PHINode: introduce setIncomingValueForBlock() function, and use it.

Summary:
There is PHINode::getBasicBlockIndex() and PHINode::setIncomingValue()
but no function to replace incoming value for a specified BasicBlock*
predecessor.
Clearly, there are a lot of places that could use that functionality.

Reviewer: craig.topper, lebedev.ri, Meinersbur, kbarton, fhahn
Reviewed By: Meinersbur, fhahn
Subscribers: fhahn, hiraditya, zzheng, jsji, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63338

llvm-svn: 363566

1 files changed, 3 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/SafeStack.cpp b/llvm/lib/CodeGen/SafeStack.cpp
index b73a22133a7..6ee5df42407 100644
--- a/llvm/lib/CodeGen/SafeStack.cpp
+++ b/llvm/lib/CodeGen/SafeStack.cpp
@@ -613,16 +613,12 @@ Value *SafeStack::moveStaticAllocasToUnsafeStack(
                                      ConstantInt::get(Int32Ty, -Offset));
       Value *Replacement = IRBUser.CreateBitCast(Off, AI->getType(), Name);
 
-      if (auto *PHI = dyn_cast<PHINode>(User)) {
+      if (auto *PHI = dyn_cast<PHINode>(User))
         // PHI nodes may have multiple incoming edges from the same BB (why??),
         // all must be updated at once with the same incoming value.
-        auto *BB = PHI->getIncomingBlock(U);
-        for (unsigned I = 0; I < PHI->getNumIncomingValues(); ++I)
-          if (PHI->getIncomingBlock(I) == BB)
-            PHI->setIncomingValue(I, Replacement);
-      } else {
+        PHI->setIncomingValueForBlock(PHI->getIncomingBlock(U), Replacement);
+      else
         U.set(Replacement);
-      }
     }
 
     AI->eraseFromParent();