DeadArgElim: arguments affect all returned sub-values by default.
Unless we meet an insertvalue on a path from some value to a return, that value
will be live if *any* of the return's components are live, so all of those
components must be added to the MaybeLiveUses.
Previously we were deleting arguments if sub-value 0 turned out to be dead.
llvm-svn: 228731
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 50698bb..596204d 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -146,7 +146,7 @@
private:
Liveness MarkIfNotLive(RetOrArg Use, UseVector &MaybeLiveUses);
Liveness SurveyUse(const Use *U, UseVector &MaybeLiveUses,
- unsigned RetValNum = 0);
+ unsigned RetValNum = -1U);
Liveness SurveyUses(const Value *V, UseVector &MaybeLiveUses);
void SurveyFunction(const Function &F);
@@ -443,9 +443,21 @@
// function's return value is live. We use RetValNum here, for the case
// that U is really a use of an insertvalue instruction that uses the
// original Use.
- RetOrArg Use = CreateRet(RI->getParent()->getParent(), RetValNum);
- // We might be live, depending on the liveness of Use.
- return MarkIfNotLive(Use, MaybeLiveUses);
+ const Function *F = RI->getParent()->getParent();
+ if (RetValNum != -1U) {
+ RetOrArg Use = CreateRet(F, RetValNum);
+ // We might be live, depending on the liveness of Use.
+ return MarkIfNotLive(Use, MaybeLiveUses);
+ } else {
+ DAE::Liveness Result;
+ for (unsigned i = 0; i < NumRetVals(F); ++i) {
+ RetOrArg Use = CreateRet(F, i);
+ // We might be live, depending on the liveness of Use. All Results
+ // should be the same since they depend only on F.
+ Result = MarkIfNotLive(Use, MaybeLiveUses);
+ }
+ return Result;
+ }
}
if (const InsertValueInst *IV = dyn_cast<InsertValueInst>(V)) {
if (U->getOperandNo() != InsertValueInst::getAggregateOperandIndex()