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vmgen.nim
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vmgen.nim
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#
#
# The Nim Compiler
# (c) Copyright 2015 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## This module implements the code generator for the VM.
# Important things to remember:
# - The VM does not distinguish between definitions ('var x = y') and
# assignments ('x = y'). For simple data types that fit into a register
# this doesn't matter. However it matters for strings and other complex
# types that use the 'node' field; the reason is that slots are
# re-used in a register based VM. Example:
#
# .. code-block:: nim
# let s = a & b # no matter what, create fresh node
# s = a & b # no matter what, keep the node
#
# Also *stores* into non-temporary memory need to perform deep copies:
# a.b = x.y
# We used to generate opcAsgn for the *load* of 'x.y' but this is clearly
# wrong! We need to produce opcAsgn (the copy) for the *store*. This also
# solves the opcLdConst vs opcAsgnConst issue. Of course whether we need
# this copy depends on the involved types.
import
strutils, ast, astalgo, types, msgs, renderer, vmdef,
trees, intsets, magicsys, options, lowerings, lineinfos
import platform
from os import splitFile
when hasFFI:
import evalffi
type
TGenFlag = enum
gfNode # Affects how variables are loaded - always loads as rkNode
gfNodeAddr # Affects how variables are loaded - always loads as rkNodeAddr
TGenFlags = set[TGenFlag]
proc debugInfo(c: PCtx; info: TLineInfo): string =
result = toFilename(c.config, info).splitFile.name & ":" & $info.line
proc codeListing(c: PCtx, result: var string, start=0; last = -1) =
# first iteration: compute all necessary labels:
var jumpTargets = initIntSet()
let last = if last < 0: c.code.len-1 else: min(last, c.code.len-1)
for i in start..last:
let x = c.code[i]
if x.opcode in relativeJumps:
jumpTargets.incl(i+x.regBx-wordExcess)
# for debugging purposes
var i = start
while i <= last:
if i in jumpTargets: result.addf("L$1:\n", i)
let x = c.code[i]
result.add($i)
let opc = opcode(x)
if opc in {opcConv, opcCast}:
let y = c.code[i+1]
let z = c.code[i+2]
result.addf("\t$#\tr$#, r$#, $#, $#", ($opc).substr(3), x.regA, x.regB,
c.types[y.regBx-wordExcess].typeToString,
c.types[z.regBx-wordExcess].typeToString)
inc i, 2
elif opc < firstABxInstr:
result.addf("\t$#\tr$#, r$#, r$#", ($opc).substr(3), x.regA,
x.regB, x.regC)
elif opc in relativeJumps:
result.addf("\t$#\tr$#, L$#", ($opc).substr(3), x.regA,
i+x.regBx-wordExcess)
elif opc in {opcLdConst, opcAsgnConst}:
let idx = x.regBx-wordExcess
result.addf("\t$#\tr$#, $# ($#)", ($opc).substr(3), x.regA,
c.constants[idx].renderTree, $idx)
elif opc in {opcMarshalLoad, opcMarshalStore}:
let y = c.code[i+1]
result.addf("\t$#\tr$#, r$#, $#", ($opc).substr(3), x.regA, x.regB,
c.types[y.regBx-wordExcess].typeToString)
inc i
else:
result.addf("\t$#\tr$#, $#", ($opc).substr(3), x.regA, x.regBx-wordExcess)
result.add("\t#")
result.add(debugInfo(c, c.debug[i]))
result.add("\n")
inc i
proc echoCode*(c: PCtx; start=0; last = -1) {.deprecated.} =
var buf = ""
codeListing(c, buf, start, last)
echo buf
proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) =
## Takes the registers `b` and `c`, applies the operation `opc` to them, and
## stores the result into register `a`
## The node is needed for debug information
assert opc.ord < 255
let ins = (opc.uint32 or (a.uint32 shl 8'u32) or
(b.uint32 shl 16'u32) or
(c.uint32 shl 24'u32)).TInstr
when false:
if ctx.code.len == 43:
writeStackTrace()
echo "generating ", opc
ctx.code.add(ins)
ctx.debug.add(n.info)
