Recognize and simplify
(A+B) == A -> B == 0
A == (A+B) -> B == 0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124567 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index fe436bc..8c5e7e4 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2341,7 +2341,17 @@
if (match(Op1, m_Sub(m_Specific(Op0), m_Value(B))))
return new ICmpInst(I.getPredicate(), B,
Constant::getNullValue(B->getType()));
-
+
+ // (A+B) == A -> B == 0
+ if (match(Op0, m_Add(m_Specific(Op1), m_Value(B))))
+ return new ICmpInst(I.getPredicate(), B,
+ Constant::getNullValue(B->getType()));
+
+ // A == (A+B) -> B == 0
+ if (match(Op1, m_Add(m_Specific(Op0), m_Value(B))))
+ return new ICmpInst(I.getPredicate(), B,
+ Constant::getNullValue(B->getType()));
+
// (X&Z) == (Y&Z) -> (X^Y) & Z == 0
if (Op0->hasOneUse() && Op1->hasOneUse() &&
match(Op0, m_And(m_Value(A), m_Value(B))) &&