<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: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=utf-8">
<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:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* 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:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
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;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@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:1901789378;
mso-list-type:hybrid;
mso-list-template-ids:-201703016 67698703 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l0:level1
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level2
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level5
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0:level8
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;}
@list l0: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="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal">Hi Scott,<o:p></o:p></p>
<p class="MsoNormal">Sorry for the late reply, I was out of office during the holidays.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">A def node can reach either a use node, or another def node. In the highlighted phi node (p3224), the def (d3225) reaches another def (1598) in statement (s1597), that’s why it’s
needed.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">The reason why the def of R11 in s1578 is not connected directly to the use in s1725 is that there may be an intervening def between them (that phi node of the register mask may be
one such def).<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">-- </span>
<span style="font-size:9.0pt;font-family:Consolas"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:8.0pt;font-family:Consolas">Krzysztof Parzyszek
<a href="mailto:kparzysz@quicinc.com"><span style="color:#0563C1">kparzysz@quicinc.com</span></a> AI tools development<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Scott Douglas Constable <sdconsta@syr.edu> <br>
<b>Sent:</b> Friday, December 27, 2019 5:58 PM<br>
<b>To:</b> Krzysztof Parzyszek <kparzysz@quicinc.com><br>
<b>Cc:</b> llvm-dev@lists.llvm.org<br>
<b>Subject:</b> [EXT] Re: [llvm-dev] Register Dataflow Analysis on X86<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<div>
<p class="MsoNormal">Hi Krzysztof,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Thanks for the reply, I'm starting to understand the graph structure and terminology much better now, especially with the document in RDFGraph.h. I'm still a bit confused about some of the behavior I'm seeing with the phi nodes that involve
aggregate registers. Here is one example:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"> b1531: --- %bb.36 --- preds(2): %bb.35, %bb.128 succs(1): %bb.37<br>
p3193: phi [+d3194<RBP>(,,u3211):, u3195<RBP>(+d3170,b1526):u1437, u3196<RBP>(d2141,b2486):u2324]<br>
p3197: phi [+d3198<RBX>(,,u3216):, u3199<RBX>(+d3138,b1526):u1465, u3200<RBX>(+d3364,b2486):]<br>
p3201: phi [+d3202<R12D>(,d1541,):, u3203<R12D>(+d3146,b1526):, u3204<R12D>(d1878,b2486):u3148]<br>
p3205: phi [+d3206<#1073741833>(,d1551,u1552):, u3207"<#1073741833>(d1521,b1526):u1524, u3779"<#1073741833>(d1517,b1526):, u3780"<#1073741833>(d1513,b1526):u1522, u3208"<#1073741833>(d2481,b2486):u2484, u3695"<#1073741833>(d2477,b2486):, u3696"<#1073741833>(d2473,b2486):u2482]<br>
s1532: ADJCALLSTACKDOWN64 [d1533<RSP>!(+d3206,\~d3647",u1557):, d1534<EFLAGS>!(+d3206,d1540,):d1533, d1535<SSP>!(+d3206,\~d3646",u1558):d1534, u1536<RSP>!(+d3206):, u1537<SSP>!(+d3206):u1536]<br>
s1538: MOV32r0 [d1539<R12D>(+d3202,,):, d1540<EFLAGS>!(d1534,d1549,):, d1541<R12>(+d3202,,u3221):d1539]<br>
s1542: MOV32ri64 [d1543<RDX>(+d3206,\~d3645",u1561):d1535]<br>
s1544: COPY [d1545<RDI>(+d3206,\~d3644",u1559):d1543, u1546<R13>(d785):]<br>
s1547: MOV32r0 [d1548<ESI>(+d3206,\~d3643",u1560):d1545, d1549<EFLAGS>!(d1540,\~d3642",):]<br>
s1550: MOV64rm [d1551<R11>(+d3206,\~d1554",u1562):d1548, u1552<RIP>(+d3206):u1537]<br>
s1553: CALL64pcrel32 __foo [\~d1554"<#1073741833>!(d1551,d1579,):, \~d3642"<#1073741833>!(d1549,,):, \~d3643"<#1073741833>!(d1548,,):, \~d3644"<#1073741833>!(d1545,,):, \~d3645"<#1073741833>!(d1543,,):, \~d3646"<#1073741833>!(d1535,,):, \~d3647"<#1073741833>!(d1533,,):,
