From e392dfa52d721c7ac23219582b57a25935373c9d Mon Sep 17 00:00:00 2001
From: Herbert Valerio Riedel <hvr@gnu.org>
Date: Thu, 18 Jan 2018 23:41:29 +0100
Subject: [PATCH] Add support for new `compareByteArrays#` primop

---
 src-ghc804/PrimOps.hs           | 6 ++++++
 src/Data/Text/Short/Internal.hs | 2 +-
 text-short.cabal                | 8 ++++++--
 3 files changed, 13 insertions(+), 3 deletions(-)
 create mode 100644 src-ghc804/PrimOps.hs

diff --git a/src-ghc804/PrimOps.hs b/src-ghc804/PrimOps.hs
new file mode 100644
index 0000000..b4faa72
--- /dev/null
+++ b/src-ghc804/PrimOps.hs
@@ -0,0 +1,6 @@
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE Unsafe    #-}
+
+module PrimOps ( compareByteArrays# ) where
+
+import           GHC.Exts (compareByteArrays#)
diff --git a/src/Data/Text/Short/Internal.hs b/src/Data/Text/Short/Internal.hs
index a4b66a5..0ad0563 100644
--- a/src/Data/Text/Short/Internal.hs
+++ b/src/Data/Text/Short/Internal.hs
@@ -92,7 +92,7 @@ import qualified PrimOps
 -- It can be shown that for realistic data <http://utf8everywhere.org/#asian UTF-16 has a space overhead of 50% over UTF-8>.
 --
 newtype ShortText = ShortText ShortByteString
-                  deriving (Monoid,Semigroup,Hashable,NFData)
+                  deriving (Monoid,Data.Semigroup.Semigroup,Hashable,NFData)
 
 instance Eq ShortText where
   {-# INLINE (==) #-}
diff --git a/text-short.cabal b/text-short.cabal
index 0ff5c71..317ecfc 100644
--- a/text-short.cabal
+++ b/text-short.cabal
@@ -37,8 +37,12 @@ library
   if !impl(ghc >= 8.0)
      build-depends: semigroups >= 0.18.2 && < 0.19
 
-  c-sources:           cbits/memcmp.c
-  hs-source-dirs:      src-ghc708
+  -- GHC version specific PrimOps
+  if impl(ghc >= 8.4)
+     hs-source-dirs:   src-ghc804
+  else
+     c-sources:        cbits/memcmp.c
+     hs-source-dirs:   src-ghc708
   other-modules:       PrimOps
 
   hs-source-dirs:      src