similar to: [LLVMdev] Weak store / Memory hints

On Fri, Dec 2, 2011 at 11:56 AM, Carl-Philip Hänsch <cphaensch at googlemail.com> wrote: > While trying to find a solution for this bug > http://llvm.org/bugs/show_bug.cgi?id=11235 , > I came to the conclusion that the following things can happen while > optimizing: >  - after gvn, I get new constants which are inserted into br and > add/sum/..., so there should be at least

While trying to find a solution for this bug http://llvm.org/bugs/show_bug.cgi?id=11235 , I came to the conclusion that the following things can happen while optimizing: - after gvn, I get new constants which are inserted into br and add/sum/..., so there should be at least one more jump-threading and/or instsimplify - after instsimplify, I get new constants which are inserted into br, so there

Might have to do with GVN's PRE (partial redundancy elimination), which tends to increase code size. H. ----- Original Message ----- From: Abhinash Jain Sent: 09/22/13 01:17 AM To: llvmdev at cs.uiuc.edu Subject: [LLVMdev] Why total number of store instructions increased in case of gvn with reg2mem? Below are the 4 cases out of which for the first 3 cases am able to understand the variation

Hi, i have the following code: define internal %"struct.dexter::ConditionConstant"* @_ZN6dexter18BinaryConditionAdd8evaluateEv5(%"class.dexter::BinaryConditionAdd"*) { entry: %1 = getelementptr inbounds %"class.dexter::BinaryConditionAdd"* %0, i32 0, i32 0, i32 1 %2 = load %"class.dexter::BaseCondition"** %1, align 8 %3 = bitcast

On Dec 2, 2011, at 11:56 AM, Carl-Philip Hänsch wrote: > While trying to find a solution for this bug http://llvm.org/bugs/show_bug.cgi?id=11235 , > I came to the conclusion that the following things can happen while optimizing: > - after gvn, I get new constants which are inserted into br and add/sum/..., so there should be at least one more jump-threading and/or instsimplify > -

Below are the 4 cases out of which for the first 3 cases am able to understand the variation on total number of store inst. But when -gvn parameters is passed (in case 4) , why does the total number of strore Instruction present on the attached file increases (instead of decrease). Please explain considering that use of -reg2mem pass is mandatory. eg. clang -emit-llvm bzip.c -c -o bzip1.bc

Hello. I experience a problem when I try to run LLVM tests on the ARM "Beagle" board with Debian Lenny installed on it. When I execute "make check", I get the following output: llvm[0]: Running test suite make[1]: Entering directory `/mnt/markhor/llvm/nativeBuild/test' Making a new site.exp file... ( ulimit -t 600 ; ulimit -d 512000 ; ulimit -m 512000 ; ulimit -v 512000

Hello. I experience a problem when I try to run LLVM tests on the ARM "Beagle" board with Debian Lenny installed on it. When I execute "make check", I get the following output: llvm[0]: Running test suite make[1]: Entering directory `/mnt/markhor/llvm/nativeBuild/test' Making a new site.exp file... ( ulimit -t 600 ; ulimit -d 512000 ; ulimit -m 512000 ; ulimit -v 512000

When you say that distribution shouldn't be used, do you mean within instcombine rather than some other pass? Or not all as an IR optimization? A dedicated optimization pass that looks for and makes factoring/distribution folds to eliminate instructions seems like it would solve the problems that I'm seeing. Ie, I'm leaning towards the proposal here: https://reviews.llvm.org/D41574

Hi all, One area where LLVM suck pretty badly is aggregate store and loads. clang do not use them so there are not seen as important, and aren't handled nicely. Other frontends work around the issue as it is not handled properly and we ends up with some kind of chicken and egg issue. I recently proposed a diff to be able to optimize load from aggregate stores in GVN without great success.

Hi, I have a scenario, roughly like this: if (...) { ... = *x *x = 0 } else { ... = *x *x = 0 } The two sides are functionally different, but both load some value and then set it to 0. After GVN Hoist, I get: *x = 0 if (...) { ... = *x } else { ... = *x } That is, the store was hoisted above the loads. The code is not exactly public, so I

I tried bu clang seems to support only target on which it has been compiled. If I use: with clang -S -emit-llvm t.c -o t.ll I've got following file for t.ll ; ModuleID = 't.c' target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" target triple =

If you run with -vectorize instead of -bb-vectorize it will schedule the cleanup passes for you. -Hal Sent from my Verizon Wireless Droid -----Original message----- From: "Carl-Philip Hänsch" <cphaensch at googlemail.com> To: Hal Finkel <hfinkel at anl.gov> Cc: llvmdev at cs.uiuc.edu Sent: Tue, Feb 14, 2012 16:10:28 GMT+00:00 Subject: Re: [LLVMdev] Vectorization: Next

Depending on the situation, you either want to use mem2reg or GVN. Sent from my iPhone On Aug 13, 2013, at 1:02 AM, "Li Bin" <richardustc at gmail.com<mailto:richardustc at gmail.com>> wrote: Hi, We are writing a binary translator with LLVM. There are a lot of duplicated load/store IR instruction generated by our binary translator. Is there any kind of optimization

Hi all, I have few sites which interconnected using a dedicated link. During these few weeks I've found that there are some mysterious traffic pass over my router with constant amount of bandwidth all over the time. I can know this because after working hours, only few applications are running and it did not generate this kind of traffic. Anyone can advice how to detect what kind of

----- Original Message ----- > From: "Daniel Berlin via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Amos Robinson" <amos.robinson at gmail.com> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org> > Sent: Tuesday, May 3, 2016 7:39:54 PM > Subject: Re: [llvm-dev] GVN pass: does global value numbering remove > duplicate computations in

PropagateEquality in gvn.cpp However, if you are going to do it, remember the goal is to make the code simpler and easier, not just pile on to the current mess to catch more cases :) On Mon, Jul 4, 2016, 7:51 AM Carlos Liam <carlos at aarzee.me> wrote: > Where would I look to change the equality propagation? > > > - CL > > On Jun 30, 2016, at 11:45 PM, Daniel Berlin

Hi, we have set up a small project in a school the following way: SITE_A(4 port analog to ip g729)------ADSL_ISP1-------ISP2--------Asterisk-----PSTN Site A has 1 Megabit of bandwith (up 512kilobit down 1 megabit) The asterisk box gets internet service via a wireless antenna. 1 Mbit of up/down bandwith Comments: So far, this means that I will need licenses for the 729. asterisk only supports 20ms

Hello, I was hoping to get some clarification on the aim of the GVN pass. I have been reading a bit about global value numbering, and from what I understand, there are polynomial time algorithms for removing duplicate computations from loops[1]. I have an example program[2] which computes the sum of an array twice, in two separate accumulators. Here, sum0 and sum1 are both sums of the array A.

It's going to be really hard to do something sane in the current infrastructure. Its possible, but it would also be slow. You would have to go looking at uses of variables compared in predicates in PropagateEquality and if the uses appear in a comparison that is dominated by the true or false edge of the existing predicate, see if it tells you something about the dominated one. On Mon, Jul