similar to: [LLVMdev] Constant Propagation Problem

On 04/26/2013 05:08 AM, tanmx_star wrote: > Hi all, Hi, thanks for the update and sorry for the delay in reviewing. I just had a look at your proposal. > I have updated my GSoS proposal: "FastPolly: Reducing LLVM-Polly Compiling overhead" (https://gist.github.com/tanstar/5441808). I think the pass ordering problem you discussed early can be also investigated in this project!

Hi all, I have updated my GSoS proposal: "FastPolly: Reducing LLVM-Polly Compiling overhead" (https://gist.github.com/tanstar/5441808). I think the pass ordering problem you discussed early can be also investigated in this project! Is there any comment or advice about my proposal? I appreciate all your help and advice. Thanks, Star Tan Proposal:

As you all have undoubtedly noticed, I recently did Yet Another Merge to Apple's GCC top-of-tree. This merge was prompted by several important fixes in the "blocks" implementation. There are still many testcases that need to be moved over, but those can come at our leisure. I compiled both the "Apple way" and the "FSF way". It also passed the tests in

I'm getting the error below on Ubuntu Hardy on ia32 on r55688. John make[3]: Entering directory `/home/regehr/llvm-gcc/build/gcc' gcc -c -g -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Wold-style-definition -Wmissing-format-attribute -DHAVE_CONFIG_H -I. -I. -I../../gcc

Hi All, It seems that I can't force some passes to run in llvm-ld as what I can do with opt. $ ~/opt/bin/llvm-ld -reassociate llvm-ld: Unknown command line argument '-reassociate. Try: 'opt/bin/llvm-ld -help' llvm-ld definitely linked with scalaropts, and RegisterPass<ReassociatePass> is in the library. Running with these passes with opt definitely work, but it'll

Thank you very much John for your answer , you understood well my problem (and the signification of my "own" PassManager). I already tried your solution but it is not enough. The problem is the same with existing AA (andersen for example) : when calling with opt, this works well, but when adding in local PassManager ( with add() ), it is not working (I test this with the

> > Now the problem is obvious.  A two dimensional array access is being > performed by a single instruction.  The arithmetic needed to address > the element is implicit, and therefore inaccessible to optimizations.  > The redundant calculations can not be eliminated, nor can strength > reduction be performed.  getelementptr needs to be broken down into > its constituent

Chris Lattner wrote: > On Tue, 9 May 2006, Nick Lewycky wrote: > >>> You could do that, but SCCPSolver isn't really useful to mainline LLVM >>> for anything other than SCCP and IPSCCP, so we don't need it in a public >>> header. Out of curiosity, what are you looking to use the latice values >>> for? Why not just run SCCP and then look at the

I'm new to the LLVM, so please forgive what might be a silly question. I'd like to use the opt bytecode-to-bytecode optimizer, but when I try running it to do, for example, dead code elimination (-dce) or global common subexpression elimination (-gcse), nothing much seems to happen: opt -gcse -dce -o bar-opt.bc bar.bc llvm2cpp -o bar-opt.cpp bar-opt.bc

I figured getelementptr exists as it does to facilitate data flow analysis, but it does need to be broken down before instruction selection. It's not just the missed optimization opportunities. It also introduces a huge amount of complexity into instruction selection as they deal with its complexity. It would also take care of many of the FIXMEs in LoopStrengthReduce. Vikram Adve

On Wed, 10 May 2006, Nick Lewycky wrote: >> Then just run the SCCP pass, and check to see if any operands satisfy >> the predicate "isa<UndefValue>(V)". LLVM explicitly represents >> undefined values. > > I have a case where it doesn't, but perhaps the SCCP pass isn't to blame: > > extern void write_char(int); > > const char foo[4] =

On Wed, 21 May 2008, Nicolas Capens wrote: > 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? Right. > What would be the code quality implications of using "-dce -simplifycfg" > instead of -adce? As far as I understand the

Well, now i added the creation of my AA just before the creation of DSE, (in the former case it was done at top of all passes list) and it's working (alias and getModRefInfo are called)... Maybe a particular pass destroyed the AliasAnalysGroup ?? However he solution is not very clean, since i don't know which pass need an AA (i guess this should be automatic whith the method

Hi, This problem may be very easy, but I can't think of how to do it. I have constructed histograms of various variables in my dataset. Some of them are negatively skewed, and hence need data transformations applied. I know that you first need to reflect the negatively skewed data and then apply another transformation such as log, square root etc to bring it towards normailty. How is it

Hello! I'm compiling code which uses pointers as iterators. For some reason--probably a silly misunderstanding of the docs--I can't eliminate duplicate pointer loads. I'll probably figure this out eventually, but if somebody else sees the answer instantly, I certainly won't complain. :-) Here are the optimizers I'm running: opt -f -simplifycfg -dce -instcombine

On Tue, 22 Feb 2005, Vikram S. Adve wrote: >> The second issue is that we need to do redundancy elimination and hoisting >> on operations that are only exposed once instruction selection is >> performed. Getelementptr expansion is just ONE particular case of this, >> but it can happen with any instructions (including the use of large integer >> (or any FP)

On Wednesday 21 May 2008 15:48, Chris Lattner wrote: > > What's the difference between GVN and GCSE, if they both perform common > > subexpression elimination? > > GVN does more, and is a better algorithm. GCSE is basically deprecated > and should be removed at some point. Er...waitaminute. Maybe there's something I don't fully grok about GVN, but in general,

Hi, I have a simple C case as following: int test(int x, int y) { return -x / -y; } With llvm-gcc -O1, I got: define i32 @test(i32 %x, i32 %y) nounwind { entry: sub i32 0, %x ; <i32>:0 [#uses=1] sub i32 0, %y ; <i32>:1 [#uses=1] sdiv i32 %0, %1 ; <i32>:2 [#uses=1] ret i32 %2 } With llvm-gcc -O2, I got: define i32 @test(i32 %x, i32 %y) nounwind { entry: sdiv i32

> The second issue is that we need to do redundancy elimination and > hoisting on operations that are only exposed once instruction > selection is performed. Getelementptr expansion is just ONE > particular case of this, but it can happen with any instructions > (including the use of large integer (or any FP) constants on RISC > machines, addressing globals with PIC code,

On Thu, 16 Mar 2006, Eric Kidd wrote: > Hello! I'm compiling code which uses pointers as iterators. For some > reason--probably a silly misunderstanding of the docs--I can't eliminate > duplicate pointer loads. I'll probably figure this out eventually, but if > somebody else sees the answer instantly, I certainly won't complain. :-) There are no stupid questions.