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| author | Keith Randall <khr@golang.org> | 2016-09-16 13:50:18 -0700 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2016-09-19 16:00:13 +0000 |
| commit | 75ce89c20dab10857ab0b5102001b34767c45b6e (patch) | |
| tree | b6d0086e53b0187137ca606d54e10d799d7f2761 /src/cmd/compile/internal/ssa/cse.go | |
| parent | 2679282da4e437ee086ec791ab73181c39ae3463 (diff) | |
| download | go-75ce89c20dab10857ab0b5102001b34767c45b6e.tar.gz go-75ce89c20dab10857ab0b5102001b34767c45b6e.zip | |
cmd/compile: cache CFG-dependent computations
We compute a lot of stuff based off the CFG: postorder traversal,
dominators, dominator tree, loop nest. Multiple phases use this
information and we end up recomputing some of it. Add a cache
for this information so if the CFG hasn't changed, we can reuse
the previous computation.
Change-Id: I9b5b58af06830bd120afbee9cfab395a0a2f74b2
Reviewed-on: https://go-review.googlesource.com/29356
Reviewed-by: David Chase <drchase@google.com>
Diffstat (limited to 'src/cmd/compile/internal/ssa/cse.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/cse.go | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/cmd/compile/internal/ssa/cse.go b/src/cmd/compile/internal/ssa/cse.go index c0ddc83681..795950e75d 100644 --- a/src/cmd/compile/internal/ssa/cse.go +++ b/src/cmd/compile/internal/ssa/cse.go @@ -131,13 +131,13 @@ func cse(f *Func) { } } - // Dominator tree (f.sdom) is computed by the generic domtree pass. + sdom := f.sdom() // Compute substitutions we would like to do. We substitute v for w // if v and w are in the same equivalence class and v dominates w. rewrite := make([]*Value, f.NumValues()) for _, e := range partition { - sort.Sort(partitionByDom{e, f.sdom}) + sort.Sort(partitionByDom{e, sdom}) for i := 0; i < len(e)-1; i++ { // e is sorted by domorder, so a maximal dominant element is first in the slice v := e[i] @@ -152,7 +152,7 @@ func cse(f *Func) { if w == nil { continue } - if f.sdom.isAncestorEq(v.Block, w.Block) { + if sdom.isAncestorEq(v.Block, w.Block) { rewrite[w.ID] = v e[j] = nil } else { |