+++ /dev/null
------------------------------------------------------------------------------
---
--- Cmm data types
---
--- (c) The University of Glasgow 2004
---
------------------------------------------------------------------------------
-
-module Cmm (
- GenCmm(..), Cmm,
- GenCmmTop(..), CmmTop,
- GenBasicBlock(..), CmmBasicBlock, blockId, blockStmts,
- CmmStmt(..),
- CmmCallTarget(..),
- CmmStatic(..), Section(..),
- CmmExpr(..), cmmExprRep,
- CmmReg(..), cmmRegRep,
- CmmLit(..), cmmLitRep,
- LocalReg(..), localRegRep,
- BlockId(..),
- GlobalReg(..), globalRegRep,
-
- node, nodeReg, spReg, hpReg,
- ) where
-
-#include "HsVersions.h"
-
-import MachOp
-import CLabel ( CLabel )
-import ForeignCall ( CCallConv )
-import Unique ( Unique, Uniquable(..) )
-import FastString ( FastString )
-import DATA_WORD ( Word8 )
-
------------------------------------------------------------------------------
--- Cmm, CmmTop, CmmBasicBlock
------------------------------------------------------------------------------
-
--- A file is a list of top-level chunks. These may be arbitrarily
--- re-orderd during code generation.
-
--- GenCmm is abstracted over
--- (a) the type of static data elements
--- (b) the contents of a basic block.
--- We expect there to be two main instances of this type:
--- (a) Plain C--, i.e. populated with CmmLit and CmmExpr respectively,
--- (b) Native code, populated with instructions
---
-newtype GenCmm d i = Cmm [GenCmmTop d i]
-
-type Cmm = GenCmm CmmStatic CmmStmt
-
--- A top-level chunk, abstracted over the type of the contents of
--- the basic blocks (Cmm or instructions are the likely instantiations).
-data GenCmmTop d i
- = CmmProc
- [d] -- Info table, may be empty
- CLabel -- Used to generate both info & entry labels
- [LocalReg] -- Argument locals live on entry (C-- procedure params)
- [GenBasicBlock i] -- Code, may be empty. The first block is
- -- the entry point. The order is otherwise initially
- -- unimportant, but at some point the code gen will
- -- fix the order.
-
- -- the BlockId of the first block does not give rise
- -- to a label. To jump to the first block in a Proc,
- -- use the appropriate CLabel.
-
- -- some static data.
- | CmmData Section [d] -- constant values only
-
-type CmmTop = GenCmmTop CmmStatic CmmStmt
-
--- A basic block containing a single label, at the beginning.
--- The list of basic blocks in a top-level code block may be re-ordered.
--- Fall-through is not allowed: there must be an explicit jump at the
--- end of each basic block, but the code generator might rearrange basic
--- blocks in order to turn some jumps into fallthroughs.
-
-data GenBasicBlock i = BasicBlock BlockId [i]
- -- ToDo: Julian suggests that we might need to annotate this type
- -- with the out & in edges in the graph, i.e. two * [BlockId]. This
- -- information can be derived from the contents, but it might be
- -- helpful to cache it here.
-
-type CmmBasicBlock = GenBasicBlock CmmStmt
-
-blockId :: GenBasicBlock i -> BlockId
--- The branch block id is that of the first block in
--- the branch, which is that branch's entry point
-blockId (BasicBlock blk_id _ ) = blk_id
-
-blockStmts :: GenBasicBlock i -> [i]
-blockStmts (BasicBlock _ stmts) = stmts
-
-
------------------------------------------------------------------------------
--- CmmStmt
--- A "statement". Note that all branches are explicit: there are no
--- control transfers to computed addresses, except when transfering
--- control to a new function.
------------------------------------------------------------------------------
-
-data CmmStmt
- = CmmNop
- | CmmComment FastString
-
- | CmmAssign CmmReg CmmExpr -- Assign to register
-
- | CmmStore CmmExpr CmmExpr -- Assign to memory location. Size is
- -- given by cmmExprRep of the rhs.
