similar to: [LLVMdev] Memory Dependence Analysis

I used LLVM already existent passes with no problems till I tried to use MemDepPrinter.cpp : http://llvm.org/doxygen/MemDepPrinter_8cpp_source.html. I got the following segfault: llvm[0]: Compiling MyMemDepPrinter.cpp for Release+Asserts build (PIC) llvm[0]: Linking Release+Asserts Loadable Module MyMemDepPrinter.so WARNING: You're attempting to print out a bitcode file. This

Hello! I am trying to retrieve all instructions from a function's body that are dependent on a specific argument. The strategy I am currently using for that is to follow all uses of the argument and record them. Also, whenever I encounter a store of a dependent value, I try to find loads in the function that are dependent on that store and resume use-tracking from there. For this purpose I am

On Sep 2, 2009, at 1:07 AM, Jakub Staszak wrote: > Hello, > > I fixed my patch as you asked. Sorry for the delay, I'd been working > on my SSU patch (http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-August/025347.html > ) > > I hope that everything is fine now. Hey Jakub, Thanks for working on this again, one more round :) Please merge the three testcases into one

On Sep 2, 2009, at 3:15 PM, Chris Lattner wrote: > Please merge the three testcases into one file. We added a new > FileCheck tool which allows you to check for the exact sequence of > instructions expected, which also allows the tests to be merged into > one file. > > +/// MemCpyOpt::pointerIsParameter - returns true iff pointer is a > parameter of > +/// C call

On Jul 22, 2009, at 1:37 PM, Jakub Staszak wrote: > Hello, > > This patch fixes PR2218. Very nice. Are you sure this fixes PR2218? The example there doesn't have any loads in it. > However, I'm not pretty sure that this optimization should be in > MemCpyOpt. I think that GVN is good place as well. Yes, you're right. My long term goal is to merge the relevant

Introduction ============ I'm currently in the middle of what initially looked to be a simple change in GVN but is turning out to have unexpected consequences that are turning out to be quite difficult to resolve, so I thought I'd send out an RFC to make sure that I'm not barking up the wrong tree with how I'm trying to do this. Motivation and current behaviour

Hello, A recent series of commits, ending with r169304 and relating to PR13303, add is_stmt to line entries for functions. This appears to be to work around problems with gdb. However, I observe is_stmt is not always applied to line entries for functions. This may only affect the arm backend. Compiling the same code with the aarch64 backend does not demonstrate this problem. It seems that

Hi, I'm having a problem with GVN removing a load instruction that I think is needed. Dump before GVN: *** IR Dump Before Global Value Numbering *** ; Function Attrs: minsize optsize define i16 @TEST__MAIN(i16 %argc.13.par, i16** %argv.14.par) #0 { %buf.17 = alloca [10 x i16], align 1 %_tmp30 = getelementptr inbounds [10 x i16], [10 x i16]* %buf.17, i16 0, i16 0, !dbg !22 call

I have a set of changes that enhances rematerialization to handle more kinds of loads, specifically loads with multiple address registers. This is a big win for some codes on x86. I plan to send these up ASAP but I want to solicit a bit of guidance first. The change requires that live interval analysis be able to determine whether and instruction is a load and whether an instruction writes to

Sorry, I misunderstood the question. The difference between a load and a read-only call is that load can be used as the value of the memory location. E.g. DeadStoreElimination pass removes a store that stores a just loaded value back into the same location. To do this it checks if the stored value is the value of load. Read-only call cannot be used like this. This being said, I don't know if

Since isLoad == false means we're looking at a store, what this does is making the store *p depend on the load *p. This is correct -- you can't move store before load, otherwise load will start returning a different value. Eugene On Fri, Jul 16, 2010 at 5:43 PM, Marc de Kruijf <dekruijf at cs.wisc.edu> wrote: > Hello, > > I'm taking a really good look at the

Hello, Sorry for my stupid mistakes. I hope that everything is fine now. This patch fixes PR2218. There are no loads in example, however "instcombine" changes memcpy() into store/load. Regards, Jakub Staszak -------------- next part -------------- A non-text attachment was scrubbed... Name: pr2218-2.patch Type: application/octet-stream Size: 6525 bytes Desc: not available URL:

Yes, I'm not arguing that there is a dependence, just that it's not a clobber dependence. The case of a load is already considered earlier in that function and with isLoad == false it returns MemDepResult::getDef(). My question is: why should a read-only call (which yields AliasAnalysis::Ref and is handled in this code fragment) be any different from e.g. a load. Isn't a read-only

In the MemoryDependenceAnalysis::getNonLocalPointerDependency overload that takes a pointer value, it is currently creating an AliasAnalysis::Location from just the pointer, which pessimistically assumes unknown size. I added code to use AliasAnalysis::getTypeStoreSize to create an AliasAnalysis::Location with a more accurate size (when target data is available) and ran it through the nightly

On Apr 13, 2009, at 12:01 PM, Anthony Danalis wrote: > I'm attaching the .bc file. Note that my analysis pass is invoked > after "-O1" and that's why the IR I included in the original email > is optimized. Hi Anthony, Sorry for the delay, things have been crazy lately. The MemDep API assumes that you will call getDependency() first, and then only call

Hi all, I am working on a project that requires 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

On Apr 25, 2009, at 5:05 PM, Chris Lattner wrote: > > On Apr 13, 2009, at 12:01 PM, Anthony Danalis wrote: > >> I'm attaching the .bc file. Note that my analysis pass is invoked >> after "-O1" and that's why the IR I included in the original email >> is optimized. > > Hi Anthony, > > Sorry for the delay, things have been crazy lately. >

Hello, I have a code similar to the following: program test integer i, j, N real B(10) call bar(N, 8) N = N+1 do i = 1, N B(i) = (i+5)/(i+3) enddo j = N/2 N = N+7 call IMPORTANT_F(B, N, i, j) end program and I am trying to use dependence

Hi, For my project, I am using internal llvm class functions to print the filename and directory associated with an instruction from the debug information. With a recent checkout of llvm and clang (svn revision 129445), the following custom code (e.g. in a pass that prints directory info for all instructions) returns the filename iso. directory whenever Scope refers to a lexical block: if (const

Based on function names and structures, this is some version of GCC :) Any way you can post the entire .ll file? Because it's globalsmodref, it's hard to debug without the other functions, since it goes over all the functions to determine address takenness, etc :) On Tue, Jul 21, 2015 at 3:23 PM, Michael Zolotukhin <mzolotukhin at apple.com> wrote: > Hi Chandler, > > We