search for: isclobb

...Dependency(), we find that they are both NonLocal, which makes sense. Chasing further, with MDA->getNonLocalPointerDependency(), I get a vector of basic blocks (the 1st and 2nd, as expected), along with indications that the query isUnknown. That surprised me; I had expected that it would suggest isClobber for both loads and both blocks. Am I doing something wrong? Or perhaps not chasing far enough? Or perhaps MemoryDependenceAnalysis is just not designed to solve my problem? Below is an example of the sort of code I'm writing to learn my way around. I apologize for giving people a chunk of...

...quires LLVM DeadStoreElimination However, when I look through the code in Transforms/Scalar/DeadStoreElimination.cpp, I see the following: // Ignore any store where we can't find a local dependence. // FIXME: cross-block DSE would be fun. :) if (!InstDep.isDef() && !InstDep.isClobber()) continue; I have two questions on this code:I have two questions on this code: 1. What is a clobber? 2. Does the local dependence mean that the dependence should reside in the same basic bloWhat does the comment (FIXME: cross-block DSE would be fun) mean in this case? Thanks, Tianyu C...

Hi Venu, > On Sep 11, 2017, at 11:00 PM, Raghavan, Venugopal via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi Krzysztof, > > Thanks for your reply. > > I agree that adding extra register units for x86 would be the right way to fix this. Do you know if there is a plan to fix this? No concrete plan, no. We've been thinking about for quite some time now, but

...else branch and can reach a common use node resulting > in multiple reaching defs for a use node. How is this handled? > 2) I am unable to locate the code that handles re-definition of the > same register. I though "clobber" refers to such situations but the > isClobbering() function which controls the setting of the > "Clobbering" attribute seems to mainly handle function calls and not > the re-definitions of registers through other types of instructions. > How are such re-definitions handled? > 3) My mental picture of reac...

...else branch and can reach a common use node resulting > in multiple reaching defs for a use node. How is this handled? > 2) I am unable to locate the code that handles re-definition of the > same register. I though "clobber" refers to such situations but the > isClobbering() function which controls the setting of the > "Clobbering" attribute seems to mainly handle function calls and not > the re-definitions of registers through other types of instructions. > How are such re-definitions handled? > 3) My mental picture of reac...

...     in multiple reaching defs for a use node. How is this handled? >      2) I am unable to locate the code that handles > re-definition of the >      same register. I though "clobber" refers to such > situations but the >      isClobbering() function which controls the setting of the >      "Clobbering" attribute seems to mainly handle function > calls and not >      the re-definitions of registers through other types of > instructions. >      How are such re-de...

...is this >>> handled? >>> 2) I am unable to locate the code that handles >>> re-definition of the >>> same register. I though "clobber" refers to such >>> situations but the >>> isClobbering() function which controls the setting of the >>> "Clobbering" attribute seems to mainly handle function >>> calls and not >>> the re-definitions of registers through other types of >>> instructions. >&...