Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fix bug in block renaming for dead code elimination #32145

Merged
merged 1 commit into from
Jul 27, 2019
Merged

fix bug in block renaming for dead code elimination #32145

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 9 additions & 5 deletions base/compiler/ssair/ir.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -499,24 +499,28 @@ mutable struct IncrementalCompact
cur_bb = 1
for i = 1:length(bb_rename)
if i != 1 && length(blocks[i].preds) == 0
bb_rename[i] = 0
bb_rename[i] = -1
else
bb_rename[i] = cur_bb
cur_bb += 1
end
end
for i = 1:length(bb_rename)
bb_rename[i] == 0 && continue
bb_rename[i] == -1 && continue
preds, succs = blocks[i].preds, blocks[i].succs
# Rename preds
for j = 1:length(preds); preds[j] = bb_rename[preds[j]]; end
for j = 1:length(preds)
if preds[j] != 0
preds[j] = bb_rename[preds[j]]
end
end
# Dead blocks get removed from the predecessor list
filter!(x->x !== 0, preds)
filter!(x->x !== -1, preds)
# Rename succs
for j = 1:length(succs); succs[j] = bb_rename[succs[j]]; end
end
let blocks=blocks
result_bbs = BasicBlock[blocks[i] for i = 1:length(blocks) if bb_rename[i] != 0]
result_bbs = BasicBlock[blocks[i] for i = 1:length(blocks) if bb_rename[i] != -1]
end
else
bb_rename = Vector{Int}()
Expand Down
16 changes: 16 additions & 0 deletions test/compiler/ssair.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,22 @@ let
end
end

# PR #32145
# Make sure IncrementalCompact can handle blocks with predecessors of index 0
# while removing blocks with no predecessors.
let cfg = CFG(BasicBlock[
make_bb([] , [2, 4]),
make_bb([1] , [4, 5]),
make_bb([] , [4] ), # should be removed
make_bb([0, 1, 2] , [5] ), # 0 predecessor should be preserved
make_bb([2, 3] , [] ),
], Int[])
code = Compiler.IRCode(
[], [], Int32[], UInt8[], cfg, LineInfoNode[], [], [], [])
compact = Compiler.IncrementalCompact(code, true)
@test length(compact.result_bbs) == 4 && 0 in compact.result_bbs[3].preds
end

# Issue #32579 - Optimizer bug involving type constraints
function f32579(x::Int, b::Bool)
if b
Expand Down