h:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="preprocessor">#ifndef</span> cl_khr_gl_sharing
<span class="preprocessor">#define</span> cl_khr_gl_sharing <span class="integer">1</span>
<span class="comment">// all data typedefs, token #defines, prototypes, and</span>
<span class="comment">// function pointer typedefs for this extension</span>
<span class="preprocessor">#define</span> CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR -<span class="integer">1000</span>
<span class="preprocessor">#define</span> CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR <span class="hex">0x2006</span>
<span class="preprocessor">#define</span> CL_DEVICES_FOR_GL_CONTEXT_KHR <span class="hex">0x2007</span>
<span class="preprocessor">#define</span> CL_GL_CONTEXT_KHR <span class="hex">0x2008</span>
<span class="preprocessor">#define</span> CL_EGL_DISPLAY_KHR <span class="hex">0x2009</span>
<span class="preprocessor">#define</span> CL_GLX_DISPLAY_KHR <span class="hex">0x200A</span>
<span class="preprocessor">#define</span> CL_WGL_HDC_KHR <span class="hex">0x200B</span>
<span class="preprocessor">#define</span> CL_CGL_SHAREGROUP_KHR <span class="hex">0x200C</span>
<span class="comment">// function pointer typedefs must use the</span>
<span class="comment">// following naming convention</span>
<span class="keyword">typedef</span> cl_int
(CL_API_CALL *clGetGLContextInfoKHR_fn)(
<span class="directive">const</span> cl_context_properties * <span class="comment">/* properties */</span>,
cl_gl_context_info <span class="comment">/* param_name */</span>,
size_t <span class="comment">/* param_value_size */</span>,
<span class="directive">void</span> * <span class="comment">/* param_value */</span>,
size_t * <span class="comment">/*param_value_size_ret*/</span>);
<span class="preprocessor">#endif</span> <span class="comment">// cl_khr_gl_sharing</span></code></pre>
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="cl_khr_icd-opencl"><a class="anchor" href="#cl_khr_icd-opencl"></a>2. Installable Client Drivers</h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="cl_khr_icd-overview"><a class="anchor" href="#cl_khr_icd-overview"></a>2.1. Overview</h3>
<div class="paragraph">
<p>This section describes a platform extension which defines a simple mechanism
through which the Khronos OpenCL installable client driver loader (ICD
Loader) may expose multiple separate vendor installable client drivers
(Vendor ICDs) for OpenCL.
An application written against the ICD Loader will be able to access all
cl_platform_ids exposed by all vendor implementations with the ICD Loader
acting as a demultiplexor.</p>
</div>
<div class="paragraph">
<p>This is a platform extension, so if this extension is supported by an
implementation, the string <strong>cl_khr_icd</strong> will be present in the
<code>CL_PLATFORM_EXTENSIONS</code> string.</p>
</div>
</div>
<div class="sect2">
<h3 id="_general_information"><a class="anchor" href="#_general_information"></a>2.2. General information</h3>
<div class="sect3">
<h4 id="_version_history"><a class="anchor" href="#_version_history"></a>2.2.1. Version history</h4>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 60%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Date</strong></th>
<th class="tableblock halign-left valign-top"><strong>Version</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">2020-04-21</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">1.0.0</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">First assigned version.</p></td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-inferring-vendors-from-function-call-arguments"><a class="anchor" href="#cl_khr_icd-inferring-vendors-from-function-call-arguments"></a>2.3. Inferring Vendors from Function Call Arguments</h3>
<div class="paragraph">
<p>At every OpenCL function call, the ICD Loader infers the vendor ICD function
to call from the arguments to the function.
An object is said to be ICD compatible if it is of the following structure:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c"><span class="keyword">struct</span> _cl_&lt;object&gt;
{
<span class="keyword">struct</span> _cl_icd_dispatch *dispatch;
<span class="comment">// ... remainder of internal data</span>
};</code></pre>
</div>
</div>
<div class="paragraph">
<p>&lt;object&gt; is one of platform_id, device_id, context, command_queue, mem,
program, kernel, event, or sampler.</p>
</div>
<div class="paragraph">
<p>The structure <code>_cl_icd_dispatch</code> is a function pointer dispatch table which
is used to direct calls to a particular vendor implementation.
