similar to: [LLVMdev] identifing mallocs with constant sizes

Ryan M. Lefever wrote: > I am writing some code to identify malloc instructions with constant > request sizes and to determine the request size if it is constant. I > have two questions. > > 1) If a malloc is for an array allocation and the array size is a > ConstantExpr, how can I obtain the value of the ConstantExpr? > The only way I know of is to determine what type

> you can't, you can only get a ConstantAggregateZero.  This is actually kind of > annoying, and means that places expecting a ConstantArray have to remember to > also check for ConstantAggregateZero.  Perhaps there's a good reason for the > current design, but if not it would be great to eliminate this wart. Well, I think the main reason it so reduce the size of .ll / .bc when

Hi Anton, >> you can't, you can only get a ConstantAggregateZero. This is actually kind of >> annoying, and means that places expecting a ConstantArray have to remember to >> also check for ConstantAggregateZero. Perhaps there's a good reason for the >> current design, but if not it would be great to eliminate this wart. > Well, I think the main reason it so

Hi all. I propose to use wrapper for this kind of constant objects. Consider next code: Constant* C = reinterpret_cast<Constant*>(I->getOperand(idx)); Constant* ArrayItem; if (!isa<ConstantAggregateZero>(C)) ArrayItem = reinterpret_cast<Constant*>(I->getOperand(ArrItemIdx)); else ArrayItem = ZeroInt; Code analog within wrapper: ConstOrZero

Hello, I noticed a bit of a gap in the current code for unions: a ConstantUnion cannot be written out to .ll. Hopefully I'm not stepping on Talin's toes by posting this, it's a fairly straightforward adaptation of the code for structs just above. Tim. -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. --------------

> On 2016-Sep-24, at 15:16, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> >> On Sep 24, 2016, at 3:06 PM, Duncan P. N. Exon Smith via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> >> r261464 added a type called ConstantData to the Value hierarchy. This >> is a parent type for constants with no operands, such as i32 0 and null. >>

r261464 added a type called ConstantData to the Value hierarchy. This is a parent type for constants with no operands, such as i32 0 and null. Since then, I've removed most instances of iterating through the use-lists of an instance of ConstantData. I'd like to make this illegal. Since the users of ConstantData are spread across an LLVMContext, most code that looks at the users is

I notice that there's a lot of inconsistency in the various LLVM classes with respect to convenience methods. Here's some examples: For creating GEPS, IRBuilder has: CreateGEP (2 overloads) CreateInBoundsGEP (2 overloads) CreateConstGEP1_32 CreateConstInBoundsGEP1_32 CreateConstGEP2_32 CreateConstInBoundsGEP2_32 CreateConstGEP1_64 CreateConstInBoundsGEP1_64

Talin wrote: > On Mon, Jan 31, 2011 at 10:57 PM, Talin <viridia at gmail.com > <mailto:viridia at gmail.com>> wrote: > > I notice that there's a lot of inconsistency in the various LLVM > classes with respect to convenience methods. Here's some examples: > > For creating GEPS, IRBuilder has: > > CreateGEP (2 overloads) >

I think our test case demonstrates that requiring the array item being initialized to be constant is incorrect. NVPTX does not crash anymore and produces correct result with the following change: --- NVPTXAsmPrinter.cpp 2012-09-03 15:14:00.000000000 +0200 +++ NVPTXAsmPrinter.cpp 2012-09-04 15:47:17.859398193 +0200 @@ -1890,17 +1890,15 @@ case Type::ArrayTyID: case Type::VectorTyID: case

On Mon, Jan 31, 2011 at 10:57 PM, Talin <viridia at gmail.com> wrote: > I notice that there's a lot of inconsistency in the various LLVM classes > with respect to convenience methods. Here's some examples: > > For creating GEPS, IRBuilder has: > > CreateGEP (2 overloads) > CreateInBoundsGEP (2 overloads) > CreateConstGEP1_32 >

Does anybody else have an opinion on this issue? I'm planning to submit a patch which would add a new get method for ConstantDataVector taking an ArrayRef<Constant*> and use that in the few places in constant propagation where convertToFloat is used. Let me know if you think there is a more obvious way to do it. Right now the only way to create a ConstantDataVector are those method:

Hi Cristianno, Thank you, it works :) with an extra cast:                                     Value *v ......                                     ConstantInt* RR = (ConstantInt *)v;                                     uint64_t VV = (RR->getValue()).getLimitedValue();                                     errs()<<"\nRR  "<<VV<<"\n";

Hi all, I have a very simple test case (thanks to bugpoint) that hit an assert in reassociate. (the assert is (C->getType()->isIntOrIntVectorTy() && "Cannot NEG a nonintegral value!"), function getNeg) The function is taking a Constant as argument, but the assert does not expect an undef. I’m not sure whose responsibility is it to handle that (caller?). Do we have to

Let me clarify my question. I have a struct array h1 as follows: dhash h1[10]; I want to get a Constant* to variable h1. It looks like I can use ConstantStruct::get(StructType*, ArrayRef<Constant *>) to do this. My question is how to get the second argument of type ArrayRef<Constant *> from the above variable h1. Thanks, Chaitra ________________________________ From: Tim Northover

I'd really rather not do this. Faking that large zero filled array is represented with ConstantArray means that the compiler will inevitably end up calling getOperand on each of those elements, burning a ton of compile time. -Chris On Jan 20, 2012, at 12:16 PM, Stepan Dyatkovskiy <STPWORLD at narod.ru> wrote: > Hi all. I propose to use wrapper for this kind of constant objects.

Hi Sanjay, Thanks, I saw this flag and it's definitely should be considered, but it appeared to me to be static characteristic of target platform. I'm not sure how appropriate it would be to change its value from a front-end. It says "Has", while optional flag would rather say "Uses" meaning that implementation cares about floating point exceptions. Regards, Sergey

On 09/04/2012 09:57 AM, Dmitry N. Mikushin wrote: > I think our test case demonstrates that requiring the array item being > initialized to be constant is incorrect. NVPTX does not crash anymore > and produces correct result with the following change: > > --- NVPTXAsmPrinter.cpp 2012-09-03 15:14:00.000000000 +0200 > +++ NVPTXAsmPrinter.cpp 2012-09-04 15:47:17.859398193 +0200 >

On 11 June 2017 at 23:03, Craig Topper <craig.topper at gmail.com> wrote: > Try value->dump() assuming you're using a debug build. > > The information displayed is non-uniform. There are two different cases based on my sample program: (1) dump() shows the Type and *some* value which I don't understand what it is (2) dump() shows the instruction that

Hello ! This may be a trivial question, but I cannot get fields from a Value type. If my Value is i32 1, how can I store 1 in a different structure (an integer) ? For the type, I have getType(). For the value, I see no method in Value.h. I tried to cast to ConstantExpr and then to get operands, or cast to ConstantDataArray and then use getAsString(), but is not working. How should I get the