What is acceptable for -ffast-math? (Was: associative law incombine)

[Gabriel Dos_Reis]

| Now, show me a case where a/b/c -> a/(b*c) is significantly less accurate?

On a 64-bit double processor just take 

	b = c = 2 * sqrt(DBL_MAX);
	a = 0.5 * DBL_MAX

a/(b*c) is 0.0 whereas a/b/c yields 0.125.

-- Gaby