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

[ghc-hetmet.git] / compiler / nativeGen / Size.hs

diff --git a/compiler/nativeGen/Size.hs b/compiler/nativeGen/Size.hs
new file mode 100644 (file)
index 0000000..3be5430
--- /dev/null
+++ b/compiler/nativeGen/Size.hs
@@ -0,0 +1,103 @@
+-- | Sizes on this architecture
+--     A Size is a combination of width and class
+-- 
+--     TODO:   Rename this to "Format" instead of "Size" to reflect
+--             the fact that it represents floating point vs integer.
+--
+--     TODO:   Signed vs unsigned?
+--
+--     TODO:   This module is currenly shared by all architectures because
+--             NCGMonad need to know about it to make a VReg. It would be better
+--             to have architecture specific formats, and do the overloading
+--             properly. eg SPARC doesn't care about FF80.
+--
+module Size (
+       Size(..),
+       intSize,
+       floatSize,
+       isFloatSize,
+       cmmTypeSize,
+       sizeToWidth
+)
+
+where
+
+import Cmm
+import Outputable
+
+-- It looks very like the old MachRep, but it's now of purely local
+-- significance, here in the native code generator.  You can change it
+-- without global consequences.
+--
+-- A major use is as an opcode qualifier; thus the opcode 
+--     mov.l a b
+-- might be encoded 
+--     MOV II32 a b
+-- where the Size field encodes the ".l" part.
+
+-- ToDo: it's not clear to me that we need separate signed-vs-unsigned sizes
+--       here.  I've removed them from the x86 version, we'll see what happens --SDM
+
+-- ToDo: quite a few occurrences of Size could usefully be replaced by Width
+
+data Size
+       = II8 
+       | II16 
+       | II32 
+       | II64 
+       | FF32 
+       | FF64 
+       | FF80
+       deriving (Show, Eq)
+
+
+-- | Get the integer size of this width.
+intSize :: Width -> Size
+intSize width
+ = case width of
+       W8      -> II8
+       W16     -> II16
+       W32     -> II32
+       W64     -> II64
+       other   -> pprPanic "Size.intSize" (ppr other)
+
+
+-- | Get the float size of this width.
+floatSize :: Width -> Size
+floatSize width
+ = case width of
+       W32     -> FF32
+       W64     -> FF64
+       other   -> pprPanic "Size.floatSize" (ppr other)
+
+
+-- | Check if a size represents a floating point value.
+isFloatSize :: Size -> Bool
+isFloatSize size
+ = case size of
+       FF32    -> True
+       FF64    -> True
+       FF80    -> True
+       _       -> False
+
+
+-- | Convert a Cmm type to a Size.
+cmmTypeSize :: CmmType -> Size
+cmmTypeSize ty 
+       | isFloatType ty        = floatSize (typeWidth ty)
+       | otherwise             = intSize (typeWidth ty)
+
+
+-- | Get the Width of a Size.
+sizeToWidth :: Size -> Width
+sizeToWidth size
+ = case size of
+       II8             -> W8
+       II16            -> W16
+       II32            -> W32
+       II64            -> W64
+       FF32            -> W32
+       FF64            -> W64
+       FF80            -> W80
+       
+