Time profiling question.

Alex Ferguson abf at cs.ucc.ie
Tue Nov 25 15:34:54 EST 2003

Let me ask this question in the abstract, lest I embarrass myself
publicly with my shoddy code:

Suppose I find that -p style profiling with -auto-all attributes the
majority of the cost of my program to a single function.  Naturally, I'd
like to refine this somewhat.  So I add additional cost centres as

f a1 ... an
   = e
   d1 = {-# SCC "d1" #-} e1
   d1 = {-# SCC "dn" #-} e1

I find it's still attributing almost all of the cost to the original CC
(f), so I add another SCC, before the RHS.  And it _still_ attributes
the same amount to f, and effectively nothing to the body CC.

So my questions are firstly, can someone explain this;  and secondly, is
there a style of adding CCs that would be more informative in such
cases?  (Or if it comes down to it, transforming the code to be more
revelatory in that respect.)


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