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| author | Alon Zakai <azakai@google.com> | 2022-11-21 15:54:21 -0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-11-21 15:54:21 -0800 |
| commit | c449f41678d5e1699d634855743f5874ae6ec6e4 (patch) | |
| tree | 029016b74efbf0608efc9c18c6fcaf94212f590c /src/passes/CodePushing.cpp | |
| parent | ea0c800b90713edef9566feb30ccb6d276beb857 (diff) | |
| download | binaryen-c449f41678d5e1699d634855743f5874ae6ec6e4.tar.gz binaryen-c449f41678d5e1699d634855743f5874ae6ec6e4.tar.bz2 binaryen-c449f41678d5e1699d634855743f5874ae6ec6e4.zip | |
Code Pushing: Ignore unreachable sets (#5284)
Normally we ignore them anyhow (unreachability is an effect, either a trap or
a control flow switch), but in traps-never-happen mode we can ignore a trap, so
we need to check this manually.
Diffstat (limited to 'src/passes/CodePushing.cpp')
| -rw-r--r-- | src/passes/CodePushing.cpp | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/passes/CodePushing.cpp b/src/passes/CodePushing.cpp index 20f16b145..2b45dda16 100644 --- a/src/passes/CodePushing.cpp +++ b/src/passes/CodePushing.cpp @@ -323,6 +323,26 @@ private: assert(i > 0); i--; auto* pushable = isPushable(list[i]); + if (pushable && pushable->type == Type::unreachable) { + // Don't try to push something unreachable. If we did, then we'd need to + // refinalize the block we are moving it from: + // + // (block $unreachable + // (local.set $x (unreachable)) + // (if (..) + // (.. (local.get $x)) + // ) + // + // The block should not be unreachable if the local.set is moved into + // the if arm (the if arm may not execute, so the if itself will not + // change type). It is simpler to avoid this complexity and leave this + // to DCE to simplify first. + // + // (Note that the side effect of trapping will normally prevent us from + // trying to push something unreachable, but in traps-never-happen mode + // we are allowed to ignore that, and so we need this check.) + pushable = nullptr; + } if (!pushable) { // Something that is staying where it is, so anything we push later must // move past it. Note the effects and continue. |