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/prelude/primops.txt.pp b/compiler/prelude/primops.txt.pp
index 45472816c0..d6bdae861d 100644
--- a/compiler/prelude/primops.txt.pp
+++ b/compiler/prelude/primops.txt.pp
@@ -363,6 +363,15 @@ primop   PopCnt64Op   "popCnt64#"   GenPrimOp   WORD64 -> Word#
 primop   PopCntOp   "popCnt#"   Monadic   Word# -> Word#
     {Count the number of set bits in a word.}
 
+primop   BSwap16Op   "byteSwap16#"   Monadic   Word# -> Word#
+    {Swap bytes in the lower 16 bits of a word. The higher bytes are undefined. }
+primop   BSwap32Op   "byteSwap32#"   Monadic   Word# -> Word#
+    {Swap bytes in the lower 32 bits of a word. The higher bytes are undefined. }
+primop   BSwap64Op   "byteSwap64#"   GenPrimOp WORD64 -> WORD64
+    {Swap bytes in a 64 bits of a word.}
+primop   BSwapOp     "byteSwap#"     Monadic   Word# -> Word#
+    {Swap bytes in a word.}
+
 ------------------------------------------------------------------------
 section "Narrowings" 
 	{Explicit narrowing of native-sized ints or words.}