diff options
| -rw-r--r-- | src/cmd/compile/internal/escape/escape.go | 2 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/main.go | 21 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/obj.go | 7 | ||||
| -rw-r--r-- | src/cmd/compile/internal/reflectdata/reflect.go | 196 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/config.go | 6 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewrite.go | 36 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssagen/ssa.go | 4 | ||||
| -rw-r--r-- | src/cmd/compile/internal/typecheck/subr.go | 8 | ||||
| -rw-r--r-- | src/cmd/compile/internal/typecheck/typecheck.go | 1 |
9 files changed, 92 insertions, 189 deletions
diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go index 842b0f4a7e..e3727bca27 100644 --- a/src/cmd/compile/internal/escape/escape.go +++ b/src/cmd/compile/internal/escape/escape.go @@ -673,7 +673,7 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) { n := n.(*ir.BinaryExpr) // Note: n.X is not needed because it can never point to memory that might escape. e.expr(k, n.Y) - case ir.OIDATA: + case ir.OIDATA, ir.OSPTR: n := n.(*ir.UnaryExpr) e.expr(k, n.X) case ir.OSLICE2ARRPTR: diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go index ce50cbb4c2..c0346c0206 100644 --- a/src/cmd/compile/internal/gc/main.go +++ b/src/cmd/compile/internal/gc/main.go @@ -181,7 +181,6 @@ func Main(archInit func(*ssagen.ArchInfo)) { typecheck.Target = new(ir.Package) - typecheck.NeedITab = func(t, iface *types.Type) { reflectdata.ITabAddr(t, iface) } typecheck.NeedRuntimeType = reflectdata.NeedRuntimeType // TODO(rsc): TypeSym for lock? base.AutogeneratedPos = makePos(src.NewFileBase("<autogenerated>", "<autogenerated>"), 1, 0) @@ -193,6 +192,11 @@ func Main(archInit func(*ssagen.ArchInfo)) { dwarfgen.RecordPackageName() + // Prepare for backend processing. This must happen before pkginit, + // because it generates itabs for initializing global variables. + typecheck.InitRuntime() + ssagen.InitConfig() + // Build init task. if initTask := pkginit.Task(); initTask != nil { typecheck.Export(initTask) @@ -252,6 +256,11 @@ func Main(archInit func(*ssagen.ArchInfo)) { base.Timer.Start("fe", "escapes") escape.Funcs(typecheck.Target.Decls) + // TODO(mdempsky): This is a hack. We need a proper, global work + // queue for scheduling function compilation so components don't + // need to adjust their behavior depending on when they're called. + reflectdata.AfterGlobalEscapeAnalysis = true + // Collect information for go:nowritebarrierrec // checking. This must happen before transforming closures during Walk // We'll do the final check after write barriers are @@ -260,17 +269,7 @@ func Main(archInit func(*ssagen.ArchInfo)) { ssagen.EnableNoWriteBarrierRecCheck() } - // Prepare for SSA compilation. - // This must be before CompileITabs, because CompileITabs - // can trigger function compilation. - typecheck.InitRuntime() - ssagen.InitConfig() - - // Just before compilation, compile itabs found on - // the right side of OCONVIFACE so that methods - // can be de-virtualized during compilation. ir.CurFunc = nil - reflectdata.CompileITabs() // Compile top level functions. // Don't use range--walk can add functions to Target.Decls. diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go index 8a2ff75583..440f898211 100644 --- a/src/cmd/compile/internal/gc/obj.go +++ b/src/cmd/compile/internal/gc/obj.go @@ -117,7 +117,7 @@ func dumpdata() { addsignats(typecheck.Target.Externs) reflectdata.WriteRuntimeTypes() reflectdata.WriteTabs() - numPTabs, numITabs := reflectdata.CountTabs() + numPTabs := reflectdata.CountPTabs() reflectdata.WriteImportStrings() reflectdata.WriteBasicTypes() dumpembeds() @@ -158,13 +158,10 @@ func dumpdata() { if numExports != len(typecheck.Target.Exports) { base.Fatalf("Target.Exports changed after compile functions loop") } - newNumPTabs, newNumITabs := reflectdata.CountTabs() + newNumPTabs := reflectdata.CountPTabs() if newNumPTabs != numPTabs { base.Fatalf("ptabs changed after