[CallSiteSplitting] Don't let debug intrinsics affect optimizations

Summary:
This solves PR35616.

We don't want the compiler to generate different code when we compile
with/without -g, so we now ignore debug intrinsics when determining if
the optimization can trigger or not.

Reviewers: junbuml

Subscribers: davide, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41068

llvm-svn: 320460

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
index d53968be612..1a8d231ddb8 100644
--- a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
+++ b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
@@ -221,7 +221,7 @@ static bool canSplitCallSite(CallSite CS) {
   // call instruction, and we do not move a call-site across any other
   // instruction.
   BasicBlock *CallSiteBB = Instr->getParent();
-  if (Instr != CallSiteBB->getFirstNonPHI())
+  if (Instr != CallSiteBB->getFirstNonPHIOrDbg())
     return false;
 
   // Need 2 predecessors and cannot split an edge from an IndirectBrInst.
@@ -278,7 +278,7 @@ static void splitCallSite(CallSite CS, BasicBlock *PredBB1, BasicBlock *PredBB2,
                           Instruction *CallInst1, Instruction *CallInst2) {
   Instruction *Instr = CS.getInstruction();
   BasicBlock *TailBB = Instr->getParent();
-  assert(Instr == (TailBB->getFirstNonPHI()) && "Unexpected call-site");
+  assert(Instr == (TailBB->getFirstNonPHIOrDbg()) && "Unexpected call-site");
 
   BasicBlock *SplitBlock1 =
       SplitBlockPredecessors(TailBB, PredBB1, ".predBB1.split");
@@ -315,7 +315,8 @@ static void splitCallSite(CallSite CS, BasicBlock *PredBB1, BasicBlock *PredBB2,
 
   // Replace users of the original call with a PHI mering call-sites split.
   if (Instr->getNumUses()) {
-    PHINode *PN = PHINode::Create(Instr->getType(), 2, "phi.call", Instr);
+    PHINode *PN = PHINode::Create(Instr->getType(), 2, "phi.call",
+                                  TailBB->getFirstNonPHI());
     PN->addIncoming(CallInst1, SplitBlock1);
     PN->addIncoming(CallInst2, SplitBlock2);
     Instr->replaceAllUsesWith(PN);
@@ -334,7 +335,7 @@ static void splitCallSite(CallSite CS, BasicBlock *PredBB1, BasicBlock *PredBB2,
 static bool isPredicatedOnPHI(CallSite CS) {
   Instruction *Instr = CS.getInstruction();
   BasicBlock *Parent = Instr->getParent();
-  if (Instr != Parent->getFirstNonPHI())
+  if (Instr != Parent->getFirstNonPHIOrDbg())
     return false;
 
   for (auto &BI : *Parent) {