d1555<RSP>!(\~d1554",d1564,u1567):, d1556<SSP>!(\~d1554",d1566,u1568):d1555, u1557<RSP>!(d1533):, u1558<SSP>!(d1535):, u1559<RDI>!(d1545):, u1560<ESI>!(d1548):, u1561<RDX>!(d1543):, u1562<R11>!(d1551):]<br>
s1563: ADJCALLSTACKUP64 [d1564<RSP>!(d1555,,u3778"):, d1565<EFLAGS>!(\~d1554",d1571,):d1556, d1566<SSP>!(d1556,,u3777"):,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> u1567<RSP>!(d1555):, u1568<SSP>!(d1556):]<br>
s1569: MOV32r0 [d1570<R10D>(\~d1554",,u3776"):d1565, d1571<EFLAGS>!(d1565,d1574,):]<br>
s1572: MOV32r0 [d1573<R8D>(\~d1554",,u3775"):d1570, d1574<EFLAGS>!(d1571,d1577,):]<br>
s1575: MOV32r0 [d1576<R9D>(\~d1554",,u3774"):d1573, d1577<EFLAGS>!(d1574,,u3773"):]<br>
---> s1578: MOV64rm [d1579<R11>(\~d1554",,u3226"):d1576]<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"> b1580: --- %bb.37 --- preds(3): %bb.36, %bb.49, %bb.64 succs(1): %bb.38<br>
p3209: phi [+d3210<RBP>(,d1731,u3212):, u3211<RBP>(+d3194,b1531):, u3212<RBP>(+d3210,b1710):, u3213<RBP>(d1857,b1874):u3466]<br>
p3214: phi [+d3215<RBX>(,,u3217):, u3216<RBX>(+d3198,b1531):, u3217<RBX>(+d3215,b1710):u3257, u3218<RBX>(+d3290,b1874):u3470]<br>
p3219: phi [+d3220<R12D>(,d1712,u1714):, u3221<R12D>(d1541,b1531):, u3222<R12D>(d1712,b1710):u1717, u3223<R12D>(d1878,b1874):u3204]<br>
---> p3224: phi [+d3225<#1073741833>(,d1598,):, u3226"<#1073741833>(d1579,b1531):, u3773"<#1073741833>(d1577,b1531):, u3774"<#1073741833>(d1576,b1531):, u3775"<#1073741833>(d1573,b1531):, u3776"<#1073741833>(d1570,b1531):, u3777"<#1073741833>(d1566,b1531):,
u3778"<#1073741833>(d1564,b1531):, u3227<#1073741833>(d1716,b1710):u1719, u3228"<#1073741833>(d1885,b1874):u3751", u3754"<#1073741833>(d1880,b1874):u1887, u3755"<#1073741833>(d1865,b1874):u3752", u3756"<#1073741833>(d1861,b1874):u3753"]<br>
s1581: IMUL64rri8 [d1582<RAX>(+d3225,d1596,u1592):, d1583<EFLAGS>!(+d3225,d1595,):d1582, u1584<R12>(+d3220):]<br>
s1585: LEA64r [d1586<RSI>(+d3225,,u3772"):d1583, u1587<R15>(d776):, u1588<RAX>(d1582):]<br>
s1589: LEA64r [d1590<RDI>(+d3225,,u3771"):d1586, u1591<R14>(+d3142):u1455, u1592<RAX>(d1582):u1588]<br>
s1593: MOV32r0 [d1594<EAX>(d1582,,):, d1595<EFLAGS>!(d1583,d1599,):, d1596<RAX>(d1582,,u3770"):d1594]<br>
s1597: MOV32r0 [d1598<ECX>(+d3225,,u3769"):d1590, d1599<EFLAGS>!(d1595,,u3231"):]<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">I have used arrows to highlight two nodes. The first node, s1578, def's d1579<R11>, which has a single reached use in phi node p3224. I am surprised that this phi node exists and has no reached uses, for two reasons. First, I built the
graph without the KeepDeadPhis option. Shouldn't this remove phi nodes without reached uses? Second, there clearly
<i>is</i> a reached use of R11 (corresponding to the instruction represented by s1578) in another basic block:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"> b1721: --- %bb.50 --- preds(1): %bb.49 succs(1): %bb.51<br>
s1722: COPY [d1723<RSI>(+d3248,,u3765"):d1713, u1724<R13>(d785):u1546]<br>
---> s1725: COPY [d1726<RDI>(+d3248,,u3764"):d1723, u1727<R11>(+d3248):]<br>
s1728: MOV32r0 [d1729<EBP>(+d3210,,):, d1730<EFLAGS>!(d1716,,u3261"):, d1731<RBP>(+d3210,,u3253):d1729]<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">I have confirmed via manual inspection and the use of a dynamic analysis tool that the next use of the R11 def in s1578 is s1725.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Could you please clarify these two points?<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Scott<o:p></o:p></p>
</div>
</div>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal">On Mon, Dec 23, 2019 at 12:46 PM Krzysztof Parzyszek <<a href="mailto:kparzysz@quicinc.com">kparzysz@quicinc.com</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in">
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi Scott,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">That #1073741833 is a register mask. They are treated as aggregate registers (essentially sets of registers), so if it includes R9D and R11D, it will be treated as being aliased