proc gABI(c: PCtx; n: PNode; opc: TOpcode; a, b: TRegister; imm: BiggestInt) =
# Takes the `b` register and the immediate `imm`, appies the operation `opc`,
# and stores the output value into `a`.
# `imm` is signed and must be within [-128, 127]
if imm >= -128 and imm <= 127:
let ins = (opc.uint32 or (a.uint32 shl 8'u32) or
(b.uint32 shl 16'u32) or
(imm+byteExcess).uint32 shl 24'u32).TInstr
c.code.add(ins)
c.debug.add(n.info)
else:
localError(c.config, n.info,
"VM: immediate value does not fit into an int8")
proc gABx(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0; bx: int) =
# Applies `opc` to `bx` and stores it into register `a`
# `bx` must be signed and in the range [-32768, 32767]
when false:
if c.code.len == 43:
writeStackTrace()
echo "generating ", opc
if bx >= -32768 and bx <= 32767:
let ins = (opc.uint32 or a.uint32 shl 8'u32 or
(bx+wordExcess).uint32 shl 16'u32).TInstr
c.code.add(ins)
c.debug.add(n.info)
else:
localError(c.config, n.info,
"VM: immediate value does not fit into an int16")
proc xjmp(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0): TPosition =
#assert opc in {opcJmp, opcFJmp, opcTJmp}
result = TPosition(c.code.len)
gABx(c, n, opc, a, 0)
proc genLabel(c: PCtx): TPosition =
result = TPosition(c.code.len)
#c.jumpTargets.incl(c.code.len)
proc jmpBack(c: PCtx, n: PNode, p = TPosition(0)) =
let dist = p.int - c.code.len
internalAssert(c.config, -0x7fff < dist and dist < 0x7fff)
gABx(c, n, opcJmpBack, 0, dist)
proc patch(c: PCtx, p: TPosition) =
# patch with current index
let p = p.int
let diff = c.code.len - p
#c.jumpTargets.incl(c.code.len)
internalAssert(c.config, -0x7fff < diff and diff < 0x7fff)
let oldInstr = c.code[p]
# opcode and regA stay the same:
c.code[p] = ((oldInstr.uint32 and 0xffff'u32).uint32 or
uint32(diff+wordExcess) shl 16'u32).TInstr
proc getSlotKind(t: PType): TSlotKind =
case t.skipTypes(abstractRange-{tyTypeDesc}).kind
of tyBool, tyChar, tyEnum, tyOrdinal, tyInt..tyInt64, tyUInt..tyUInt64:
slotTempInt
of tyString, tyCString:
slotTempStr
of tyFloat..tyFloat128:
slotTempFloat
else:
slotTempComplex
const
HighRegisterPressure = 40
proc bestEffort(c: PCtx): TLineInfo =
(if c.prc == nil: c.module.info else: c.prc.sym.info)
proc getTemp(cc: PCtx; tt: PType): TRegister =
let typ = tt.skipTypesOrNil({tyStatic})
let c = cc.prc
# we prefer the same slot kind here for efficiency. Unfortunately for
# discardable return types we may not know the desired type. This can happen
# for e.g. mNAdd[Multiple]:
let k = if typ.isNil: slotTempComplex else: typ.getSlotKind
for i in 0 .. c.maxSlots-1:
if c.slots[i].kind == k and not c.slots[i].inUse:
c.slots[i].inUse = true
return TRegister(i)
# if register pressure is high, we re-use more aggressively:
if c.maxSlots >= HighRegisterPressure and false:
for i in 0 .. c.maxSlots-1:
if not c.slots[i].inUse:
c.slots[i] = (inUse: true, kind: k)
return TRegister(i)
if c.maxSlots >= high(TRegister):
globalError(cc.config, cc.bestEffort, "VM problem: too many registers required")
result = TRegister(c.maxSlots)
c.slots[c.maxSlots] = (inUse: true, kind: k)
inc c.maxSlots
proc freeTemp(c: PCtx; r: TRegister) =
let c = c.prc
if c.slots[r].kind in {slotSomeTemp..slotTempComplex}: c.slots[r].inUse = false
proc getTempRange(cc: PCtx; n: int; kind: TSlotKind): TRegister =
# if register pressure is high, we re-use more aggressively:
let c = cc.prc
if c.maxSlots >= HighRegisterPressure or c.maxSlots+n >= high(TRegister):
for i in 0 .. c.maxSlots-n:
if not c.slots[i].inUse:
block search:
for j in i+1 .. i+n-1:
if c.slots[j].inUse: break search
result = TRegister(i)
for k in result .. result+n-1: c.slots[k] = (inUse: true, kind: kind)
return
if c.maxSlots+n >= high(TRegister):
globalError(cc.config, cc.bestEffort, "VM problem: too many registers required")
result = TRegister(c.maxSlots)
inc c.maxSlots, n
for k in result .. result+n-1: c.slots[k] = (inUse: true, kind: kind)
proc freeTempRange(c: PCtx; start: TRegister, n: int) =
for i in start .. start+n-1: c.freeTemp(TRegister(i))
template withTemp(tmp, typ, body: untyped) {.dirty.} =
var tmp = getTemp(c, typ)
body
c.freeTemp(tmp)
proc popBlock(c: PCtx; oldLen: int) =
for f in c.prc.blocks[oldLen].fixups:
c.patch(f)
c.prc.blocks.setLen(oldLen)
template withBlock(labl: PSym; body: untyped) {.dirty.} =
var oldLen {.gensym.} = c.prc.blocks.len
c.prc.blocks.add TBlock(label: labl, fixups: @[])
body
popBlock(c, oldLen)
proc gen(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags = {})
proc gen(c: PCtx; n: PNode; dest: TRegister; flags: TGenFlags = {}) =
var d: TDest = dest
gen(c, n, d, flags)
#internalAssert c.config, d == dest # issue #7407
proc gen(c: PCtx; n: PNode; flags: TGenFlags = {}) =
var tmp: TDest = -1
gen(c, n, tmp, flags)
#if n.typ.isEmptyType: InternalAssert tmp < 0
proc genx(c: PCtx; n: PNode; flags: TGenFlags = {}): TRegister =
var tmp: TDest = -1
gen(c, n, tmp, flags)
#internalAssert c.config, tmp >= 0 # 'nim check' does not like this internalAssert.
