search for: lsrinstance

Hi Geoff, Firstly, I think it will be great if you have a small reproducer of this issue (which I can make fail after re-applying D18001 to ToT). > I’ve run into what appears to be a bug in ScalarEvolution, but I’m not sure > if it is instead caused by me missing an implicit assumption between LSR and > SCEV. > > This issue is caused by the change D18001, which is an attempt to

Hi All, I've run into what appears to be a bug in ScalarEvolution, but I'm not sure if it is instead caused by me missing an implicit assumption between LSR and SCEV. This issue is caused by the change D18001 <http://reviews.llvm.org/D18001> , which is an attempt to increase SCEV-inserted instruction re-use by picking a more canonical insertion position in the case where a new

...shl()). Another way that I can think of, is to keep ashr32(shl32()) together and then it's possible to replace both instructions with one asm instruction (a la "move %eax, %rax") and avoid an additional register for monitoring end of loop. I'm not sure what is the right point in LSRInstance::LSRInstance to avoid this optimization. Do you think that the first way is ok? If you think that this should be done in the second way or a third way I will appreciate your guidance. Thanks, Anat The IR after LSR: define void @ArrayAdd1(float* nocapture %a, float* nocapture %b, float*...

Hi Tim, Thank you for your reply. It actually helped a lot to narrow the issue, as previously I didn’t even know where to look. I have been following the code in the debugger, specially the LSRInstance::SolveRecurse function. This function traverses recursively all possible ‘Formulae’, and determines the best instruction combination for the loop generation, based on minimal cost. The SolveRecurse function uses Cost::RateFormula as the basis for the cost computation. I found that the RateFormula...

That source file was removed from LLVM in r232397 on March 16, 2015. It looks like lljvm hasn't been updated in a long time. LLVM's C++ APIs are not stable, so there is no expectation that a project built against LLVM's C++ API in 2015 would build or reasonably function against LLVM trunk. The project probably works against LLVM 3.6.2 which was (I believe) the last LLVM release to

I come across a situation that I am having a hard time to understand. When I compile the following code : char *tst( char *dest, const char *src, unsigned int len ) { for (int i=0 ; i<len ; i++) { dest[i] = src[i]; } return dest; } Clang generates this for the ‘for’ body: for.body: ; preds = %for.cond %arrayidx = getelementptr inbounds i8,