diff options
Diffstat (limited to 'src/cmd/compile/internal/ssa/poset.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/poset.go | 54 |
1 files changed, 27 insertions, 27 deletions
diff --git a/src/cmd/compile/internal/ssa/poset.go b/src/cmd/compile/internal/ssa/poset.go index f5a2b3a8c2..1e04b48ba4 100644 --- a/src/cmd/compile/internal/ssa/poset.go +++ b/src/cmd/compile/internal/ssa/poset.go @@ -136,13 +136,13 @@ type posetNode struct { // Most internal data structures are pre-allocated and flat, so for instance adding a // new relation does not cause any allocation. For performance reasons, // each node has only up to two outgoing edges (like a binary tree), so intermediate -// "dummy" nodes are required to represent more than two relations. For instance, +// "extra" nodes are required to represent more than two relations. For instance, // to record that A<I, A<J, A<K (with no known relation between I,J,K), we create the // following DAG: // // A // / \ -// I dummy +// I extra // / \ // J K // @@ -223,7 +223,7 @@ func (po *poset) addchild(i1, i2 uint32, strict bool) { po.setchr(i1, e2) po.upush(undoSetChr, i1, 0) } else { - // If n1 already has two children, add an intermediate dummy + // If n1 already has two children, add an intermediate extra // node to record the relation correctly (without relating // n2 to other existing nodes). Use a non-deterministic value // to decide whether to append on the left or the right, to avoid @@ -231,27 +231,27 @@ func (po *poset) addchild(i1, i2 uint32, strict bool) { // // n1 // / \ - // i1l dummy + // i1l extra // / \ // i1r n2 // - dummy := po.newnode(nil) + extra := po.newnode(nil) if (i1^i2)&1 != 0 { // non-deterministic - po.setchl(dummy, i1r) - po.setchr(dummy, e2) - po.setchr(i1, newedge(dummy, false)) + po.setchl(extra, i1r) + po.setchr(extra, e2) + po.setchr(i1, newedge(extra, false)) po.upush(undoSetChr, i1, i1r) } else { - po.setchl(dummy, i1l) - po.setchr(dummy, e2) - po.setchl(i1, newedge(dummy, false)) + po.setchl(extra, i1l) + po.setchr(extra, e2) + po.setchl(i1, newedge(extra, false)) po.upush(undoSetChl, i1, i1l) } } } // newnode allocates a new node bound to SSA value n. -// If n is nil, this is a dummy node (= only used internally). +// If n is nil, this is an extra node (= only used internally). func (po *poset) newnode(n *Value) uint32 { i := po.lastidx + 1 po.lastidx++ @@ -380,9 +380,9 @@ func (po *poset) newconst(n *Value) { case higherptr != 0: // Higher bound only. To record n < higher, we need - // a dummy root: + // an extra root: // - // dummy + // extra // / \ // root \ // / n @@ -395,11 +395,11 @@ func (po *poset) newconst(n *Value) { if r2 != po.roots[0] { // all constants should be in root #0 panic("constant not in root #0") } - dummy := po.newnode(nil) - po.changeroot(r2, dummy) - po.upush(undoChangeRoot, dummy, newedge(r2, false)) - po.addchild(dummy, r2, false) - po.addchild(dummy, i, false) + extra := po.newnode(nil) + po.changeroot(r2, extra) + po.upush(undoChangeRoot, extra, newedge(r2, false)) + po.addchild(extra, r2, false) + po.addchild(extra, i, false) po.addchild(i, i2, true) } @@ -612,7 +612,7 @@ func (po *poset) findroot(i uint32) uint32 { panic("findroot didn't find any root") } -// mergeroot merges two DAGs into one DAG by creating a new dummy root +// mergeroot merges two DAGs into one DAG by creating a new extra root func (po *poset) mergeroot(r1, r2 uint32) uint32 { // Root #0 is special as it contains all constants. Since mergeroot // discards r2 as root and keeps r1, make sure that r2 is not root #0, @@ -1004,7 +1004,7 @@ func (po *poset) setOrder(n1, n2 *Value, strict bool) bool { case !f1 && f2: // n1 is not in any DAG but n2 is. If n2 is a root, we can put // n1 in its place as a root; otherwise, we need to create a new - // dummy root to record the relation. + // extra root to record the relation. i1 = po.newnode(n1) if po.isroot(i2) { @@ -1020,17 +1020,17 @@ func (po *poset) setOrder(n1, n2 *Value, strict bool) bool { // Re-parent as follows: // - // dummy + // extra // r / \ // \ ===> r i1 // i2 \ / // i2 // - dummy := po.newnode(nil) - po.changeroot(r, dummy) - po.upush(undoChangeRoot, dummy, newedge(r, false)) - po.addchild(dummy, r, false) - po.addchild(dummy, i1, false) + extra := po.newnode(nil) + po.changeroot(r, extra) + po.upush(undoChangeRoot, extra, newedge(r, false)) + po.addchild(extra, r, false) + po.addchild(extra, i1, false) po.addchild(i1, i2, strict) case f1 && f2: |