if tmp >= 0:
result = TRegister(tmp)
proc clearDest(c: PCtx; n: PNode; dest: var TDest) {.inline.} =
# stmt is different from 'void' in meta programming contexts.
# So we only set dest to -1 if 'void':
if dest >= 0 and (n.typ.isNil or n.typ.kind == tyVoid):
c.freeTemp(dest)
dest = -1
proc isNotOpr(n: PNode): bool =
n.kind in nkCallKinds and n.sons[0].kind == nkSym and
n.sons[0].sym.magic == mNot
proc isTrue(n: PNode): bool =
n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or
n.kind == nkIntLit and n.intVal != 0
proc genWhile(c: PCtx; n: PNode) =
# L1:
# cond, tmp
# fjmp tmp, L2
# body
# jmp L1
# L2:
let L1 = c.genLabel
withBlock(nil):
if isTrue(n.sons[0]):
c.gen(n.sons[1])
c.jmpBack(n, L1)
elif isNotOpr(n.sons[0]):
var tmp = c.genx(n.sons[0].sons[1])
let L2 = c.xjmp(n, opcTJmp, tmp)
c.freeTemp(tmp)
c.gen(n.sons[1])
c.jmpBack(n, L1)
c.patch(L2)
else:
var tmp = c.genx(n.sons[0])
let L2 = c.xjmp(n, opcFJmp, tmp)
c.freeTemp(tmp)
c.gen(n.sons[1])
c.jmpBack(n, L1)
c.patch(L2)
proc genBlock(c: PCtx; n: PNode; dest: var TDest) =
withBlock(n.sons[0].sym):
c.gen(n.sons[1], dest)
c.clearDest(n, dest)
proc genBreak(c: PCtx; n: PNode) =
let L1 = c.xjmp(n, opcJmp)
if n.sons[0].kind == nkSym:
#echo cast[int](n.sons[0].sym)
for i in countdown(c.prc.blocks.len-1, 0):
if c.prc.blocks[i].label == n.sons[0].sym:
c.prc.blocks[i].fixups.add L1
return
globalError(c.config, n.info, "VM problem: cannot find 'break' target")
else:
c.prc.blocks[c.prc.blocks.high].fixups.add L1
proc genIf(c: PCtx, n: PNode; dest: var TDest) =
# if (!expr1) goto L1;
# thenPart
# goto LEnd
# L1:
# if (!expr2) goto L2;
# thenPart2
# goto LEnd
# L2:
# elsePart
# Lend:
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
var endings: seq[TPosition] = @[]
for i in countup(0, len(n) - 1):
var it = n.sons[i]
if it.len == 2:
withTemp(tmp, it.sons[0].typ):
var elsePos: TPosition
if isNotOpr(it.sons[0]):
c.gen(it.sons[0].sons[1], tmp)
elsePos = c.xjmp(it.sons[0].sons[1], opcTJmp, tmp) # if true
else:
c.gen(it.sons[0], tmp)
elsePos = c.xjmp(it.sons[0], opcFJmp, tmp) # if false
c.clearDest(n, dest)
c.gen(it.sons[1], dest) # then part
if i < sonsLen(n)-1:
endings.add(c.xjmp(it.sons[1], opcJmp, 0))
c.patch(elsePos)
else:
c.clearDest(n, dest)
c.gen(it.sons[0], dest)
for endPos in endings: c.patch(endPos)
c.clearDest(n, dest)
proc isTemp(c: PCtx; dest: TDest): bool =
result = dest >= 0 and c.prc.slots[dest].kind >= slotTempUnknown
proc genAndOr(c: PCtx; n: PNode; opc: TOpcode; dest: var TDest) =
# asgn dest, a
# tjmp|fjmp L1
# asgn dest, b
# L1:
let copyBack = dest < 0 or not isTemp(c, dest)
let tmp = if copyBack:
getTemp(c, n.typ)
else:
TRegister dest
c.gen(n.sons[1], tmp)
let L1 = c.xjmp(n, opc, tmp)
c.gen(n.sons[2], tmp)
c.patch(L1)
if dest < 0:
dest = tmp
elif copyBack:
c.gABC(n, opcAsgnInt, dest, tmp)
freeTemp(c, tmp)
proc canonValue*(n: PNode): PNode =
result = n
proc rawGenLiteral(c: PCtx; n: PNode): int =
result = c.constants.len
#assert(n.kind != nkCall)
n.flags.incl nfAllConst
c.constants.add n.canonValue
internalAssert c.config, result < 0x7fff
proc sameConstant*(a, b: PNode): bool =
result = false
if a == b:
result = true
elif a != nil and b != nil and a.kind == b.kind:
case a.kind
of nkSym: result = a.sym == b.sym
