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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have a task to complete and I’m getting stuck. I can’t find anything comparable in the documentation. The shortest explanation I can give is as follows: I need to use double-precision floating point values for floating-point multiplies.
I’ll not go into why: That would take the discussion away from the essential problem. E.g.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> Replace:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="Default" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#0070C0"> fmuls %f20,%f21,%f8<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span lang="EN-US" style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-align:justify"><span lang="EN-US" style="font-family:"Times New Roman","serif""> with the sequence:
<o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify"><span lang="EN-US" style="font-family:"Times New Roman","serif""><o:p> </o:p></span></p>
<p class="Default" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#0070C0"> fstod %f20,%f0<o:p></o:p></span></p>
<p class="Default" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#0070C0"> fstod %f21,%f2<o:p></o:p></span></p>
<p class="Default" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#0070C0"> fmuld %f0,%f2,%f8
<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This is for a Sparc derived back-end and I’m already at the MachineInstr phase. The essential code I have now is as follows, but it doesn’t work. I’ve had much larger pieces of code, but I believe my mistake lies somewhere in here. I’m
not sure if I’m heading down the right path with this. Please, any help would be appreciated – or any reference to an example, even better.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[code is iterating through the MachineBasicBlock – this code is pretty straightforward and you can probably guess what’s in it]<o:p></o:p></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black">
</span><b><span style="font-size:10.0pt;font-family:Monospace;color:#7F0055">if</span></b><span style="font-size:10.0pt;font-family:Monospace;color:black"> (Opcode ==
<u>SP::FMULS</u>)</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black"> {</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black">
</span><span style="font-size:10.0pt;font-family:Monospace;color:#005032">MachineOperand</span><span style="font-size:10.0pt;font-family:Monospace;color:black">& MO = MI.getOperand(0);</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black">
</span><span style="font-size:10.0pt;font-family:Monospace;color:#005032">DebugLoc</span><span style="font-size:10.0pt;font-family:Monospace;color:black"> DL = MBBI->getDebugLoc();</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black">
<u>BuildMI</u>(MBB, MBBI, DL, TII.<u>get</u>(<u>SP::FSTOD</u>), MO.getReg());<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black"> [ Then we’d do the second fstod and the fmuld, but I’ve not included this because the basic problem of generating the MachineInstr has
happened already for this first MachineInstr]</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:Monospace;color:black"> MI.eraseFromParent();</span><span style="font-size:10.0pt;font-family:Monospace"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:Monospace;color:black"> }<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:Monospace;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:Monospace;color:black">Chris Dewhurst,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:Monospace;color:black">University of Limerick, Ireland</span><o:p></o:p></p>
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