70 lines
1.1 KiB
Go
70 lines
1.1 KiB
Go
package irutil
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import (
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"honnef.co/go/tools/ir"
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)
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func Reachable(from, to *ir.BasicBlock) bool {
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if from == to {
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return true
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}
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if from.Dominates(to) {
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return true
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}
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found := false
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Walk(from, func(b *ir.BasicBlock) bool {
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if b == to {
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found = true
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return false
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}
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return true
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})
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return found
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}
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func Walk(b *ir.BasicBlock, fn func(*ir.BasicBlock) bool) {
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seen := map[*ir.BasicBlock]bool{}
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wl := []*ir.BasicBlock{b}
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for len(wl) > 0 {
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b := wl[len(wl)-1]
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wl = wl[:len(wl)-1]
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if seen[b] {
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continue
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}
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seen[b] = true
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if !fn(b) {
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continue
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}
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wl = append(wl, b.Succs...)
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}
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}
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func Vararg(x *ir.Slice) ([]ir.Value, bool) {
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var out []ir.Value
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slice, ok := x.X.(*ir.Alloc)
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if !ok {
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return nil, false
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}
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for _, ref := range *slice.Referrers() {
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if ref == x {
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continue
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}
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if ref.Block() != x.Block() {
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return nil, false
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}
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idx, ok := ref.(*ir.IndexAddr)
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if !ok {
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return nil, false
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}
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if len(*idx.Referrers()) != 1 {
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return nil, false
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}
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store, ok := (*idx.Referrers())[0].(*ir.Store)
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if !ok {
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return nil, false
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}
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out = append(out, store.Val)
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}
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return out, true
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}
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