of nkIdent: result = a.ident.id == b.ident.id
of nkCharLit..nkUInt64Lit: result = a.intVal == b.intVal
of nkFloatLit..nkFloat64Lit: result = a.floatVal == b.floatVal
of nkStrLit..nkTripleStrLit: result = a.strVal == b.strVal
of nkType, nkNilLit: result = a.typ == b.typ
of nkEmpty: result = true
else:
if sonsLen(a) == sonsLen(b):
for i in countup(0, sonsLen(a) - 1):
if not sameConstant(a.sons[i], b.sons[i]): return
result = true
proc genLiteral(c: PCtx; n: PNode): int =
# types do not matter here:
for i in 0 ..< c.constants.len:
if sameConstant(c.constants[i], n): return i
result = rawGenLiteral(c, n)
proc unused(c: PCtx; n: PNode; x: TDest) {.inline.} =
if x >= 0:
#debug(n)
globalError(c.config, n.info, "not unused")
proc genCase(c: PCtx; n: PNode; dest: var TDest) =
# if (!expr1) goto L1;
# thenPart
# goto LEnd
# L1:
# if (!expr2) goto L2;
# thenPart2
# goto LEnd
# L2:
# elsePart
# Lend:
if not isEmptyType(n.typ):
if dest < 0: dest = getTemp(c, n.typ)
else:
unused(c, n, dest)
var endings: seq[TPosition] = @[]
withTemp(tmp, n.sons[0].typ):
c.gen(n.sons[0], tmp)
# branch tmp, codeIdx
# fjmp elseLabel
for i in 1 ..< n.len:
let it = n.sons[i]
if it.len == 1:
# else stmt:
c.gen(it.sons[0], dest)
else:
let b = rawGenLiteral(c, it)
c.gABx(it, opcBranch, tmp, b)
let elsePos = c.xjmp(it.lastSon, opcFJmp, tmp)
c.gen(it.lastSon, dest)
if i < sonsLen(n)-1:
endings.add(c.xjmp(it.lastSon, opcJmp, 0))
c.patch(elsePos)
c.clearDest(n, dest)
for endPos in endings: c.patch(endPos)
proc genType(c: PCtx; typ: PType): int =
for i, t in c.types:
if sameType(t, typ): return i
result = c.types.len
c.types.add(typ)
internalAssert(c.config, result <= 0x7fff)
proc genTry(c: PCtx; n: PNode; dest: var TDest) =
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
var endings: seq[TPosition] = @[]
let elsePos = c.xjmp(n, opcTry, 0)
c.gen(n.sons[0], dest)
c.clearDest(n, dest)
c.patch(elsePos)
for i in 1 ..< n.len:
let it = n.sons[i]
if it.kind != nkFinally:
var blen = len(it)
# first opcExcept contains the end label of the 'except' block:
let endExcept = c.xjmp(it, opcExcept, 0)
for j in countup(0, blen - 2):
assert(it.sons[j].kind == nkType)
let typ = it.sons[j].typ.skipTypes(abstractPtrs-{tyTypeDesc})
c.gABx(it, opcExcept, 0, c.genType(typ))
if blen == 1:
# general except section:
c.gABx(it, opcExcept, 0, 0)
c.gen(it.lastSon, dest)
c.clearDest(n, dest)
if i < sonsLen(n)-1:
endings.add(c.xjmp(it, opcJmp, 0))
c.patch(endExcept)
for endPos in endings: c.patch(endPos)
let fin = lastSon(n)
# we always generate an 'opcFinally' as that pops the safepoint
# from the stack
c.gABx(fin, opcFinally, 0, 0)
if fin.kind == nkFinally:
c.gen(fin.sons[0])
c.clearDest(n, dest)
c.gABx(fin, opcFinallyEnd, 0, 0)
proc genRaise(c: PCtx; n: PNode) =
let dest = genx(c, n.sons[0])
c.gABC(n, opcRaise, dest)
c.freeTemp(dest)
proc genReturn(c: PCtx; n: PNode) =
if n.sons[0].kind != nkEmpty:
gen(c, n.sons[0])
c.gABC(n, opcRet)
proc genLit(c: PCtx; n: PNode; dest: var TDest) =
# opcLdConst is now always valid. We produce the necessary copy in the
# assignments now:
#var opc = opcLdConst
if dest < 0: dest = c.getTemp(n.typ)
#elif c.prc.slots[dest].kind == slotFixedVar: opc = opcAsgnConst
let lit = genLiteral(c, n)
c.gABx(n, opcLdConst, dest, lit)
