[LLVMdev] Trunc Load

Johannes Birgmeier e0902998 at student.tuwien.ac.at
Thu Oct 27 10:40:31 PDT 2011

> This is contradictory: on a little-endian processor, the address for
> loading a 64-bit value is same as the address of the low word.  Are
> you sure you're modeling the semantics of your lddw and stddw
> instructions correctly?
... I thought so until now. Because I implemented stdw (store 
doubleword) completely analogous to lddw: Just print out stdw with the 
given pointer and the register pair, just like lddw. (This seems obvious.)

Well, ****. I just read the documentation very carefully (yeah I know. 
I'm sorry) and it seems that stdw doesn't care about the big/little 
endian setting, it always writes the regpair into memory in big endian. 
lddw, however, DOES care about the setting - if little endian is 
enabled, the result register pair gets switched. What kind of confusion 
could have provoked the TI engineers to create such a horrible 
instruction set?

OK, thanks for the hints. I'll try to sort this out.


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