All objects created from ICD compatible objects must be ICD compatible.</p>
</div>
<div class="paragraph">
<p>The definition for <code>_cl_icd_dispatch</code> is provided along with the OpenCL
headers. Existing members can never be removed from that structure but new
members can be appended.</p>
</div>
<div class="paragraph">
<p>Functions which do not have an argument from which the vendor implementation
may be inferred have been deprecated and may be ignored.</p>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-icd-data"><a class="anchor" href="#cl_khr_icd-icd-data"></a>2.4. ICD Data</h3>
<div class="paragraph">
<p>A Vendor ICD is defined by two pieces of data:</p>
</div>
<div class="ulist">
<ul>
<li>
<p>The Vendor ICD library specifies a library which contains the OpenCL
entry points for the vendor&#8217;s OpenCL implementation.
The vendor ICD&#8217;s library file name should include the vendor name, or a
vendor-specific implementation identifier.</p>
</li>
<li>
<p>The Vendor ICD extension suffix is a short string which specifies the
default suffix for extensions implemented only by that vendor.
The vendor suffix string is optional.</p>
</li>
</ul>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-icd-loader-vendor-enumeration-on-windows"><a class="anchor" href="#cl_khr_icd-icd-loader-vendor-enumeration-on-windows"></a>2.5. ICD Loader Vendor Enumeration on Windows</h3>
<div class="paragraph">
<p>To enumerate Vendor ICDs on Windows, the ICD Loader will first
scan for REG_SZ string values in the "Display Adapter" and
"Software Components" HKR registry keys. The exact registry
keys to scan should be obtained via PnP Configuration Manager
APIs, but will look like:</p>
</div>
<div class="paragraph">
<p>For 64-bit ICDs:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>HKLM\SYSTEM\CurrentControlSet\Control\Class\
{Display Adapter GUID}\{Instance ID}\OpenCLDriverName, or
HKLM\SYSTEM\CurrentControlSet\Control\Class\
{Software Component GUID}\{Instance ID}\OpenCLDriverName</pre>
</div>
</div>
<div class="paragraph">
<p>For 32-bit ICDs:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>HKLM\SYSTEM\CurrentControlSet\Control\Class\
{Display Adapter GUID}\{Instance ID}\OpenCLDriverNameWoW, or
HKLM\SYSTEM\CurrentControlSet\Control\Class\
{Software Component GUID}\{Instance ID}\OpenCLDriverNameWoW</pre>
</div>
</div>
<div class="paragraph">
<p>These registry values contain the path to the Vendor ICD library.
For example, if the registry contains the value:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>[HKLM\SYSTEM\CurrentControlSet\Control\Class\{GUID}\{Instance}]
"OpenCLDriverName"="c:\\vendor a\\vndra_ocl.dll"</pre>
</div>
</div>
<div class="paragraph">
<p>Then the ICD Loader will open the Vendor ICD library:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>c:\vendor a\vndra_ocl.dll</pre>
</div>
</div>
<div class="paragraph">
<p>The ICD Loader will also scan for REG_DWORD values in the registry
key:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>HKLM\SOFTWARE\Khronos\OpenCL\Vendors</pre>
</div>
</div>
<div class="paragraph">
<p>For each registry value in this key which has data set to 0, the
ICD Loader will open the Vendor ICD library specified by the name
of the registry value.</p>
</div>
<div class="paragraph">
<p>For example, if the registry contains the value:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>[HKLM\SOFTWARE\Khronos\OpenCL\Vendors]
"c:\\vendor a\\vndra_ocl.dll"=dword:00000000</pre>
</div>
</div>
<div class="paragraph">
<p>Then the ICD will open the Vendor ICD library:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>c:\vendor a\vndra_ocl.dll</pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-icd-loader-vendor-enumeration-on-linux"><a class="anchor" href="#cl_khr_icd-icd-loader-vendor-enumeration-on-linux"></a>2.6. ICD Loader Vendor Enumeration on Linux</h3>
<div class="paragraph">
<p>To enumerate vendor ICDs on Linux, the ICD Loader scans the files in the
path <code>/etc/OpenCL/vendors</code>.
For each file in this path, the ICD Loader opens the file as a text file.
The expected format for the file is a single line of text which specifies
the Vendor ICD&#8217;s library.
The ICD Loader will attempt to open that file as a shared object using
dlopen().
Note that the library specified may be an absolute path or just a file name.</p>
</div>
<div class="paragraph">
<p>For example, if the following file exists</p>
</div>
<div class="listingblock">
<div class="content">
<pre>/etc/OpenCL/vendors/VendorA.icd</pre>
</div>
</div>
<div class="paragraph">
<p>and contains the text</p>
</div>
<div class="listingblock">
<div class="content">
<pre>libVendorAOpenCL.so</pre>
</div>
</div>
<div class="paragraph">
<p>then the ICD Loader will load the library <code>libVendorAOpenCL.so</code>.</p>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-icd-loader-vendor-enumeration-on-android"><a class="anchor" href="#cl_khr_icd-icd-loader-vendor-enumeration-on-android"></a>2.7. ICD Loader Vendor Enumeration on Android</h3>
<div class="paragraph">
<p>To enumerate vendor ICDs on Android, the ICD Loader scans the files in the
path <code>/system/vendor/Khronos/OpenCL/vendors</code>.
For each file in this path, the ICD Loader opens the file as a text file.
The expected format for the file is a single line of text which specifies
the Vendor ICD&#8217;s library.
The ICD Loader will attempt to open that file as a shared object using
dlopen().
Note that the library specified may be an absolute path or just a file name.</p>
</div>
<div class="paragraph">
<p>For example, if the following file exists</p>
</div>
<div class="listingblock">
<div class="content">
<pre>/system/vendor/Khronos/OpenCL/vendors/VendorA.icd</pre>
</div>
</div>
<div class="paragraph">
<p>and contains the text</p>
</div>
<div class="listingblock">
<div class="content">
<pre>libVendorAOpenCL.so</pre>
</div>
</div>
<div class="paragraph">
<p>then the ICD Loader will load the library <code>libVendorAOpenCL.so</code>.</p>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-adding-a-vendor-library"><a class="anchor" href="#cl_khr_icd-adding-a-vendor-library"></a>2.8. Adding a Vendor Library</h3>
<div class="paragraph">
<p>Upon successfully loading a Vendor ICD&#8217;s library, the ICD Loader queries the
following functions from the library: <strong>clIcdGetPlatformIDsKHR</strong>,
<strong>clGetPlatformInfo</strong>, and <strong>clGetExtensionFunctionAddress</strong> (note:
<strong>clGetExtensionFunctionAddress</strong> has been deprecated, but is still required
for the ICD loader).
If any of these functions are not present then the ICD Loader will close and
ignore the library.</p>
</div>
<div class="paragraph">
<p>Next the ICD Loader queries available ICD-enabled platforms in the library
using <strong>clIcdGetPlatformIDsKHR</strong>.
For each of these platforms, the ICD Loader queries the platform&#8217;s extension
string to verify that <strong>cl_khr_icd</strong> is supported, then queries the platform&#8217;s
Vendor ICD extension suffix using <strong>clGetPlatformInfo</strong> with the value
CL_PLATFORM_ICD_SUFFIX_KHR.</p>
</div>
<div class="paragraph">
<p>If any of these steps fail, the ICD Loader will ignore the Vendor ICD and
continue on to the next.</p>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-new-procedures-and-functions"><a class="anchor" href="#cl_khr_icd-new-procedures-and-functions"></a>2.9. New Procedures and Functions</h3>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c">cl_int clIcdGetPlatformIDsKHR(cl_uint num_entries,
cl_platform_id *platforms,
cl_uint *num_platforms);</code></pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-new-tokens"><a class="anchor" href="#cl_khr_icd-new-tokens"></a>2.10. New Tokens</h3>
<div class="paragraph">
<p>Accepted as <em>param_name</em> to the function <strong>clGetPlatformInfo</strong>:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>CL_PLATFORM_ICD_SUFFIX_KHR</pre>
</div>
</div>
<div class="paragraph">
<p>Returned by <strong>clGetPlatformIDs</strong> when no platforms are found:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>CL_PLATFORM_NOT_FOUND_KHR</pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-additions-to-chapter-4"><a class="anchor" href="#cl_khr_icd-additions-to-chapter-4"></a>2.11. Additions to Chapter 4 of the OpenCL 2.2 Specification</h3>
<div class="paragraph">
<p>In <em>section 4.1</em>, replace the description of the return values of
<strong>clGetPlatformIDs</strong> with:</p>
</div>
<div class="paragraph">
<p>"clGetPlatformIDs* returns CL_SUCCESS if the function is executed
successfully and there are a non zero number of platforms available.
