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<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal">It seems that ConstantFoldCastInstruction in ConstantFold.cpp folds inttoptr instruction with 0 as operand to a null pointer. It makes sense, when talking about a C-style frontend, as the C99 spec (6.3.2.3) states:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-left:.5in;text-autospace:none">“An integer constant expression with the value 0, or such an expression cast to type void *, is called a null pointer constant.”<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">On the other hand, some architectures use 0 as a valid memory location, and this constant folding seems to be possibly harmful when the code actually tries to access the memory location at address 0.<o:p></o:p></p>
<p class="MsoNormal">Is this behavior intentional? Do I miss something? Will a load from address null try to access address 0, or may it become an undef value?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal"> Guy<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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