Remove target dependent CPP for Word64/Int64 (#11470)

Primops types were dependent on the target word-size at *compiler*
compilation time. It's an issue for multi-target as GHC may not have the
correct primops types for the target.

This patch fixes some primops types: if they take or return fixed 64-bit
values they now always use `Int64#/Word64#`, even on 64-bit
architectures (where they used `Int#/Word#` before). Users of these
primops may now need to convert from Int64#/Word64# to Int#/Word# (a
no-op at runtime).

This is a stripped down version of !3658 which goes the all way of
changing the underlying primitive types of Word64/Int64. This is left
for future work.

T12545 allocations increase ~4% on some CI platforms and decrease ~3% on
AArch64.

Metric Increase:
    T12545

Metric Decrease:
    T12545

2 files changed, 17 insertions, 17 deletions

diff --git a/libraries/ghc-bignum/src/GHC/Num/BigNat.hs b/libraries/ghc-bignum/src/GHC/Num/BigNat.hs
index fa8b84eccd..5fa81b7e5b 100644
--- a/libraries/ghc-bignum/src/GHC/Num/BigNat.hs
+++ b/libraries/ghc-bignum/src/GHC/Num/BigNat.hs
@@ -263,6 +263,16 @@ bigNatToWord64# b
          in uncheckedShiftL64# wh 32# `or64#` wl
       else wl
 
+#else
+
+-- | Convert a Word64# into a BigNat on 64-bit architectures
+bigNatFromWord64# :: Word64# -> BigNat#
+bigNatFromWord64# w64 = bigNatFromWord# (word64ToWord# w64)
+
+-- | Convert a BigNat into a Word64# on 64-bit architectures
+bigNatToWord64# :: BigNat# -> Word64#
+bigNatToWord64# b = wordToWord64# (bigNatToWord# b)
+
 #endif
 
 -- | Encode (# BigNat mantissa, Int# exponent #) into a Double#
diff --git a/libraries/ghc-bignum/src/GHC/Num/Integer.hs b/libraries/ghc-bignum/src/GHC/Num/Integer.hs
index e2a020619e..d85148fc05 100644
--- a/libraries/ghc-bignum/src/GHC/Num/Integer.hs
+++ b/libraries/ghc-bignum/src/GHC/Num/Integer.hs
@@ -998,14 +998,12 @@ integerIsPowerOf2# (IS i)
 integerIsPowerOf2# (IN _) = (# (# #) | #)
 integerIsPowerOf2# (IP w) = bigNatIsPowerOf2# w
 
-#if WORD_SIZE_IN_BITS == 32
-
--- | Convert an Int64# into an Integer on 32-bit architectures
+-- | Convert an Int64# into an Integer
 integerFromInt64# :: Int64# -> Integer
 {-# NOINLINE integerFromInt64# #-}
 integerFromInt64# !i
-  | isTrue# ((i `leInt64#` intToInt64#  0x7FFFFFFF#)
-      &&# (i `geInt64#` intToInt64# -0x80000000#))
+  | isTrue# ((i `leInt64#` intToInt64#  INT_MAXBOUND#)
+      &&# (i `geInt64#` intToInt64# INT_MINBOUND#))
   = IS (int64ToInt# i)
 
   | isTrue# (i `geInt64#` intToInt64# 0#)
@@ -1014,37 +1012,29 @@ integerFromInt64# !i
   | True
   = IN (bigNatFromWord64# (int64ToWord64# (negateInt64# i)))
 
--- | Convert a Word64# into an Integer on 32-bit architectures
+-- | Convert a Word64# into an Integer
 integerFromWord64# :: Word64# -> Integer
 {-# NOINLINE integerFromWord64# #-}
 integerFromWord64# !w
-  | isTrue# (w `leWord64#` wordToWord64# 0x7FFFFFFF##)
+  | isTrue# (w `leWord64#` wordToWord64# INT_MAXBOUND##)
   = IS (int64ToInt# (word64ToInt64# w))
   | True
   = IP (bigNatFromWord64# w)
 
--- | Convert an Integer into an Int64# on 32-bit architectures
+-- | Convert an Integer into an Int64#
 integerToInt64# :: Integer -> Int64#
 {-# NOINLINE integerToInt64# #-}
 integerToInt64# (IS i) = intToInt64# i
 integerToInt64# (IP b) = word64ToInt64# (bigNatToWord64# b)
 integerToInt64# (IN b) = negateInt64# (word64ToInt64# (bigNatToWord64# b))
 
--- | Convert an Integer into a Word64# on 32-bit architectures
+-- | Convert an Integer into a Word64#
 integerToWord64# :: Integer -> Word64#
 {-# NOINLINE integerToWord64# #-}
 integerToWord64# (IS i) = int64ToWord64# (intToInt64# i)
 integerToWord64# (IP b) = bigNatToWord64# b
 integerToWord64# (IN b) = int64ToWord64# (negateInt64# (word64ToInt64# (bigNatToWord64# b)))
 
-#else
-
--- | Convert an Int64# into an Integer on 64-bit architectures
-integerFromInt64# :: Int# -> Integer
-integerFromInt64# !x = IS x
-
-#endif
-
 ----------------------------------------------------------------------------
 -- Conversions to/from floating point
 ----------------------------------------------------------------------------