similar to: Removing constants from a constant array?

As the question asks. IIRC, I have only seen constants use to: 1. setup globals 2. as "constant parameters" to instructions. In both these cases, from what I understand, they will have a single use. Is it possible to create a Constant with multiple use(r)s? Thanks, Siddharth -- Sending this from my phone, please excuse any typos! -------------- next part -------------- An HTML

Dear John, I intend to implement the improvements on DSA. After running DSA on SPEC, I found DSA gives low precision for mcf and bzip2. I have checked the most imprecise c files in mcf an found that the code seems to be a mixture of "PHI" and "GEP" instructions. Could you please give me some hints about what the big picture of the improvement should be and how to start? Thank

I'm a bit confused. For the Type did you mean something like: ArrayType *type = ArrayType::get(Type::getInt8PtrTy(M.getContext()), 4); This does not work, it gives me ""Wrong type in array element initializer" at runtime. Also it doesn't look like ConstantExpr inherits ConstantArray, so I'm not sure how I could use this instead. Thanks On Thu, Oct 20, 2011 at

Hi all, extracting datafields of globals, the API code ends up in a Constant * Constant* const_ptr_103 = ConstantExpr::getGetElementPtr(gvar_struct_foo, const_ptr_103_indices); it can be used to initialize e.g. a new instruction like: StoreInst* void_119 = new StoreInst(const_float_102, const_ptr_103, false, label_entry_113); But how about replacing the operand of an already existing

Dear all, I am trying to reproduce the "Percent May Alias" result described in PLDI 07's paper "Making Context-Sensitive Points-to Analysis with Heap Cloning Practical For The Real World" (http://llvm.org/pubs/2007-06-10-PLDI-DSA.html ). However, my "Percent May Alias" for all the benchmarks is much greater, especially "bzip2". The DSA code I use is

On 10/20/11 11:34 AM, ret val wrote: > I'm a bit confused. For the Type did you mean something like: > ArrayType *type = ArrayType::get(Type::getInt8PtrTy(M.getContext()), 4); I assume that creates an ArrayType of 4 elements whose elements are pointers to 8-bit values. If so, then this is what I meant. > This does not work, it gives me ""Wrong type in array

Hello All, We want to write a transformation pass such that the array accesses use a base register other than ebp (assuming that the code is compiled for x86 architecture). For example, The below C code ->int a[5]; ->a[2] = 2 by default, gets compiled to something like this: ->mov dword ptr [ebp - 28], eax However, we want our pass to emit the something similar to the following

hey john, yes indeed, that's what I'm trying, retreiving the values of %a and %b in an LLVM pass, sorry about the confusion. On Apr 24, 2016 7:18 AM, "John Criswell" <jtcriswel at gmail.com> wrote: > Dear Ammar, > > It is not clear what you are asking. %a and %b in your code below are not > constants; there is no way, at compile time, to determine what

I'm trying to create a ConstantArray(whose contents will be of types Function*, GlobalVariable *) so I can immediately create a new GlobalVariable(that will be in its own section). I'm doing this so I have these address stored. In order to create this ConstantArray I need a valid ArrayType, but I'm not sure what to use for the element type. I want this to be done at compile time, so I

John, you are right. I 'browsed' the doxygen's inheritance diagram. Shouldn't I then be able to cast Constant * to Value*? Plugging the retrieved Constant* (from ConstantExpr::getGetElementPtr) into Instruction->setOperand compiles, but gives me an assertion failure at runtime. I have no access to the code at the moment. I will gather more information possibly tomorrow.

Hi John, Thank you so much for the valuable answer! :) However, i have one tough issue that i need to solve, in my pass : let's say here %s = add %a, %b I need to check if the value of %a or %b is 2 or 4 and then apply a transformation to the other operand accordingly, for example if the value of %a = 2 the i'll multiply %b by 2 in my transform pass. I'm having a hard time

Thanks for the fast response John. On Thu, Oct 1, 2015, at 04:51 PM, John Criswell wrote: > Dear Ed, > > First, someone has updated the DSA code in the poolalloc project to LLVM > 3.7, and a Master's student worked for me over the summer to update a > large chunk of SAFECode to LLVM 3.7. However, the update to LLVM 3.7 > isn't finished (we need to finish integrating

On 10/20/11 10:43 AM, ret val wrote: > I'm trying to create a ConstantArray(whose contents will be of types > Function*, GlobalVariable *) so I can immediately create a new > GlobalVariable(that will be in its own section). I'm doing this so I > have these address stored. In order to create this ConstantArray I > need a valid ArrayType, but I'm not sure what to use for

Thanks John. Does this solve the problem of analysis availability though? If I still have to run the function analyses manually, I might as well keep rolling with the CallGraphSCCPass. (I probably should have mentioned that this is what I’m using right now.) Félix > Le 2015-05-19 à 10:12:32, John Criswell <jtcriswel at gmail.com> a écrit : > > On 5/18/15 10:45 PM, Félix Cloutier

Hi, All. Does anybody know about ConstantExpr in llvm? What's it? Since it always appears after llvm optimization such as -O2 level, what is it supposed to be to codegen? I am wondering it represents constant value which can be determined or computed at compile-time(actually is link-time) to improve performance. Although we do not know the actual constant value util the object file is linked.

John, Yes, I'm taking care about application as usual. On Tue, Feb 17, 2015 at 4:48 AM, Eric Christopher <echristo at gmail.com> wrote: > I believe Anton was going to do so. > > > On Mon, Feb 16, 2015, 5:14 PM John Criswell <jtcriswel at gmail.com> wrote: >> >> Dear All, >> >> Has someone registered LLVM as an organization for Google Summer of

Sir, I am interested in adding a new analysis or optimization pass and building the getting started guide as a project for gsoc. On Mon, Mar 21, 2016 at 1:29 AM, John Criswell <jtcriswel at gmail.com> wrote: > On 3/17/16 10:58 AM, Om Shivom Nagpal wrote: > > No i have not worked previously on llvm. I have looked through the > projects but because of no prior experience i am

John, thanks for your helpful advice. My ultimate goal is to construct a full instruction-level program dependence graph for a given IR file. The hard point is how to establish the correct data dependence edges when some function arguments are multi-level pointers. To solve this problem I hope to check the point-to level for each pointer variable. I think the data dependence through pointers can

Dear LLVMers, I’m investigating the response time of my JIT, and according to profiling, optimization takes 85% of the compile time, while the rest is being split evenly between the front-end and machine code generation. Much of the optimizer time is spent in various alias analysis passes. I’m happy with the generated code quality and wouldn’t like to lower the optimization level (O2). Would

Hi Simon, > From: Simone Atzeni <simone.at at gmail.com> > To: John Criswell <jtcriswel at gmail.com> > Cc: llvmdev at cs.uiuc.edu > Subject: Re: [LLVMdev] Walking thru CallGraph bottom up > Message-ID: <318EBA41-2040-4EFE-B330-5813C817C2A2 at gmail.com> > Content-Type: text/plain; charset="windows-1252" > > I think I got it and the example is