X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FOptimizationFuel.hs;h=175dcd09b18a4c602cb9531796d0f4b7abf89673;hb=2bb3a439c106935d97fae7f7a0b60c21493d1bef;hp=83cb84e324f961ccb4f0bd233a19c69265433fdd;hpb=1e50fd4185479a62e02d987bdfcb1c62712859ca;p=ghc-hetmet.git

diff --git a/compiler/cmm/OptimizationFuel.hs b/compiler/cmm/OptimizationFuel.hs
index 83cb84e..175dcd0 100644
--- a/compiler/cmm/OptimizationFuel.hs
+++ b/compiler/cmm/OptimizationFuel.hs
@@ -1,3 +1,9 @@
+-- | Optimisation fuel is used to control the amount of work the optimiser does.
+--
+-- Every optimisation step consumes a certain amount of fuel and stops when
+-- it runs out of fuel.  This can be used e.g. to debug optimiser bugs: Run
+-- the optimiser with varying amount of fuel to find out the exact number of
+-- steps where a bug is introduced in the output.
 module OptimizationFuel
     ( OptimizationFuel,  canRewriteWithFuel, maybeRewriteWithFuel, oneLessFuel
     , OptFuelState, initOptFuelState --, setTotalFuel