[LLVMdev] readnone

[Garrison Venn]

Thanks for the answer Nick. Now you got me on a chase through FunctionAttrs.cpp
trying to find out what analysis passes "... which answers no to everything", means. :-)

Garrison

On Sep 10, 2011, at 13:52, Nick Lewycky wrote:

> Nick Lewycky wrote:
>> I was sure that I remember "opt -functionattrs" being taught to do this,
>> but I just tried it out and it doesn't. This is a missed optz'n
>> opportunity, testcase:
>> 
>>    @x = constant i32 0
>>    define void @foo() {
>>      load i32* @x
>>      ret void
>>    }
>> 
>> is only marked readonly when it should be readnone. Could I interest you
>> in fixing that? :)
> 
> Never mind, it's because the default AA is no-aa, which answers no to everything. "opt -basicaa -functionattrs" gets this testcase right (and the one that stores, too!)
> 
> Nick