similar to: [LLVMdev] !dbg metadata not generated for if.else->if.end branch

My two-address target machine has sign-extension instructions to extend i8->i32 and i16->i32. When I compile this simple program: int sext (unsigned a, unsigned b, int c) { return (signed char) a + (signed short) b + c; } I get this IR: define i32 @sext(i32 %a, i32 %b, i32 %c) nounwind readnone { entry: %conv = trunc i32 %a to i8 ; <i8>

Hello all, I'm new to the llvm community. I'm learning how things work. I noticed that there has been some interest in improving how unions are handled. Bug 21725 is one example. I figured it might be a interesting place to start. I discussed this with a couple people, and below is a suggestion on how to represent unions. I would like some comments on how this fits in with how

Hi Sanjay, > Am 02.08.2016 um 21:39 schrieb Sanjay Patel <spatel at rotateright.com>: > > Hi Matthias - > > Sorry for the delayed reply. I think you're on the right path with D22864. No problem, thank you for your answer! > If I'm understanding it correctly, my foo() example and zext_or_icmp_icmp() will be equivalent after your patch is added to InstCombine.

Hi Sanjay, thank you a lot for your answer. I understand that in your examples it is desirable that `foo` and `goo` are canonicalized to the same IR, i.e., something like `@goo`. However, I still have a few open questions, but please correct me in case I'm thinking in the wrong direction. > Am 21.07.2016 um 18:51 schrieb Sanjay Patel <spatel at rotateright.com>: > > I've

Hi Michael, >Interesting approach but how do you handle more complex offsets, e.g., when the pointer is part of an aggregate? Only one offset does not seem enough to handle generic cases. Yes, correct, this a little bit changed example is not working. #include <x86intrin.h> __m256d vsht_d4_fold(const double* ptr, unsigned long long i) { __m256d foo = (__m256d){ ptr[i], ptr[i+1],

On 09/13/2017 04:46 PM, Dinar Temirbulatov via llvm-dev wrote: > Hi Michael, >> I have a case where InstCombine removes a store and your approach would be >> valuable for me if the entire access to an aggregate could be restored. > Yes, no problem and we could add the aggregate pointer to this new > intrinsic and in my particular case I should ignore it, but I am > looking

Hi Michael, >I have a case where InstCombine removes a store and your approach would be >valuable for me if the entire access to an aggregate could be restored. Yes, no problem and we could add the aggregate pointer to this new intrinsic and in my particular case I should ignore it, but I am looking now at "speculation_marker" metadata and I am still not sure how to implement it

I was looking through the InstCombine pass, and I was wondering why signed division is not considered a valid operation to combine in the canEvaluateTruncated function. This means, given the following code: %conv = sext i16 %0 to i32 %conv1 = sext i16 %1 to i32 %div = sdiv i32 %conv, %conv1 %conv2 = trunc i32 %div to i16 * Assume %0 and %1 are registers created from simple 16-bit loads. We

Hi All, I am trying to unroll the below loop, but couldn't as SCEV returns TripCount as 0. void foo(int x) { int p, i = 1; int mat[6][6][6]; for (p = x+3 ; p<= x+6 ;p++) mat[x][p][i] = mat[x][p][i] + 5; } For a quick reference I have added the generated IR compiled with clang using -O3. Please let me know if this is an known issue in SCEV or I am missing something here ? ;

I have modified the example test case for UB error, still it didn’t unroll void foo(int x) { int p, i = 1; int mat[9][9][9]; for (p = (x+1) ; p < (x+3) ;p++) mat[x][p-1][i] = mat[x][p-1][i] + 5; } Regard, Deepali From: Kevin Choi [mailto:code.kchoi at gmail.com] Sent: Friday, September 16, 2016 1:20 PM To: Rai, Deepali Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] SCEV

Hi Hal, >Are you primarily concerned with being able to widen loads later in the pipeline? Could we attached metadata to the remaining loads indicating that it would be legal to widen them? no, I don't have any concerns about intrinsic way of implementation, and intrinsic way looks safer for me since we somehow detach our information about memory from that actual load instruction. I updated

Hi, I noticed that when dividing with signed 8-bit values the IR uses a 32-bit signed divide, however, when unsigned 8-bit values are used the IR uses an 8-bit unsigned divide. Why not use a 8-bit signed divide when using 8-bit signed values? Here is the C code and IR: char idiv8(char a, char b) { char c = a / b; return c; } define signext i8 @idiv8(i8 signext %a, i8 signext %b) nounwind

I'm investigating a miscompilation bug ( http://llvm.org/bugs/show_bug.cgi?id=19823 ), but I've run into a problem: the output of the program is different when I compile the IR with clang compared to opt | llc | clang. Any clues on how to resolve this difference? $ ./opt -O1 19823.ll | ./llc | ./clang -x assembler - -o a.out ; ./a.out ; echo $? 1 $ ./opt -O2 19823.ll | ./llc | ./clang -x

On 09/26/2017 08:31 AM, Dinar Temirbulatov wrote: > Hi Hal, >> Are you primarily concerned with being able to widen loads later in the pipeline? Could we attached metadata to the remaining loads indicating that it would be legal to widen them? > no, I don't have any concerns about intrinsic way of implementation, > and intrinsic way looks safer for me since we somehow detach our

Hello everyone, please I need your help. To reproduce my problem I created simple pass for backends (TestPass.cpp in attached files). That pass I call from Mips backend in this way (MipsTargetMachine.cpp): bool MipsPassConfig::addPreRegAlloc() { addPass(createTestPass()); return false; } The problem becomes, when I am trying compile file ldtoa.ll (in attached files). Compiling

> Then why does the Release Note say > " the operation is guaranteed to not overflow". It means that the person who wrote the IR has guaranteed that there's no overflow (by some means) so LLVM can assume it during optimisation. This guarantee might come from doing explicit checks before executing the add/sub; or perhaps from performing the operation after a sext so that the

On 2/22/11 1:31 PM, Arushi Aggarwal wrote: > Hi, > > I want to clone a given function, and add an argument to it. I then > want to add a call to that new function. I have a callInstruction CI, > which I want to transform to call this new function, and to take a new > argument. If I understand correctly, you're cloning the function first and then adding a new argument to

Hi, I want to clone a given function, and add an argument to it. I then want to add a call to that new function. I have a callInstruction CI, which I want to transform to call this new function, and to take a new argument. The code I added was as follows CI->getCalledFunction()->dump(); Function* DirectF = CloneFunction(CI->getCalledFunction());

Dear all, Hi! Recently, I notice a situation where I cannot infer the size of the outermost dimension of array in the function interface. To concretely depict the problem, I show the C source code and the generated IR code at the end. The array size of A[] is 51 but this information is lost in the generated IR. How can I maintain such information in IR? Should I set some argument for

Hi, I have the below test case. --snip-- struct st { int a; int b; }; int * ptr; int x,y; void bar(int *x); void foo() { struct st obj; bar(&obj.b); if(x) obj.a =x; else obj.a =y; for (int i=0; i<obj.a;i++) ptr[i]=i; } --snip-- LLVM IR produced at -O3 is shown below. ref: https://godbolt.org/z/WPlmfr --Snip-- %8 = getelementptr inbounds %struct.st,