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| author | Anders Carlsson <andersca@mac.com> | 2011-01-30 22:01:13 +0000 |
|---|---|---|
| committer | Anders Carlsson <andersca@mac.com> | 2011-01-30 22:01:13 +0000 |
| commit | f23a6da271dd9be949e5f3cb12bc15a9a9d98712 (patch) | |
| tree | a283bfd8db93f372c03afa003b8089778c26af02 /llvm/lib/Transforms/InstCombine | |
| parent | a03f3a85cb8d7ed86943c12030088fddc05ba1b3 (diff) | |
| download | bcm5719-llvm-f23a6da271dd9be949e5f3cb12bc15a9a9d98712.tar.gz bcm5719-llvm-f23a6da271dd9be949e5f3cb12bc15a9a9d98712.zip | |
Recognize and simplify
(A+B) == A -> B == 0
A == (A+B) -> B == 0
llvm-svn: 124567
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index fe436bce210..8c5e7e48c44 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2341,7 +2341,17 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { 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))) && |
