search for: m_or

Displaying 4 results from an estimated 4 matches for "m_or".

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2008 Nov 09
0
[LLVMdev] m_Not Pattern Question
..."B", which seems weird and > wrong to me. This is deliberate. m_Foo(V) means "match any Foo and put its result into V." The way it's generally used is to declare empty variables, match against them, and test the equality: Value *A, *B, *C, *D; if (match(Expr, m_Or(m_And(A, B), m_And(C, D))) { if (B == D) { ... do optimization ... Nick > -bw > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev &g...
2008 Nov 09
2
[LLVMdev] m_Not Pattern Question
I have a question about the pattern matching stuff that's used in the Instruction Combiner. If I have code like this: 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); and we match, the program fails during the
2010 Jan 05
0
[LLVMdev] [llvm-commits] [llvm] r92458 - in /llvm/trunk: lib/Target/README.txt lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/or.ll
...gt;> - V1 = 0; V2 = 0; V3 = 0; >> + >> + // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2) >> + // iff (C1&C2) == 0 and (N&~C1) == 0 >> + if ((C1->getValue() & C2->getValue()) == 0) { >> + if (match(A, m_Or(m_Value(V1), m_Value(V2))) && >> + ((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N) >> + (V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V) >> + return BinaryOperator::CreateAnd(A, >&gt...
2005 Oct 05
1
[LLVMdev] Cast instructions
The following situation comes up a lot in what I'm doing. I want to check if a value is a certain kind of instruction. The test also needs to succeed if the value is a *cast* of the instruction (or a cast of a cast, etc.) I.e., I need to "see through" any intervening casts to get to the "real" value. It's trivial to write a function that does this, but does