search for: m_not

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 "SelectInst::Create" phase. The problem is because B is now a Constant with "-2" as its value, so it has 0 operands. It appears that the...

Bill Wendling wrote: > 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 "SelectInst::Create" phase. > The problem is because B is now a Constant with "-2" as its value, so > it has 0 oper...

...-------------- Would adding to the existing InstCombine logic folds to handle this kind of pattern be a welcome enhancement? I don't know if it's possible to make the matchers handle this case without adding a new matcher. Eg: // ((~A & B) | A) -> (A | B) if (match(Op0, m_c_And(m_Not(m_Specific(Op1)), m_Value(A)))) return BinaryOperator::CreateOr(A, Op1); Is there a way to make "m_Not(m_Specific())" match an inverted compare? This optimization hole can manifest in strange ways: https://godbolt.org/g/gjpAVo We got it right for C++, but C managed to fall through...

Hello all Im using sftp 1:4.7p1-8ubuntu1.2 in a batchjob Ive noticed that sftp needs a long time for sending a filelist. The timespan increases exponential if many files are on the remoteserver. for example "ls -la *.txt" needs 10 seconds for 2000 files but needs 50 seconds for 4000 files. For 150.000 Files i have to wait 15 minutes for example but the

Thanks Sean for the reference. I will go through it and see if i can implement it for generic boolean expression minimization. Regards, Suyog On Wed, Aug 13, 2014 at 2:30 AM, Sean Silva <chisophugis at gmail.com> wrote: > Re-adding the mailing list (remember to hit "reply all") > > > On Tue, Aug 12, 2014 at 9:36 AM, suyog sarda <sardask01 at gmail.com> wrote: