<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
        {font-family:"Cambria Math";
        panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
        {font-family:Calibri;
        panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
        {font-family:\00A0-apple-system;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
        {mso-style-priority:99;
        color:#0563C1;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {mso-style-priority:99;
        color:#954F72;
        text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
        {mso-style-priority:34;
        margin-top:0in;
        margin-right:0in;
        margin-bottom:0in;
        margin-left:.5in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri",sans-serif;}
span.EmailStyle17
        {mso-style-type:personal-compose;
        font-family:"Calibri",sans-serif;
        color:windowtext;}
.MsoChpDefault
        {mso-style-type:export-only;
        font-family:"Calibri",sans-serif;}
@page WordSection1
        {size:8.5in 11.0in;
        margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
        {page:WordSection1;}
/* List Definitions */
@list l0
        {mso-list-id:22481998;
        mso-list-type:hybrid;
        mso-list-template-ids:1206541052 -1142249374 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l0:level1
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:20.4pt;
        text-indent:-.25in;
        mso-ansi-font-size:10.5pt;
        font-family:\00A0-apple-system;
        color:#333333;}
@list l0:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:56.4pt;
        text-indent:-.25in;}
@list l0:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:92.4pt;
        text-indent:-9.0pt;}
@list l0:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:128.4pt;
        text-indent:-.25in;}
@list l0:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:164.4pt;
        text-indent:-.25in;}
@list l0:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:200.4pt;
        text-indent:-9.0pt;}
@list l0:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:236.4pt;
        text-indent:-.25in;}
@list l0:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:272.4pt;
        text-indent:-.25in;}
@list l0:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:308.4pt;
        text-indent:-9.0pt;}
@list l1
        {mso-list-id:97994749;
        mso-list-type:hybrid;
        mso-list-template-ids:142097574 865251192 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l1:level1
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:38.4pt;
        text-indent:-.25in;
        mso-ansi-font-size:10.5pt;
        font-family:\00A0-apple-system;
        color:#333333;}
@list l1:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:74.4pt;
        text-indent:-.25in;}
@list l1:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:110.4pt;
        text-indent:-9.0pt;}
@list l1:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:146.4pt;
        text-indent:-.25in;}
@list l1:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:182.4pt;
        text-indent:-.25in;}
@list l1:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:218.4pt;
        text-indent:-9.0pt;}
@list l1:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:254.4pt;
        text-indent:-.25in;}
@list l1:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        margin-left:290.4pt;
        text-indent:-.25in;}
@list l1:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        margin-left:326.4pt;
        text-indent:-9.0pt;}
@list l2
        {mso-list-id:219706664;
        mso-list-type:hybrid;
        mso-list-template-ids:1089900450 67698703 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l2:level1
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l2:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l2:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l2:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l3
        {mso-list-id:402064253;
        mso-list-type:hybrid;
        mso-list-template-ids:-1064772774 67698703 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l3:level1
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l3:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l3:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l3:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
ol
        {margin-bottom:0in;}
ul
        {margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">Hi!<o:p></o:p></p>
<p class="MsoNormal">In single source programming models (like CUDA, OpenMP) there are both "host" and "device" code in the same source file/translation unit.  This causes some issues with system headers and standard library headers when compilation is performed
 for device target. Reason is that even when compiling for the device, host code must be semantically analyzable.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">For example, in case of compilation to ‘spir’ target with -std=gnu++11 flag we will get an error:<o:p></o:p></p>
<p class="MsoNormal">error: __float128 is not supported on this target<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Also, in headers there could be other things like inline asm, intrinsics not lowerable in device.<o:p></o:p></p>
<p class="MsoNormal">Since the problem is not new, my question is about the possible solutions of this problem.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="text-autospace:none">I tried to look into the approach currently implemented in clang for single source programming models.<o:p></o:p></p>
<p class="MsoNormal" style="text-autospace:none">As far as I understood:<o:p></o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:2.4pt;mso-list:l1 level1 lfo4;text-autospace:none">
Host headers are used for device compilation.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:2.4pt;mso-list:l1 level1 lfo4;text-autospace:none">
-aux-triple for host device and triple for target device are used to enable defines and builtins for both targets unconditionally.<o:p></o:p></li><li class="MsoNormal" style="margin-left:2.4pt;mso-list:l1 level1 lfo4">Deferred diagnostics approach is used to emit diagnostics only when we know that something unsupported is used on device.
<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:2.4pt;mso-list:l1 level1 lfo4;text-autospace:none">
For unsupported types we still emit these types by emit errors only for operations with such types.<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is this an approach which is used in clang to solve the problem with headers in single source programming languages?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Best regards, <o:p></o:p></p>
<p class="MsoNormal">Artur Gainullin<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>