diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/gc/plive.go | 72 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/syntax.go | 3 |
2 files changed, 27 insertions, 48 deletions
diff --git a/src/cmd/compile/internal/gc/plive.go b/src/cmd/compile/internal/gc/plive.go index 3f2eb76c37..4811037311 100644 --- a/src/cmd/compile/internal/gc/plive.go +++ b/src/cmd/compile/internal/gc/plive.go @@ -117,6 +117,7 @@ type Liveness struct { fn *Node f *ssa.Func vars []*Node + idx map[*Node]int32 stkptrsize int64 be []BlockEffects @@ -148,31 +149,20 @@ func livenessShouldTrack(n *Node) bool { return n.Op == ONAME && (n.Class() == PAUTO || n.Class() == PPARAM || n.Class() == PPARAMOUT) && types.Haspointers(n.Type) } -// getvariables returns the list of on-stack variables that we need to track. -func getvariables(fn *Node) []*Node { +// getvariables returns the list of on-stack variables that we need to track +// and a map for looking up indices by *Node. +func getvariables(fn *Node) ([]*Node, map[*Node]int32) { var vars []*Node for _, n := range fn.Func.Dcl { - if n.Op == ONAME { - // The Node.opt field is available for use by optimization passes. - // We use it to hold the index of the node in the variables array - // (nil means the Node is not in the variables array). - // The Node.curfn field is supposed to be set to the current function - // already, but for some compiler-introduced names it seems not to be, - // so fix that here. - // Later, when we want to find the index of a node in the variables list, - // we will check that n.Curfn == lv.fn and n.Opt() != nil. Then n.Opt().(int32) - // is the index in the variables list. - n.SetOpt(nil) - n.Name.Curfn = fn - } - if livenessShouldTrack(n) { - n.SetOpt(int32(len(vars))) vars = append(vars, n) } } - - return vars + idx := make(map[*Node]int32, len(vars)) + for i, n := range vars { + idx[n] = int32(i) + } + return vars, idx } func (lv *Liveness) initcache() { @@ -238,9 +228,9 @@ const ( // valueEffects returns the index of a variable in lv.vars and the // liveness effects v has on that variable. // If v does not affect any tracked variables, it returns -1, 0. -func (lv *Liveness) valueEffects(v *ssa.Value) (pos int32, effect liveEffect) { +func (lv *Liveness) valueEffects(v *ssa.Value) (int32, liveEffect) { n, e := affectedNode(v) - if e == 0 { + if e == 0 || n == nil || n.Op != ONAME { // cheapest checks first return -1, 0 } @@ -255,11 +245,7 @@ func (lv *Liveness) valueEffects(v *ssa.Value) (pos int32, effect liveEffect) { } } - pos = lv.liveIndex(n) - if pos < 0 { - return -1, 0 - } - + var effect liveEffect if n.Addrtaken() { if v.Op != ssa.OpVarKill { effect |= avarinit @@ -283,7 +269,14 @@ func (lv *Liveness) valueEffects(v *ssa.Value) (pos int32, effect liveEffect) { } } - return + if effect == 0 { + return -1, 0 + } + + if pos, ok := lv.idx[n]; ok { + return pos, effect + } + return -1, 0 } // affectedNode returns the *Node affected by v @@ -326,32 +319,15 @@ func affectedNode(v *ssa.Value) (*Node, ssa.SymEffect) { return n, e } -// liveIndex returns the index of n in the set of tracked vars. -// If n is not a tracked var, liveIndex returns -1. -// If n is not a tracked var but should be tracked, liveIndex crashes. -func (lv *Liveness) liveIndex(n *Node) int32 { - if n == nil || n.Name.Curfn != lv.fn || !livenessShouldTrack(n) { - return -1 - } - - pos, ok := n.Opt().(int32) // index in vars - if !ok { - Fatalf("lost track of variable in liveness: %v (%p, %p)", n, n, n.Orig) - } - if pos >= int32(len(lv.vars)) || lv.vars[pos] != n { - Fatalf("bad bookkeeping in liveness: %v (%p, %p)", n, n, n.Orig) - } - return pos -} - // Constructs a new liveness structure used to hold the global state of the // liveness computation. The cfg argument is a slice of *BasicBlocks and the // vars argument is a slice of *Nodes. -func newliveness(fn *Node, f *ssa.Func, vars []*Node, stkptrsize int64) *Liveness { +func newliveness(fn *Node, f *ssa.Func, vars []*Node, idx map[*Node]int32, stkptrsize int64) *Liveness { lv := &Liveness{ fn: fn, f: f, vars: vars, + idx: idx, stkptrsize: stkptrsize, be: make([]BlockEffects, f.NumBlocks()), } @@ -1308,8 +1284,8 @@ func livenessemit(lv *Liveness, argssym, livesym *obj.LSym) { // Returns a map from GC safe points to their corresponding stack map index. func liveness(e *ssafn, f *ssa.Func) map[*ssa.Value]int { // Construct the global liveness state. - vars := getvariables(e.curfn) - lv := newliveness(e.curfn, f, vars, e.stkptrsize) + vars, idx := getvariables(e.curfn) + lv := newliveness(e.curfn, f, vars, idx, e.stkptrsize) // Run the dataflow framework. livenessprologue(lv) diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go index 7c7f08653e..234ebad41c 100644 --- a/src/cmd/compile/internal/gc/syntax.go +++ b/src/cmd/compile/internal/gc/syntax.go @@ -214,6 +214,9 @@ func (n *Node) mayBeShared() bool { // funcname returns the name of the function n. func (n *Node) funcname() string { + if n == nil || n.Func == nil || n.Func.Nname == nil { + return "<nil>" + } return n.Func.Nname.Sym.Name } |