proc genCall(c: PCtx; n: PNode; dest: var TDest) =
# it can happen that due to inlining we have a 'n' that should be
# treated as a constant (see issue #537).
#if n.typ != nil and n.typ.sym != nil and n.typ.sym.magic == mPNimrodNode:
# genLit(c, n, dest)
# return
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
let x = c.getTempRange(n.len, slotTempUnknown)
# varargs need 'opcSetType' for the FFI support:
let fntyp = skipTypes(n.sons[0].typ, abstractInst)
for i in 0..<n.len:
#if i > 0 and i < sonsLen(fntyp):
# let paramType = fntyp.n.sons[i]
# if paramType.typ.isCompileTimeOnly: continue
var r: TRegister = x+i
c.gen(n.sons[i], r)
if i >= fntyp.len:
internalAssert c.config, tfVarargs in fntyp.flags
c.gABx(n, opcSetType, r, c.genType(n.sons[i].typ))
if dest < 0:
c.gABC(n, opcIndCall, 0, x, n.len)
else:
c.gABC(n, opcIndCallAsgn, dest, x, n.len)
c.freeTempRange(x, n.len)
template isGlobal(s: PSym): bool = sfGlobal in s.flags and s.kind != skForVar
proc isGlobal(n: PNode): bool = n.kind == nkSym and isGlobal(n.sym)
proc needsAsgnPatch(n: PNode): bool =
n.kind in {nkBracketExpr, nkDotExpr, nkCheckedFieldExpr,
nkDerefExpr, nkHiddenDeref} or (n.kind == nkSym and n.sym.isGlobal)
proc genField(c: PCtx; n: PNode): TRegister =
if n.kind != nkSym or n.sym.kind != skField:
globalError(c.config, n.info, "no field symbol")
let s = n.sym
if s.position > high(result):
globalError(c.config, n.info,
"too large offset! cannot generate code for: " & s.name.s)
result = s.position
proc genIndex(c: PCtx; n: PNode; arr: PType): TRegister =
if arr.skipTypes(abstractInst).kind == tyArray and (let x = firstOrd(c.config, arr);
x != 0):
let tmp = c.genx(n)
# freeing the temporary here means we can produce: regA = regA - Imm
c.freeTemp(tmp)
result = c.getTemp(n.typ)
c.gABI(n, opcSubImmInt, result, tmp, x.int)
else:
result = c.genx(n)
proc genAsgnPatch(c: PCtx; le: PNode, value: TRegister) =
case le.kind
of nkBracketExpr:
let dest = c.genx(le.sons[0], {gfNode})
let idx = c.genIndex(le.sons[1], le.sons[0].typ)
c.gABC(le, opcWrArr, dest, idx, value)
c.freeTemp(dest)
c.freeTemp(idx)
of nkDotExpr, nkCheckedFieldExpr:
# XXX field checks here
let left = if le.kind == nkDotExpr: le else: le.sons[0]
let dest = c.genx(left.sons[0], {gfNode})
let idx = genField(c, left.sons[1])
c.gABC(left, opcWrObj, dest, idx, value)
c.freeTemp(dest)
of nkDerefExpr, nkHiddenDeref:
let dest = c.genx(le.sons[0], {gfNode})
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
of nkSym:
if le.sym.isGlobal:
let dest = c.genx(le, {gfNodeAddr})
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
else:
discard
proc genNew(c: PCtx; n: PNode) =
let dest = if needsAsgnPatch(n.sons[1]): c.getTemp(n.sons[1].typ)
else: c.genx(n.sons[1])
# we use the ref's base type here as the VM conflates 'ref object'
# and 'object' since internally we already have a pointer.
c.gABx(n, opcNew, dest,
c.genType(n.sons[1].typ.skipTypes(abstractVar-{tyTypeDesc}).sons[0]))
c.genAsgnPatch(n.sons[1], dest)
c.freeTemp(dest)
proc genNewSeq(c: PCtx; n: PNode) =
let t = n.sons[1].typ
let dest = if needsAsgnPatch(n.sons[1]): c.getTemp(t)
else: c.genx(n.sons[1])
let tmp = c.genx(n.sons[2])
c.gABx(n, opcNewSeq, dest, c.genType(t.skipTypes(
abstractVar-{tyTypeDesc})))
c.gABx(n, opcNewSeq, tmp, 0)
c.freeTemp(tmp)
c.genAsgnPatch(n.sons[1], dest)
c.freeTemp(dest)
proc genNewSeqOfCap(c: PCtx; n: PNode; dest: var TDest) =
let t = n.typ
let tmp = c.getTemp(n.sons[1].typ)
c.gABx(n, opcLdNull, dest, c.genType(t))
c.gABx(n, opcLdImmInt, tmp, 0)
c.gABx(n, opcNewSeq, dest, c.genType(t.skipTypes(
abstractVar-{tyTypeDesc})))
c.gABx(n, opcNewSeq, tmp, 0)
c.freeTemp(tmp)
proc genUnaryABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let tmp = c.genx(n.sons[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp)
c.freeTemp(tmp)
proc genUnaryABI(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode; imm: BiggestInt=0) =
