diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/gc/plive.go | 41 |
1 files changed, 12 insertions, 29 deletions
diff --git a/src/cmd/compile/internal/gc/plive.go b/src/cmd/compile/internal/gc/plive.go index ac94381af6..bf3129cf21 100644 --- a/src/cmd/compile/internal/gc/plive.go +++ b/src/cmd/compile/internal/gc/plive.go @@ -24,11 +24,6 @@ import ( "strings" ) -const ( - UNVISITED = 0 - VISITED = 1 -) - // An ordinary basic block. // // Instructions are threaded together in a doubly-linked list. To iterate in @@ -54,7 +49,6 @@ type BasicBlock struct { first *obj.Prog // first instruction in block last *obj.Prog // last instruction in block rpo int // reverse post-order number (also index in cfg) - mark int // mark bit for traversals lastbitmapindex int // for livenessepilogue // Summary sets of block effects. @@ -132,7 +126,6 @@ func newblock(prog *obj.Prog) *BasicBlock { result := &b.result result.rpo = -1 - result.mark = UNVISITED result.first = prog result.last = prog result.pred = b.pred[:0] @@ -270,19 +263,6 @@ func printcfg(cfg []*BasicBlock) { } } -// Assigns a reverse post order number to each connected basic block using the -// standard algorithm. Unconnected blocks will not be affected. -func reversepostorder(root *BasicBlock, rpo *int32) { - root.mark = VISITED - for _, bb := range root.succ { - if bb.mark == UNVISITED { - reversepostorder(bb, rpo) - } - } - *rpo -= 1 - root.rpo = int(*rpo) -} - // Comparison predicate used for sorting basic blocks by their rpo in ascending // order. type blockrpocmp []*BasicBlock @@ -352,6 +332,18 @@ func newcfg(firstp *obj.Prog) []*BasicBlock { } } + bb.rpo = 0 + rpo := 1 + for p := firstp; p != nil && p.As != obj.AEND; p = p.Link { + if p.Opt != nil { + p.Opt.(*BasicBlock).rpo = rpo + rpo++ + } + } + if rpo != len(cfg) { + Fatalf("newcfg: inconsistent block counts: %d != %d", rpo, len(cfg)) + } + // Loop through all basic blocks maximally growing the list of // contained instructions until a label is reached. Add edges // for branches and fall-through instructions. @@ -398,15 +390,6 @@ func newcfg(firstp *obj.Prog) []*BasicBlock { } } - // Find a depth-first order and assign a depth-first number to - // all basic blocks. - for _, bb := range cfg { - bb.mark = UNVISITED - } - bb = cfg[0] - rpo := int32(len(cfg)) - reversepostorder(bb, &rpo) - // Sort the basic blocks by their depth first number. The // slice is now a depth-first spanning tree with the first // node being the root. |