SPARC NCG: Reorganise Reg and RegInfo

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

diff --git a/compiler/nativeGen/SPARC/ShortcutJump.hs b/compiler/nativeGen/SPARC/ShortcutJump.hs
new file mode 100644 (file)
index 0000000..f560f82
--- /dev/null
+++ b/compiler/nativeGen/SPARC/ShortcutJump.hs
@@ -0,0 +1,61 @@
+
+module SPARC.ShortcutJump (
+       JumpDest(..),
+       canShortcut,
+       shortcutJump,
+       shortcutStatic,
+       shortBlockId
+)
+
+where
+
+import SPARC.Instr
+import SPARC.Imm
+
+import CLabel
+import BlockId
+import Cmm
+
+import Panic
+
+
+
+data JumpDest 
+       = DestBlockId BlockId 
+       | DestImm Imm
+
+
+canShortcut :: Instr -> Maybe JumpDest
+canShortcut _ = Nothing
+
+
+shortcutJump :: (BlockId -> Maybe JumpDest) -> Instr -> Instr
+shortcutJump _ other = other
+
+
+shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
+
+shortcutStatic fn (CmmStaticLit (CmmLabel lab))
+       | Just uq <- maybeAsmTemp lab 
+       = CmmStaticLit (CmmLabel (shortBlockId fn (BlockId uq)))
+
+shortcutStatic fn (CmmStaticLit (CmmLabelDiffOff lbl1 lbl2 off))
+       | Just uq <- maybeAsmTemp lbl1
+       = CmmStaticLit (CmmLabelDiffOff (shortBlockId fn (BlockId uq)) lbl2 off)
+
+-- slightly dodgy, we're ignoring the second label, but this
+-- works with the way we use CmmLabelDiffOff for jump tables now.
+shortcutStatic _ other_static
+        = other_static
+
+
+shortBlockId :: (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
+shortBlockId fn blockid@(BlockId uq) =
+   case fn blockid of
+      Nothing -> mkAsmTempLabel uq
+      Just (DestBlockId blockid')  -> shortBlockId fn blockid'
+      Just (DestImm (ImmCLbl lbl)) -> lbl
+      _other -> panic "shortBlockId"
+
+
+