similar to: Disabling select instructions

I agree with John; also, if you decide to go this route, you can reuse the code from CodeGenPrepare::optimizeSelectInst: https://github.com/llvm/llvm-project/blob/master/llvm/lib/CodeGen/CodeGenPrepare.cpp#L6065 Alexey On Thu, Jan 30, 2020 at 9:00 PM John Regehr via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Several different passes introduce select instructions, such as >

Hello all, There is a missing vectorization opportunity issue with clang 4.0 with the file attached. Indeed, when compiled with -O2, the "op_distance" function get vectorized, but not the "op" one. For information, this test case has been reduced from a file generated by the Pythran compiler (https://github.com/serge-sans-paille/pythran). If we take a look at the generated

Hi, I am observing a strange behaviour in which Clang ignores __restirct when I include some standard headers. For example, this code: void vec_add(int* __restrict a, int* __restrict b, int n) { #pragma unroll 4 for(int i=0; i<n; ++i) { a[i] += b[i]; } } results in: ; Function Attrs: nofree norecurse nounwind define dso_local void @_Z7vec_addPiS_i(i32*

Hi, I noticed an inconsistency in how ScalarEvolution orders instruction operands. This inconsistency can result in creation of separate (%a * %b) and (%b * %a) SCEVs as demonstrated by the example IR below (attached as gep-phi.ll)- target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128" define void @foo(i8* nocapture %arr, i32 %n, i32* %A, i32* %B) local_unnamed_addr {

On 07/04/2013 01:39 PM, Stéphane Letz wrote: > Hi, > > Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some

Hi, Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some informations that are needed by the vectorization passes to

Dear LLVM, Consider two loops with one interation - First with constant lower bound, second with usual non-constant lower bound: int main(int argc, char ** argv) { int numOfIterations= 1; int stride=1; int lowerBound = 1000; - 1st | int lowerBound = argc; - 2nd int upperBound = lowerBound + (numOfIterations - 1)*stride; int i = lowerBound;

I'd missed the fact that j wasn't just being decremented. This isn't as easy as I said. Philip On 03/03/2016 02:36 PM, Philip Reames via llvm-dev wrote: > SCEV should be able to easily prove that j is positive here. I'm not > sure where the right place to use that information would be in this > case. Sanjoy, can you comment? > > Philip > > On 03/03/2016

On Mon, Feb 27, 2012 at 9:30 AM, Benjamin Kramer <benny.kra at googlemail.com> wrote: > > On 27.02.2012, at 17:13, Николай Лихогруд wrote: > >> Dear LLVM, >> >>     Consider two loops with one interation - >>     First with constant lower bound, second with usual non-constant lower bound: >> >>     int main(int argc, char ** argv) >>     {

Hello all, I just noticed that LLVM has trouble recognizing nested simple select operations. My testcase is as follows: -------------------------- snip ------------------------------ #include <stdio.h> int main(int argc, char **argv) { int a; scanf("%d", &a); a = a > 255 ? 255 : a < 0 ? 0 : a; printf("A: %d\n", a); return 0; }

Hi all, I have investigated the 6X extra compile-time overhead when Polly compiles the simple nestedloop benchmark in LLVM-testsuite. (http://188.40.87.11:8000/db_default/v4/nts/31?compare_to=28&baseline=28). Preliminary results show that such compile-time overhead is resulted by the complicated polly-dependence analysis. However, the key seems to be the polly-prepare pass, which introduces

Hi, I compiled the following code on a Sparc machine, basically it produce different results than a X86 machine. ------------------------------------------------------------------------------------------------------------------- ; MduleID = '<stdin>' target datalayout =

Hi guys, Thanks for the input. However, it seems that the code still produces the wrong output on a Sparc machine. My current llvm_print.bc code is: -------------------------------------------------------------------------------------------------- ; MduleID = '<stdin>' target datalayout =

Hi, The compilation of the following code void f(int *a, int b[], int n) { int i; for(i=0; i< n; ++i) a[i] = b[i]; } gives the IR: define void @f(i32* nocapture %a, i32* nocapture %b, i32 %n) nounwind { %1 = icmp sgt i32 %n, 0 br i1 %1, label %.lr.ph, label %._crit_edge .lr.ph: ; preds = %0 %tmp = zext i32 %n to i64 br label %2 ;

Hi Sebpop, Thanks for your explanation. I noticed that Polly would finally run the SROA pass to transform these load/store instructions into scalar operations. Is it possible to run such a pass before polly-dependence analysis? Star Tan At 2013-08-15 21:12:53,"Sebastian Pop" <sebpop at gmail.com> wrote: >Codeprepare and independent blocks are introducing these loads and

On 27.02.2012, at 17:13, Николай Лихогруд wrote: > Dear LLVM, > > Consider two loops with one interation - > First with constant lower bound, second with usual non-constant lower bound: > > int main(int argc, char ** argv) > { > int numOfIterations= 1; > int stride=1; > int lowerBound = 1000; - 1st | int lowerBound =

On 2/25/2013 2:08 PM, Redmond, Paul wrote: > > I've been looking through past threads looking for an answer to why the loop metadata is attached to the loop latch branch. What is the reason for putting the metadata inside the loop rather than outside (for example on the branch into the loop header.) Latch is a branch to the header. What branch in particular do you have in mind? Loop

On 27.02.2012, at 18:49, Eli Friedman wrote: > On Mon, Feb 27, 2012 at 9:30 AM, Benjamin Kramer > <benny.kra at googlemail.com> wrote: >> >> On 27.02.2012, at 17:13, Николай Лихогруд wrote: >> >>> Dear LLVM, >>> >>> Consider two loops with one interation - >>> First with constant lower bound, second with usual

Codeprepare and independent blocks are introducing these loads and stores. These are prepasses that polly runs prior to building the dependence graph to transform scalar dependences into data dependences. Ether was working on eliminating the rewrite of scalar dependences. On Thu, Aug 15, 2013 at 5:32 AM, Star Tan <tanmx_star at yeah.net> wrote: > Hi all, > > I have investigated the

Hi I have this program in which fooBuf can only take on NULL or the address of local_fooBuf, and fooBuf and local_fooBuf have scope of the foo function. Therefore there is no way for the fooPtr argument to alias with fooBuf. However, LLVM basicaa and globalsmodref-aa say the 2 pointers may alias. I am thinking whether i should implement a limited form of point-to alias on the fooBuf pointer in