import AbsCStixGen ( genCodeAbstractC )
import AbsCSyn ( AbstractC, MagicId )
import AsmRegAlloc ( runRegAllocate )
-import OrdList ( OrdList, flattenOrdList )
import PrimOp ( commutableOp, PrimOp(..) )
import RegAllocInfo ( mkMRegsState, MRegsState, findReservedRegs )
import Stix ( StixTree(..), StixReg(..),
- pprStixTrees, CodeSegment(..) )
+ pprStixTrees, ppStixTree, CodeSegment(..),
+ stixCountTempUses, stixSubst,
+ NatM, initNat, mapNat,
+ NatM_State, mkNatM_State,
+ uniqOfNatM_State, deltaOfNatM_State )
import PrimRep ( isFloatingRep, PrimRep(..) )
import UniqSupply ( returnUs, thenUs, mapUs, initUs,
initUs_, UniqSM, UniqSupply )
-import UniqFM ( UniqFM, emptyUFM, addToUFM, lookupUFM )
import MachMisc ( IF_ARCH_i386(i386_insert_ffrees,) )
+import OrdList ( fromOL, concatOL )
import Outputable
\end{code}
nativeCodeGen :: AbstractC -> UniqSupply -> (SDoc, SDoc)
nativeCodeGen absC us
= let (stixRaw, us1) = initUs us (genCodeAbstractC absC)
- stixOpt = map (map genericOpt) stixRaw
+ stixOpt = map genericOpt stixRaw
insns = initUs_ us1 (codeGen stixOpt)
debug_stix = vcat (map pprStixTrees stixOpt)
in
- trace "--------- native code generator ---------"
+ trace "nativeGen: begin"
(debug_stix, insns)
\end{code}
docs = map (vcat . map pprInstr) static_instrss
-- for debugging only
- docs_prealloc = map (vcat . map pprInstr . flattenOrdList)
+ docs_prealloc = map (vcat . map pprInstr . fromOL)
dynamic_codes
text_prealloc = vcat (intersperse (char ' ' $$ char ' ') docs_prealloc)
in
-- trace (showSDoc text_prealloc) (
returnUs (vcat (intersperse (char ' '
- $$ text "# ___stg_split_marker"
+ $$ ptext SLIT("# ___stg_split_marker")
$$ char ' ')
docs))
-- )
\end{code}
-Top level code generator for a chunk of stix code:
-\begin{code}
-genMachCode :: [StixTree] -> UniqSM InstrList
+Top level code generator for a chunk of stix code. For this part of
+the computation, we switch from the UniqSM monad to the NatM monad.
+The latter carries not only a Unique, but also an Int denoting the
+current C stack pointer offset in the generated code; this is needed
+for creating correct spill offsets on architectures which don't offer,
+or for which it would be prohibitively expensive to employ, a frame
+pointer register. Viz, x86.
+
+The offset is measured in bytes, and indicates the difference between
+the current (simulated) C stack-ptr and the value it was at the
+beginning of the block. For stacks which grow down, this value should
+be either zero or negative.
-genMachCode stmts
- = mapUs stmt2Instrs stmts `thenUs` \ blocks ->
- returnUs (foldr (.) id blocks asmVoid)
+Switching between the two monads whilst carrying along the same Unique
+supply breaks abstraction. Is that bad?
+
+\begin{code}
+genMachCode :: [StixTree] -> UniqSM InstrBlock
+
+genMachCode stmts initial_us
+ = let initial_st = mkNatM_State initial_us 0
+ (blocks, final_st) = initNat initial_st
+ (mapNat stmt2Instrs stmts)
+ instr_list = concatOL blocks
+ final_us = uniqOfNatM_State final_st
+ final_delta = deltaOfNatM_State final_st
+ in
+ if final_delta == 0
+ then (instr_list, final_us)
+ else pprPanic "genMachCode: nonzero final delta"
+ (int final_delta)
\end{code}
The next bit does the code scheduling. The scheduler must also deal
might be needed.
\begin{code}
-scheduleMachCode :: [InstrList] -> [[Instr]]
+scheduleMachCode :: [InstrBlock] -> [[Instr]]
scheduleMachCode
= map (runRegAllocate freeRegsState findReservedRegs)
address manipulations.
\begin{code}
-genericOpt :: StixTree -> StixTree
+genericOpt :: [StixTree] -> [StixTree]
+genericOpt = map stixConFold . stixPeep
+
+
+
+stixPeep :: [StixTree] -> [StixTree]
+
+-- This transformation assumes that the temp assigned to in t1
+-- is not assigned to in t2; for otherwise the target of the
+-- second assignment would be substituted for, giving nonsense
+-- code. As far as I can see, StixTemps are only ever assigned
+-- to once. It would be nice to be sure!
