similar to: [LLVMdev] Scalar replacement of arrays

On Wed, Mar 7, 2012 at 12:47 PM, Nicolas Capens <nicolas.capens at gmail.com> wrote: > Hi all, > > I'm implementing a virtual processor which features dynamic register > indexing, and I'm struggling to make LLVM 3.0 produce good code for it. > The register set is implemented as an LLVM array so it can be > dynamically indexed using GEP. However, most of the time the

Nicolas Capens wrote: > [...] > I'm not sure if that's going to help achieve optimal code > for when the array is sometimes being dynamically indexed. > Essentially there should be some kind of store to load copy > propagation. As far as I know that's exactly what mem2reg > does, except that it only considers scalars and not elements > of arrays. > > So would

On 1 July 2011 13:35, Vasiliy Korchagin <vasiliy.korchagin at gmail.com> wrote: > On 01.07.2011 12:03, Eli Friedman wrote: >> On Fri, Jul 1, 2011 at 12:53 AM, Корчагин Василий >> <vasiliy.korchagin at gmail.com>  wrote: >>> The problem is that C backend doesn't support integers wider than 64 >>> bits, but I need to use it on programs with wide

On 01.07.2011 12:03, Eli Friedman wrote: > On Fri, Jul 1, 2011 at 12:53 AM, Корчагин Василий > <vasiliy.korchagin at gmail.com> wrote: >> Hello, LLVMdev. >> >> The problem is that C backend doesn't support integers wider than 64 >> bits, but I need to use it on programs with wide integers in LLVM IR. My >> question is how to deny LLVM to generate wide

Hi Bill, Comments inline: On 24/10/2011 9:50 PM, Bill Wendling wrote: > On Oct 20, 2011, at 8:42 AM, Nicolas Capens wrote: > >> Hi all, >> >> I'm working on a graphics project which uses LLVM for dynamic code >> generation, and I noticed a major performance regression when upgrading >> from LLVM 2.8 to 3.0-rc1 (LLVM 2.9 didn't support Win64 so I

On May 20, 2008, at 8:57 AM, David Greene wrote: > On Tuesday 20 May 2008 07:03, Nicolas Capens wrote: > >> 1) Does ScalarReplAggregates totally superscede >> PromoteMemoryToRegister? I > > Nope, they are different. Mem2Reg is really important if you want > register > allocation. Actually SROA does fully subsume Mem2Reg. It iterates between breaking up

Jack Howarth wrote: > I've had better luck compiling all of pymol 1.1r2 with > -O4 on darwin9. Everythink links and there appears to be > no regressions in the resulting code. I take it that LTO > in llvm 2.5 is still limited to dead code elimination, > correct? No. libLTO does the equivalent to opt -internalize -ipsccp -globalopt -constmerge -deadargelim -instcombine

On Oct 26, 2011, at 1:18 PM, Nicolas Capens wrote: > On 24/10/2011 9:50 PM, Bill Wendling wrote: >> On Oct 20, 2011, at 8:42 AM, Nicolas Capens wrote: >> >>> Hi all, >>> >>> I'm working on a graphics project which uses LLVM for dynamic code >>> generation, and I noticed a major performance regression when upgrading >>> from LLVM

On 19 June 2011 14:44, Suresh Purini <suresh.purini at gmail.com> wrote: >  I am doing few experiments to do understand optimization phase > interactions. Here is a brief description of my experiements. > > 1. I picked the list of machine independent optimizations acting on > llvm IR (those that are enabled at O3). > 2.  for each optimzation in the optimization-list >  

I've had better luck compiling all of pymol 1.1r2 with -O4 on darwin9. Everythink links and there appears to be no regressions in the resulting code. I take it that LTO in llvm 2.5 is still limited to dead code elimination, correct? Will LTO ever be extended to inlining across files as well as constant-folding and global data allocation optimizations? Or does the reliance on gcc-4.2 as the

Hi Chris, Thanks for your reply. You said that scalarRepl gets shy about loads and stores of the entire aggregate. Then I use a test case: ; ModuleID = 'test1.ll' define i32 @fun(i32* nocapture %X, i32 %i) nounwind uwtable readonly { %stackArray = alloca <4 x i32> %XC = bitcast i32* %X to <4 x i32>* %arrayVal = load <4 x i32>* %XC store <4 x i32>

Hi Fan, > You said that scalarRepl gets shy about loads and stores of the entire > aggregate. Then I use a test case: > > ; ModuleID = 'test1.ll' > define i32 @fun(i32* nocapture %X, i32 %i) nounwind uwtable readonly { > %stackArray = alloca <4 x i32> > %XC = bitcast i32* %X to <4 x i32>* > %arrayVal = load <4 x i32>* %XC > store

Dear all, I am doing few experiments to do understand optimization phase interactions. Here is a brief description of my experiements. 1. I picked the list of machine independent optimizations acting on llvm IR (those that are enabled at O3). 2. for each optimzation in the optimization-list a) Compiled the program using 'clang -c O0 -flto program.c' b) opt

Hi, I've been thinking about how to keep the line number with the llvm transform/Analysis passes. Basically, I agree with Chris's notes ( http://www.nondot.org/sabre/LLVMNotes/DebugInfoImprovements.txt), and I will follow his way to turn on the line number information when optimization enabled. Here is a detailed proposal: 1. Introduction At the time of this writing, LLVM's

Hi Chris, Thanks for the detailed explanations. I have a few remaining questions: Am I correct that ScalarReplAggregates is hardly more expensive than Mem2Reg and therefore generally preferable? What would be the code quality implications of using "-dce -simplifycfg" instead of -adce? As far as I understand the algorithms involved, -dce would hardly ever miss a dead instruction if

On Mar 10, 2012, at 9:34 AM, Fan Dawei wrote: > Hi all, > > I want to use scalarrepl pass to eliminate the allocation of mat_alloc which is of type [4 x <4 x float>] in the following program. > > $cat test.ll > > ; ModuleID = 'test.ll' > > define void @main(<4 x float>* %inArg, <4 x float>* %outArg, [4 x <4 x float>]* %constants)

Hi all, I'm getting more impressed by LLVM day by day, but what's a bit unclear to me now is the order of optimization passes, and their performance. I think I have a pretty solid understanding of what each pass does at a high level, but I couldn't find any documentation about how they interact at a lower level. I'd like to use LLVM for generating high-performance stream

On Dec 7, 2007, at 1:43 AM, Wojciech Matyjewicz wrote: > Recently, I was looking into the bug #1227. I wanted to check if > reordering optimization passes could solve it. To start with, I > tried to > reproduce the output of llvm-g++ -O3 using the combination of llvm-g++ > -O0 and opt with the appropriate passes. However, I was unable to. I > use > SVN versions of llvm and

On 3/21/06, Chris Lattner <sabre at nondot.org> wrote: > On Mon, 20 Mar 2006, Michael McCracken wrote: > > > Hi, I'm trying to access an analysis pass from the Inliner pass, and > > I'm having a lot of trouble getting that to work - I can verify that > > my pass is loaded and run (it is a dynamically loaded pass that is > > part of an analysisgroup),

Hi all, I want to use scalarrepl pass to eliminate the allocation of mat_alloc which is of type [4 x <4 x float>] in the following program. $cat test.ll ; ModuleID = 'test.ll' define void @main(<4 x float>* %inArg, <4 x float>* %outArg, [4 x <4 x float>]* %constants) nounwind { entry: %inArg1 = load <4 x float>* %inArg %mat_alloc = alloca [4 x <4 x