similar to: [LLVMdev] MemoryDependenceAnalysis Bug or Feature?

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

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

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

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

How can extract memory dependence among of instructions. I used the following code but it find only one dep for a instruction.I want to get all dependences for an instruction. MemoryDependenceAnalysis &mda = getAnalysis<MemoryDependenceAnalysis>(); MemDepResult mdr = mda.getDependency(inst); if (mdr.isDef()) { Instruction *dep =

Howdy, I'm working on writing a dependence analyzer (rather like what LoopDependenceAnalysis wants to be, except a bit more general). While this is a problem of many parts, I'm currently focusing on finding pairs of memory references to test for dependence. Consider this contrived C code: double test2(int n, double *restrict A, double *restrict B, bool flag) { if (flag) { A[0] =

Updated testcases to have MayAlias/note issues as FIXME. On Tue Jan 20 2015 at 3:54:10 PM Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "Daniel Berlin" <dberlin at dberlin.org> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "Jiangning Liu" <Jiangning.Liu at arm.com>, "George

Hello everyone ! I am trying to determine for certain Load instructions from my pass their corresponding Alloca instructions (that can be in other previous blocks). The chain can be something like : `TargetLoad(var) -> other stores/loads that use var (or dependencies on var) -> alloca(var).` , linked on several basic blocks. Do you know how can I do it? I tried to use the methods from

On Wed Jan 21 2015 at 12:30:50 PM Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "Daniel Berlin" <dberlin at dberlin.org> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "Jiangning Liu" <Jiangning.Liu at arm.com>, "George Burgess IV" < > george.burgess.iv at gmail.com>,

> Should we be added an edge from the inttoptr to all other pointer values? Is there a better way? We can add a special "Unknown" StratifiedAttr and query it before anything else, i.e: // in CFLAliasAnalysis::query, as the first potential return if (AttrsA[AttrUnknown] || AttrsB[AttrUnknown]) return MayAlias; The only *potential* issue with this approach would be that in the

Hello everyone ! I am trying to get the dependencies for the variables of ICMP instructions. Do you know if I can use an already existing method? I tried to use getDependency() method of class MemoryDependenceAnalysis. Does it work only for particular instruction types? Its definition is MemDepResult MemoryDependenceAnalysis::getDependency ( Instruction * QueryInst ) When I running my pass

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

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 Fri, Jul 17, 2015 at 9:13 AM Evgeny Astigeevich < evgeny.astigeevich at arm.com> wrote: > It’s Dhrystone. > Dhrystone has historically not been a good indicator of real-world performance fluctuations, especially at this small of a shift. I'd like to see if we see any fluctuation on larger and more realistic application benchmarks. One advantage of the flag being set is that we

Unfortuantely we don't know if a particular load is a real 2d image (as would be a cube face or 2d array element), or a layer of a 3d image. Since we pass in the TIC reference, the instruction's type has to match what's in the TIC (experimentally). In order to properly support bindless images, this also can't be done by looking at the current bindings and generating appropriate

Works for me On Thu, Jan 22, 2015 at 8:27 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > We should use graph edges, so we can do something better at set build time > :) > > > On Thu Jan 22 2015 at 5:20:46 PM George Burgess IV < > george.burgess.iv at gmail.com> wrote: > >> > Should we be added an edge from the inttoptr to all other pointer >>

So, I can make all these testcases work, but it's a little tricky (it involves tracking some things, like GEP byte range, and then checking bases and using getObjectSize, much like BasicAA does). Because i really don't want to put that much "not well tested" code in a bugfix, and honestly, i'm not sure we will catch any cases here that BasicAA does not, i've attached a

Split the source immediate value into two new values and create OP_MOV instructions the two newly created values. Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de> --- .../drivers/nouveau/codegen/nv50_ir_peephole.cpp | 23 ++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp

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

Retrieving the high 32 bits of a signed multiply is rather annoying. It appears that the simplest way to do this is to compute the absolute value of the arguments, and perform a u32 x u32 -> u64 operation. If the arguments' signs differ, then negate the result. Since there is no u64 support in the cvt instruction, we have the perform the 2's complement negation "by hand".