NCG: Split up the native code generator into arch specific modules

  - nativeGen/Instruction defines a type class for a generic
    instruction set. Each of the instruction sets we have, 
    X86, PPC and SPARC are instances of it.
  
  - The register alloctors use this type class when they need
    info about a certain register or instruction, such as
    regUsage, mkSpillInstr, mkJumpInstr, patchRegs..
  
  - nativeGen/Platform defines some data types enumerating
    the architectures and operating systems supported by the 
    native code generator.
  
  - DynFlags now keeps track of the current build platform, and 
    the PositionIndependentCode module uses this to decide what
    to do instead of relying of #ifdefs.
  
  - It's not totally retargetable yet. Some info info about the
    build target is still hardwired, but I've tried to contain
    most of it to a single module, TargetRegs.
  
  - Moved the SPILL and RELOAD instructions into LiveInstr.
  
  - Reg and RegClass now have their own modules, and are shared
    across all architectures.

1 files changed, 31 insertions, 0 deletions

diff --git a/compiler/nativeGen/RegClass.hs b/compiler/nativeGen/RegClass.hs
new file mode 100644
index 0000000000..8b6b2d4160
--- /dev/null
+++ b/compiler/nativeGen/RegClass.hs
@@ -0,0 +1,31 @@
+
+-- | An architecture independent description of a register's class.
+module RegClass 
+	( RegClass (..) )
+
+where
+
+import	Outputable
+import	Unique
+
+
+-- | The class of a register. 
+--	Used in the register allocator.
+--	We treat all registers in a class as being interchangable.
+--
+data RegClass 
+	= RcInteger 
+	| RcFloat
+	| RcDouble
+	deriving Eq
+
+
+instance Uniquable RegClass where
+    getUnique RcInteger	= mkUnique 'L' 0
+    getUnique RcFloat	= mkUnique 'L' 1
+    getUnique RcDouble	= mkUnique 'L' 2
+
+instance Outputable RegClass where
+    ppr RcInteger	= Outputable.text "I"
+    ppr RcFloat		= Outputable.text "F"
+    ppr RcDouble	= Outputable.text "D"