Vm-dev May 2023

vm-dev@lists.squeakfoundation.org

3 participants
21 discussions

[OpenSmalltalk/opensmalltalk-vm] BitBlt rgbMul is broken for depth 1 and not correctly rounded above depth 4 (Issue #651)
by Nicolas Cellier 24 Nov '23

24 Nov '23

In depth 1, the resulting bits will always be 0. It's not a big problem because rgbMul is just a bitAnd operation at this depth. So a quick workaround would be to detect the case in BitBltSimulation destDepth = 1 ifTrue: [^self bitAnd: sourceWord with: destinationWord]. That would also accelerate the Bit BLock Transfer operation, so it's a good hack. But there is more. What we want is multiply ratios in interval [0,1]. dstRatio * srcRatio Our implementation is scaled ratio (scaled by `1 << nBits - 1`): src := (srcRatio * scale) rounded. dst := (dstRatio * scale) rounded. So what we want is: ((dst/scale) * (src/scale) * scale) rounded that is: (dst*src / (1<<nBits-1)) rounded Unfortunately, that's the other grief with the current implementation used for rounding: (dst+1)*(src+1) - 1 >> nBits It only equals correctly rounded operation for depths 2 and 4. For rounding we might use: (((dst/scale) * (src/scale) + 0.5) * scale) truncated. that is expressed with truncated division: dst*src + (scale+1//2) // scale So here is a nicer formulation for doing the job at any depth (including 5bits rgb channels for 16 bits depth) with correctly rounded division: aux := src * dst + (1 << (nBits - 1)). "add mid-scale for rounding" result := aux << (nBits - 1) + aux << (nBits -1). "divide by scale" This is because instead of dividing by scale, we can multiply by shifted inverse (sort of double precision), then shift right. (2 to: 32) allSatisfy: [:nBits | (1 << (nBits * 2) / (1 << nBits - 1)) rounded = (1 << nBits + 1)]. Multiplying by this inverse is easy and cheap: x * (1 << nBits + 1) = (x << nBits + x). And then applying the right shift `>> (2 * nBits)` is equivalent to: x >> nBits + x >> nBits. We must first add 0.5 (scaled), that is `src * dst + (1 << (nBits -1))` - our formulation of aux, and we're done. We verify: { (0 to: 1<<20-1) allSatisfy: [:i | (1<<9+i)>>10+ (1<<9+i)>>10 = (i/1023) rounded]. (0 to: 1<<18-1) allSatisfy: [:i | (1<<8+i)>>9+ (1<<8+i)>>9 = (i/511) rounded]. (0 to: 1<<16-1) allSatisfy: [:i | (1<<7+i)>>8+ (1<<7+i)>>8 = (i/255) rounded]. (0 to: 1<<14-1) allSatisfy: [:i | (1<<6+i)>>7+ (1<<6+i)>>7 = (i/127) rounded]. (0 to: 1<<12-1) allSatisfy: [:i | (1<<5+i)>>6+ (1<<5+i)>>6 = (i/63) rounded]. (0 to: 1<<10-1) allSatisfy: [:i | (1<<4+i)>>5+ (1<<4+i)>>5 = (i/31) rounded]. (0 to: 1<<8-1) allSatisfy: [:i | (1<<3+i)>>4+ (1<<3+i)>>4 = (i/15) rounded]. (0 to: 1<<6-1) allSatisfy: [:i | (1<<2+i)>>3+ (1<<2+i)>>3 = (i/7) rounded]. (0 to: 1<<4-1) allSatisfy: [:i | (1<<1+i)>>2+ (1<<1+i)>>2 = (i/3) rounded]. } allSatisfy: #yourself. The nice thing is that above down-scaling operation can be multiplexed. Suppose that we have p groups of 2*nBits `M` holding square-scale multiplication of each channel concatenated in a double-Word-Mul. doubleWordMul = Mp .... M5 M3 M1 Note we arrange to have odd channels in low word, and even channels in high word. We first form a `groupMask` on a word with (p+1)/2 groups of nBits alternating all one `i` and all zero `o`, `oioi...ioi`. channelMask := 1 << nBits - 1. groupMask := 0. 0 to: wordBits // (2 * nBits) do: [:i | groupMask = groupMask << (2 * nBits) + channelMask]. Where wordBits is the number of bits in a word (usually we want to operate on 32 bits words in BitBlt). We form the `doubleGroupMask` on a double-word with p groups of 2*nBits `oi`: doubleGroupMask := groupMask >> nBits. doubleGroupMask := doubleGroupMask << wordBits + groupMask. And we perform the division by scale: doubleWordMul := (doubleWordMul >> nBits bitAnd: doubleGroupMask) + doubleWord >> nBits bitAnd: doubleGroupMask. At this stage we obtain a double word containing scaled multiplicands interleaved with groups of nBits zeros: o mp ... o m3 o m1 Now the final result can be obtained by shifting back: doubleWordMul >> (wordBits - nBits) + (doubleWordMul bitAnd: groupMask) The only problem remaining is how to obtain the squared-scale multiplicands. It would be easy to form the alternate even-odd channels for each src and dst operands: doubleWordSrc := src >> nBits bitAnd: groupMask. doubleWordSrc := doubleWordSrc << wordBits + (src bitAnd: groupMask). doubleWordDst := dst >> nBits bitAnd: groupMask. doubleWordDst := doubleWordDst << wordBits + (dst bitAnd: groupMask). we now get `o sp ... o s3 o s1` and `0 dp ... o d3 o d1`, but we would now need a SIMD integer multiplication operating on groups of 2*nBits in parallel... We don't have that, at least in portable C code. So we still have to emulate it with a loop. half := 1 << (nBits - 1). shift := 0. doubleWordMul := 0 0 to: nChannels - 1 do: [:i | doubleWordMul := doubleWordMul + (((doubleWordSrc >> shift bitAnd: channelMask) * (doubleWordSrc >> shift bitAnd: channelMask) + half) << shift). shift := shift + nBits + nBits]. We know that each operation cannot overflow on upper neighbour group of 2*nBits, because the maximum value is: (1<<nBits-1) squared + (1 << (nBits-1)) = 1 << (2*nBits) - (2*(1<<nBits)) + (1 << (nBits-1)) - 1 < (1 << (2*nBits) - 1) It remains the odd case of 16 bits depth, which has 3 groups of 5 bits and a leading zero. I believe that above algorithm works without splitting in two half-words... To be tested. We have gathered the pieces for a correctly rounded almost-multiplexed rgbMul. Somehow have our cake and eat it too. -- Reply to this email directly or view it on GitHub: https://github.com/OpenSmalltalk/opensmalltalk-vm/issues/651 You are receiving this because you are subscribed to this thread. Message ID: <OpenSmalltalk/opensmalltalk-vm/issues/651(a)github.com>

