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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hello,</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I search information in order to access address (i.e. value) of label
directly in llvm assembler file.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>This can be useful to realize jump table from address, etc.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I generate the file <i><span style='font-style:italic'>branch.ll</span></i>
from a C file.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>In this file, we saw that branches are realized by affecting virtually
an id to each label and use a switch in order to find the right target.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I want to know if there is another way to do this, for instance, by
accessing the address of label and to branch directly to it? </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>In order to optimize the program (to decrease the cost of branch
dispatch), I use the following command line:</span></font></p>
<p class=MsoNormal><i><font size=3 face="Times New Roman"><span
style='font-size:12.0pt;font-style:italic'>llvmc –O5 –o branch_opt
branch.bc</span></font></i></p>
<p class=MsoNormal><i><font size=3 face="Times New Roman"><span
style='font-size:12.0pt;font-style:italic'>llc –march=arm –mcpu=arm1136j-s
–mattr=+v6 –f –o branch_opt.s branch_opt.bc</span></font></i></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>In the optimized program (<i><span style='font-style:italic'>branch_opt.arm</span></i>),
I saw that all branches are not suppressed.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I want to know, if it is possible to suppress the remaining useless
branches? if yes, how ?</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Thanks in advance.</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Mikaël.</span></font></p>
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