Add support for byte endian swapping for Word 16/32/64.

* Exposes bSwap{,16,32,64}# primops
* Add a new machops MO_BSwap
* Use a Stg implementation (hs_bswap{16,32,64}) for other implementation
  in NCG.
* Generate bswap in X86 NCG for 32 and 64 bits, and for 16 bits, bswap+shr
  instead of using xchg.
* Generate llvm.bswap intrinsics in llvm codegen.

Patch from Vincent Hanquez.

1 files changed, 9 insertions, 0 deletions

diff --git a/compiler/nativeGen/CPrim.hs b/compiler/nativeGen/CPrim.hs
index dd9d38f434..a6f4cab7bd 100644
--- a/compiler/nativeGen/CPrim.hs
+++ b/compiler/nativeGen/CPrim.hs
@@ -1,6 +1,7 @@
 -- | Generating C symbol names emitted by the compiler.
 module CPrim
     ( popCntLabel
+    , bSwapLabel
     , word2FloatLabel
     ) where
 
@@ -16,6 +17,14 @@ popCntLabel w = "hs_popcnt" ++ pprWidth w
     pprWidth W64 = "64"
     pprWidth w   = pprPanic "popCntLabel: Unsupported word width " (ppr w)
 
+bSwapLabel :: Width -> String
+bSwapLabel w = "hs_bswap" ++ pprWidth w
+  where
+    pprWidth W16 = "16"
+    pprWidth W32 = "32"
+    pprWidth W64 = "64"
+    pprWidth w   = pprPanic "bSwapLabel: Unsupported word width " (ppr w)
+
 word2FloatLabel :: Width -> String
 word2FloatLabel w = "hs_word2float" ++ pprWidth w
   where