2 4

Re: [Newbies] FreeBSD VM
by Tobias Pape 30 Sep '23

30 Sep '23

Hi David > On 30. Mar 2023, at 16:09, David Gray <dgray(a)iesl.forth.gr> wrote: > > I’ve been trying to get a working VM for FreeBSD. However even though I manage to get the system to start and update itself it gives a segmentation error when I open a workspace and type any character at all. I used the latest linux64x64 cog.spur. > Both the 6.0 and 5.3 images behaved the same. To get it to compile I had the comment out the Joystick plugin and edit the baud rates inside the serial plugin. I’m a complete beginner with squeak so I don’t know how to proceed from here. Based on your comments, I went and tried to verify that the VM still builds. I have made similar adjustments and was able to build a VM with the recents commits to the Cog branch of the VM. Can you please build a debug vm and try to recreate the error? I am very interested in that. Best regards -Tobias

4 5

In reference to: Minifying Woes
by Tom Braun 28 Aug '23

28 Aug '23

Hi all, I am new to the list, so I couldn’t answer directly to Minifying Woes (or at least didn’t know how to). I identified 75 VM intern objects in Tom’s (tobe) image, by loading it in the simulator and setting a halt after loading the image. With the following code: | collection | collection := OrderedCollection new. self allOldSpaceEntitiesDo: [:obj | (((self classIndexOf: obj) < self lastClassIndexPun) and: (self isImmediate: obj) not) ifTrue: [ collection add: obj] ]. (collection sorted: [:a :b | (self bytesInBody: a) > (self bytesInBody: b)]) collect: [:ea | ea hex -> (self bytesInBody: ea)] I get the following 75 objects: 1. A free chunk after all other objects. Can be ignored for the sake of minimising image size 2. Remembered set -> 1048592 byte 3. hiddenRootsObj -> 32848 byte 4 - 61. Pages of the mark and weakling stack -> respectively 32752 byte 62 - 74. arrays of the class table -> respectively 8208 byte 75. specialObjectsOop -> 520 byte As far as I can judge the stack pages and remembered set could be removed from the image to minimize it further. If I understand correctly the StackPages could be removed by using the SpurImagePreener. The remembered set Could be removed in the SpurImagePreener too (when the VM initialises the memory it initialises a new remembered set too, if it is nil). After a quick read of the SpurImagePreener I didn’t see that the remembered set gets removed. When I tried using the preener it resulted in an unusable image (both simulator and compiled VM couldn’t load it). I tried both: SpurImagePreener new preenImage: '/Users/tombraun/Desktop/Squeak6.0-22104-64bit copy.image' SpurImagePreener new writeDefaultHeader: true; savedWindowSize: 1@1; preenImage: '/Users/tombraun/Desktop/Squeak6.0-22104-64bit copy.image' Could be a me problem, as I did some changes to the memory management in my VMMaker image, although this shouldn’t influence the preener…. On this note @Eliot: why the decision to make the object stacks and the remembered set VM managed objects instead of allocating them separately? 1. We don’t need to keep them in a snapshot. All object stacks are empty after GC and as we flushed the new space pre snapshot The remembered set shouldn't need to be persisted too. 2. During GC we simply mark all stack pages and keep them alive. When we at least freed empty pages (after a limit, to prevent the running VM from having to allocate too many pages every GC?) I would see the value. What did I overlook or does it simply have historical reasons? Best, Tom (WoC)

