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Re: GCC floating point usage


>>>>> "Mark" == Mark Mitchell <mark@codesourcery.com> writes:

 Mark> ...Since you think the semantics are unclear, I'll make an effort
 Mark> to state them again:

 Mark> If the user does not explicitly use floating point at the
 Mark> source level, the compiler will not generate reads to or writes
 Mark> from the floating point registers that can ever be executed by
 Mark> the program, unless that program calls "setjmp" or makes use of
 Mark> exception-handling.

Why are setjmp and exception handling excluded from the rule?  If a
program doesn't use floating point registers, then setjmp and
exception handling have no need to do so, either.

It may be that a particular platform has these services implemented in
such a way that they unconditional fiddle with the float registers.
But that need not be true for all platforms, so the
platform-independent statement of the intended semantics should not
make this rule as far as I can see.

     paul



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