similar to: [LLVMdev] PR9112

Hi, I was playing with the Constant::getAllOnesValue() method and found that it doesn't handlesPointerTypes correctly. When receiving a "i32*" argument, it was returning with some big integer vector, such as <12113216 x i32>. When you call this method passing a PointerType, the following code is executed: 00152 VectorType *VTy = cast<VectorType>(Ty);00153 return

I found a bug in the expansion code for SUB going back to at least LLVM 2.6 and still shows up in trunk. case ISD::SUB: { EVT VT = Node->getValueType(0); assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) && TLI.isOperationLegalOrCustom(ISD::XOR, VT) && "Don't know how to expand this subtraction!"); Tmp1 = DAG.getNode(ISD::XOR, dl,

Hi all, Hi Eli, No, that appears to be something unrelated. I'm currently using revision 75246, while that patch only seems to apply to some later revision. Anyway, I actually located the real bug. Right at the end of InstCombiner::SimplifyDemandedUseBits, there's this piece of code: // If the client is only demanding bits that we know, return the known // constant. if

On Thu, Jul 30, 2009 at 5:57 AM, Nicolas Capens<nicolas at capens.net> wrote: > No, that appears to be something unrelated. I'm currently using revision > 75246, while that patch only seems to apply to some later revision. I don't see the connection... anyway, I can't easily help you with an old revision. > Anyway, I actually located the real bug. Right at the end of

On May 21, 2012, at 11:21 AM, Villmow, Micah wrote: > I found a bug in the expansion code for SUB going back to at least LLVM 2.6 and still shows up in trunk. > case ISD::SUB: { > EVT VT = Node->getValueType(0); > assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) && > TLI.isOperationLegalOrCustom(ISD::XOR, VT) && > "Don't

I'm trying to reason about how to find certain bit positions of the absolute value of a given integer value. Specifically, I want to know the highest possibly set bit and lowest possibly set bit of the absolute value, in order to find the range between the two. Note that I'm specifically trying to be as conservative as possible. This is what I have so far: If the sign bit of the

I think I understood the problem you're trying to solve. I didn't, however, understand the problems you are having (maybe you're not running mem2reg?). I do have a little piece of code that I think does (more or less) what you want. Take a look at it, try understanding it, and see if it helps you out. You might have to change it a bit since you're replacing uses after an

Hi all, I have encountered the following instruction: %.0.i = phi i8* [ %9, %8 ], [ %11, %10 ] How can I get the %8 and %10? I'm using http://llvm.org/doxygen/classllvm_1_1PHINode.html as a reference but I cannot understand how to do that. Thanks -------------- next part -------------- An HTML attachment was scrubbed... URL:

Thanks for the reply. For the source code: int main() { int a = 0; int *p; p = &a; call_arnamoy(p); int *p1; p1 = p; return 1; } The bit code: %retval = alloca i32, align 4 %a = alloca i32, align 4 %p = alloca i32*, align 8 %p1 = alloca i32*, align 8 store i32 0, i32* %retval store i32 0, i32* %a, align 4 store i32* %a, i32** %p, align 8 %0 = load i32** %p, align 8 %call = call i32

The enlosed patch for IndVarSimplify.cpp works even when the pointer increment is deeply nested wrt pointer initialization, but note that it needs to have loop structures preserved, as in the following: int A[3000000], B[20000], C[100], Z; volatile int I, J, K; int main() { int i, j, k, *a, *b, *c; for ( a = &A[0], i = 0; i != 300; i++ ) { I++;

Hi folks, Hope this is not a silly question. But it bothers me when I am thinking about it. My question is: 1. In the implementation of serverSplitPHINodes(), why it only checks the first PHI node for possible multiple inputs from outside the region to extract. There could be more than one PHI nodes in the header block, and the code only checks the first one. I don't quite get it.

Hi, On Mon, May 1, 2017 at 8:47 AM, Daniel Berlin via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> Today, the IR requires that if you have multiple edges from A to B >> (typically with a switch) any phi nodes in B must have an equal number of >> entries for A, but that all of them must have the same value. > >> This seems rather annoying.... >> 1) It

Hello all; So here is my goal: *** If there is a Call instruction to myFunction(int * val), I need to identify all the instructions that uses val in the IR and replace the uses with a newly created pointer. I will also be changing the argument of myFunction to the new pointer. int * val = malloc/calloc; ... myFunction(val); .... *val = 45; becomes== int * val = malloc/calloc; int * val1 =

Can someone explain what this function is supposed to do? I've looked at PowerPC, Sparc, etc.. and can't really figure out what I should be doing here. Thanks, Micah Villmow Systems Engineer Advanced Technology & Performance Advanced Micro Devices Inc. 4555 Great America Pkwy, Santa Clara, CA. 95054 P: 408-572-6219 F: 408-572-6596 -------------- next part

On Wed, Jul 29, 2009 at 3:45 AM, Nicolas Capens<nicolas at capens.net> wrote: > So could anyone who knows the ins and outs of this code have a look at how > to make it handle vectors correctly? Or if that’s not an option right now, > please revert the broken optimizations. Note that there might be more things > affected than visitAnd, visitOr and vistXor, I’ve only been able to

Am Di., 17. März 2020 um 16:56 Uhr schrieb Chawla, Pankaj via llvm-dev <llvm-dev at lists.llvm.org>: > All I am expecting from DA is a direction vector containing (*). There seems to be a bug in DI, see Felipe's answer. > I think the main problem is that currently there is no exact way DA can query AliasAnalysis in a ‘conservatively correct’ manner. > > Using UnknownSize

Hi All, I found a regression which triggers the asserts: "Binary operator types must match!" and "Op types should be identical!". It's happening with a piece of vector code, and the asserts happen because a logic operation is attempted between a vector and a scalar (which is not present in the original code, but created by InstCombine). It's caused by revision

On 06/11/2018 02:33 PM, Friedman, Eli via llvm-dev wrote: > On 6/11/2018 10:06 AM, jingu at codeplay.com via llvm-dev wrote: >> Hello All, >> >> I have met one may-alias case from llvm's alias analysis. The code >> snippet is as following: >> >> char buf[4]; >> >> void test (int idx) { >> char *a = &buf[3 - idx]; >> char *b =

Hi all, I was trying to implement an obfuscation tool for C-code on the basis of LLVM. I got a prototype of the simple obfuscation transformation which converting control flow graph to something like a state machine. I am not sure I will have time to work on extending further this tool with new transformations like opaque predicates and decided to put here source code I have by now with hope

On Wed, May 20, 2009 at 5:26 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Wed, May 20, 2009 at 4:55 PM, Dan Gohman <gohman at apple.com> wrote: >> Can you explain why you chose the approach of using a new pass? >> I pictured removing LegalizeDAG's type legalization code would >> mostly consist of finding all the places that use TLI.getTypeAction