Re: failure due to compiler?

|> I am looking for pointers or references to descriptions where software
|> has compiled without error and later failed due to compiler-introduced
|> errors in the resultant program. In other words, the source was deemed
|> to be error free but the compiler botched the code generation.


I once used a compiler that would sometimes compile this:


    a = b >> 8;


Into:


    move ax, b
    move al, ah
    move ah, 0
    move a, ax


Which worked.
But sometimes it would compile it into this:


    move si, b
    <garbage>
    <garbage>
    move a, si


It seemed that the compiler thought that it could
generate instructions to access the two halves of
the si (or di) register independantly using the
pattern that worked for ax (or bx, cx, or dx).


--
dennis@netcom.com (Dennis Yelle)
--

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