ghc-testsuite-6.6 on Macs

Simon Marlow simonmarhaskell at
Tue Nov 21 08:11:12 EST 2006

Thorkil Naur wrote:

> As I have already mentioned, I think my patch is a mistake. Depending on what 
> anyone can tell me about the barton-mangler-bug, additional work would seem 
> to go in one of two directions: If the floating point numbers are involved 
> incidentally and the mangler bug still threatens, work should attempt to 
> remove the floating point numbers from the output and produce a test case 
> that exposes the bug more succinctly. I would certainly need some additional 
> help to do this. On the other hand, if the floating point difference 
> between, e.g., opt and normal is the real issue, it would still seem 
> advantageous and quite possible to reduce the size of the test case, to make 
> it easier to figure out the cause of the difference.

Sounds like we should modify the test to output floating point values to lesser 
precision, smoothing over the differences between implementations.

Still, sometimes I really like to see these tiny differences: in one case I 
remember it pointed me to a fairly obscure problem in the x86_64 native code 
generator that resulted in floating point answers that were bogusly different 
from the via-C version.


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