Ignore dbg intrinsics while propagating conditional expression info. Take 2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63898 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 6 deletions

diff --git a/lib/Transforms/Scalar/CondPropagate.cpp b/lib/Transforms/Scalar/CondPropagate.cpp
index c4e2b1a..9c753df 100644
--- a/lib/Transforms/Scalar/CondPropagate.cpp
+++ b/lib/Transforms/Scalar/CondPropagate.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Constants.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/Pass.h"
 #include "llvm/Type.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -134,8 +135,8 @@ void CondProp::SimplifyBlock(BasicBlock *BB) {
 // jump directly to the destination instead of going through this block.
 void CondProp::SimplifyPredecessors(BranchInst *BI) {
   // TODO: We currently only handle the most trival case, where the PHI node has
-  // one use (the branch), and is the only instruction besides the branch in the
-  // block.
+  // one use (the branch), and is the only instruction besides the branch and dbg
+  // intrinsics in the block.
   PHINode *PN = cast<PHINode>(BI->getCondition());
 
   if (PN->getNumIncomingValues() == 1) {
@@ -148,7 +149,12 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) {
   if (!PN->hasOneUse()) return;
 
   BasicBlock *BB = BI->getParent();
-  if (&*BB->begin() != PN || &*next(BB->begin()) != BI)
+  if (&*BB->begin() != PN)
+    return;
+  BasicBlock::iterator BBI = BB->begin();
+  BasicBlock::iterator BBE = BB->end();
+  while (BBI != BBE && isa<DbgInfoIntrinsic>(++BBI));
+  if (&*BBI != BI)
     return;
 
   // Ok, we have this really simple case, walk the PHI operands, looking for
@@ -176,13 +182,18 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) {
 // the destination instead of going through this block.
 void CondProp::SimplifyPredecessors(SwitchInst *SI) {
   // TODO: We currently only handle the most trival case, where the PHI node has
-  // one use (the branch), and is the only instruction besides the branch in the
-  // block.
+  // one use (the branch), and is the only instruction besides the branch and 
+  // dbg intrinsics in the block.
   PHINode *PN = cast<PHINode>(SI->getCondition());
   if (!PN->hasOneUse()) return;
 
   BasicBlock *BB = SI->getParent();
-  if (&*BB->begin() != PN || &*next(BB->begin()) != SI)
+  if (&*BB->begin() != PN)
+    return;
+  BasicBlock::iterator BBI = BB->begin();
+  BasicBlock::iterator BBE = BB->end();
+  while (BBI != BBE && isa<DbgInfoIntrinsic>(++BBI));
+  if (&*BBI != SI)
     return;
 
   bool RemovedPreds = false;