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, 62 insertions, 0 deletions

diff --git a/compiler/nativeGen/PPC/Cond.hs b/compiler/nativeGen/PPC/Cond.hs
new file mode 100644
index 0000000000..7345ee5f1d
--- /dev/null
+++ b/compiler/nativeGen/PPC/Cond.hs
@@ -0,0 +1,62 @@
+
+module PPC.Cond (
+	Cond(..),
+	condNegate,
+	condUnsigned,
+	condToSigned,
+	condToUnsigned,
+)
+
+where
+
+import Panic
+
+data Cond
+	= ALWAYS
+	| EQQ
+	| GE
+	| GEU
+	| GTT
+	| GU
+	| LE
+	| LEU
+	| LTT
+	| LU
+	| NE
+	deriving Eq
+
+
+condNegate :: Cond -> Cond
+condNegate ALWAYS  = panic "condNegate: ALWAYS"
+condNegate EQQ     = NE
+condNegate GE      = LTT
+condNegate GEU     = LU
+condNegate GTT     = LE
+condNegate GU      = LEU
+condNegate LE      = GTT
+condNegate LEU     = GU
+condNegate LTT     = GE
+condNegate LU      = GEU
+condNegate NE      = EQQ
+
+-- Condition utils
+condUnsigned :: Cond -> Bool
+condUnsigned GU  = True
+condUnsigned LU  = True
+condUnsigned GEU = True
+condUnsigned LEU = True
+condUnsigned _   = False
+
+condToSigned :: Cond -> Cond
+condToSigned GU  = GTT
+condToSigned LU  = LTT
+condToSigned GEU = GE
+condToSigned LEU = LE
+condToSigned x   = x
+
+condToUnsigned :: Cond -> Cond
+condToUnsigned GTT = GU
+condToUnsigned LTT = LU
+condToUnsigned GE  = GEU
+condToUnsigned LE  = LEU
+condToUnsigned x   = x