compile functions loop") } - if newNumITabs != numITabs { - base.Fatalf("itabs changed after compile functions loop") - } } func dumpLinkerObj(bout *bio.Writer) { diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go index f4a0619935..9e070895a0 100644 --- a/src/cmd/compile/internal/reflectdata/reflect.go +++ b/src/cmd/compile/internal/reflectdata/reflect.go @@ -28,23 +28,13 @@ import ( "cmd/internal/src" ) -type itabEntry struct { - t, itype *types.Type - lsym *obj.LSym // symbol of the itab itself - - // symbols of each method in - // the itab, sorted by byte offset; - // filled in by CompileITabs - entries []*obj.LSym -} - type ptabEntry struct { s *types.Sym t *types.Type } -func CountTabs() (numPTabs, numITabs int) { - return len(ptabs), len(itabs) +func CountPTabs() int { + return len(ptabs) } // runtime interface and reflection data structures @@ -56,7 +46,6 @@ var ( gcsymmu sync.Mutex // protects gcsymset and gcsymslice gcsymset = make(map[*types.Type]struct{}) - itabs []itabEntry ptabs []*ir.Name ) @@ -841,16 +830,16 @@ func TypePtr(t *types.Type) *ir.AddrExpr { return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr) } -func ITabAddr(t, itype *types.Type) *ir.AddrExpr { - if t == nil || (t.IsPtr() && t.Elem() == nil) || t.IsUntyped() || !itype.IsInterface() || itype.IsEmptyInterface() { - base.Fatalf("ITabAddr(%v, %v)", t, itype) - } - s, existed := ir.Pkgs.Itab.LookupOK(t.ShortString() + "," + itype.ShortString()) +// ITabAddr returns an expression representing a pointer to the itab +// for concrete type typ implementing interface iface. +func ITabAddr(typ, iface *types.Type) *ir.AddrExpr { + s, existed := ir.Pkgs.Itab.LookupOK(typ.ShortString() + "," + iface.ShortString()) + lsym := s.Linksym() + if !existed { - itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: s.Linksym()}) + writeITab(lsym, typ, iface) } - lsym := s.Linksym() n := ir.NewLinksymExpr(base.Pos, lsym, types.Types[types.TUINT8]) return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr) } @@ -1223,83 +1212,6 @@ func InterfaceMethodOffset(ityp *types.Type, i int64) int64 { return int64(commonSize()+4*types.PtrSize+uncommonSize(ityp)) + i*8 } -// for each itabEntry, gather the methods on -// the concrete type that implement the interface -func CompileITabs() { - for i := range itabs { - tab := &itabs[i] - methods := genfun(tab.t, tab.itype) - if len(methods) == 0 { - continue - } - tab.entries = methods - } -} - -// for the given concrete type and interface -// type, return the (sorted) set of methods -// on the concrete type that implement the interface -func genfun(t, it *types.Type) []*obj.LSym { - if t == nil || it == nil { - return nil - } - sigs := imethods(it) - methods := methods(t) - out := make([]*obj.LSym, 0, len(sigs)) - // TODO(mdempsky): Short circuit before calling methods(t)? - // See discussion on CL 105039. - if len(sigs) == 0 { - return nil - } - - // both sigs and methods are sorted by name, - // so we can find the intersect in a single pass - for _, m := range methods { - if m.name == sigs[0].name { - out = append(out, m.isym) - sigs = sigs[1:] - if len(sigs) == 0 { - break - } - } - } - - if len(sigs) != 0 { - base.Fatalf("incomplete itab") - } - - return out -} - -// ITabSym uses the information gathered in -// CompileITabs to de-virtualize interface methods. -// Since this is called by the SSA backend, it shouldn't -// generate additional Nodes, Syms, etc. -func ITabSym(it *obj.LSym, offset int64) *obj.LSym { - var syms []*obj.LSym - if it == nil { - return nil - } - - for i := range itabs { - e := &itabs[i] - if e.lsym == it { - syms = e.entries - break - } - } - if syms == nil { - return nil - } - - // keep this arithmetic in sync with *itab layout - methodnum := int((offset - 2*int64(types.PtrSize) - 8) / int64(types.PtrSize)) - if methodnum >= len(syms) { - return nil - } - return syms[methodnum] -} - // NeedRuntimeType ensures that a runtime type descriptor is emitted for t. func NeedRuntimeType(t *types.Type) { if