Adjust integrate output for ghc-9

ghc-9 introduces a regression(?) in FP precision (See ghc ticket #19569).
While this is unfortunate we want nofib to be useable with ghc 8.10 and
9.0 as far as possible.

So I added an additional argument to the benchmark which controls if we
output the benchmark result or not, which is off by default.

This allows easy checking of the output manually without causing
benchmark errors because the output differs.

I've also added the benchmark to the ghc testsuite to avoid future
regressions.

imaginary/integrate/Main.hs

@@ -17,8 +17,8 @@ integrate1D l u f =
         (f u)*0.5]
 
 integrate2D l1 u1 l2 u2 f = integrate1D l2 u2
-				    (\y->integrate1D l1 u1
-						  (\x->f x y))
+            (\y->integrate1D l1 u1
+              (\x->f x y))
 
 zark u v = integrate2D 0.0 u 0.0 v (\x->(\y->x*y))
 
@@ -37,7 +37,7 @@ etotal n = sum (take n es)
 
 -- The (analytical) result should be zero
 main = do
-	[range] <- getArgs
-	putStrLn $ show $ etotal $ read range
-
-
+  [with_output,range] <- getArgs
+  if (read with_output)
+    then putStrLn $ show $ etotal $ read range
+    else seq (etotal $ read range) (putStrLn "Exact result hidden for lack of stability.\nPass 'True' as first argument to the benchmark if you want to view the computed output for testing purposes.")

imaginary/integrate/Makefile

@@ -4,6 +4,6 @@ include $(TOP)/mk/boilerplate.mk
 -include opts.mk
 include $(TOP)/mk/target.mk
 
-FAST_OPTS =  100000
-NORM_OPTS = 1000000
-SLOW_OPTS = 5000000
+FAST_OPTS = False 100000
+NORM_OPTS = False 1000000
+SLOW_OPTS = False 5000000

imaginary/integrate/integrate.faststdout

-0.0

imaginary/integrate/integrate.slowstdout

-1.3615586841036482e34

imaginary/integrate/integrate.stdout

-9.093955583391733e28
+Exact result hidden for lack of stability.
+Pass 'True' as first argument to the benchmark if you want to view the computed output for testing purposes.