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Hi, I have a question about ConstantRange::sub(const ConstantRange &Other) at lib/Support/ConstantRange.cpp:524. The code computes the new bounds as follows. APInt NewLower = getLower() - Other.getLower(); APInt NewUpper = getUpper() - Other.getUpper() + 1; Could someone explain this to me? I was expecting something like APInt NewLower = getLower() - Other.getUpper() + 1; APInt

Hmmm... why? Duncan Sands wrote: > Hi Stepan, > >> Well... each case is represented as pair<BB, vector<Range> >. Right? > > after thinking about this some more I think you are right to not use > ConstantRange, and instead to build your own set abstraction. > > Ciao, Duncan. > _______________________________________________ > LLVM Developers mailing

Hi Stepan, > Hmmm... why? because you basically want pairs (set, destination) where set could be a arbitrary set of integers. As in practice these sets are a union of a small number of intervals, the set abstraction should efficiently represent unions of intervals, but that's more of an optimization than anything else. Probably for the needs of switch lowering you will need to expose the

...;  unionWith result is differs from set union, since it produces single set always >>  while set operations may produce two sets. > > this is true, but that's inevitable if the result is to be a single > ConstantRange.  You can of course define methods that returns a pair > of ConstantRanges and does what you want.  But why do you need these > methods anyway?  A "switch" is just going to be a (probably ordered) > list of disjoint ranges.  Where do set operations come in? > > Ciao, Duncan. > >>  E.g.: >>  For ranges >>  [1, 5) and [10,15) >&...

Hi, Duncan. unionWith result is differs from set union, since it produces single set always while set operations may produce two sets. E.g.: For ranges [1, 5) and [10,15) unionWith produces [1,15), while set union should just keep these sets without changing, probably with indication that sets are not intersected. Implementation of set union is simple though. The "symmetric

Sure. I will submit a patch. BTW, what's the difference between the bounds I was expecting APInt NewLower = getLower() - Other.getUpper() + 1; APInt NewUpper = getUpper() - Other.getLower(); and the two you mentioned NewLower = Lower - (Upper-1) NewUpper = (Upper-1) - Lower + 1 They look equivalent to me. Did I miss anything? Thanks. - xi On Jun 22, 2011, at 2:39 PM, Nick Lewycky

Thanks, I think you've found a serious bug! Would you be willing to fix it? Please add a test to unittests/Support/ConstantRangeTest.cpp and then mail llvm-commits with the patch to fix it and add the test. On 20 June 2011 23:09, Xi Wang <xi.wang at gmail.com> wrote: > Hi, > > I have a question about ConstantRange::sub(const ConstantRange &Other) at >

Hi Stepan, > unionWith result is differs from set union, since it produces single set always > while set operations may produce two sets. this is true, but that's inevitable if the result is to be a single ConstantRange. You can of course define methods that returns a pair of ConstantRanges and does what you want. But why do you need these methods anyway? A "switch" is just going to be a (probably ordered) list of disjoint ranges. Where do set operations come in? Ciao, Duncan. > > E.g.: > For ranges > [1, 5) and [10,15) > unionWith produces [1,15), while...

On 22 June 2011 12:51, Xi Wang <xi.wang at gmail.com> wrote: > Sure. I will submit a patch. > > BTW, what's the difference between the bounds I was expecting > > APInt NewLower = getLower() - Other.getUpper() + 1; > APInt NewUpper = getUpper() - Other.getLower(); > > and the two you mentioned > > NewLower = Lower - (Upper-1) > NewUpper = (Upper-1) -

Hi Duncan. I have strange problems with you mailbox, my posts are lost sometimes on this way. I just want to duplicate answer on your question in this thread: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120305/138785.html ConstantRange has a little bit another purposes. It is not a classical range. Yes it has Lower and Upper, but "sub" and "add" operations

Hello. This question has come up in https://reviews.llvm.org/D70043 There, i'm teaching ConstantRange how no-wrap flags affect the range of `mul` instruction, with end goal of exploiting this in LVI/CVP. There are certain combinations of ranges and no-wrap flags that result in always-overflowing `mul`. For example, `mul nuw nsw i4 [2,0), [4,0)` always overflows:

Hi Stepan, > Hi Duncan. I have strange problems with you mailbox, my posts are lost sometimes on this way. OK, sorry about that. Do you have any details? > I just want to duplicate answer on your question in this thread: > http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120305/138785.html > > ConstantRange has a little bit another purposes. It is not a classical

Hi Stepan, > Well... each case is represented as pair<BB, vector<Range> >. Right? after thinking about this some more I think you are right to not use ConstantRange, and instead to build your own set abstraction. Ciao, Duncan.

I've addressed a "TODO" in ConstantRange and several in its unit test by implementing a stricter "multiply" method (it had been returning a "full" set for anything that wasn't "empty", which broader than necessary) and updated the unit test to match, but I'm not completely confident that I understand ConstantRange and APInt and was hoping someone

On Mon, Jul 24, 2017 at 2:29 PM, John Regehr via llvm-dev < llvm-dev at lists.llvm.org> wrote: > On 7/24/17 3:16 PM, Hongbin Zheng via llvm-dev wrote: > >> Thanks, maybe we could use ScalarEvolution in LazyValueInfo if it is >> available? >> > > This should be fairly easy to try, if you want to propose a patch and run > some experiments. The question is

On Jul 10, 2009, at 2:03 PM, Ryan Flynn <parseerror at gmail.com> wrote: > I've addressed a "TODO" in ConstantRange and several in its unit test > by implementing a stricter "multiply" method (it had been returning a > "full" set for anything that wasn't "empty", which broader than > necessary) > and updated the unit test to

Hi, Both LazyValueInfo and ScalarEvolution can calculate a constant range for an LLVM Value. I found that some times they do not agree, may be I interpreted them incorrectly For example in the following IR: bb85: ; preds = %bb85, %bb73 %tmp86 = phi i32 [ 1, %bb73 ], [ %tmp95, %bb85 ] %tmp95 = add nsw i32 %tmp86, 1 %tmp96 = icmp slt i32 %tmp95,

On Fri, Jul 10, 2009 at 8:35 PM, Dan Gohman<gohman at apple.com> wrote: > > > On Jul 10, 2009, at 2:03 PM, Ryan Flynn <parseerror at gmail.com> wrote: > >> I've addressed a "TODO" in ConstantRange and several in its unit test >> by implementing a stricter "multiply" method (it had been returning a >> "full" set for

Hello, I currently write my own LLVM (function) pass and intend to use the following project to enable the use of range analysis information in my code: https://code.google.com/p/range-analysis/. Since I use Eclipse (with CMake) to build LLVM I did the following: 1. Provide each subfolder with a CMakeLists.txt (add_llvm_loadable_module). 2. Re-create the CMake config (cmake ../llvm -G

dw <dw.dev.mailing at gmail.com> writes: [snip] > Everything compiles fine, but loading the pass in LLVM gives me the > following error: > >> /opt/llvm/bin/opt: symbol lookup error: ./build/lib/RangeAnalysis.so: undefined symbol: _ZN4llvm13ConstantRangeC1ENS_5APIntES1_ >> error: unable to interface with target machine > > I use LLVM 3.4svn on Ubuntu x64. >