Instruction counters must skip the bitcasts that

feed into llvm.dbg.declare nodes, as well as
the debug directives themselves.

llvm-svn: 65976

2 files changed, 11 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index 64dd1031db9..8f094b747c1 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11484,7 +11484,11 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
   for (unsigned ScanInsts = 6; BBI != SI.getParent()->begin() && ScanInsts;
        --ScanInsts) {
     // Don't count debug info directives, lest they affect codegen.
-    if (isa<DbgInfoIntrinsic>(BBI)) {
+    // Likewise, we skip bitcasts that feed into a llvm.dbg.declare; these are
+    // not present when debugging is off.
+    if (isa<DbgInfoIntrinsic>(BBI) ||
+        (isa<BitCastInst>(BBI) && BBI->hasOneUse() &&
+         isa<DbgDeclareInst>(BBI->use_begin()))) {
       ScanInsts++;
       --BBI;
       continue;
diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 2887bdc46b5..fd7b7da76fb 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -477,6 +477,12 @@ Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
     Instruction *Inst = --ScanFrom;
     if (isa<DbgInfoIntrinsic>(Inst))
       continue;
+    // Likewise, we skip bitcasts that feed into a llvm.dbg.declare; these are
+    // not present when debugging is off.
+    if (isa<BitCastInst>(Inst) && Inst->hasOneUse() &&
+        isa<DbgDeclareInst>(Inst->use_begin()))
+      continue;
+
     // Restore ScanFrom to expected value in case next test succeeds
     ScanFrom++;