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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Renato,<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, that's a helpful explanation of the position. I sympathise with your 'co-operation over following' view, though I'm also not sure how.<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'm not convinced that having both -mcpu and -march makes the driver any more mind boggling - I'm sure we could implement something tidier than what happened for the ARM32 side. But I think Amara's superset proposal would have a simpler implementation, so let's move on with that for now.<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'>Regards,<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'>Bernie<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><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><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 [mailto:renato.golin@linaro.org] <br><b>Sent:</b> 08 January 2014 12:58<br><b>To:</b> Bernard Ogden<br><b>Cc:</b> Eric Christopher; LLVM Developers Mailing List; Clang Dev; Amara Emerson<br><b>Subject:</b> Re: [cfe-dev] [LLVMdev] AArch64 Clang CLI interface proposal<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><div><p class=MsoNormal>On 8 January 2014 12:32, Bernard Ogden <<a href="mailto:Bernard.Ogden@arm.com" target="_blank">Bernard.Ogden@arm.com</a>> wrote:<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:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I don't think there's software that *needs* the compatibility, but it is easier for GCC projects to switch to clang if that compatibility is there - which I think is why we go for GCC compatibility in the first place?</span><o:p></o:p></p></div></div></div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Hi Bernie,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>GCC compatibility is always considered to be an important feature of LLVM, not the *most* important one. We'll never go beyond reason to add GCC compatibility just because, especially one that is poorly or not at all documented.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The general rule of thumb is to ask the questions:<o:p></o:p></p></div><div><p class=MsoNormal> * Do we really need it?<o:p></o:p></p></div><div><p class=MsoNormal> * Isn't there any other way?<o:p></o:p></p></div><div><p class=MsoNormal> * Is this sane? Or should the original authors re-write their programs?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>There has been some progress on both GCC and LLVM to co-operate, rather than follow each other blindly, and I can see this as the only future for both toolchains.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>In this specific case, I'd strongly oppose to follow whatever GCC does, since the Clang driver is already mind bogging. The only reasonable course of action from here is to open the discussion in the GCC and LLVM community together (not sure how, but we'll *have* to figure it out), and follow from there. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>cheers,<o:p></o:p></p></div><div><p class=MsoNormal>--renato<o:p></o:p></p></div></div></div></div></body></html>