let tmp = c.genx(n.sons[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABI(n, opc, dest, tmp, imm)
c.freeTemp(tmp)
proc genBinaryABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n.sons[1])
tmp2 = c.genx(n.sons[2])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
proc genBinaryABCD(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n.sons[1])
tmp2 = c.genx(n.sons[2])
tmp3 = c.genx(n.sons[3])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp, tmp2)
c.gABC(n, opc, tmp3)
c.freeTemp(tmp)
c.freeTemp(tmp2)
c.freeTemp(tmp3)
proc genNarrow(c: PCtx; n: PNode; dest: TDest) =
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
# uint is uint64 in the VM, we we only need to mask the result for
# other unsigned types:
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
elif t.kind in {tyInt8..tyInt32} or (t.kind == tyInt and t.size < 8):
c.gABC(n, opcNarrowS, dest, TRegister(t.size*8))
proc genNarrowU(c: PCtx; n: PNode; dest: TDest) =
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
# uint is uint64 in the VM, we we only need to mask the result for
# other unsigned types:
if t.kind in {tyUInt8..tyUInt32, tyInt8..tyInt32} or
(t.kind in {tyUInt, tyInt} and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
proc genBinaryABCnarrow(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
genBinaryABC(c, n, dest, opc)
genNarrow(c, n, dest)
proc genBinaryABCnarrowU(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
genBinaryABC(c, n, dest, opc)
genNarrowU(c, n, dest)
proc genSetType(c: PCtx; n: PNode; dest: TRegister) =
let t = skipTypes(n.typ, abstractInst-{tyTypeDesc})
if t.kind == tySet:
c.gABx(n, opcSetType, dest, c.genType(t))
proc genBinarySet(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n.sons[1])
tmp2 = c.genx(n.sons[2])
if dest < 0: dest = c.getTemp(n.typ)
c.genSetType(n.sons[1], tmp)
c.genSetType(n.sons[2], tmp2)
c.gABC(n, opc, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
proc genBinaryStmt(c: PCtx; n: PNode; opc: TOpcode) =
let
dest = c.genx(n.sons[1])
tmp = c.genx(n.sons[2])
c.gABC(n, opc, dest, tmp, 0)
c.freeTemp(tmp)
proc genBinaryStmtVar(c: PCtx; n: PNode; opc: TOpcode) =
var x = n.sons[1]
if x.kind in {nkAddr, nkHiddenAddr}: x = x.sons[0]
let
dest = c.genx(x)
tmp = c.genx(n.sons[2])
c.gABC(n, opc, dest, tmp, 0)
#c.genAsgnPatch(n.sons[1], dest)
c.freeTemp(tmp)
proc genUnaryStmt(c: PCtx; n: PNode; opc: TOpcode) =
let tmp = c.genx(n.sons[1])
c.gABC(n, opc, tmp, 0, 0)
c.freeTemp(tmp)
proc genVarargsABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
if dest < 0: dest = getTemp(c, n.typ)
var x = c.getTempRange(n.len-1, slotTempStr)
for i in 1..n.len-1:
var r: TRegister = x+i-1
c.gen(n.sons[i], r)
c.gABC(n, opc, dest, x, n.len-1)
c.freeTempRange(x, n.len)
proc isInt8Lit(n: PNode): bool =
if n.kind in {nkCharLit..nkUInt64Lit}:
result = n.intVal >= low(int8) and n.intVal <= high(int8)
proc isInt16Lit(n: PNode): bool =
if n.kind in {nkCharLit..nkUInt64Lit}:
result = n.intVal >= low(int16) and n.intVal <= high(int16)
proc genAddSubInt(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
if n.sons[2].isInt8Lit:
let tmp = c.genx(n.sons[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABI(n, succ(opc), dest, tmp, n.sons[2].intVal)
c.freeTemp(tmp)
else:
genBinaryABC(c, n, dest, opc)
c.genNarrow(n, dest)
proc genConv(c: PCtx; n, arg: PNode; dest: var TDest; opc=opcConv) =
if n.typ.kind == arg.typ.kind and arg.typ.kind == tyProc:
# don't do anything for lambda lifting conversions:
gen(c, arg, dest)
return
let tmp = c.genx(arg)
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp)
c.gABx(n, opc, 0, genType(c, n.typ.skipTypes({tyStatic})))
c.gABx(n, opc, 0, genType(c, arg.typ.skipTypes({tyStatic})))
c.freeTemp(tmp)
proc genCard(c: PCtx; n: PNode; dest: var TDest) =
let tmp = c.genx(n.sons[1])
if dest < 0: dest = c.getTemp(n.typ)
c.genSetType(n.sons[1], tmp)
c.gABC(n, opcCard, dest, tmp)
c.freeTemp(tmp)