+stixPeep ( t1@(StAssign pka (StReg (StixTemp u pk)) rhs)
+ : t2
+ : ts )
+ | stixCountTempUses u t2 == 1
+ && sum (map (stixCountTempUses u) ts) == 0
+ = trace ("nativeGen: stixInline: " ++ showSDoc (ppStixTree rhs))
+ (stixPeep (stixSubst u rhs t2 : ts))
+
+stixPeep (t1:t2:ts) = t1 : stixPeep (t2:ts)
+stixPeep [t1] = [t1]
+stixPeep [] = []
\end{code}
For most nodes, just optimize the children.
\begin{code}
-genericOpt (StInd pk addr) = StInd pk (genericOpt addr)
+stixConFold :: StixTree -> StixTree
-genericOpt (StAssign pk dst src)
- = StAssign pk (genericOpt dst) (genericOpt src)
+stixConFold (StInd pk addr) = StInd pk (stixConFold addr)
-genericOpt (StJump addr) = StJump (genericOpt addr)
+stixConFold (StAssign pk dst src)
+ = StAssign pk (stixConFold dst) (stixConFold src)
-genericOpt (StCondJump addr test)
- = StCondJump addr (genericOpt test)
+stixConFold (StJump addr) = StJump (stixConFold addr)
-genericOpt (StCall fn cconv pk args)
- = StCall fn cconv pk (map genericOpt args)
+stixConFold (StCondJump addr test)
+ = StCondJump addr (stixConFold test)
+
+stixConFold (StCall fn cconv pk args)
+ = StCall fn cconv pk (map stixConFold args)
\end{code}
Fold indices together when the types match:
\begin{code}
-genericOpt (StIndex pk (StIndex pk' base off) off')
+stixConFold (StIndex pk (StIndex pk' base off) off')
| pk == pk'
- = StIndex pk (genericOpt base)
- (genericOpt (StPrim IntAddOp [off, off']))
+ = StIndex pk (stixConFold base)
+ (stixConFold (StPrim IntAddOp [off, off']))
-genericOpt (StIndex pk base off)
- = StIndex pk (genericOpt base) (genericOpt off)
+stixConFold (StIndex pk base off)
+ = StIndex pk (stixConFold base) (stixConFold off)
\end{code}
For PrimOps, we first optimize the children, and then we try our hand
at some constant-folding.
\begin{code}
-genericOpt (StPrim op args) = primOpt op (map genericOpt args)
+stixConFold (StPrim op args) = stixPrimFold op (map stixConFold args)
\end{code}
Replace register leaves with appropriate StixTrees for the given
target.
\begin{code}
-genericOpt leaf@(StReg (StixMagicId id))
+stixConFold leaf@(StReg (StixMagicId id))
= case (stgReg id) of
- Always tree -> genericOpt tree
+ Always tree -> stixConFold tree
Save _ -> leaf
-genericOpt other = other
+stixConFold other = other
\end{code}
Now, try to constant-fold the PrimOps. The arguments have already
been optimized and folded.
\begin{code}
-primOpt
+stixPrimFold
:: PrimOp -- The operation from an StPrim
-> [StixTree] -- The optimized arguments
-> StixTree
-primOpt op arg@[StInt x]
+stixPrimFold op arg@[StInt x]
= case op of
IntNegOp -> StInt (-x)
_ -> StPrim op arg
-primOpt op args@[StInt x, StInt y]
+stixPrimFold op args@[StInt x, StInt y]
= case op of
CharGtOp -> StInt (if x > y then 1 else 0)
CharGeOp -> StInt (if x >= y then 1 else 0)
possible.
\begin{code}
-primOpt op [x@(StInt _), y] | commutableOp op = primOpt op [y, x]
+stixPrimFold op [x@(StInt _), y] | commutableOp op = stixPrimFold op [y, x]
\end{code}
We can often do something with constants of 0 and 1 ...
\begin{code}
-primOpt op args@[x, y@(StInt 0)]
+stixPrimFold op args@[x, y@(StInt 0)]
= case op of
IntAddOp -> x
IntSubOp -> x
ISllOp -> x
ISraOp -> x
ISrlOp -> x
+ IntNeOp | is_comparison -> x
_ -> StPrim op args
+ where
+ is_comparison
+ = case x of
+ StPrim opp [_, _] -> opp `elem` comparison_ops
+ _ -> False
-primOpt op args@[x, y@(StInt 1)]
+stixPrimFold op args@[x, y@(StInt 1)]
= case op of
IntMulOp -> x
IntQuotOp -> x
Now look for multiplication/division by powers of 2 (integers).
\begin{code}
-primOpt op args@[x, y@(StInt n)]
+stixPrimFold op args@[x, y@(StInt n)]
= case op of
IntMulOp -> case exactLog2 n of
Nothing -> StPrim op args
Anything else is just too hard.
\begin{code}
-primOpt op args = StPrim op args
+stixPrimFold op args = StPrim op args
\end{code}
+
+\begin{code}
+comparison_ops
+ = [ CharGtOp , CharGeOp , CharEqOp , CharNeOp , CharLtOp , CharLeOp,
+ IntGtOp , IntGeOp , IntEqOp , IntNeOp , IntLtOp , IntLeOp,
+ WordGtOp , WordGeOp , WordEqOp , WordNeOp , WordLtOp , WordLeOp,
+ AddrGtOp , AddrGeOp , AddrEqOp , AddrNeOp , AddrLtOp , AddrLeOp,
+ FloatGtOp , FloatGeOp , FloatEqOp , FloatNeOp , FloatLtOp , FloatLeOp,
+ DoubleGtOp, DoubleGeOp, DoubleEqOp, DoubleNeOp, DoubleLtOp, DoubleLeOp
+ ]
+\end{code}
\ No newline at end of file
projects / ghc-hetmet.git / blobdiff