SPARC NCG: Reorganise Reg and RegInfo

[ghc-hetmet.git] / compiler / nativeGen / SPARC / AddrMode.hs

diff --git a/compiler/nativeGen/SPARC/AddrMode.hs b/compiler/nativeGen/SPARC/AddrMode.hs
new file mode 100644 (file)
index 0000000..bd72cb3
--- /dev/null
+++ b/compiler/nativeGen/SPARC/AddrMode.hs
@@ -0,0 +1,42 @@
+
+module SPARC.AddrMode (
+       AddrMode(..),
+       addrOffset
+)
+
+where
+
+import SPARC.Imm
+import SPARC.Base
+import Reg
+
+-- addressing modes ------------------------------------------------------------
+
+-- | Represents a memory address in an instruction.
+--     Being a RISC machine, the SPARC addressing modes are very regular.
+--
+data AddrMode
+       = AddrRegReg    Reg Reg         -- addr = r1 + r2
+       | AddrRegImm    Reg Imm         -- addr = r1 + imm
+
+
+-- | Add an integer offset to the address in an AddrMode.
+--
+addrOffset :: AddrMode -> Int -> Maybe AddrMode
+addrOffset addr off
+  = case addr of
+      AddrRegImm r (ImmInt n)
+       | fits13Bits n2 -> Just (AddrRegImm r (ImmInt n2))
+       | otherwise     -> Nothing
+       where n2 = n + off
+
+      AddrRegImm r (ImmInteger n)
+       | fits13Bits n2 -> Just (AddrRegImm r (ImmInt (fromInteger n2)))
+       | otherwise     -> Nothing
+       where n2 = n + toInteger off
+
+      AddrRegReg r (RealReg 0)
+       | fits13Bits off -> Just (AddrRegImm r (ImmInt off))
+       | otherwise     -> Nothing
+       
+      _ -> Nothing