[Bug middle-end/20674] unexpected result from floating compare

["dberlin at dberlin dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-03-29 04:58 -------
Subject: Re:  unexpected result from floating compare

On Mon, 2005-03-28 at 23:05 +0000, piaget at us dot ibm dot com wrote:
> ------- Additional Comments From piaget at us dot ibm dot com  2005-03-28 23:05 -------
> 323 compares 2 values across a function call ... somthing a programmer can 
> reasonably consider. My problem occurs with 2 successive lines of code 
> admittedly with 2 compares per line). I don't have a problem that the value of 
> the variable changes after precision truncation ... but it seems like a bug 
> that the compiler uses a full precision value for the 1st test and a truncated 
> value for the 2nd test (the 2nd test being the next line of C++ code).

Except, the value could have been spilled and reloaded from registers
between those two source lines, which on x86, is where the problem comes
from.
The problem is no different simply because the *source* lines happen to
be right next to each other.




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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20674