5 5

[OpenSmalltalk/opensmalltalk-vm] Allow choosing an image via zenity when no arguments are provided (#408)
by Leon Matthes 05 Jun '23

05 Jun '23

You can view, comment on, or merge this pull request online at: https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/408 -- Commit Summary -- * Add file chooser dialog to squeak.sh.in * Add file chooser dialog to bin.squeak.sh.in -- File Changes -- M platforms/unix/config/bin.squeak.sh.in (13) M platforms/unix/config/squeak.sh.in (13) -- Patch Links -- https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/408.patch https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/408.diff -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/408

4 8

Mailing lists updated | Please reclaim your mail address
by Marcel Taeumel 29 May '23

29 May '23

Hi all -- We successfully migrated our mailing lists from mailman2 and pipermail to mailman3 and HyperKitty: - https://lists.squeakfoundation.org/mailman3/lists/ - https://lists.squeakfoundation.org/archives/ Your subscriptions were transferred to the new system so that mail delivery continued to function as expected. To manage mail delivery and other preferences, you can now create an actual account using your mail address. Please do so at your earliest convenience: - https://lists.squeakfoundation.org/accounts/signup/?next=/mailman3/lists/ You might want to use a different password as mailman2 stored those in plaintext, which enabled the system to remind you of your current password as a "feature" ... ;-) This is not possible anymore. Best, Marcel

1 0

[OpenSmalltalk/opensmalltalk-vm] b0f09d: For Windows 64-bit, add build files for squeak.sis...
by Marcel Taeumel 10 May '23

10 May '23

Branch: refs/heads/virtend Home: https://github.com/OpenSmalltalk/opensmalltalk-vm Commit: b0f09d78ac5ca91a3e3db5c100073821f9a1421d https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/b0f09d78ac5ca91a3e… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: A building/win64x64/squeak.sista.spur/Croquet.def.in A building/win64x64/squeak.sista.spur/Croquet.exe.manifest A building/win64x64/squeak.sista.spur/Croquet.ico A building/win64x64/squeak.sista.spur/Croquet.rc A building/win64x64/squeak.sista.spur/GreenCogSqueak.ico A building/win64x64/squeak.sista.spur/Makefile A building/win64x64/squeak.sista.spur/Squeak.def.in A building/win64x64/squeak.sista.spur/Squeak.exe.manifest A building/win64x64/squeak.sista.spur/Squeak.rc A building/win64x64/squeak.sista.spur/mvm A building/win64x64/squeak.sista.spur/plugins.ext A building/win64x64/squeak.sista.spur/plugins.int A building/win64x64/squeak.sista.spur/squeak.ico Log Message: ----------- For Windows 64-bit, add build files for squeak.sista.spur flavor. Commit: 7bf078323eda072cefb2afbb9fe95b5f75232120 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/7bf078323eda072cef… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: M building/win32x86/common/Makefile M building/win64x64/common/Makefile Log Message: ----------- Fix typo in print-tools output. Commit: a85389f48f8bba91561db84c29809c98346b4a32 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/a85389f48f8bba9156… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: M .github/workflows.ignore/win.yml Log Message: ----------- Attempt to get cherry-pciking working for the latest commits to Cog Commit: a6f0ba329dc617f20b5483257e1e16e7aeb5b633 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/a6f0ba329dc617f20b… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: M src/plugins/VectorEnginePlugin/VectorEnginePlugin.c Log Message: ----------- VectorEnginePlugin as per VectorEnginePlugin-mt.16 See https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev/commit/89cc00e8638c5d9… See https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev/commits/master/Package… Commit: fd9c8702a0474ceefa647fb6c2d9eae1625ad02e https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/fd9c8702a0474ceefa… Author: Eliot Miranda <eliot.miranda(a)gmail.com> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: R .github/workflows.ignore/extra-arm.yml R .github/workflows.ignore/extra.yml R .github/workflows.ignore/linux-arm.yml R .github/workflows.ignore/linux.yml R .github/workflows.ignore/macos-arm.yml R .github/workflows.ignore/macos.yml R .github/workflows.ignore/win.yml A .github/workflows/extra-arm.yml A .github/workflows/extra.yml A .github/workflows/linux-arm.yml A .github/workflows/linux.yml A .github/workflows/macos-arm.yml A .github/workflows/macos.yml A .github/workflows/win.yml Log Message: ----------- Again attempting to fix cherry-picking from Cog Commit: 8b9eef141de07dedd0f8c085d360f9e20fa34be9 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/8b9eef141de07dedd0… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: M .github/workflows/extra-arm.yml M .github/workflows/extra.yml M .github/workflows/linux-arm.yml M .github/workflows/linux.yml M .github/workflows/macos-arm.yml M .github/workflows/macos.yml M .github/workflows/win.yml Log Message: ----------- Yet another attempt Commit: f5a0a68dda2f9f9511c7891398309b4bb26ad7b8 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/f5a0a68dda2f9f9511… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-10 (Wed, 10 May 2023) Changed paths: M src/spur32.cog.lowcode/cointerp.h M src/spur64.cog.lowcode/cointerp.h Log Message: ----------- For spur.cog.lowcode flavors, minor fix for cointerp.h via VMMaker.oscog-mt.3327 [ci skip] Compare: https://github.com/OpenSmalltalk/opensmalltalk-vm/compare/8657ff7dff19...f5…

