similar to: [LLVMdev] llvm.loop metadata placement and critical edge splitting

I'm happy with any representation that works for optimizer. I can prepare a patch for clang to update the 'omp simd' and 'clang loop' CodeGen. We do not use LoopInfo in front-end, but it's no problem to go to the block's single predecessor and attach the metadata there. Regards, Alexander -----Original Message----- From: Tobias Grosser [mailto:tobias at grosser.es]

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

Recently wrote a pass that inserts a preheader for a loop that doesn't have one. When I tried to run it, I ran into a problem that became obvious in hindsight - the PHINodes need to be updated in places where the incoming control-edge has changed. Is there anything else that can be affected when a block is inserted into the CFG? Also, planning to write a helper function which will take care

Hi all, this (altough a big patch) is actually pretty straight forward: It (tries) to preserve ProfileInfo in all -std-compile-opts passes and all X86-Backend passes. There is still some passes that have corner cases where the ProfileInfo is not correct after the pass. Some passes are still missing... How shall I proceed with this? Andi -------------- next part -------------- A non-text

Seems that adding -extra-vectorizer-passes doesn't help to vectorizer in my case. LoopRotation re-run does nothing. 2014-10-15 2:54 GMT+04:00 Chandler Carruth <chandlerc at google.com>: > > On Tue, Oct 14, 2014 at 3:50 PM, Hal Finkel <hfinkel at anl.gov> wrote: >> >> > I have and will continue to push >> > back on trying to add it until we at least

On Jul 23, 2011, at 2:00 AM, Jakob Stoklund Olesen wrote: > On Jul 23, 2011, at 1:11 AM, Bill Wendling wrote: > >> On Jul 22, 2011, at 11:44 PM, Jakob Stoklund Olesen wrote: >>> Could we add: >>> >>> - A landing pad block is not the destination of any other kind of terminator. Only unwind edges are allowed. >>> >>> - The landingpad

Hello, Here are a few misc. comments on this patch. Would it make sense to mark the ProfileInfo passes as "CFGOnly?" If so, that would let them be automatically preserved by passes which don't modify the CFG (and that call AU.setPreservesCFG()). > + if (ProfileInfo* PI = getAnalysisIfAvailable<ProfileInfo>()) { > + PI->splitEdge(OrigPreHeader, NewHeader,

Hi Robert, Can you ping the code owners about these patches. It might be good to write a separate email per code owner and cc the appropriate -commits list. Thanks, Tom On Wed, Apr 02, 2014 at 06:16:44PM +0400, Robert Khasanov wrote: > Hi Tom, > > I would like to nominate the following patches to be backported to 3.4.1 > > Clang: > 1. r204742 - Zinovy Nis <zinovy.nis at

In order to vectorize code like this LLVM needs to prove that “A[i*7]” does not wrap in the address space. It fails to do so and so LLVM doesn’t vectorize this loop even if we try to force it. The following loop will be vectorized if we force it: int foo(int * A, int * B, int n, int k) { for (int i = 0; i < 1024; ++i) A[i] += B[i*k]; } So will this loop: int foo(int * restrict A, int

On Jul 23, 2011, at 4:15 PM, Bill Wendling wrote: > On Jul 23, 2011, at 2:00 AM, Jakob Stoklund Olesen wrote: >> Yes. You scared me with 'requires considerable care'. Does that mean anything other than 'you have to duplicate the landing pad instead of splitting the unwind edge'. Is special magic required to duplicate a landingpad instruction? >> > There

Hi, I'm reading "http://llvm.org/docs/Vectorizers.html" and have few question. Hope someone has answers on it. The Loop Vectorizer can vectorize code that becomes a sequence of scalar instructions that scatter/gathers memory. ( http://llvm.org/docs/Vectorizers.html#scatter-gather) int foo(int *A, int *B, int n, int k) { for (int i = 0; i < n; ++i) A[i*7] += B[i*k]; } I

On Aug 5, 2011, at 10:57 AM, Peter Lawrence wrote: > However it seems that if a landingpad-block has multiple predecessors (often the case, > multiple InvokeInst in the main body of a try-statement all go to the same landingpad- > block), then you cannot move the LandingpadInst in order to break a critical edge unless > you do it for _all_ landingpad-block predecessor edges

Hi, There's several, to my eyes, somewhat related looking bugs: Bug 36743 - Cannot select: X86ISD::CALL ICE with -mx32 -O2 -fno-plt https://bugs.llvm.org/show_bug.cgi?id=36743 Bug 34268 - JITting of x32 code on x64 fails with crash or instruction selection error. https://bugs.llvm.org/show_bug.cgi?id=34268 There's unfortunately been no investigation. I'm asking because I hit

Can you please post the code to split a MachineBasicBlock? I am trying to split a MachineBasicBlock at a specific instruction in the MBB, let us say, into MBB1 and MBB2. This instruction should go into MBB2. Also MBB1 should have an unconditional branch to MBB2 as the terminator. (quite similar to splitBasicBlock in BasicBlock.cpp) Meanwhile, I am trying to come up with a variant of

On Jul 22, 2011, at 10:29 PM, Bill Wendling wrote: > // Restrictions: > > There are several new invariants which will be enforced by the verifier: > > 1. A landing pad block is a basic block which is the unwind destination of an > invoke instruction. > 2. A landing pad block must have a landingpad instruction as its first non-PHI > instruction. > 3. The landingpad

On Jul 22, 2011, at 11:44 PM, Jakob Stoklund Olesen wrote: > On Jul 22, 2011, at 10:29 PM, Bill Wendling wrote: > >> // Restrictions: >> >> There are several new invariants which will be enforced by the verifier: >> >> 1. A landing pad block is a basic block which is the unwind destination of an >> invoke instruction. >> 2. A landing pad block

I've added a straw-man of some extra optimization passes that help specific benchmarks here or there by either preparing code better on the way into the vectorizer or cleaning up afterward. These are off by default until there is some consensus on the right path forward, but this way we can all test out the same set of flags, and collaborate on any tweaks to them. The primary principle here

Hi I run into an issue as part of splitting a critical edge during LICM. When a new basic block is created and needs to be added into the dominator tree, the block is already in the dominator tree. I print the dominator tree and I see it is added into the tree as child of node it is supposed to dominate. How do I debug to find out why/when its getting added into the tree. ? Tips/suggestions on

Is LiveVariables updated correctly when TII->RemoveBranch and TII->InsertBranch are called in the following piece of code? - MachineBasicBlock::updateTerminator() line 307 of MachineBasicBlock.cpp: if (FBB) { // The block has a non-fallthrough conditional branch. If one of its // successors is its layout successor, rewrite it to a fallthrough // conditional branch.

Guys, on second thought... doesn't making the exception registers live from the InvokeInst to the LandingpadInst create problems for critical-edge-splitting ? if a landingpad-edge is critical and needs to be split, won't we be creating and inserting a new BB between the "invoke-block" and the "landingpad-block", and if we do then isn't there the