t.HasTParam() { @@ -1346,29 +1258,57 @@ func WriteRuntimeTypes() { } } -func WriteTabs() { - // process itabs - for _, i := range itabs { - // dump empty itab symbol into i.sym - // type itab struct { - // inter *interfacetype - // _type *_type - // hash uint32 - // _ [4]byte - // fun [1]uintptr // variable sized - // } - o := objw.SymPtr(i.lsym, 0, writeType(i.itype), 0) - o = objw.SymPtr(i.lsym, o, writeType(i.t), 0) - o = objw.Uint32(i.lsym, o, types.TypeHash(i.t)) // copy of type hash - o += 4 // skip unused field - for _, fn := range genfun(i.t, i.itype) { - o = objw.SymPtrWeak(i.lsym, o, fn, 0) // method pointer for each method - } - // Nothing writes static itabs, so they are read only. - objw.Global(i.lsym, int32(o), int16(obj.DUPOK|obj.RODATA)) - i.lsym.Set(obj.AttrContentAddressable, true) +// writeITab writes the itab for concrete type typ implementing +// interface iface. +func writeITab(lsym *obj.LSym, typ, iface *types.Type) { + // TODO(mdempsky): Fix methodWrapper, geneq, and genhash (and maybe + // others) to stop clobbering these. + oldpos, oldfn := base.Pos, ir.CurFunc + defer func() { base.Pos, ir.CurFunc = oldpos, oldfn }() + + if typ == nil || (typ.IsPtr() && typ.Elem() == nil) || typ.IsUntyped() || iface == nil || !iface.IsInterface() || iface.IsEmptyInterface() { + base.Fatalf("writeITab(%v, %v)", typ, iface) + } + + sigs := iface.AllMethods().Slice() + entries := make([]*obj.LSym, 0, len(sigs)) + + // both sigs and methods are sorted by name, + // so we can find the intersection in a single pass + for _, m := range methods(typ) { + if m.name == sigs[0].Sym { + entries = append(entries, m.isym) + sigs = sigs[1:] + if len(sigs) == 0 { + break + } + } + } + if len(sigs) != 0 { + base.Fatalf("incomplete itab") + } + + // dump empty itab symbol into i.sym + // type itab struct { + // inter *interfacetype + // _type *_type + // hash uint32 + // _ [4]byte + // fun [1]uintptr // variable sized + // } + o := objw.SymPtr(lsym, 0, writeType(iface), 0) + o = objw.SymPtr(lsym, o, writeType(typ), 0) + o = objw.Uint32(lsym, o, types.TypeHash(typ)) // copy of type hash + o += 4 // skip unused field + for _, fn := range entries { + o = objw.SymPtrWeak(lsym, o, fn, 0) // method pointer for each method } + // Nothing writes static itabs, so they are read only. + objw.Global(lsym, int32(o), int16(obj.DUPOK|obj.RODATA)) + lsym.Set(obj.AttrContentAddressable, true) +} +func WriteTabs() { // process ptabs if types.LocalPkg.Name == "main" && len(ptabs) > 0 { ot := 0 @@ -1926,20 +1866,10 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy ir.CurFunc = fn typecheck.Stmts(fn.Body) - // TODO(mdempsky): Make this unconditional. The exporter now - // includes all of the inline bodies we need, and the "importedType" - // logic above now correctly suppresses compiling out-of-package - // types that we might not have inline bodies for. The only problem - // now is that the extra inlining can now introduce further new - // itabs, and gc.dumpdata's ad hoc compile loop doesn't handle this. - // - // CL 327871 will address this by writing itabs and generating - // wrappers as part of the loop, so we won't have to worry about - // "itabs changed after compile functions loop" errors anymore. - if rcvr.IsPtr() && rcvr.Elem() == method.Type.Recv().Type && rcvr.Elem().Sym() != nil { + if AfterGlobalEscapeAnalysis { inline.InlineCalls(fn) + escape.Batch([]*ir.Func{fn}, false) } - escape.Batch([]*ir.Func{fn}, false) ir.CurFunc = nil typecheck.Target.Decls = append(typecheck.Target.Decls, fn) @@ -1947,6 +1877,12 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy return lsym } +// AfterGlobalEscapeAnalysis tracks whether package gc has already +// performed the main, global escape analysis pass. If so, +// methodWrapper takes responsibility for escape analyzing any +// generated wrappers. +var AfterGlobalEscapeAnalysis bool + var ZeroSize int64 // MarkTypeUsedInInterface marks that type t is converted to an interface. diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go