It returns CL_PLATFORM_NOT_FOUND_KHR if zero platforms are available.
It returns CL_INVALID_VALUE if <em>num_entries</em> is equal to zero and
<em>platforms</em> is not <code>NULL</code> or if both <em>num_platforms</em> and <em>platforms</em> are
<code>NULL</code>."</p>
</div>
<div class="paragraph">
<p>In <em>section 4.1</em>, add the following after the description of
<strong>clGetPlatformIDs</strong>:</p>
</div>
<div class="paragraph">
<p>"The list of platforms accessible through the Khronos ICD Loader can be
obtained using the following function:
</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="CodeRay highlight"><code data-lang="c">cl_int clIcdGetPlatformIDsKHR(cl_uint num_entries,
cl_platform_id *platforms,
cl_uint *num_platforms);</code></pre>
</div>
</div>
<div class="paragraph">
<p><em>num_entries</em> is the number of cl_platform_id entries that can be added to
<em>platforms</em>.
If <em>platforms</em> is not <code>NULL</code>, then <em>num_entries</em> must be greater than zero.</p>
</div>
<div class="paragraph">
<p><em>platforms</em> returns a list of OpenCL platforms available for access through
the Khronos ICD Loader.
The cl_platform_id values returned in <em>platforms</em> are ICD compatible and can
be used to identify a specific OpenCL platform.
If the <em>platforms</em> argument is <code>NULL</code>, then this argument is ignored.
The number of OpenCL platforms returned is the minimum of the value
specified by <em>num_entries</em> or the number of OpenCL platforms available.</p>
</div>
<div class="paragraph">
<p><em>num_platforms</em> returns the number of OpenCL platforms available.
If <em>num_platforms</em> is <code>NULL</code>, then this argument is ignored.</p>
</div>
<div class="paragraph">
<p><strong>clIcdGetPlatformIDsKHR</strong> returns CL_SUCCESS if the function is executed
successfully and there are a non zero number of platforms available.
It returns CL_PLATFORM_NOT_FOUND_KHR if zero platforms are available.
It returns CL_INVALID_VALUE if <em>num_entries</em> is equal to zero and
<em>platforms</em> is not <code>NULL</code> or if both <em>num_platforms</em> and <em>platforms</em> are
<code>NULL</code>."</p>
</div>
<div class="paragraph">
<p>Add the following to <em>table 4.1</em>:</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 40%;">
<col style="width: 20%;">
<col style="width: 40%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>cl_platform_info enum</strong></th>
<th class="tableblock halign-left valign-top"><strong>Return Type</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>CL_PLATFORM_ICD_SUFFIX_KHR</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">char[]</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">The function name suffix used to identify extension functions to be
directed to this platform by the ICD Loader.</p></td>
</tr>
</tbody>
</table>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-source-code"><a class="anchor" href="#cl_khr_icd-source-code"></a>2.12. Source Code</h3>
<div class="paragraph">
<p>The official source for the ICD loader is available on github, at:</p>
</div>
<div class="paragraph">
<p><a href="https://github.com/KhronosGroup/OpenCL-ICD-Loader" class="bare">https://github.com/KhronosGroup/OpenCL-ICD-Loader</a></p>
</div>
<div class="paragraph">
<p>The complete <code>_cl_icd_dispatch</code> structure is defined in the header
<strong>cl_icd.h</strong>, which is available as a part of the OpenCL headers.</p>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_icd-issues"><a class="anchor" href="#cl_khr_icd-issues"></a>2.13. Issues</h3>
<div class="olist arabic">
<ol class="arabic">
<li>
<p>Some OpenCL functions do not take an object argument from which their
vendor library may be identified (e.g, clUnloadCompiler), how will they
be handled?</p>
<div class="openblock">
<div class="content">
<div class="paragraph">
<p>RESOLVED: Such functions will be a noop for all calls through the ICD.</p>
</div>
</div>
</div>
</li>
<li>
<p>How are OpenCL extension to be handled?</p>
<div class="openblock">
<div class="content">
<div class="paragraph">
<p>RESOLVED: OpenCL extension functions may be added to the ICD as soon as they
are implemented by any vendor.
