mirrors/Nim
1
0
Fork 0
mirror of https://github.com/nim-lang/Nim.git synced 2025-12-28 17:04:41 +00:00
Code Issues Packages Projects Releases Wiki Activity

exploit the fact that empty seqs don't have to allocate in the code generator

Browse Source
This commit is contained in:
Andreas Rumpf
2018-08-18 16:59:59 +02:00
parent b2d5bfd076
commit 792829ad25
2 changed files with 15 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
compiler/ccgexprs.nim
View File

@@ -1176,7 +1176,7 @@ proc genNew(p: BProc, e: PNode) =
rawGenNew(p, a, nil)
gcUsage(p.config, e)
proc genNewSeqAux(p: BProc, dest: TLoc, length: Rope) =
proc genNewSeqAux(p: BProc, dest: TLoc, length: Rope; lenIsZero: bool) =
let seqtype = skipTypes(dest.t, abstractVarRange)
let args = [getTypeDesc(p.module, seqtype),
genTypeInfo(p.module, seqtype, dest.lode.info), length]
@@ -1187,17 +1187,23 @@ proc genNewSeqAux(p: BProc, dest: TLoc, length: Rope) =
linefmt(p, cpsStmts, "if ($1) { #nimGCunrefRC1($1); $1 = NIM_NIL; }$n", dest.rdLoc)
else:
linefmt(p, cpsStmts, "if ($1) { #nimGCunrefNoCycle($1); $1 = NIM_NIL; }$n", dest.rdLoc)
call.r = ropecg(p.module, "($1) #newSeqRC1($2, $3)", args)
linefmt(p, cpsStmts, "$1 = $2;$n", dest.rdLoc, call.rdLoc)
if not lenIsZero:
call.r = ropecg(p.module, "($1) #newSeqRC1($2, $3)", args)
linefmt(p, cpsStmts, "$1 = $2;$n", dest.rdLoc, call.rdLoc)
else:
call.r = ropecg(p.module, "($1) #newSeq($2, $3)", args)
if lenIsZero:
call.r = rope"NIM_NIL"
else:
call.r = ropecg(p.module, "($1) #newSeq($2, $3)", args)
genAssignment(p, dest, call, {})
proc genNewSeq(p: BProc, e: PNode) =
var a, b: TLoc
initLocExpr(p, e.sons[1], a)
initLocExpr(p, e.sons[2], b)
genNewSeqAux(p, a, b.rdLoc)
let lenIsZero = optNilSeqs notin p.options and
e[2].kind == nkIntLit and e[2].intVal == 0
genNewSeqAux(p, a, b.rdLoc, lenIsZero)
gcUsage(p.config, e)
proc genNewSeqOfCap(p: BProc; e: PNode; d: var TLoc) =
@@ -1297,7 +1303,8 @@ proc genSeqConstr(p: BProc, n: PNode, d: var TLoc) =
elif d.k == locNone:
getTemp(p, n.typ, d)
# generate call to newSeq before adding the elements per hand:
genNewSeqAux(p, dest[], intLiteral(sonsLen(n)))
genNewSeqAux(p, dest[], intLiteral(sonsLen(n)),
optNilSeqs notin p.options and n.len == 0)
for i in countup(0, sonsLen(n) - 1):
initLoc(arr, locExpr, n[i], OnHeap)
arr.r = ropecg(p.module, "$1$3[$2]", rdLoc(dest[]), intLiteral(i), dataField(p))
@@ -1320,7 +1327,7 @@ proc genArrToSeq(p: BProc, n: PNode, d: var TLoc) =
getTemp(p, n.typ, d)
# generate call to newSeq before adding the elements per hand:
let L = int(lengthOrd(p.config, n.sons[1].typ))
genNewSeqAux(p, d, intLiteral(L))
genNewSeqAux(p, d, intLiteral(L), optNilSeqs notin p.options and L == 0)
initLocExpr(p, n.sons[1], a)
# bug #5007; do not produce excessive C source code:
if L < 10:

2
compiler/ccgtrav.nim
View File

@@ -107,7 +107,7 @@ proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
var i: TLoc
getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo(), tyInt), i)
let oldCode = p.s(cpsStmts)
lineF(p, cpsStmts, "for ($1 = 0; $1 < $2->$3; $1++) {$n",
lineF(p, cpsStmts, "for ($1 = 0; $1 < ($2 ? $2->$3 : 0); $1++) {$n",
[i.r, accessor, lenField(c.p)])
let oldLen = p.s(cpsStmts).len
genTraverseProc(c, "$1$3[$2]" % [accessor, i.r, dataField(c.p)], typ.sons[0])