------- Comment #4 from jv244 at cam dot ac dot uk 2006-01-13 17:33 ------- (In reply to comment #3) > This needs to be done by the frontend, as the folded 2/3 or 4/3 is not exactly > representable in the target FP format (and such cannot be checked for). > Making > this a frontend bug, rather than just closing as WONTFIX ;)
Without fully understanding the above in all details. some target FP format might still have that 2./3. == 2 * 1./3. ? Furthermore, I would think that under -ffast-math these kind of transformations should be allowed if these equalities hold 'at machine precision'. E.g. x**p is replaced by cuberoot(p) if p is the FP number that is closest to 1./3. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25620