The suffix mechanism provides access for vendor extensions which are not yet
added to the ICD.</p>
</div>
</div>
</div>
</li>
<li>
<p>How will the ICD handle a <code>NULL</code> cl_platform_id?</p>
<div class="openblock">
<div class="content">
<div class="paragraph">
<p>RESOLVED: The ICD will by default choose the first enumerated platform as
the <code>NULL</code> platform.
The user can override this default by setting an environment variable
OPENCL_ICD_DEFAULT_PLATFORM to the desired platform index.
The API calls that deal with platforms will return CL_INVALID_PLATFORM if
the index is not between zero and (number of platforms - 1), both inclusive.</p>
</div>
</div>
</div>
</li>
<li>
<p>There exists no mechanism to unload the ICD, should there be one?</p>
<div class="openblock">
<div class="content">
<div class="paragraph">
<p>RESOLVED: As there is no standard mechanism for unloading a vendor
implementation, do not add one for the ICD.</p>
</div>
</div>
</div>
</li>
<li>
<p>How will the ICD loader handle <code>NULL</code> objects passed to the OpenCL
functions?</p>
<div class="openblock">
<div class="content">
<div class="paragraph">
<p>RESOLVED: The ICD loader will check for <code>NULL</code> objects passed to the OpenCL
functions without trying to dereference the <code>NULL</code> objects for obtaining the
ICD dispatch table.
On detecting a <code>NULL</code> object it will return one of the CL_INVALID_* error
values corresponding to the object in question.</p>
</div>
</div>
</div>
</li>
</ol>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="cl_khr_byte_addressable_store"><a class="anchor" href="#cl_khr_byte_addressable_store"></a>3. Byte Addressable Stores</h2>
<div class="sectionbody">
<div class="paragraph">
<p>This section describes the <strong>cl_khr_byte_addressable_store</strong> extension.
This extension relaxes restrictions on pointers to <code>char</code>, <code>uchar</code>, <code>char2</code>, <code>uchar2</code>, <code>short</code>, <code>ushort</code> and <code>half</code> that were present in <em>Section 6.8m: Restrictions</em> of the OpenCL 1.0 specification.
With this extension, applications are able to read from and write to pointers to these types.</p>
</div>
<div class="paragraph">
<p>This extension became a core feature in OpenCL 1.1.</p>
</div>
<div class="sect2">
<h3 id="_general_information_2"><a class="anchor" href="#_general_information_2"></a>3.1. General information</h3>
<div class="sect3">
<h4 id="_version_history_2"><a class="anchor" href="#_version_history_2"></a>3.1.1. Version history</h4>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 60%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Date</strong></th>
<th class="tableblock halign-left valign-top"><strong>Version</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">2020-04-21</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">1.0.0</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">First assigned version.</p></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="cl_khr_3d_image_writes"><a class="anchor" href="#cl_khr_3d_image_writes"></a>4. Writing to 3D Image Objects</h2>
<div class="sectionbody">
<div class="paragraph">
<p>This section describes the <strong>cl_khr_3d_image_writes</strong> extension.</p>
</div>
<div class="paragraph">
<p>This extension adds built-in functions that allow a kernel to write to 3D image objects in addition to 2D image objects.</p>
</div>
<div class="paragraph">
<p>This extension became a core feature in OpenCL 2.0.</p>
</div>
<div class="sect2">
<h3 id="_general_information_3"><a class="anchor" href="#_general_information_3"></a>4.1. General information</h3>
<div class="sect3">
<h4 id="_version_history_3"><a class="anchor" href="#_version_history_3"></a>4.1.1. Version history</h4>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 60%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Date</strong></th>
<th class="tableblock halign-left valign-top"><strong>Version</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">2020-04-21</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">1.0.0</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">First assigned version.</p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
<p>The new built-in functions are described in the table below:</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 1. <em>3D Image Built-in Image Write Functions</em></caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Function</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">void <strong>write_imagef</strong> (<br>
image3d_t <em>image</em>,<br>
int4 <em>coord</em>,<br>
float4 <em>color</em>)<br>
<br>
void <strong>write_imagei</strong> (<br>
image3d_t <em>image</em>,<br>
int4 <em>coord</em>,<br>
int4 <em>color</em>)<br>
<br>
void <strong>write_imageui</strong> (<br>
image3d_t <em>image</em>,<br>
int4 <em>coord</em>,<br>
uint4 <em>color</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Write <em>color</em> value to the location specified by coordinate (<em>x</em>, <em>y</em>, <em>z</em>) in the 3D image specified by <em>image</em>.