index 61c65f9e54..b08a394368 100644 --- a/src/cmd/compile/internal/ssa/config.go +++ b/src/cmd/compile/internal/ssa/config.go @@ -149,12 +149,6 @@ type Frontend interface { // for the parts of that compound type. SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot - // DerefItab dereferences an itab function - // entry, given the symbol of the itab and - // the byte offset of the function pointer. - // It may return nil. - DerefItab(sym *obj.LSym, offset int64) *obj.LSym - // Line returns a string describing the given position. Line(src.XPos) string diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go index 375c4d5a56..115d563933 100644 --- a/src/cmd/compile/internal/ssa/rewrite.go +++ b/src/cmd/compile/internal/ssa/rewrite.go @@ -745,27 +745,21 @@ func uaddOvf(a, b int64) bool { return uint64(a)+uint64(b) < uint64(a) } -// de-virtualize an InterCall -// 'sym' is the symbol for the itab -func devirt(v *Value, aux Aux, sym Sym, offset int64) *AuxCall { - f := v.Block.Func - n, ok := sym.(*obj.LSym) - if !ok { +// loadLSymOffset simulates reading a word at an offset into a +// read-only symbol's runtime memory. If it would read a pointer to +// another symbol, that symbol is returned. Otherwise, it returns nil. +func loadLSymOffset(lsym *obj.LSym, offset int64) *obj.LSym { + if lsym.Type != objabi.SRODATA { return nil } - lsym := f.fe.DerefItab(n, offset) - if f.pass.debug > 0 { - if lsym != nil { - f.Warnl(v.Pos, "de-virtualizing call") - } else { - f.Warnl(v.Pos, "couldn't de-virtualize call") + + for _, r := range lsym.R { + if int64(r.Off) == offset && r.Type&^objabi.R_WEAK == objabi.R_ADDR && r.Add == 0 { + return r.Sym } } - if lsym == nil { - return nil - } - va := aux.(*AuxCall) - return StaticAuxCall(lsym, va.abiInfo) + + return nil } // de-virtualize an InterLECall @@ -776,18 +770,14 @@ func devirtLESym(v *Value, aux Aux, sym Sym, offset int64) *obj.LSym { return nil } - f := v.Block.Func - lsym := f.fe.DerefItab(n, offset) - if f.pass.debug > 0 { + lsym := loadLSymOffset(n, offset) + if f := v.Block.Func; f.pass.debug > 0 { if lsym != nil { f.Warnl(v.Pos, "de-virtualizing call") } else { f.Warnl(v.Pos, "couldn't de-virtualize call") } } - if lsym == nil { - return nil - } return lsym } diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go index 0fbb39cfbb..7a6bf878e1 100644 --- a/src/cmd/compile/internal/ssagen/ssa.go +++ b/src/cmd/compile/internal/ssagen/ssa.go @@ -7401,10 +7401,6 @@ func (e *ssafn) Auto(pos src.XPos, t *types.Type) *ir.Name { return typecheck.TempAt(pos, e.curfn, t) // Note: adds new auto to e.curfn.Func.Dcl list } -func (e *ssafn) DerefItab(it *obj.LSym, offset int64) *obj.LSym { - return reflectdata.ITabSym(it, offset) -} - // SplitSlot returns a slot representing the data of parent starting at offset. func (e *ssafn) SplitSlot(parent *ssa.LocalSlot, suffix string, offset int64, t *types.Type) ssa.LocalSlot { node := parent.N diff --git a/src/cmd/compile/internal/typecheck/subr.go b/src/cmd/compile/internal/typecheck/subr.go index 0e306eaea8..79b2402fe7 100644 --- a/src/cmd/compile/internal/typecheck/subr.go +++ b/src/cmd/compile/internal/typecheck/subr.go @@ -379,14 +379,6 @@ func Assignop(src, dst *types.Type) (ir.Op, string) { var missing, have *types.Field var ptr int if implements(src, dst, &missing, &have, &ptr) { - // Call NeedITab/ITabAddr so that (src, dst) - // gets added to itabs early, which allows - // us to de-virtualize calls through this - // type/interface pair later. See CompileITabs in reflect.go - if types.IsDirectIface(src) && !dst.IsEmptyInterface() { - NeedITab(src, dst) - } - return ir.OCONVIFACE, "" } diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go index 8454b8d5b3..b1a4e193d6 100644 --- a/src/cmd/compile/internal/typecheck/typecheck.go +++ b/src/cmd/compile/internal/typecheck/typecheck.go @@ -24,7 +24,6 @@ var inimport bool // set during import var TypecheckAllowed bool var ( - NeedITab = func(t, itype *types.Type) {} NeedRuntimeType = func(*types.Type) {} ) |