similar to: [RFC] Improving integer divide optimization (related to D12082)

> On Aug 19, 2015, at 3:48 PM, escha via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > >> On Aug 19, 2015, at 1:45 PM, Steve King via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >> In the targets I know, shifts are >> cheaper than divides in both speed and size. > > From what I remember, udiv by

> On Aug 20, 2015, at 9:46 AM, Steve King <steve at metrokings.com> wrote: > > On Wed, Aug 19, 2015 at 10:58 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: >> >> Isn’t the problem the fact that the patch makes it harder for a target to >> get the generic code to reach its custom hook? >> Now the "cheap pow2 sdiv” is merged with the generic

> On Aug 20, 2015, at 10:22 AM, escha <escha at apple.com> wrote: > >> >> On Aug 20, 2015, at 9:59 AM, Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>> wrote: >> >>> >>> On Aug 20, 2015, at 9:46 AM, Steve King <steve at metrokings.com <mailto:steve at metrokings.com>> wrote: >>>

Hi all. Using the following code: plot(bsa, abs, col='blue', pch=16, xlim=c(0, 25), ylim=c(0.0, 1.0), xlab = expression(paste(BSA, " (", mu, "g)", sep="")), ylab=expression(A[595])) plot(unknown1, abs2, col='blue', pch=16, xlim=c(0, 25), ylim=c(0.0, 1.0), xlab = expression(paste(Unknown_1, " (", mu, "g)", sep="")),

Dear R users, I have the "any" function of R  any(ind.c, ind.r, ind.sgn) all are logical factors  it works fine when any of three is true but when they are combined it doesnt work. i tried this any(ind.c, ind.r, ind.sgn,((ind.c==TRUE) & (ind.r==TRUE)), ((ind.c==TRUE) & (ind.sgn==TRUE)),((ind.r==TRUE) & (ind.sgn==TRUE)),  ((ind.c==TRUE) & (ind.r==TRUE) &

> This is not true. The mathematically correct result for sqrt might not be a representable value in floating point, so rounding may occur between the two steps. In that case, pow2(sqrt(x)) != x. > > --Owen I think what Christoph is saying is that x will always be at least as accurate as pow2(sqrt(x)), so it's only unsafe in so far as one's code is actually depending on an

On Apr 23, 2013, at 7:15 PM, Stephen Lin <swlin at post.harvard.edu> wrote: >> This is not true. The mathematically correct result for sqrt might not be a representable value in floating point, so rounding may occur between the two steps. In that case, pow2(sqrt(x)) != x. > > I think what Christoph is saying is that x will always be at least as > accurate as pow2(sqrt(x)),

R> round(100000/3, -2) - 33300 [1] -7.275958e-12 I would have hoped for 0. The problem seems to be specifically for negative "digits". This is in 1.3.1 on Solaris 2.6 (full description at bottom). [Apologies for making everyone read this 3 times; my bug.report() burped.] Peter Dalgaard <p.dalgaard@biostat.ku.dk> says the problem is in fround.c, which reads in part:

* Andreas Dilger <adilger@dilger.ca> hat geschrieben: > The "lifetime writes" value has not been around forever, so if the > filesystem was originally created and populated on an older kernel > (e.g. using ext3) it would not contain a record of those writes. It was created as stable ext4 in the first place. So only if there was a stable ext4 release which didn't

The LegalizeDAG.cpp file has this code in SelectionDAGLegalize::PromoteNode: case ISD::BSWAP: { unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits(); Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Tmp1); Tmp1 = DAG.getNode(ISD::BSWAP, dl, NVT, Tmp1); Tmp1 = DAG.getNode(ISD::SRL, dl, NVT, Tmp1, DAG.getConstant(DiffBits, TLI.getShiftAmountTy()));

Hi, I am working on PR34474 and try to add a new optimization to InstCombine. Like in other parts of the visitMul function I add a Shl through the IR builder and create a new BinaryOp which I return from visitMul. If I understand correctly the new BinaryOp returned from visitMul should replace the original Instruction in the Worklist. However, I end up in an infinite loop and the Instruction

Hi all, I'm trying to convers some Cisco SSCP phones to the SIP formware. The phone boots, I see it tries to fetch a bunch of files on my TFTP: Jun 17 09:37:45 firewall dnsmasq-dhcp[21202]: DHCPACK(eth2) 192.168.10.103 6c:50:4d:da:f0:67 SEP6C504DDAF067 Jun 17 09:38:10 firewall in.tftpd[22666]: RRQ from 192.168.10.103 filename CTLSEP6C504DDAF067.tlv Jun 17 09:38:10 firewall in.tftpd[22666]:

Hi all! I've been tinkering with LLVM's code-base for a few days, hoping to start on one of the ideas mentioned in the "Open Projects" page (I was told 'Improving the current system'/'Miscellaneous Improvements'/5 would be a good start). While I was at it, I also took a stab at finishing up one of the TODOs. I've attached the patch for review. --

Hi As I understand live variable analysis will set the def/kill properties of operands. In that case, is it still needed to set the kill flags when possible during lowering? thanks dz

There is in fact a transform out there somewhere that reverses yours. define i64 @foo(i64 %a) { %b = shl i64 %a, 5 %c = add i64 %b, %a ret i64 %c } becomes define i64 @foo(i64 %a) { %c = mul i64 %a, 33 ret i64 %c } ~Craig On Wed, Sep 13, 2017 at 10:11 AM, Craig Topper <craig.topper at gmail.com> wrote: > Your code seems fine. InstCombine can infinite loop if some other

Hi Craig, thanks for digging into this. So InstCombine is the wrong place for fixing PR34474. Can you give me a hint where such an optimization should go into CodeGen? I am not really familiar with stuff that happens after the MidLevel. Cheers, Michael Am 13.09.2017 um 19:21 schrieb Craig Topper: > And that is less instructions. So from InstCombine's perspective the > multiply is

Is this piece of code in DAGCombiner::visitLOAD removing a dead node? 06155 if (N->use_empty()) { 06156 removeFromWorkList(N); 06157 DAG.DeleteNode(N); 06158 } If it is, is there a reason it doesn't push its operands to the work list as done in line 974-975? 00970 // If N has no uses, it is dead. Make sure to revisit all N's operands once

Hello, Am Dienstag, 23. April 2013, 13:26:19 schrieb Owen Anderson: > That's a pretty seriously unsafe floating point optimization. It could be > done in fast-math mode, but I doubt we currently do it. I just saw this thread and wonder why it's "seriously" unsafe? I see only one problematic corner case. For x >= 0.0 the result cannot lose precision. For x = NaN the

Dear R users, i want to put the results of a list to a for loop. i will give an example m1<-matrix(rep(1,15),ncol=5)   ind.sgn <- lapply(1:ncol(m1), combn, x = ncol(m1))  ind.sgn [[1]]      [,1] [,2] [,3] [,4] [,5] [1,]    1    2    3    4    5 [[2]]      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,]    1    1    1    1    2    2    2    3    3     4 [2,]    2    3    4    5   

On Apr 23, 2013, at 3:33 PM, Christoph Grenz <christophg+llvm at grenz-bonn.de> wrote: > Hello, > > Am Dienstag, 23. April 2013, 13:26:19 schrieb Owen Anderson: >> That's a pretty seriously unsafe floating point optimization. It could be >> done in fast-math mode, but I doubt we currently do it. > > I just saw this thread and wonder why it's