with both.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">These separate defs are there because they reach disjoint registers.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:9.0pt;font-family:Consolas">--
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:8.0pt;font-family:Consolas">Krzysztof Parzyszek
<a href="mailto:kparzysz@quicinc.com" target="_blank"><span style="color:#0563C1">kparzysz@quicinc.com</span></a> AI tools development</span><o:p></o:p></p>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div style="border:none;border-left:solid windowtext 1.5pt;padding:0in 0in 0in 4.0pt;border-color:currentColor currentColor currentColor blue">
<div>
<div style="border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:currentColor currentColor">
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>From:</b> Scott Douglas Constable <<a href="mailto:sdconsta@syr.edu" target="_blank">sdconsta@syr.edu</a>>
<br>
<b>Sent:</b> Monday, December 23, 2019 2:10 PM<br>
<b>To:</b> Scott Douglas Constable <<a href="mailto:sdconsta@syr.edu" target="_blank">sdconsta@syr.edu</a>><br>
<b>Cc:</b> Krzysztof Parzyszek <<a href="mailto:kparzysz@quicinc.com" target="_blank">kparzysz@quicinc.com</a>>;
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<b>Subject:</b> [EXT] Re: [llvm-dev] Register Dataflow Analysis on X86<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Revisiting this thread. I have been experimenting with the RDF module on the X86 target. For the most part, building the data-flow graph and following def-use chains seems to work
fine. But I am also observing some strange behavior in the phi nodes. For example, I have one basic block which begins with the following 4 phi nodes:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">b585: --- %bb.25 --- preds(5): %bb.24, %bb.20, %bb.22, %bb.49, %bb.52 succs(2): %bb.18, %bb.37<br>
p1095: phi [+d1096<EBP>(,d668,):, u1097<EBP>(d540,b477):u555, u1098<EBP>(d427,b448):u450, u1099<EBP>(d427,b462):u464, u1100<EBP>(d427,b1009):u1011, u1101<EBP>(d427,b1027):u1029]<br>
p1102: phi [+d1103<R13D>(,,u1075):, u1104<R13D>(d557,b477):u563, u1105<R13D>(d411,b448):, u1106<R13D>(d411,b462):u459, u1107<R13D>(d411,b1009):u1106, u1108<R13D>(d411,b1027):u1107]<br>
p1109: phi [+d1110<R14D>(,d625,u612):, u1111<R14D>(d584,b477):, u1112<R14D>(d452,b448):, u1113<R14D>(d466,b462):, u1114<R14D>(d1013,b1009):, u1115<R14D>(d1031,b1027):]<br>
p1116: phi [+d1117<#1073741833>(,d645,u648):, u1118"<#1073741833>(d579,b477):, u1466"<#1073741833>(d578,b477):, u1467"<#1073741833>(d569,b477):u581, u1468"<#1073741833>(d546,b477):, u1469"<#1073741833>(d543,b477):, u1470"<#1073741833>(d524,b477):u530, u1119"<#1073741833>(d453,b448):,
u1436"<#1073741833>(d420,b448):, u1437"<#1073741833>(d404,b448):u445, u1120"<#1073741833>(d467,b462):, u1438"<#1073741833>(d420,b462):u1436", u1439"<#1073741833>(d404,b462):u473, u1121"<#1073741833>(d1014,b1009):, u1440"<#1073741833>(d420,b1009):u1006, u1441"<#1073741833>(d404,b1009):u1439",
u1122"<#1073741833>(d1032,b1027):, u1442"<#1073741833>(d420,b1027):u1440", u1443"<#1073741833>(d404,b1027):u1441"]<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">The first three make perfect sense to me, and seem to reflect the post-allocation MIR correctly. The fourth phi node seems entirely composed of defs and uses for some unnamed register
#1073741833 (what exactly is the significance of unnamed registers?). Moreover, this phi seems to be introducing false def-use relationships into the DFG. For example, the phi introduces the following dependency chain, which as far as I can tell is not valid:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">// R11D is def'ed, def ID is d524<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">s523: SUB32rr [d524<R11D>(d519,,u1470"):, d525<EFLAGS>!(d520,d533,):, u526<R11D>(d519):, u527<ESI>(d508):]<br>
...<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">// d524 is used in the phi node to def d1117, corresponding to unnamed register #1073741833<br>
p1116: phi [+d1117<#1073741833>(,d645,u648):, u1118"<#1073741833>(d579,b477):, u1466"<#1073741833>(d578,b477):, u1467"<#1073741833>(d569,b477):u581, u1468"<#1073741833>(d546,b477):, u1469"<#1073741833>(d543,b477):, u1470"<#1073741833>(d524,b477):u530, u1119"<#1073741833>(d453,b448):,