The appropriate data format conversion to the specified image format is done before writing the color value.
<em>coord.x</em>, <em>coord.y</em>, and <em>coord.z</em> are considered to be unnormalized coordinates and must be in the range 0 &#8230;&#8203; image width - 1, 0 &#8230;&#8203; image height - 1, and 0 &#8230;&#8203; image depth - 1.<br>
<br>
<strong>write_imagef</strong> can only be used with image objects created with <em>image_channel_data_type</em> set to one of the pre-defined packed formats or set to CL_SNORM_INT8, CL_UNORM_INT8, CL_SNORM_INT16, CL_UNORM_INT16, CL_HALF_FLOAT, or CL_FLOAT. Appropriate data format conversion will be done to convert the channel data from a floating-point value to the actual data format in which the channels are stored.<br>
<br>
<strong>write_imagei</strong> can only be used with image objects created with <em>image_channel_data_type</em> set to one of the following values:<br>
CL_SIGNED_INT8,<br>
CL_SIGNED_INT16, or<br>
CL_SIGNED_INT32.<br>
<br>
<strong>write_imageui</strong> can only be used with image objects created with <em>image_channel_data_type</em> set to one of the following values:<br>
CL_UNSIGNED_INT8,<br>
CL_UNSIGNED_INT16, or<br>
CL_UNSIGNED_INT32.<br>
<br>
The behavior of <strong>write_imagef</strong>, <strong>write_imagei</strong>, and <strong>write_imageui</strong> for image objects created with <em>image_channel_data_type</em> values not specified in the description above, or with (<em>x</em>, <em>y</em>, <em>z</em>) coordinate values that are not in the range (0 &#8230;&#8203; image width - 1, 0 &#8230;&#8203; image height - 1, 0 &#8230;&#8203; image depth - 1) respectively, is undefined.</p></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="cl_khr_fp16"><a class="anchor" href="#cl_khr_fp16"></a>5. Half Precision Floating-Point</h2>
<div class="sectionbody">
<div class="paragraph">
<p>This section describes the <strong>cl_khr_fp16</strong> extension.
This extension adds support for half scalar and vector types as built-in
types that can be used for arithmetic operations, conversions etc.</p>
</div>
<div class="sect2">
<h3 id="_general_information_4"><a class="anchor" href="#_general_information_4"></a>5.1. General information</h3>
<div class="sect3">
<h4 id="_version_history_4"><a class="anchor" href="#_version_history_4"></a>5.1.1. Version history</h4>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 60%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Date</strong></th>
<th class="tableblock halign-left valign-top"><strong>Version</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">2020-04-21</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">1.0.0</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">First assigned version.</p></td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="sect2">
<h3 id="cl_khr_fp16-additions-to-chapter-6-of-the-opencl-2.0-specification"><a class="anchor" href="#cl_khr_fp16-additions-to-chapter-6-of-the-opencl-2.0-specification"></a>5.2. Additions to Chapter 6 of the OpenCL 2.0 C Specification</h3>
<div class="paragraph">
<p>The list of built-in scalar, and vector data types defined in <em>tables 6.1</em>,
and <em>6.2</em> are extended to include the following:</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 25%;">
<col style="width: 75%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Type</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half2</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A 2-component half-precision floating-point vector.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half3</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A 3-component half-precision floating-point vector.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half4</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A 4-component half-precision floating-point vector.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half8</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A 8-component half-precision floating-point vector.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half16</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A 16-component half-precision floating-point vector.</p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
<p>The built-in vector data types for <code>halfn</code> are also declared as appropriate
types in the OpenCL API (and header files) that can be used by an
application.