1 0

squeak.org research info updated for 2022
by Marcel Taeumel 09 May '23

09 May '23

Hi all -- I just updated our list of publications around Squeak/Smalltalk for 2022 and even some of 2023: https://squeak.org/research/ [https://squeak.org/research/] Please let us know if you know of other publications. Best, Marcel

1 0

[OpenSmalltalk/opensmalltalk-vm] 9efde1: For spur.cog.lowcode flavors, minor fix for cointe...
by Marcel Taeumel 08 May '23

08 May '23

Branch: refs/heads/Cog Home: https://github.com/OpenSmalltalk/opensmalltalk-vm Commit: 9efde1b938072dd26fdd9c9b296ea6335a45c237 https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/9efde1b938072dd26f… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-08 (Mon, 08 May 2023) Changed paths: M src/spur32.cog.lowcode/cointerp.h M src/spur64.cog.lowcode/cointerp.h Log Message: ----------- For spur.cog.lowcode flavors, minor fix for cointerp.h via VMMaker.oscog-mt.3327 [ci skip]

1 0

VM Maker: VMMaker.oscog-mt.3327.mcz
by commits＠source.squeak.org 08 May '23

08 May '23

Marcel Taeumel uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscog-mt.3327.mcz ==================== Summary ==================== Name: VMMaker.oscog-mt.3327 Author: mt Time: 8 May 2023, 11:41:13.509362 am UUID: 1192a8e3-a0b5-f645-bb2b-8afc7cebc1e1 Ancestors: VMMaker.oscog-mt.3326 Add missing API pragma to #getThisSessionID bc. the JIT of spur*.cog.lowcode flavors need it. =============== Diff against VMMaker.oscog-mt.3326 =============== Item was changed: ----- Method: StackInterpreter>>getThisSessionID (in category 'plugin support') ----- getThisSessionID "return the global session ID value" + <api> <inline: false> ^globalSessionID!

1 0

[OpenSmalltalk/opensmalltalk-vm] edfb26: Bump CI runners to macOS-11. There is no support f...
by Marcel Taeumel 08 May '23

08 May '23

Branch: refs/heads/Cog Home: https://github.com/OpenSmalltalk/opensmalltalk-vm Commit: edfb26ae5036c3e365fe6e1cdfd2451484feabbf https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/edfb26ae5036c3e365… Author: Marcel Taeumel <marcel.taeumel(a)hpi.de> Date: 2023-05-08 (Mon, 08 May 2023) Changed paths: M .github/workflows/extra.yml M .github/workflows/macos-arm.yml M .github/workflows/macos.yml Log Message: ----------- Bump CI runners to macOS-11. There is no support for macOS-10.15 anymore.

1 0

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

Vm-dev May 2023