diff options
Diffstat (limited to 'testsuite/tests/array/should_run/arr017.hs')
| -rw-r--r-- | testsuite/tests/array/should_run/arr017.hs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/testsuite/tests/array/should_run/arr017.hs b/testsuite/tests/array/should_run/arr017.hs new file mode 100644 index 0000000000..18314b8e28 --- /dev/null +++ b/testsuite/tests/array/should_run/arr017.hs @@ -0,0 +1,30 @@ +-- Caused a crash in GHC 6.4 when optimising, due to inlining of runST too early. + +-- Spectral Norm benchmark + +import Data.Array +import System.Environment (getArgs) + +main = do + --[arg] <- getArgs + --let n = (read arg) - 1 + let n = 80 + let init = listArray (0,n) (repeat 1.0) + let (v:u:rest) = drop 19 $ iterate (eval_AtA_times_u n) init + let vBv = sum [(u!i)*(v!i) |i<-[0..n]] + let vv = sum [(v!i)*(v!i) |i<-[0..n]] + print $ sqrt (vBv/vv) + +eval_AtA_times_u n u = eval_At_times_u n v + where v = eval_A_times_u n u + +eval_A x y = 1.0/((i+j)*(i+j+1)/2+i+1) + where i = fromIntegral x + j = fromIntegral y + +eval_A_times_u n u = accumArray (+) 0 (0,n) + [(i,(eval_A i j) * u!j)|i<-[0..n], j<-[0..n]] + +eval_At_times_u n u = accumArray (+) 0 (0,n) + [(i,(eval_A j i) * u!j)|i<-[0..n], j<-[0..n]] + |