[Debug] Add a utility to propagate dbg.value to new PHIs, NFC
This simply moves an existing utility to Utils for reuse.
Split out of: https://reviews.llvm.org/D42551
Patch by Matt Davis!
llvm-svn: 323471
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 4459d3c..a7eaffd 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -73,6 +73,7 @@
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
#include <algorithm>
#include <cassert>
#include <climits>
@@ -1341,6 +1342,43 @@
return true;
}
+/// Propagate dbg.value intrinsics through the newly inserted PHIs.
+void llvm::insertDebugValuesForPHIs(BasicBlock *BB,
+ SmallVectorImpl<PHINode *> &InsertedPHIs) {
+ assert(BB && "No BasicBlock to clone dbg.value(s) from.");
+ if (InsertedPHIs.size() == 0)
+ return;
+
+ // Map existing PHI nodes to their dbg.values.
+ ValueToValueMapTy DbgValueMap;
+ for (auto &I : *BB) {
+ if (auto DbgII = dyn_cast<DbgInfoIntrinsic>(&I)) {
+ if (auto *Loc = dyn_cast_or_null<PHINode>(DbgII->getVariableLocation()))
+ DbgValueMap.insert({Loc, DbgII});
+ }
+ }
+ if (DbgValueMap.size() == 0)
+ return;
+
+ // Then iterate through the new PHIs and look to see if they use one of the
+ // previously mapped PHIs. If so, insert a new dbg.value intrinsic that will
+ // propagate the info through the new PHI.
+ LLVMContext &C = BB->getContext();
+ for (auto PHI : InsertedPHIs) {
+ for (auto VI : PHI->operand_values()) {
+ auto V = DbgValueMap.find(VI);
+ if (V != DbgValueMap.end()) {
+ auto *DbgII = cast<DbgInfoIntrinsic>(V->second);
+ Instruction *NewDbgII = DbgII->clone();
+ auto PhiMAV = MetadataAsValue::get(C, ValueAsMetadata::get(PHI));
+ NewDbgII->setOperand(0, PhiMAV);
+ BasicBlock *Parent = PHI->getParent();
+ NewDbgII->insertBefore(Parent->getFirstNonPHIOrDbgOrLifetime());
+ }
+ }
+ }
+}
+
/// Finds all intrinsics declaring local variables as living in the memory that
/// 'V' points to. This may include a mix of dbg.declare and
/// dbg.addr intrinsics.