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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Oliver,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks. The updated patch and reasoning LGTM.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">James<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Oliver Stannard
<br>
<b>Sent:</b> 07 February 2014 10:51<br>
<b>To:</b> 'Renato Golin'; James Molloy<br>
<b>Cc:</b> LLVM Commits<br>
<b>Subject:</b> RE: [PATCH] AAPCS-VFP: Do not use any more VFP registers after allocating a CPRC to the stack<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">For the first line, the AAPCS states that all registers must be shadowed (“The NCRN is set to r4” in AAPCS terminology). I cannot think of any case where the
original version would cause incorrect behaviour, but I’m not certain, and the modified version more explicitly reflects the intent of the AAPCS.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">As for the second line, again I cannot think of a case in which the original version is incorrect, but it more explicitly reflects the AAPCS rule that no GPRs
should be used after a non-CPRC argument has been allocated on the stack.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I have attached an updated patch which fixed the typo and alignment error.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I will mention the change to the GPR shadowing in the commit message.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Oliver<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Renato Golin [<a href="mailto:renato.golin@linaro.org">mailto:renato.golin@linaro.org</a>]
<br>
<b>Sent:</b> 07 February 2014 10:19<br>
<b>To:</b> James Molloy<br>
<b>Cc:</b> Oliver Stannard; LLVM Commits<br>
<b>Subject:</b> Re: [PATCH] AAPCS-VFP: Do not use any more VFP registers after allocating a CPRC to the stack<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On 7 February 2014 10:08, James Molloy <<a href="mailto:james.molloy@arm.com" target="_blank">james.molloy@arm.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The first line did shadow just R3 but now shadows all registers. I suspect that actually this was
a bug, which you have now fixed incidentally? Your patch description only mentions coprocessor registers so can you just confirm this is deliberate?</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The second line has changed behaviour – previously in the i32 case no registers were shadowed – now
R0-R3 are shadowed. Why is this correct? (not saying it’s not, but some justification would be good).</span><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I assumed both cases were the same "fix" that weren't mentioned in the commit message (and that's why I was unsure of the "fix").<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If that's correct, I agree would be good to have a mention in the commit message. ;)<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">cheers,<o:p></o:p></p>
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<p class="MsoNormal">--renato<o:p></o:p></p>
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