Vm-dev November 2014

vm-dev@lists.squeakfoundation.org

36 participants
165 discussions

Translation of bitClear:
by Nicolas Cellier 11 Nov '14

11 Nov '14

I suggest using a bit xor ^ rather than subtraction - in generated code (receiver|mask)^mask because it is a simpler operation (it does not involve any carry) But generally, clearing a mask is rather written with bit and and bit inverse in C receiver & ~mask The last one is even better because ~mask is trivial to evaluate at compile time if ever mask is a constant. I didn't try to measure if it makes any difference though.

3 5

[commit][3129] Just another manic monday
by commits＠squeakvm.org 10 Nov '14

10 Nov '14

Revision: 3129 Author: eliot Date: 2014-11-10 10:34:19 -0800 (Mon, 10 Nov 2014) Log Message: ----------- Just another manic monday Modified Paths: -------------- branches/Cog/platforms/unix/vm/sqUnixMain.c Property Changed: ---------------- branches/Cog/platforms/Cross/vm/sqSCCSVersion.h Property changes on: branches/Cog/platforms/Cross/vm/sqSCCSVersion.h ___________________________________________________________________ Modified: checkindate - Mon Nov 10 10:15:48 PST 2014 + Mon Nov 10 10:34:43 PST 2014 Modified: branches/Cog/platforms/unix/vm/sqUnixMain.c =================================================================== --- branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-10 18:15:29 UTC (rev 3128) +++ branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-10 18:34:19 UTC (rev 3129) @@ -912,7 +912,7 @@ char pwd[MAXPATHLEN+1]; printf("blocking e.g. to allow attaching debugger\n"); - printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getwp(pwd)); + printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getwd(pwd)); while (1) { while_away_the_hours.tv_sec = 3600; nanosleep(&while_away_the_hours, 0);

1 0

[commit][3128] oops. getpw?? => getwd
by commits＠squeakvm.org 10 Nov '14

10 Nov '14

Revision: 3128 Author: eliot Date: 2014-11-10 10:15:29 -0800 (Mon, 10 Nov 2014) Log Message: ----------- oops. getpw?? => getwd Modified Paths: -------------- branches/Cog/platforms/Mac OS/vm/sqMacMain.c branches/Cog/platforms/unix/vm/sqUnixMain.c Property Changed: ---------------- branches/Cog/platforms/Cross/vm/sqSCCSVersion.h Property changes on: branches/Cog/platforms/Cross/vm/sqSCCSVersion.h ___________________________________________________________________ Modified: checkindate - Mon Nov 10 10:11:51 PST 2014 + Mon Nov 10 10:15:48 PST 2014 Modified: branches/Cog/platforms/Mac OS/vm/sqMacMain.c =================================================================== --- branches/Cog/platforms/Mac OS/vm/sqMacMain.c 2014-11-10 18:12:05 UTC (rev 3127) +++ branches/Cog/platforms/Mac OS/vm/sqMacMain.c 2014-11-10 18:15:29 UTC (rev 3128) @@ -290,7 +290,7 @@ char pwd[PATH_MAX+1]; printf("blocking e.g. to allow attaching debugger\n"); - printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getpw(pwd)); + printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getwd(pwd)); while (1) { while_away_the_hours.tv_sec = 3600; nanosleep(&while_away_the_hours, 0); Modified: branches/Cog/platforms/unix/vm/sqUnixMain.c =================================================================== --- branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-10 18:12:05 UTC (rev 3127) +++ branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-10 18:15:29 UTC (rev 3128) @@ -912,7 +912,7 @@ char pwd[MAXPATHLEN+1]; printf("blocking e.g. to allow attaching debugger\n"); - printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getpw(pwd)); + printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getwp(pwd)); while (1) { while_away_the_hours.tv_sec = 3600; nanosleep(&while_away_the_hours, 0);

1 0

[commit][3127] Have the Unix & Mac VMs print the process id and working directory when blocking
by commits＠squeakvm.org 10 Nov '14

