The method of doing the matching with a 'select' instruction was wrong. The
original code was matching like this:
if (match(A, m_Not(m_Value(B))))
B was already matched as a 'select' instruction. However, this isn't matching
what we think it's matching. It would match B as a 'Value', so basically
anything would match to it. In this case, a Constant matched. B was replaced
with a constant representation. And then the wrong value would be used in the
SelectInst::Create statement, causing a crash.
After thinking on this for a moment, and after Nick L. told me how the pattern
matching stuff was supposed to work, the solution was to match NOT an m_Value,
but an m_Select.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 60b907e..fa0704c 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -4352,55 +4352,62 @@
}
}
+#define SELECT_MATCH(Val) \
+ m_Select(m_Value(Val), m_ConstantInt(0), m_ConstantInt(-1))
+#define GET_SELECT_COND(Val) \
+ cast<User>(Val)->getOperand(0)
+
// (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants
if (match(A, m_Select(m_Value(), m_ConstantInt(-1), m_ConstantInt(0)))) {
- if (match(D, m_Not(m_Value(A))))
- return SelectInst::Create(cast<User>(A)->getOperand(0), C, B);
- if (match(B, m_Not(m_Value(A))))
- return SelectInst::Create(cast<User>(A)->getOperand(0), C, D);
+ if (match(D, m_Not(SELECT_MATCH(A))))
+ return SelectInst::Create(GET_SELECT_COND(D), C, B);
+ if (match(B, m_Not(SELECT_MATCH(A))))
+ return SelectInst::Create(GET_SELECT_COND(B), C, D);
}
if (match(B, m_Select(m_Value(), m_ConstantInt(-1), m_ConstantInt(0)))) {
- if (match(C, m_Not(m_Value(B))))
- return SelectInst::Create(cast<User>(B)->getOperand(0), A, D);
- if (match(A, m_Not(m_Value(B))))
- return SelectInst::Create(cast<User>(B)->getOperand(0), C, D);
+ if (match(C, m_Not(SELECT_MATCH(B))))
+ return SelectInst::Create(GET_SELECT_COND(C), A, D);
+ if (match(A, m_Not(SELECT_MATCH(B))))
+ return SelectInst::Create(GET_SELECT_COND(A), C, D);
}
if (match(C, m_Select(m_Value(), m_ConstantInt(-1), m_ConstantInt(0)))) {
- if (match(D, m_Not(m_Value(C))))
- return SelectInst::Create(cast<User>(C)->getOperand(0), A, B);
- if (match(B, m_Not(m_Value(C))))
- return SelectInst::Create(cast<User>(C)->getOperand(0), A, D);
+ if (match(D, m_Not(SELECT_MATCH(C))))
+ return SelectInst::Create(GET_SELECT_COND(D), A, B);
+ if (match(B, m_Not(SELECT_MATCH(C))))
+ return SelectInst::Create(GET_SELECT_COND(B), A, D);
}
if (match(D, m_Select(m_Value(), m_ConstantInt(-1), m_ConstantInt(0)))) {
- if (match(C, m_Not(m_Value(D))))
- return SelectInst::Create(cast<User>(D)->getOperand(0), A, B);
- if (match(A, m_Not(m_Value(D))))
- return SelectInst::Create(cast<User>(D)->getOperand(0), C, B);
+ if (match(C, m_Not(SELECT_MATCH(D))))
+ return SelectInst::Create(GET_SELECT_COND(C), A, B);
+ if (match(A, m_Not(SELECT_MATCH(D))))
+ return SelectInst::Create(GET_SELECT_COND(A), C, B);
}
if (match(A, m_Select(m_Value(), m_ConstantInt(0), m_ConstantInt(-1)))) {
- if (match(D, m_Not(m_Value(A))))
- return SelectInst::Create(cast<User>(A)->getOperand(0), B, C);
- if (match(B, m_Not(m_Value(A))))
- return SelectInst::Create(cast<User>(A)->getOperand(0), D, C);
+ if (match(D, m_Not(SELECT_MATCH(A))))
+ return SelectInst::Create(GET_SELECT_COND(D), B, C);
+ if (match(B, m_Not(SELECT_MATCH(A))))
+ return SelectInst::Create(GET_SELECT_COND(B), D, C);
}
if (match(B, m_Select(m_Value(), m_ConstantInt(0), m_ConstantInt(-1)))) {
- if (match(C, m_Not(m_Value(B))))
- return SelectInst::Create(cast<User>(B)->getOperand(0), D, A);
- if (match(A, m_Not(m_Value(B))))
- return SelectInst::Create(cast<User>(B)->getOperand(0), D, C);
+ if (match(C, m_Not(SELECT_MATCH(B))))
+ return SelectInst::Create(GET_SELECT_COND(C), D, A);
+ if (match(A, m_Not(SELECT_MATCH(B))))
+ return SelectInst::Create(GET_SELECT_COND(A), D, C);
}
if (match(C, m_Select(m_Value(), m_ConstantInt(0), m_ConstantInt(-1)))) {
- if (match(D, m_Not(m_Value(C))))
- return SelectInst::Create(cast<User>(C)->getOperand(0), B, A);
- if (match(B, m_Not(m_Value(C))))
- return SelectInst::Create(cast<User>(C)->getOperand(0), D, A);
+ if (match(D, m_Not(SELECT_MATCH(C))))
+ return SelectInst::Create(GET_SELECT_COND(D), B, A);
+ if (match(B, m_Not(SELECT_MATCH(C))))
+ return SelectInst::Create(GET_SELECT_COND(B), D, A);
}
if (match(D, m_Select(m_Value(), m_ConstantInt(0), m_ConstantInt(-1)))) {
- if (match(C, m_Not(m_Value(D))))
- return SelectInst::Create(cast<User>(D)->getOperand(0), B, A);
- if (match(A, m_Not(m_Value(D))))
- return SelectInst::Create(cast<User>(D)->getOperand(0), B, C);
+ if (match(C, m_Not(SELECT_MATCH(D))))
+ return SelectInst::Create(GET_SELECT_COND(C), B, A);
+ if (match(A, m_Not(SELECT_MATCH(D))))
+ return SelectInst::Create(GET_SELECT_COND(A), B, C);
}
+#undef SELECT_MATCH
+#undef GET_SELECT_COND
}
// (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts.