[RFC PATCH] Convert pow(10.0,x) -> exp10(x), etc...

[Kaveh R. Ghazi]

 > long double test1l(long double x)
 > {
 >   return powl(10.0, x);
 > }

Also, your testcases only ensure that GCC compiles the given code, not
that the transformation succeeds.  Instead you can write code like
this:

	if (powl(10.0, x) != exp10(x))
	  link_error();

This should get folded into

	if (exp10(x) != exp10(x))

And since with -ffast-math exp10 is a const function, this expr is
always false and therefore link_error is never called and thus not
emitted.  If the transformation fails, then the if-stmt isn't folded
away and the call to link_error() is emitted and the compilation
fails.  So you can tell if the transformation was done using a compile
test.

Again, look at what I did in gcc.dg/torture/builtin-explog-1.c.
I also macroized everything to avoid cut-n-paste typos.

		--Kaveh
--
Kaveh R. Ghazi			ghazi@caip.rutgers.edu