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<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>But they both follow the same calling
convention. There are two possibilities in the caller:</span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>1) Call node returns sizeof(int) or larger:
in this case there is no truncation.</span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>2) Call node returns smaller than sizeof(int):
in this case callee always has to return an int so it has to consistently either
sign extend or zero extend because int is either signed or unsigned
consistently for that port. Assuming that caller and callee follow the same
calling convention, caller always knows (hence the llvm pass knows) that, if
the return value of the called function is being truncated, it is because of
return value promotion. It also knows the calling convention, so it knows
whether it is sign or zero extended. This is regardless of translation unit
where the callee is in.</span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'> </span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>></span></font>No, because the callee
and caller may be in different translation units.</p>
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