-
- | CmmCall -- A foreign call, with
- CmmCallTarget
- [(CmmReg,MachHint)] -- zero or more results
- [(CmmExpr,MachHint)] -- zero or more arguments
- (Maybe [GlobalReg]) -- Global regs that may need to be saved
- -- if they will be clobbered by the call.
- -- Nothing <=> save *all* globals that
- -- might be clobbered.
-
- | CmmBranch BlockId -- branch to another BB in this fn
-
- | CmmCondBranch CmmExpr BlockId -- conditional branch
-
- | CmmSwitch CmmExpr [Maybe BlockId] -- Table branch
- -- The scrutinee is zero-based;
- -- zero -> first block
- -- one -> second block etc
- -- Undefined outside range, and when there's a Nothing
-
- | CmmJump CmmExpr [LocalReg] -- Jump to another function, with these
- -- parameters.
-
------------------------------------------------------------------------------
--- CmmCallTarget
---
--- The target of a CmmCall.
------------------------------------------------------------------------------
-
-data CmmCallTarget
- = CmmForeignCall -- Call to a foreign function
- CmmExpr -- literal label <=> static call
- -- other expression <=> dynamic call
- CCallConv -- The calling convention
-
- | CmmPrim -- Call to a "primitive" (eg. sin, cos)
- CallishMachOp -- These might be implemented as inline
- -- code by the backend.
-
------------------------------------------------------------------------------
--- CmmExpr
--- An expression. Expressions have no side effects.
------------------------------------------------------------------------------
-
-data CmmExpr
- = CmmLit CmmLit -- Literal
- | CmmLoad CmmExpr MachRep -- Read memory location
- | CmmReg CmmReg -- Contents of register
- | CmmMachOp MachOp [CmmExpr] -- Machine operation (+, -, *, etc.)
- | CmmRegOff CmmReg Int
- -- CmmRegOff reg i
- -- ** is shorthand only, meaning **
- -- CmmMachOp (MO_S_Add rep (CmmReg reg) (CmmLit (CmmInt i rep)))
- -- where rep = cmmRegRep reg
-
-cmmExprRep :: CmmExpr -> MachRep
-cmmExprRep (CmmLit lit) = cmmLitRep lit
-cmmExprRep (CmmLoad _ rep) = rep
-cmmExprRep (CmmReg reg) = cmmRegRep reg
-cmmExprRep (CmmMachOp op _) = resultRepOfMachOp op
-cmmExprRep (CmmRegOff reg _) = cmmRegRep reg
-
-data CmmReg
- = CmmLocal LocalReg
- | CmmGlobal GlobalReg
- deriving( Eq )
-
-cmmRegRep :: CmmReg -> MachRep
-cmmRegRep (CmmLocal reg) = localRegRep reg
-cmmRegRep (CmmGlobal reg) = globalRegRep reg
-
-data LocalReg
- = LocalReg !Unique MachRep
-
-instance Eq LocalReg where
- (LocalReg u1 _) == (LocalReg u2 _) = u1 == u2
-
-instance Uniquable LocalReg where
- getUnique (LocalReg uniq _) = uniq
-
-localRegRep :: LocalReg -> MachRep
-localRegRep (LocalReg _ rep) = rep
-
-data CmmLit
- = CmmInt Integer MachRep
- -- Interpretation: the 2's complement representation of the value
- -- is truncated to the specified size. This is easier than trying
- -- to keep the value within range, because we don't know whether
- -- it will be used as a signed or unsigned value (the MachRep doesn't
- -- distinguish between signed & unsigned).
- | CmmFloat Rational MachRep
- | CmmLabel CLabel -- Address of label
- | CmmLabelOff CLabel Int -- Address of label + byte offset
-
- -- Due to limitations in the C backend, the following
- -- MUST ONLY be used inside the info table indicated by label2
- -- (label2 must be the info label), and label1 must be an
- -- SRT, a slow entrypoint or a large bitmap (see the Mangler)
- -- Don't use it at all unless tablesNextToCode.
