Fix a problem with incomplete equality testing of PHINodes in
Instruction::IsIdenticalToWhenDefined.
This manifested itself when inlining two calls to the same function. The
inlined function had a switch statement that returned one of a set of
global variables. Without this modification, the two phi instructions that
chose values from the branches of the switch instruction inlined from the
callee were considered equivalent and jump-threading replaced a load for the
first switch value with a phi selecting from the second switch, thereby
producing incorrect code.
This patch has been tested with "make check-all", "lnt runteste nt", and
llvm self-hosted, and on the original program that had this problem,
wireshark.
<rdar://problem/11025519>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156548 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index 5449714..c1d6387 100644
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -226,7 +226,14 @@
RMWI->isVolatile() == cast<AtomicRMWInst>(I)->isVolatile() &&
RMWI->getOrdering() == cast<AtomicRMWInst>(I)->getOrdering() &&
RMWI->getSynchScope() == cast<AtomicRMWInst>(I)->getSynchScope();
-
+ if (const PHINode *thisPHI = dyn_cast<PHINode>(this)) {
+ const PHINode *otherPHI = cast<PHINode>(I);
+ for (unsigned i = 0, e = thisPHI->getNumOperands(); i != e; ++i) {
+ if (thisPHI->getIncomingBlock(i) != otherPHI->getIncomingBlock(i))
+ return false;
+ }
+ return true;
+ }
return true;
}