proc genIntCast(c: PCtx; n: PNode; dest: var TDest) =
const allowedIntegers = {tyInt..tyInt64, tyUInt..tyUInt64, tyChar}
var signedIntegers = {tyInt8..tyInt32}
var unsignedIntegers = {tyUInt8..tyUInt32, tyChar}
let src = n.sons[1].typ.skipTypes(abstractRange)#.kind
let dst = n.sons[0].typ.skipTypes(abstractRange)#.kind
let src_size = getSize(c.config, src)
if c.config.target.intSize < 8:
signedIntegers.incl(tyInt)
unsignedIntegers.incl(tyUInt)
if src_size == getSize(c.config, dst) and src.kind in allowedIntegers and
dst.kind in allowedIntegers:
let tmp = c.genx(n.sons[1])
var tmp2 = c.getTemp(n.sons[1].typ)
let tmp3 = c.getTemp(n.sons[1].typ)
if dest < 0: dest = c.getTemp(n[0].typ)
proc mkIntLit(ival: int): int =
result = genLiteral(c, newIntTypeNode(nkIntLit, ival, getSysType(c.graph, n.info, tyInt)))
if src.kind in unsignedIntegers and dst.kind in signedIntegers:
# cast unsigned to signed integer of same size
# signedVal = (unsignedVal xor offset) -% offset
let offset = 1 shl (src_size * 8 - 1)
c.gABx(n, opcLdConst, tmp2, mkIntLit(offset))
c.gABC(n, opcBitxorInt, tmp3, tmp, tmp2)
c.gABC(n, opcSubInt, dest, tmp3, tmp2)
elif src.kind in signedIntegers and dst.kind in unsignedIntegers:
# cast signed to unsigned integer of same size
# unsignedVal = (offset +% signedVal +% 1) and offset
let offset = (1 shl (src_size * 8)) - 1
c.gABx(n, opcLdConst, tmp2, mkIntLit(offset))
c.gABx(n, opcLdConst, dest, mkIntLit(offset+1))
c.gABC(n, opcAddu, tmp3, tmp, dest)
c.gABC(n, opcNarrowU, tmp3, TRegister(src_size*8))
c.gABC(n, opcBitandInt, dest, tmp3, tmp2)
else:
c.gABC(n, opcAsgnInt, dest, tmp)
c.freeTemp(tmp)
c.freeTemp(tmp2)
c.freeTemp(tmp3)
else:
globalError(c.config, n.info, "VM is only allowed to 'cast' between integers of same size")
proc genVoidABC(c: PCtx, n: PNode, dest: TDest, opcode: TOpcode) =
unused(c, n, dest)
var
tmp1 = c.genx(n[1])
tmp2 = c.genx(n[2])
tmp3 = c.genx(n[3])
c.gABC(n, opcode, tmp1, tmp2, tmp3)
c.freeTemp(tmp1)
c.freeTemp(tmp2)
c.freeTemp(tmp3)
proc genBindSym(c: PCtx; n: PNode; dest: var TDest) =
# nah, cannot use c.config.features because sempass context
# can have local experimental switch
# if dynamicBindSym notin c.config.features:
if n.len == 2: # hmm, reliable?
# bindSym with static input
if n[1].kind in {nkClosedSymChoice, nkOpenSymChoice, nkSym}:
let idx = c.genLiteral(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcNBindSym, dest, idx)
else:
localError(c.config, n.info, "invalid bindSym usage")
else:
# experimental bindSym
if dest < 0: dest = c.getTemp(n.typ)
let x = c.getTempRange(n.len, slotTempUnknown)
# callee symbol
var tmp0 = TDest(x)
c.genLit(n.sons[0], tmp0)
# original parameters
for i in 1..<n.len-2:
var r = TRegister(x+i)
c.gen(n.sons[i], r)
# info node
var tmp1 = TDest(x+n.len-2)
c.genLit(n.sons[^2], tmp1)
# payload idx
var tmp2 = TDest(x+n.len-1)
c.genLit(n.sons[^1], tmp2)
c.gABC(n, opcNDynBindSym, dest, x, n.len)
c.freeTempRange(x, n.len)
proc genMagic(c: PCtx; n: PNode; dest: var TDest; m: TMagic) =
case m
of mAnd: c.genAndOr(n, opcFJmp, dest)
of mOr: c.genAndOr(n, opcTJmp, dest)
of mUnaryLt:
let tmp = c.genx(n.sons[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABI(n, opcSubImmInt, dest, tmp, 1)
c.freeTemp(tmp)
of mPred, mSubI:
c.genAddSubInt(n, dest, opcSubInt)
of mSucc, mAddI:
c.genAddSubInt(n, dest, opcAddInt)
of mInc, mDec:
unused(c, n, dest)
let opc = if m == mInc: opcAddInt else: opcSubInt
let d = c.genx(n.sons[1])
if n.sons[2].isInt8Lit:
c.gABI(n, succ(opc), d, d, n.sons[2].intVal)
else:
let tmp = c.genx(n.sons[2])
c.gABC(n, opc, d, d, tmp)
c.freeTemp(tmp)
c.genNarrow(n.sons[1], d)
c.genAsgnPatch(n.sons[1], d)
c.freeTemp(d)
of mOrd, mChr, mArrToSeq: c.gen(n.sons[1], dest)
of mNew, mNewFinalize:
unused(c, n, dest)
c.genNew(n)
of mNewSeq:
unused(c, n, dest)
c.genNewSeq(n)
of mNewSeqOfCap: c.genNewSeqOfCap(n, dest)
of mNewString:
genUnaryABC(c, n, dest, opcNewStr)
# XXX buggy
of mNewStringOfCap:
