[IRCE] Use dyn_cast instead of explicit isa/cast; NFC

llvm-svn: 278607

1 files changed, 8 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 2f644406c0f..b3bd1f01232 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -930,10 +930,10 @@ void LoopConstrainer::cloneLoop(LoopConstrainer::ClonedLoop &Result,
         continue; // not an exit block
 
       for (Instruction &I : *SBB) {
-        if (!isa<PHINode>(&I))
+        auto *PN = dyn_cast<PHINode>(&I);
+        if (!PN)
           break;
 
-        PHINode *PN = cast<PHINode>(&I);
         Value *OldIncoming = PN->getIncomingValueForBlock(OriginalBB);
         PN->addIncoming(GetClonedValue(OldIncoming), ClonedBB);
       }
@@ -1066,11 +1066,10 @@ LoopConstrainer::RewrittenRangeInfo LoopConstrainer::changeIterationSpaceEnd(
   // each of the PHI nodes in the loop header.  This feeds into the initial
   // value of the same PHI nodes if/when we continue execution.
   for (Instruction &I : *LS.Header) {
-    if (!isa<PHINode>(&I))
+    auto *PN = dyn_cast<PHINode>(&I);
+    if (!PN)
       break;
 
-    PHINode *PN = cast<PHINode>(&I);
-
     PHINode *NewPHI = PHINode::Create(PN->getType(), 2, PN->getName() + ".copy",
                                       BranchToContinuation);
 
@@ -1103,11 +1102,10 @@ void LoopConstrainer::rewriteIncomingValuesForPHIs(
 
   unsigned PHIIndex = 0;
   for (Instruction &I : *LS.Header) {
-    if (!isa<PHINode>(&I))
+    auto *PN = dyn_cast<PHINode>(&I);
+    if (!PN)
       break;
 
-    PHINode *PN = cast<PHINode>(&I);
-
     for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i)
       if (PN->getIncomingBlock(i) == ContinuationBlock)
         PN->setIncomingValue(i, RRI.PHIValuesAtPseudoExit[PHIIndex++]);
@@ -1124,10 +1122,10 @@ BasicBlock *LoopConstrainer::createPreheader(const LoopStructure &LS,
   BranchInst::Create(LS.Header, Preheader);
 
   for (Instruction &I : *LS.Header) {
-    if (!isa<PHINode>(&I))
+    auto *PN = dyn_cast<PHINode>(&I);
+    if (!PN)
       break;
 
-    PHINode *PN = cast<PHINode>(&I);
     for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i)
       replacePHIBlock(PN, OldPreheader, Preheader);
   }