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<div style="text-indent:-17.85pt;padding-left:46.2pt;">Hi all,</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">I’m working on an out-of-tree target and encountered the following problem:</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">InstCombiner “normalizes” GEPs and extends Index operand to the Pointer width.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">It works fine if you can convert pointer to integer for address calculation and I assume that all registered targets do this.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">The target I’m working on has very restricted ISA for the pointer calculation:</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">ptr + int, ptr - int, ptr - ptr and ptr-compare</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">I have full arithmetic set for 32-bit integers, but the Ptr is wider. Extending index to the Ptr width requires full arithmetic support for pointers.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">But, actually, it does not come from C-sources (casting Ptr to int means truncation).</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">I’d like to add TTI (TargetTransformInfo) to InstCombiner in order to configure the width of GEP indices.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">The current default behavior will be preserved.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">What do you think?</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;">Thanks.</div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
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<font face="Times New Roman" size="3" color="#2F5496"><span style="font-size:12pt;">
<li><b><i> Elena</i></b></li></span></font>
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<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
<div style="text-indent:-17.85pt;padding-left:46.2pt;"> </div>
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