# we ignore the 'cap' argument and translate it as 'newString(0)'.
# eval n.sons[1] for possible side effects:
c.freeTemp(c.genx(n.sons[1]))
var tmp = c.getTemp(n.sons[1].typ)
c.gABx(n, opcLdImmInt, tmp, 0)
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opcNewStr, dest, tmp)
c.freeTemp(tmp)
# XXX buggy
of mLengthOpenArray, mLengthArray, mLengthSeq, mXLenSeq:
genUnaryABI(c, n, dest, opcLenSeq)
of mLengthStr, mXLenStr:
genUnaryABI(c, n, dest, opcLenStr)
of mIncl, mExcl:
unused(c, n, dest)
var d = c.genx(n.sons[1])
var tmp = c.genx(n.sons[2])
c.genSetType(n.sons[1], d)
c.gABC(n, if m == mIncl: opcIncl else: opcExcl, d, tmp)
c.freeTemp(d)
c.freeTemp(tmp)
of mCard: genCard(c, n, dest)
of mMulI: genBinaryABCnarrow(c, n, dest, opcMulInt)
of mDivI: genBinaryABCnarrow(c, n, dest, opcDivInt)
of mModI: genBinaryABCnarrow(c, n, dest, opcModInt)
of mAddF64: genBinaryABC(c, n, dest, opcAddFloat)
of mSubF64: genBinaryABC(c, n, dest, opcSubFloat)
of mMulF64: genBinaryABC(c, n, dest, opcMulFloat)
of mDivF64: genBinaryABC(c, n, dest, opcDivFloat)
of mShrI:
# the idea here is to narrow type if needed before executing right shift
# inlined modified: genNarrowU(c, n, dest)
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
# uint is uint64 in the VM, we we only need to mask the result for
# other unsigned types:
let tmp = c.genx(n.sons[1])
if t.kind in {tyUInt8..tyUInt32, tyInt8..tyInt32}:
c.gABC(n, opcNarrowU, tmp, TRegister(t.size*8))
# inlined modified: genBinaryABC(c, n, dest, opcShrInt)
let tmp2 = c.genx(n.sons[2])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opcShrInt, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
of mShlI:
genBinaryABC(c, n, dest, opcShlInt)
# genNarrowU modified
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
elif t.kind in {tyInt8..tyInt32} or (t.kind == tyInt and t.size < 8):
c.gABC(n, opcSignExtend, dest, TRegister(t.size*8))
of mAshrI: genBinaryABC(c, n, dest, opcAshrInt)
of mBitandI: genBinaryABC(c, n, dest, opcBitandInt)
of mBitorI: genBinaryABC(c, n, dest, opcBitorInt)
of mBitxorI: genBinaryABC(c, n, dest, opcBitxorInt)
of mAddU: genBinaryABCnarrowU(c, n, dest, opcAddu)
of mSubU: genBinaryABCnarrowU(c, n, dest, opcSubu)
of mMulU: genBinaryABCnarrowU(c, n, dest, opcMulu)
of mDivU: genBinaryABCnarrowU(c, n, dest, opcDivu)
of mModU: genBinaryABCnarrowU(c, n, dest, opcModu)
of mEqI, mEqB, mEqEnum, mEqCh:
genBinaryABC(c, n, dest, opcEqInt)
of mLeI, mLeEnum, mLeCh, mLeB:
genBinaryABC(c, n, dest, opcLeInt)
of mLtI, mLtEnum, mLtCh, mLtB:
genBinaryABC(c, n, dest, opcLtInt)
of mEqF64: genBinaryABC(c, n, dest, opcEqFloat)
of mLeF64: genBinaryABC(c, n, dest, opcLeFloat)
of mLtF64: genBinaryABC(c, n, dest, opcLtFloat)
of mLePtr, mLeU, mLeU64: genBinaryABC(c, n, dest, opcLeu)
of mLtPtr, mLtU, mLtU64: genBinaryABC(c, n, dest, opcLtu)
of mEqProc, mEqRef, mEqUntracedRef:
genBinaryABC(c, n, dest, opcEqRef)
of mXor: genBinaryABC(c, n, dest, opcXor)
of mNot: genUnaryABC(c, n, dest, opcNot)
of mUnaryMinusI, mUnaryMinusI64:
genUnaryABC(c, n, dest, opcUnaryMinusInt)
genNarrow(c, n, dest)
of mUnaryMinusF64: genUnaryABC(c, n, dest, opcUnaryMinusFloat)
of mUnaryPlusI, mUnaryPlusF64: gen(c, n.sons[1], dest)
of mBitnotI:
genUnaryABC(c, n, dest, opcBitnotInt)
#genNarrowU modified, do not narrow signed types
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
of mToFloat, mToBiggestFloat, mToInt,
mToBiggestInt, mCharToStr, mBoolToStr, mIntToStr, mInt64ToStr,
mFloatToStr, mCStrToStr, mStrToStr, mEnumToStr:
genConv(c, n, n.sons[1], dest)
of mZe8ToI, mZe8ToI64, mZe16ToI, mZe16ToI64, mZe32ToI64, mZeIToI64: