[ValueTracking] recognize a 'not' of an assumed condition as false

Also, add the corresponding match to the AssumptionCache's 'Affected Values' list.

Differential Revision: https://reviews.llvm.org/D28485

llvm-svn: 292239

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Analysis/AssumptionCache.cpp b/llvm/lib/Analysis/AssumptionCache.cpp
index 5851594700a..4e287e5f6bc 100644
--- a/llvm/lib/Analysis/AssumptionCache.cpp
+++ b/llvm/lib/Analysis/AssumptionCache.cpp
@@ -47,9 +47,11 @@ void AssumptionCache::updateAffectedValues(CallInst *CI) {
     } else if (auto *I = dyn_cast<Instruction>(V)) {
       Affected.push_back(I);
 
-      if (I->getOpcode() == Instruction::BitCast ||
-          I->getOpcode() == Instruction::PtrToInt) {
-        auto *Op = I->getOperand(0);
+      // Peek through unary operators to find the source of the condition.
+      Value *Op;
+      if (match(I, m_BitCast(m_Value(Op))) ||
+          match(I, m_PtrToInt(m_Value(Op))) ||
+          match(I, m_Not(m_Value(Op)))) {
         if (isa<Instruction>(Op) || isa<Argument>(Op))
           Affected.push_back(Op);
       }