Skip to content

[MLIR] Fix LivenessAnalysis/RemoveDeadValues handling of dead function arguments #160755

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

Merged
merged 2 commits into from
Sep 26, 2025
Merged

[MLIR] Fix LivenessAnalysis/RemoveDeadValues handling of dead function arguments #160755

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
0dafe00
[MLIR] Fix LivenessAnalysis/RemoveDeadValues handling of dead functio…
joker-eph Sep 25, 2025
01f94d8
Add newline at end of remove-dead-values.mlir
joker-eph Sep 26, 2025
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
2 changes: 0 additions & 2 deletions mlir/lib/Analysis/DataFlow/LivenessAnalysis.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -299,8 +299,6 @@ RunLivenessAnalysis::RunLivenessAnalysis(Operation *op) {
// The framework doesn't visit operations in dead blocks, so we need to
// explicitly mark them as dead.
op->walk([&](Operation *op) {
if (op->getNumResults() == 0)
return;
for (auto result : llvm::enumerate(op->getResults())) {
if (getLiveness(result.value()))
continue;
Expand Down
3 changes: 2 additions & 1 deletion mlir/lib/Transforms/RemoveDeadValues.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -287,7 +287,8 @@ static void processSimpleOp(Operation *op, RunLivenessAnalysis &la,
static void processFuncOp(FunctionOpInterface funcOp, Operation *module,
RunLivenessAnalysis &la, DenseSet<Value> &nonLiveSet,
RDVFinalCleanupList &cl) {
LDBG() << "Processing function op: " << funcOp.getOperation()->getName();
LDBG() << "Processing function op: "
<< OpWithFlags(funcOp, OpPrintingFlags().skipRegions());
if (funcOp.isPublic() || funcOp.isExternal()) {
LDBG() << "Function is public or external, skipping: "
<< funcOp.getOperation()->getName();
Expand Down
34 changes: 34 additions & 0 deletions mlir/test/Transforms/remove-dead-values.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -615,3 +615,37 @@ module @last_block_not_exit {
// CHECK-LABEL: @call_private_but_not_use
// CHECK: call @terminated_with_condbr(%false, %true) : (i1, i1)
}

// -----

// Test the elimination of function arguments.

// CHECK-LABEL: func private @single_parameter
// CHECK-SAME: () {
func.func private @single_parameter(%arg0: index) {
return
}

// CHECK-LABEL: func.func private @mutl_parameter(
// CHECK-SAME: %[[ARG0:.*]]: index)
// CHECK: return %[[ARG0]]
func.func private @mutl_parameter(%arg0: index, %arg1: index, %arg2: index) -> index {
return %arg1 : index
}

// CHECK-LABEL: func private @eliminate_parameter
// CHECK-SAME: () {
func.func private @eliminate_parameter(%arg0: index, %arg1: index) {
call @single_parameter(%arg0) : (index) -> ()
return
}

// CHECK-LABEL: func @callee
// CHECK-SAME: (%[[ARG0:.*]]: index, %[[ARG1:.*]]: index, %[[ARG2:.*]]: index)
func.func @callee(%arg0: index, %arg1: index, %arg2: index) -> index {
// CHECK: call @eliminate_parameter() : () -> ()
call @eliminate_parameter(%arg0, %arg1) : (index, index) -> ()
// CHECK: call @mutl_parameter(%[[ARG1]]) : (index) -> index
%res = call @mutl_parameter(%arg0, %arg1, %arg2) : (index, index, index) -> (index)
return %res : index
}