similar to: Verify that we only get loop metadata on latches

An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200320/34cdec77/attachment.html> -------------- next part -------------- Hi all, I have encountered some issues with the preservation of the location of llvm.loop metadata (containing optimisation hints), and would appreciate some feedback on the issue. The IR language description states that

For example, I have the following IR code, for.cond.preheader: ; preds = %if.end18 %mul = mul i32 %12, %3 %cmp21128 = icmp sgt i32 %mul, 0 br i1 %cmp21128, label %for.body.preheader, label %return for.body.preheader: ; preds = %for.cond.preheader %19 = mul i32 %12, %3 %20 = add i32 %19, -1 %21 = zext i32 %20 to i64 %22 =

I've been playing with approaches to getting better optimization of loops which contain infrequently executed slow paths. I've gotten as far as throwing together a proof of concept implementation of a profile guided optimization to separate a single loop with multiple latches into a loop nest, but I want to get feedback from interested parties before investing much more effort. The

Hi, 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.) Note that I'm asking about llvm.loop.parallel not llvm.mem.parallel_loop_access which obviously must be inside the loop. It seems

Tobias, I am working on one very well hidden issue with Polly loop structure. Here is a brief description. In polly::createLoop() we create something like this (topology is important): polly.start: ; preds = %polly.split_new_and_old ... <some code> br label %polly.loop_header polly.loop_after: ; preds =

Hello. I tried to get the trip count of a loop with Scalar evolution. I got inspired from http://stackoverflow.com/questions/13834364/how-to-get-loop-bounds-in-llvm . However the analysis described there doesn't work well for the second inner loop of thes function below (although if we declare Bcols a short it works well): void MatMul(int Arows, int Acols, int Brows, int

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

Hi, Look at the following code: Look at the following C code seqence: unsigned char mainGtU ( unsigned int i1, unsigned int i2, unsigned char* block) { unsigned char c1, c2; c1 = block[i1]; c2 = block[i2]; if (c1 != c2) return (c1 > c2); i1++; i2++; c1 = block[i1]; c2 = block[i2]; if (c1 != c2) return (c1 > c2); i1++; i2++; .. ..

> On Jan 7, 2015, at 5:33 PM, Chandler Carruth <chandlerc at google.com> wrote: > > > On Wed, Jan 7, 2015 at 5:19 PM, Philip Reames <listmail at philipreames.com <mailto:listmail at philipreames.com>> wrote: > I've been playing with approaches to getting better optimization of loops which contain infrequently executed slow paths. I've gotten as far as

On 01/07/2015 05:33 PM, Chandler Carruth wrote: > How does this compare with classical approaches of loop peeling, > partitioning, fission, or whatever you might call it? I'm still developing a good sense for this, but let me lay out some observations. Fair warning, this is going to be long and rambling. Let's start with a toy example: while(c) { x = this->x; y =

Hi, The following arbitrary example makes the code generators to get stuck (llvmc won't return from command line, Jit won't return from function call) Basically it is a CFG with circles, (the function will return by comparing a branch counter to a threshold on runtime - see the "Brancher" blocks below) Any idea what goes wrong? Is it a bug in llvm ? ; ModuleID =

Hi All,   For the test snippet below, int func(int dd, int ds, int *rm) {   int d_sn = 0;   int dv_sn = 0;   unsigned int d, r;   if (dd < 0) { d_sn = 1; dd = -dd; };   if (ds < 0) { dv_sn = 1; ds = -ds ; };     d = func1( dd, ds, &r);     if (d_sn && dv_sn){ r = -r;}   else if (d_sn) { d = -d; r = -r; }   else if (dv_sn) { d = -d; };     if (rm) { *rm = (signed int)r; }  

Hi Sorry, that the previous email is sent out before I complete it due to my mistake. Please read this I am using the LLVM function pass to help me to do code analysis. However, I found that the block LLVM identified will ignore the function call. For example, the below IR should not be a basic block. %call17 = call i32* @__errno_location() #14, !dbg !1384 %18 = load i32, i32* %call17,

> On 29 May 2018, at 22:40, Muhui Jiang via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi > > Sorry, that the previous email is sent out before I complete it due to my mistake. Please read this > > I am using the LLVM function pass to help me to do code analysis. However, I found that the block LLVM identified will ignore the function call. > > For

Hello, everyone, I created a dense map like this: DenseMap<Loop *, int> ls; And I have a module which contains 3 functions: function F and it has a loop which is " Loop at depth 1 containing: %1<header><exiting>,%3,%5<latch> " function G and it has two loops which are " Loop at depth 1 containing: %8<header><exiting>,%10,%14<latch>

Dear John, First thing, the 3 loops in Densemap are all " Loop at depth 1 containing: %1<header><exiting>,%3,%5<latch> " in the 3 functions. The dense map is in a ImmutablePass. I got it in FunctionPass and tried insert the information in this FunctionPass. So to turn the FunctionPass to ModulePass may be a better idea? Another interesting thing: if just before

Dear all, Here's an updated version of the parallel loop metadata patch. It includes documentation for the new metadata types with a semantics description. -- Pekka -------------- next part -------------- A non-text attachment was scrubbed... Name: parallel-loop-metadata.patch Type: text/x-patch Size: 12972 bytes Desc: not available URL:

Hi, On 2013-02-25, at 5:11 PM, Krzysztof Parzyszek wrote: > 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.) > >

On Wed, Jan 30, 2013 at 12:35 PM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > Thank you all for comments, > > > On 01/30/2013 11:22 AM, David Tweed wrote: >> >> In a personal capacity I'm quite interested in the issues of producing >> from a >> high-level language some LLVM IR which is labelled with vectorization info >> (including

Hi all, I would like to propose an improvement of the “almost dead” block elimination in Transforms/Local.cpp so that it will preserve the canonical loop form for loops with a volatile iteration variable. *** Problem statement Nested loops in LCALS Subset B (https://codesign.llnl.gov/LCALS.php) are not vectorized with LLVM -O3 because the LLVM loop vectorizer fails the test whether the loop