- -- It is also used inside the NCG during when generating
- -- position-independent code.
- | CmmLabelDiffOff CLabel CLabel Int -- label1 - label2 + offset
-
-cmmLitRep :: CmmLit -> MachRep
-cmmLitRep (CmmInt _ rep) = rep
-cmmLitRep (CmmFloat _ rep) = rep
-cmmLitRep (CmmLabel _) = wordRep
-cmmLitRep (CmmLabelOff _ _) = wordRep
-cmmLitRep (CmmLabelDiffOff _ _ _) = wordRep
-
------------------------------------------------------------------------------
--- A local label.
-
--- Local labels must be unique within a single compilation unit.
-
-newtype BlockId = BlockId Unique
- deriving (Eq,Ord)
-
-instance Uniquable BlockId where
- getUnique (BlockId u) = u
-
------------------------------------------------------------------------------
--- Static Data
------------------------------------------------------------------------------
-
-data Section
- = Text
- | Data
- | ReadOnlyData
- | RelocatableReadOnlyData
- | UninitialisedData
- | ReadOnlyData16 -- .rodata.cst16 on x86_64, 16-byte aligned
- | OtherSection String
-
-data CmmStatic
- = CmmStaticLit CmmLit
- -- a literal value, size given by cmmLitRep of the literal.
- | CmmUninitialised Int
- -- uninitialised data, N bytes long
- | CmmAlign Int
- -- align to next N-byte boundary (N must be a power of 2).
- | CmmDataLabel CLabel
- -- label the current position in this section.
- | CmmString [Word8]
- -- string of 8-bit values only, not zero terminated.
-
------------------------------------------------------------------------------
--- Global STG registers
------------------------------------------------------------------------------
-
-data GlobalReg
- -- Argument and return registers
- = VanillaReg -- pointers, unboxed ints and chars
- {-# UNPACK #-} !Int -- its number
-
- | FloatReg -- single-precision floating-point registers
- {-# UNPACK #-} !Int -- its number
-
- | DoubleReg -- double-precision floating-point registers
- {-# UNPACK #-} !Int -- its number
-
- | LongReg -- long int registers (64-bit, really)
- {-# UNPACK #-} !Int -- its number
-
- -- STG registers
- | Sp -- Stack ptr; points to last occupied stack location.
- | SpLim -- Stack limit
- | Hp -- Heap ptr; points to last occupied heap location.
- | HpLim -- Heap limit register
- | CurrentTSO -- pointer to current thread's TSO
- | CurrentNursery -- pointer to allocation area
- | HpAlloc -- allocation count for heap check failure
-
- -- We keep the address of some commonly-called
- -- functions in the register table, to keep code
- -- size down:
- | GCEnter1 -- stg_gc_enter_1
- | GCFun -- stg_gc_fun
-
- -- Base offset for the register table, used for accessing registers
- -- which do not have real registers assigned to them. This register
- -- will only appear after we have expanded GlobalReg into memory accesses
- -- (where necessary) in the native code generator.
- | BaseReg
-
- -- Base Register for PIC (position-independent code) calculations
- -- Only used inside the native code generator. It's exact meaning differs
- -- from platform to platform (see module PositionIndependentCode).
- | PicBaseReg
-
- deriving( Eq
-#ifdef DEBUG
- , Show
-#endif
- )
-
--- convenient aliases
-spReg, hpReg, nodeReg :: CmmReg
-spReg = CmmGlobal Sp
-hpReg = CmmGlobal Hp
-nodeReg = CmmGlobal node
-
-node :: GlobalReg
-node = VanillaReg 1
-
-globalRegRep :: GlobalReg -> MachRep
-globalRegRep (VanillaReg _) = wordRep
-globalRegRep (FloatReg _) = F32
-globalRegRep (DoubleReg _) = F64
-globalRegRep (LongReg _) = I64
-globalRegRep _ = wordRep
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