GlobalDCE: Teach isEmptyFunction() to ignore debug intrinsics.
This fixes PR39669.
https://bugs.llvm.org/show_bug.cgi?id=39669
llvm-svn: 347065
diff --git a/llvm/lib/Transforms/IPO/GlobalDCE.cpp b/llvm/lib/Transforms/IPO/GlobalDCE.cpp
index c77ea04..34de874 100644
--- a/llvm/lib/Transforms/IPO/GlobalDCE.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalDCE.cpp
@@ -19,6 +19,7 @@
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/IPO.h"
@@ -75,13 +76,17 @@
return new GlobalDCELegacyPass();
}
-/// Returns true if F contains only a single "ret" instruction.
+/// Returns true if F is effectively empty.
static bool isEmptyFunction(Function *F) {
BasicBlock &Entry = F->getEntryBlock();
- if (Entry.size() != 1 || !isa<ReturnInst>(Entry.front()))
- return false;
- ReturnInst &RI = cast<ReturnInst>(Entry.front());
- return RI.getReturnValue() == nullptr;
+ for (auto &I : Entry) {
+ if (isa<DbgInfoIntrinsic>(I))
+ continue;
+ if (auto *RI = dyn_cast<ReturnInst>(&I))
+ return !RI->getReturnValue();
+ break;
+ }
+ return false;
}
/// Compute the set of GlobalValue that depends from V.