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sanirudh pushed a commit to branch unity
in repository https://gitbox.apache.org/repos/asf/tvm.git
The following commit(s) were added to refs/heads/unity by this push:
new e7c7314046 [Unity][Transform] Keep R.ExternFunc in dead-code
elimination (#16118)
e7c7314046 is described below
commit e7c73140469ba59a6ac3c1d585a49626f064566a
Author: Eric Lunderberg <[email protected]>
AuthorDate: Tue Nov 14 08:21:05 2023 -0600
[Unity][Transform] Keep R.ExternFunc in dead-code elimination (#16118)
Prior to this commit, the `DeadCodeElimination` and `FuseTIR` passes
treated `R.ExternFunc` differently with respect to removal of internal
functions: `DeadCodeElimination` treated these functions as internal,
to be removed if there are no internal callers, while `FuseTIR`
treated these functions as external, to be retained in all cases.
Because the visibility of a function is determined by the
`tvm::attr::kGlobalSymbol` attribute; which is present for `PrimFunc`
and `relax::Function`, but missing for `relax::ExternFunc`; there is
no information in the `IRModule` that can determine whether a
`relax::ExternFunc` should be visible externally.
For consistency, and to allow the use of `DeadCodeElimination` in
future refactors of `FuseTIR`, this commit updates
`DeadCodeElimination` to retain instances of `relax::ExternFunc`.
---
src/relax/transform/dead_code_elimination.cc | 2 +-
tests/python/relax/test_transform_dead_code_elimination.py | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/src/relax/transform/dead_code_elimination.cc
b/src/relax/transform/dead_code_elimination.cc
index 6d9f25296a..248e4c1c00 100644
--- a/src/relax/transform/dead_code_elimination.cc
+++ b/src/relax/transform/dead_code_elimination.cc
@@ -124,7 +124,7 @@ IRModule DeadCodeElimination(const IRModule& arg_mod,
Array<runtime::String> ent
entry_functions.insert(mod->GetGlobalVar(name));
}
for (const auto& [gv, func] : mod->functions) {
- if (func->GetLinkageType() == LinkageType::kExternal) {
+ if (func.as<ExternFuncNode>() || func->GetLinkageType() ==
LinkageType::kExternal) {
entry_functions.insert(gv);
}
}
diff --git a/tests/python/relax/test_transform_dead_code_elimination.py
b/tests/python/relax/test_transform_dead_code_elimination.py
index 7b749d6778..c0a2d47b19 100644
--- a/tests/python/relax/test_transform_dead_code_elimination.py
+++ b/tests/python/relax/test_transform_dead_code_elimination.py
@@ -497,5 +497,15 @@ def test_unused_dfb2():
verify(Input, Expected)
+def test_extern_func():
+ """DeadCodeElimination should retain the ExternFunc in the IRModule."""
+
+ builder = tvm.relax.BlockBuilder()
+ builder.add_func(tvm.relax.extern("extern_func"), "extern_func")
+ before = builder.get()
+
+ verify(before, before)
+
+
if __name__ == "__main__":
tvm.testing.main()
