igloo:
On Wed, Mar 19, 2008 at 05:31:08PM +0000, Ian Lynagh wrote:
On Tue, Mar 18, 2008 at 04:12:35PM -0000, GHC wrote:
(don't worry, this often catches me out too. Perhaps a strict let should be indicated more explicitly in `-ddump-simpl`).
I'd certainly find it useful if it was clearer.
In fact, simpl hides more than I'd realised. With these definitions:
f :: Integer -> Integer -> Integer -> Integer f x y z | y == 1 = x * z | otherwise = f (x * x) y (z * z)
g :: Integer -> Integer -> Integer -> Integer g x y z | y == 1 = x | otherwise = g (x * x) y (z * z)
simpl shows
B.f (GHC.Num.timesInteger x_a5B x_a5B) y_a5D (GHC.Num.timesInteger z_a5F z_a5F);
and
B.g (GHC.Num.timesInteger x_a74 x_a74) y_a76 (GHC.Num.timesInteger z_a78 z_a78);
for the recursive calls, although in the STG you can see that the multiplication of z is done strictly in f but not g (which is correct, as g is not strict in z).
So perhaps the solution is just that I should look at the STG rather than the simpl when I want to see what's going on.
Thanks
We really need an official and blessed view of the optimised core, with full, relevant information, in human readable form. Just simplifiying the obvious qualified names would be a start, and some simple alpha renaming. -- Don