[llvm] f96ab6c - Revert "[Inline] Attempt to delete any discardable if unused functions"
Arthur Eubanks via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 7 13:13:08 PST 2022
Author: Arthur Eubanks
Date: 2022-01-07T13:12:40-08:00
New Revision: f96ab6cc1b2016374a6e8500774f8cb2c3725b04
URL: https://github.com/llvm/llvm-project/commit/f96ab6cc1b2016374a6e8500774f8cb2c3725b04
DIFF: https://github.com/llvm/llvm-project/commit/f96ab6cc1b2016374a6e8500774f8cb2c3725b04.diff
LOG: Revert "[Inline] Attempt to delete any discardable if unused functions"
This reverts commit 335a3163aab4ab3a52c7c15d03bcf1ce9ba79fbb.
Causes crashes when building llvm-test-suite's kc under ReleaseLTO-g.
Added:
Modified:
llvm/lib/Transforms/IPO/Inliner.cpp
Removed:
llvm/test/Transforms/Inline/delete-unused-function.ll
################################################################################
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
index a9cc25f26e048..81b9ad04571a9 100644
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -823,10 +823,6 @@ PreservedAnalyses InlinerPass::run(LazyCallGraph::SCC &InitialC,
// defer deleting these to make it easier to handle the call graph updates.
SmallVector<Function *, 4> DeadFunctions;
- // Track potentially dead non-local functions with comdats to see if they can
- // be deleted as a batch after inlining.
- SmallVector<Function *, 4> DeadFunctionsInComdats;
-
// Loop forward over all of the calls.
while (!Calls->empty()) {
// We expect the calls to typically be batched with sequences of calls that
@@ -939,33 +935,28 @@ PreservedAnalyses InlinerPass::run(LazyCallGraph::SCC &InitialC,
// Merge the attributes based on the inlining.
AttributeFuncs::mergeAttributesForInlining(F, Callee);
- // For local functions or discardable functions without comdats, check
- // whether this makes the callee trivially dead. In that case, we can drop
- // the body of the function eagerly which may reduce the number of callers
- // of other functions to one, changing inline cost thresholds. Non-local
- // discardable functions with comdats are checked later on.
+ // For local functions, check whether this makes the callee trivially
+ // dead. In that case, we can drop the body of the function eagerly
+ // which may reduce the number of callers of other functions to one,
+ // changing inline cost thresholds.
bool CalleeWasDeleted = false;
- if (Callee.isDiscardableIfUnused()) {
+ if (Callee.hasLocalLinkage()) {
// To check this we also need to nuke any dead constant uses (perhaps
// made dead by this operation on other functions).
Callee.removeDeadConstantUsers();
if (Callee.use_empty() && !CG.isLibFunction(Callee)) {
- if (Callee.hasLocalLinkage() || !Callee.hasComdat()) {
- Calls->erase_if([&](const std::pair<CallBase *, int> &Call) {
- return Call.first->getCaller() == &Callee;
- });
- // Clear the body and queue the function itself for deletion when we
- // finish inlining and call graph updates.
- // Note that after this point, it is an error to do anything other
- // than use the callee's address or delete it.
- Callee.dropAllReferences();
- assert(!is_contained(DeadFunctions, &Callee) &&
- "Cannot put cause a function to become dead twice!");
- DeadFunctions.push_back(&Callee);
- CalleeWasDeleted = true;
- } else {
- DeadFunctionsInComdats.push_back(&Callee);
- }
+ Calls->erase_if([&](const std::pair<CallBase *, int> &Call) {
+ return Call.first->getCaller() == &Callee;
+ });
+ // Clear the body and queue the function itself for deletion when we
+ // finish inlining and call graph updates.
+ // Note that after this point, it is an error to do anything other
+ // than use the callee's address or delete it.
+ Callee.dropAllReferences();
+ assert(!is_contained(DeadFunctions, &Callee) &&
+ "Cannot put cause a function to become dead twice!");
+ DeadFunctions.push_back(&Callee);
+ CalleeWasDeleted = true;
}
}
if (CalleeWasDeleted)
@@ -1028,15 +1019,6 @@ PreservedAnalyses InlinerPass::run(LazyCallGraph::SCC &InitialC,
FAM.invalidate(F, PreservedAnalyses::none());
}
- // We must ensure that we only delete functions with comdats if every function
- // in the comdat is going to be deleted.
- if (!DeadFunctionsInComdats.empty()) {
- filterDeadComdatFunctions(DeadFunctionsInComdats);
- for (auto *Callee : DeadFunctionsInComdats)
- Callee->dropAllReferences();
- DeadFunctions.append(DeadFunctionsInComdats);
- }
-
// Now that we've finished inlining all of the calls across this SCC, delete
// all of the trivially dead functions, updating the call graph and the CGSCC
// pass manager in the process.
diff --git a/llvm/test/Transforms/Inline/delete-unused-function.ll b/llvm/test/Transforms/Inline/delete-unused-function.ll
deleted file mode 100644
index 319a6a6bcab53..0000000000000
--- a/llvm/test/Transforms/Inline/delete-unused-function.ll
+++ /dev/null
@@ -1,63 +0,0 @@
-; RUN: opt -passes=inline < %s -S | FileCheck %s
-
-; CHECK: define {{.*}}@caller
-; CHECK: define {{.*}}@f1
-; CHECK-NOT: define {{.*}}@f2
-; CHECK-NOT: define {{.*}}@f3
-; CHECK-NOT: define {{.*}}@f4
-; CHECK-NOT: define {{.*}}@f5
-; CHECK: define {{.*}}@f6
-; CHECK-NOT: define {{.*}}@f7
-; CHECK-NOT: define {{.*}}@f8
-
-$c1 = comdat any
-$c2 = comdat any
-$c3 = comdat any
-
-define void @caller() {
- call void @f1()
- call void @f2()
- call void @f3()
- call void @f4()
- call void @f5()
- call void @f6()
- call void @f7()
- call void @f8()
- ret void
-}
-
-define void @f1() {
- ret void
-}
-
-define internal void @f2() {
- ret void
-}
-
-define private void @f3() {
- ret void
-}
-
-define linkonce_odr void @f4() {
- ret void
-}
-
-define linkonce_odr void @f5() comdat($c1) {
- ret void
-}
-
-define linkonce_odr void @f6() comdat($c2) {
- ret void
-}
-
-define linkonce_odr void @g() comdat($c2) {
- ret void
-}
-
-define linkonce_odr void @f7() comdat($c3) {
- ret void
-}
-
-define linkonce_odr void @f8() comdat($c3) {
- ret void
-}
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