(j3.2006) SQRT of square to ABS

Robert Corbett Robert.Corbett
Tue Jan 8 00:34:55 EST 2008

If the modules IEEE_EXCEPTIONS and IEEE_FEATURES are used in a
program unit, may a standard-conforming implementation transform
the expression SQRT(X**2) into ABS(X)?  The first expression
might signal invalid operand, overflow, underflow and imprecise
exception.  However, it might also be implemented, for example
on an x87, in a way that produces only the invalid exception.
The second expression might signal an invalid operand exception,
or it might signal no exception at all.

Bob Corbett

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