u1436"<#1073741833>(d420,b448):, u1437"<#1073741833>(d404,b448):u445, u1120"<#1073741833>(d467,b462):, u1438"<#1073741833>(d420,b462):u1436", u1439"<#1073741833>(d404,b462):u473, u1121"<#1073741833>(d1014,b1009):, u1440"<#1073741833>(d420,b1009):u1006, u1441"<#1073741833>(d404,b1009):u1439",
u1122"<#1073741833>(d1032,b1027):, u1442"<#1073741833>(d420,b1027):u1440", u1443"<#1073741833>(d404,b1027):u1441"]<br>
...<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">// d1117 is used in def d645 of register R9D<br>
s644: ADD32rr [d645<R9D>(+d1117,d694,u659):d634, d646<EFLAGS>!(d633,d651,):, u647<R9D>(+d1117):u637, u648<R9D>(+d1117):u647]<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">But after examining the corresponding MIR, I do not think that R11D flows into R9D. So it looks to me as though this phi node is erroneous.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Any help wold be much appreciated!<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I'm using the LLVM 8.0.1 release.<o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Fri, Nov 8, 2019 at 10:35 AM Scott Douglas Constable via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid windowtext 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt;border-color:currentColor currentColor currentColor rgb(204,204,204)">
<div>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Do you know whether it has been fixed on the 8.0.1 release?<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Scott<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Fri, Nov 8, 2019 at 9:45 AM Krzysztof Parzyszek <<a href="mailto:kparzysz@quicinc.com" target="_blank">kparzysz@quicinc.com</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid windowtext 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt;border-color:currentColor currentColor currentColor rgb(204,204,204)">
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">The one blocking issue that existed in the past has been fixed. I haven’t had time to do any work on it lately, but I’m not aware of any fundamental problems that would make it
not work on x86.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:9.0pt;font-family:Consolas">--
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:8.0pt;font-family:Consolas">Krzysztof Parzyszek
<a href="mailto:kparzysz@quicinc.com" target="_blank"><span style="color:#0563C1">kparzysz@quicinc.com</span></a> AI tools development</span><o:p></o:p></p>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div style="border:none;border-left:solid windowtext 1.5pt;padding:0in 0in 0in 4.0pt;border-color:currentColor currentColor currentColor blue">
<div>
<div style="border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:currentColor">
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>From:</b> llvm-dev <<a href="mailto:llvm-dev-bounces@lists.llvm.org" target="_blank">llvm-dev-bounces@lists.llvm.org</a>>
<b>On Behalf Of </b>Scott Douglas Constable via llvm-dev<br>
<b>Sent:</b> Friday, November 8, 2019 10:59 AM<br>
<b>To:</b> <a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<b>Subject:</b> [EXT] [llvm-dev] Register Dataflow Analysis on X86<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222">I came across this thread from a couple years ago:</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222"><a href="http://lists.llvm.org/pipermail/llvm-dev/2017-November/119346.html" target="_blank"><span style="color:#1155CC">http://lists.llvm.org/pipermail/llvm-dev/2017-November/119346.html</span></a></span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222">Has there been any progress on RDF for X86? Or is there some other preferred alternative for performing
reachability analysis after register allocation?</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222">Thanks,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222">Scott Constable</span><o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank">https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><o:p></o:p></p>
</blockquote>
</div>
</div>
</div>
</div>
</blockquote>
</div>
</div>
</div>
</body>
</html>