Add more INLINABLE and INLINE pragmas to `Enum Int*` instances

Otherwise the instances aren't good list producers.
See Note [Stable Unfolding for list producers].

3 files changed, 64 insertions, 4 deletions

diff --git a/libraries/base/GHC/Int.hs b/libraries/base/GHC/Int.hs
index 4e10e0ca41..df25e1cbe4 100644
--- a/libraries/base/GHC/Int.hs
+++ b/libraries/base/GHC/Int.hs
@@ -129,7 +129,11 @@ instance Enum Int8 where
                         = I8# (intToInt8# i#)
         | otherwise     = toEnumError "Int8" i (minBound::Int8, maxBound::Int8)
     fromEnum (I8# x#)   = I# (int8ToInt# x#)
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
@@ -336,7 +340,11 @@ instance Enum Int16 where
                         = I16# (intToInt16# i#)
         | otherwise     = toEnumError "Int16" i (minBound::Int16, maxBound::Int16)
     fromEnum (I16# x#)  = I# (int16ToInt# x#)
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
@@ -540,7 +548,11 @@ instance Enum Int32 where
         | otherwise     = toEnumError "Int32" i (minBound::Int32, maxBound::Int32)
 #endif
     fromEnum (I32# x#)  = I# (int32ToInt# x#)
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
@@ -747,9 +759,17 @@ instance Enum Int64 where
         | x >= fromIntegral (minBound::Int) && x <= fromIntegral (maxBound::Int)
                         = I# (int64ToInt# x#)
         | otherwise     = fromEnumError "Int64" x
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = integralEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = integralEnumFromThen
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromTo #-}
     enumFromTo          = integralEnumFromTo
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThenTo #-}
     enumFromThenTo      = integralEnumFromThenTo
 
 -- | @since 2.01
@@ -941,7 +961,11 @@ instance Enum Int64 where
         | otherwise     = predError "Int64"
     toEnum (I# i#)      = I64# i#
     fromEnum (I64# x#)  = I# x#
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
diff --git a/libraries/base/GHC/Real.hs b/libraries/base/GHC/Real.hs
index e71a91007e..a4d97b0497 100644
--- a/libraries/base/GHC/Real.hs
+++ b/libraries/base/GHC/Real.hs
@@ -813,9 +813,13 @@ lcm x y         =  abs ((x `quot` (gcd x y)) * y)
 "gcd/Word->Word->Word"          gcd = gcdWord
  #-}
 
+-- See Note [Stable Unfolding for list producers] in GHC.Enum
+{-# INLINABLE integralEnumFrom #-}
 integralEnumFrom :: (Integral a, Bounded a) => a -> [a]
 integralEnumFrom n = map fromInteger [toInteger n .. toInteger (maxBound `asTypeOf` n)]
 
+-- See Note [Stable Unfolding for list producers] in GHC.Enum
+{-# INLINABLE integralEnumFromThen #-}
 integralEnumFromThen :: (Integral a, Bounded a) => a -> a -> [a]
 integralEnumFromThen n1 n2
   | i_n2 >= i_n1  = map fromInteger [i_n1, i_n2 .. toInteger (maxBound `asTypeOf` n1)]
@@ -824,9 +828,13 @@ integralEnumFromThen n1 n2
     i_n1 = toInteger n1
     i_n2 = toInteger n2
 
+-- See Note [Stable Unfolding for list producers] in GHC.Enum
+{-# INLINABLE integralEnumFromTo #-}
 integralEnumFromTo :: Integral a => a -> a -> [a]
 integralEnumFromTo n m = map fromInteger [toInteger n .. toInteger m]
 
+-- See Note [Stable Unfolding for list producers] in GHC.Enum
+{-# INLINABLE integralEnumFromThenTo #-}
 integralEnumFromThenTo :: Integral a => a -> a -> a -> [a]
 integralEnumFromThenTo n1 n2 m
   = map fromInteger [toInteger n1, toInteger n2 .. toInteger m]
diff --git a/libraries/base/GHC/Word.hs b/libraries/base/GHC/Word.hs
index dd803c55b4..be44bfd541 100644
--- a/libraries/base/GHC/Word.hs
+++ b/libraries/base/GHC/Word.hs
@@ -136,7 +136,11 @@ instance Enum Word8 where
                         = W8# (wordToWord8# (int2Word# i#))
         | otherwise     = toEnumError "Word8" i (minBound::Word8, maxBound::Word8)
     fromEnum (W8# x#)   = I# (word2Int# (word8ToWord# x#))
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
@@ -322,7 +326,11 @@ instance Enum Word16 where
                         = W16# (wordToWord16# (int2Word# i#))
         | otherwise     = toEnumError "Word16" i (minBound::Word16, maxBound::Word16)
     fromEnum (W16# x#)  = I# (word2Int# (word16ToWord# x#))
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 
 -- | @since 2.01
@@ -555,7 +563,11 @@ instance Enum Word32 where
     enumFromThenTo      = integralEnumFromThenTo
 #else
     fromEnum (W32# x#)  = I# (word2Int# (word32ToWord# x#))
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = boundedEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = boundedEnumFromThen
 #endif
 
@@ -724,9 +736,17 @@ instance Enum Word64 where
         | x <= fromIntegral (maxBound::Int)
                         = I# (word2Int# (word64ToWord# x#))
         | otherwise     = fromEnumError "Word64" x
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
     enumFrom            = integralEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
     enumFromThen        = integralEnumFromThen
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromTo #-}
     enumFromTo          = integralEnumFromTo
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThenTo #-}
     enumFromThenTo      = integralEnumFromThenTo
 
 -- | @since 2.01
@@ -869,10 +889,18 @@ instance Enum Word64 where
         | otherwise     = fromEnumError "Word64" x
 
 #if WORD_SIZE_IN_BITS < 64
-    enumFrom       = integralEnumFrom
-    enumFromThen   = integralEnumFromThen
-    enumFromTo     = integralEnumFromTo
-    enumFromThenTo = integralEnumFromThenTo
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFrom #-}
+    enumFrom            = integralEnumFrom
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThen #-}
+    enumFromThen        = integralEnumFromThen
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromTo #-}
+    enumFromTo          = integralEnumFromTo
+    -- See Note [Stable Unfolding for list producers] in GHC.Enum
+    {-# INLINE enumFromThenTo #-}
+    enumFromThenTo      = integralEnumFromThenTo
 #else
     -- See Note [Stable Unfolding for list producers] in GHC.Enum
     {-# INLINABLE enumFrom #-}