The following table describes the built-in vector data types for <code>halfn</code> as
defined in the OpenCL C programming language and the corresponding data type
available to the application:</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Type in OpenCL Language</strong></th>
<th class="tableblock halign-left valign-top"><strong>API type for application</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half2</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>cl_half2</strong></p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half3</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>cl_half3</strong></p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half4</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>cl_half4</strong></p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half8</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>cl_half8</strong></p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>half16</strong></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><strong>cl_half16</strong></p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
<p>The relational, equality, logical and logical unary operators described in
<em>section 6.3</em> can be used with <code>half</code> scalar and <code>halfn</code> vector types and
shall produce a scalar <code>int</code> and vector <code>shortn</code> result respectively.</p>
</div>
<div class="paragraph">
<p>The OpenCL compiler accepts an h and H suffix on floating point literals,
indicating the literal is typed as a half.</p>
</div>
<div class="sect3">
<h4 id="cl_khr_fp16-conversions"><a class="anchor" href="#cl_khr_fp16-conversions"></a>5.2.1. Conversions</h4>
<div class="paragraph">
<p>The implicit conversion rules specified in <em>section 6.2.1</em> now include the
<code>half</code> scalar and <code>halfn</code> vector data types.</p>
</div>
<div class="paragraph">
<p>The explicit casts described in <em>section 6.2.2</em> are extended to take a
<code>half</code> scalar data type and a <code>halfn</code> vector data type.</p>
</div>
<div class="paragraph">
<p>The explicit conversion functions described in <em>section 6.2.3</em> are extended
to take a <code>half</code> scalar data type and a <code>halfn</code> vector data type.</p>
</div>
<div class="paragraph">
<p>The <code>as_typen()</code> function for re-interpreting types as described in <em>section
6.2.4.2</em> is extended to allow conversion-free casts between <code>shortn</code>,
<code>ushortn</code>, and <code>halfn</code> scalar and vector data types.</p>
</div>
</div>
<div class="sect3">
<h4 id="cl_khr_fp16-math-functions"><a class="anchor" href="#cl_khr_fp16-math-functions"></a>5.2.2. Math Functions</h4>
<div class="paragraph">
<p>The built-in math functions defined in <em>table 6.8</em> (also listed below) are
extended to include appropriate versions of functions that take <code>half</code> and
<code>half{2|3|4|8|16}</code> as arguments and return values.
<code>gentype</code> now also includes <code>half</code>, <code>half2</code>, <code>half3</code>, <code>half4</code>, <code>half8</code>, and
<code>half16</code>.</p>
</div>
<div class="paragraph">
<p>For any specific use of a function, the actual type has to be the same for
all arguments and the return type.</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 2. <em>Half Precision Built-in Math Functions</em></caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top"><strong>Function</strong></th>
<th class="tableblock halign-left valign-top"><strong>Description</strong></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>acos</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Arc cosine function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>acosh</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Inverse hyperbolic cosine.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>acospi</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <strong>acos</strong> (<em>x</em>) / π.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>asin</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Arc sine function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>asinh</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Inverse hyperbolic sine.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>asinpi</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <strong>asin</strong> (<em>x</em>) / π.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>atan</strong> (gentype <em>y_over_x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Arc tangent function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>atan2</strong> (gentype <em>y</em>, gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Arc tangent of <em>y</em> / <em>x</em>.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>atanh</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Hyperbolic arc tangent.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>atanpi</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <strong>atan</strong> (<em>x</em>) / π.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>atan2pi</strong> (gentype <em>y</em>, gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <strong>atan2</strong> (<em>y</em>, <em>x</em>) / π.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>cbrt</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute cube-root.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>ceil</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Round to integral value using the round to positive infinity rounding
mode.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>copysign</strong> (gentype <em>x</em>, gentype <em>y</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Returns <em>x</em> with its sign changed to match the sign of <em>y</em>.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>cos</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute cosine.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>cosh</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute hyperbolic cosine.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>cospi</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <strong>cos</strong><em>x</em>).</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>erfc</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Complementary error function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>erf</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Error function encountered in integrating the normal distribution.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>exp</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute the base- e exponential of <em>x</em>.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>exp2</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Exponential base 2 function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>exp10</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Exponential base 10 function.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>expm1</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute <em>e<sup>x</sup></em>- 1.0.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>fabs</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Compute absolute value of a floating-point number.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>fdim</strong> (gentype <em>x</em>, gentype <em>y</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><em>x</em> - <em>y</em> if <em>x</em> &gt; <em>y</em>, +0 if x is less than or equal to y.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">gentype <strong>floor</strong> (gentype <em>x</em>)</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Round to integral value using the round to negative infinity rounding
mode.</p></td>
</tr>
<tr>