Comments

diff --git a/compiler/simplCore/SimplUtils.lhs b/compiler/simplCore/SimplUtils.lhs
index fbee984..2664752 100644 (file)
--- a/compiler/simplCore/SimplUtils.lhs
+++ b/compiler/simplCore/SimplUtils.lhs
@@ -475,9 +475,9 @@ On the other hand, it is bad not to do ANY inlining into an
 InlineRule, because then recursive knots in instance declarations
 don't get unravelled.
 
 InlineRule, because then recursive knots in instance declarations
 don't get unravelled.
 

-However, *sometimes* SimplGently must do no call-site inlining at all.
-Before full laziness we must be careful not to inline wrappers,
-because doing so inhibits floating
+However, *sometimes* SimplGently must do no call-site inlining at all
+(hence sm_inline = False).  Before full laziness we must be careful
+not to inline wrappers, because doing so inhibits floating

     e.g. ...(case f x of ...)...
     ==> ...(case (case x of I# x# -> fw x#) of ...)...
     ==> ...(case x of I# x# -> case fw x# of ...)...
     e.g. ...(case f x of ...)...
     ==> ...(case (case x of I# x# -> fw x#) of ...)...
     ==> ...(case x of I# x# -> case fw x# of ...)...

@@ -502,6 +502,9 @@ RULES are enabled when doing "gentle" simplification.  Two reasons:
     to work in Template Haskell when simplifying
     splices, so we get simpler code for literal strings
 
     to work in Template Haskell when simplifying
     splices, so we get simpler code for literal strings
 

+But watch out: list fusion can prevent floating.  So use phase control
+to switch off those rules until after floating.
+

 Note [Simplifying inside InlineRules]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 We must take care with simplification inside InlineRules (which come from
 Note [Simplifying inside InlineRules]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 We must take care with simplification inside InlineRules (which come from