10 Nov '14

Revision: 3127 Author: eliot Date: 2014-11-10 10:12:05 -0800 (Mon, 10 Nov 2014) Log Message: ----------- Have the Unix & Mac VMs print the process id and working directory when blocking on error or assert fail. Add scripts for the ARM VM archives. Modified Paths: -------------- branches/Cog/platforms/Mac OS/vm/sqMacMain.c branches/Cog/platforms/unix/vm/sqUnixMain.c Added Paths: ----------- branches/Cog/scripts/mkARMstackvmarchives branches/Cog/scripts/uploadARMvms Property Changed: ---------------- branches/Cog/platforms/Cross/vm/sqSCCSVersion.h Property changes on: branches/Cog/platforms/Cross/vm/sqSCCSVersion.h ___________________________________________________________________ Modified: checkindate - Wed Nov 5 12:46:58 PST 2014 + Mon Nov 10 10:11:51 PST 2014 Modified: branches/Cog/platforms/Mac OS/vm/sqMacMain.c =================================================================== --- branches/Cog/platforms/Mac OS/vm/sqMacMain.c 2014-11-05 20:48:12 UTC (rev 3126) +++ branches/Cog/platforms/Mac OS/vm/sqMacMain.c 2014-11-10 18:12:05 UTC (rev 3127) @@ -287,8 +287,10 @@ static void block() { struct timespec while_away_the_hours; + char pwd[PATH_MAX+1]; printf("blocking e.g. to allow attaching debugger\n"); + printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getpw(pwd)); while (1) { while_away_the_hours.tv_sec = 3600; nanosleep(&while_away_the_hours, 0); Modified: branches/Cog/platforms/unix/vm/sqUnixMain.c =================================================================== --- branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-05 20:48:12 UTC (rev 3126) +++ branches/Cog/platforms/unix/vm/sqUnixMain.c 2014-11-10 18:12:05 UTC (rev 3127) @@ -909,8 +909,10 @@ static void block() { struct timespec while_away_the_hours; + char pwd[MAXPATHLEN+1]; printf("blocking e.g. to allow attaching debugger\n"); + printf("pid: %d pwd: %s vm:%s\n", (int)getpid(), argVec[0], getpw(pwd)); while (1) { while_away_the_hours.tv_sec = 3600; nanosleep(&while_away_the_hours, 0); Added: branches/Cog/scripts/mkARMstackvmarchives =================================================================== --- branches/Cog/scripts/mkARMstackvmarchives (rev 0) +++ branches/Cog/scripts/mkARMstackvmarchives 2014-11-10 18:12:05 UTC (rev 3127) @@ -0,0 +1,50 @@ +#!/bin/sh +# Create the ARM Stack VM archives in products. Output a check of version numbers +# etc to products/MASVALOG +IFS=" +" + +case `uname -m` in + armv6* ) armarch="v6";; + armv7* ) armarch="v7";; + * ) echo "Error: this script is for ARM only." + exit 1;; +esac + +cd `dirname $0`/../products +SQB=squeak.stack.v3 +REV= +TAG= +EXES= + +while [ -n "$1" ]; do + case $1 in + -r) shift;REV="$1";; + -t) shift;TAG="$1";; + -?|-h) echo usage: $0 [-r REV -t TAG] + exit 0 + esac + shift +done + +test -n "$REV" || REV=`grep 'SvnRawRevisionString.*Rev:' ../platforms/Cross/vm/sqSCCSVersion.h \ + | sed 's/^.*Rev: $[0-9][0-9]*$ $";/\1/'` +test -n "$TAG" || TAG=`date +%g.%U.`$REV +echo REV=$REV TAG=$TAG + +for archive in stklinuxhtARM stkspurlinuxhtARM; do + rm -rf $archive$armarch-$TAG.tgz + echo $archive '=>' $archive$armarch-$TAG.tgz + COPYFILE_DISABLE=1 tar czf $archive$armarch-$TAG.tgz $archive + EXES="$EXES $archive/lib/squeak/[0-9.-]*/squeak" +done + +for vm in $EXES +do + echo + echo checking $vm version +# strings - $vm | egrep '\$Rev: |Interp.*VMMaker|Cogit.*VMMaker| built on ' | grep -v 'Unix built on "__DATE__ " "__TIME__" Compiler: "__VERSION__' | sed 's/ uuid:.*//' + strings - $vm | egrep '\$Rev: |Interp.*VMMaker|Cogit.*VMMaker| built on ' | sed 's/ uuid:.*//' + echo checking $vm for asserts + strings - $vm | grep "assert[^0-9]*[0-9][0-9][0-9]" +done 2>&1 | tee MASVALOG Property changes on: branches/Cog/scripts/mkARMstackvmarchives ___________________________________________________________________ Added: svn:executable + * Added: branches/Cog/scripts/uploadARMvms =================================================================== --- branches/Cog/scripts/uploadARMvms (rev 0) +++ branches/Cog/scripts/uploadARMvms 2014-11-10 18:12:05 UTC (rev 3127) @@ -0,0 +1,61 @@ +#!/bin/sh +# Upload archives from products to a web/ftp site via ssh. +RemoteUser=eliotmiranda(a)highland-park.dreamhost.com +RemoteRoot=mirandabanda.org/files/Cog/VM +IFS=" +" + +case `uname -m` in + armv6* ) ARMARCH="v6";; + armv7* ) ARMARCH="v7";; + * ) echo "Error: this script is for ARM only." + exit 1;; +esac + +REV= +TAG= +cd `dirname $0`/../products +VERBOSE= + +while [ -n "$1" ]; do + case $1 in + -r) shift;REV="$1";; + -t) shift;TAG="$1";; + -?|-h) echo usage: $0 [-r REV -t TAG]; exit 0;; + *) echo usage: $0 [-r REV -t TAG]; exit 1;; + esac + shift +done + +if [ -z "$REV" ]; then + REV="`svnversion .. | sed 's/^.*://'`" + case $REV in + *M) echo -n "source tree is modified, are you sure you want to continue? " + read a + case $a in + y|Y) ;; + *) exit 1 + esac + REV="`svnversion | sed 's/^.*://' | sed 's/M//'`";; + esac +fi + +if [ -z "$TAG" ]; then + TAG=`date +%g.%U.`$REV +fi +echo REV=$REV TAG=$TAG + +ARCHIVES="stklinuxhtARM$ARMARCH-$TAG.tgz stkspurlinuxhtARM$ARMARCH-$TAG.tgz" + +for a in $ARCHIVES; do + echo upload $a +done + + +ssh -x $RemoteUser mkdir $RemoteRoot/VM.r$REV + +echo scp -p $ARCHIVES "$@" $RemoteUser:$RemoteRoot/VM.r$REV +scp -p $ARCHIVES "$@" $RemoteUser:$RemoteRoot/VM.r$REV +echo ssh $RemoteUser chmod a-w $RemoteRoot/VM.r$REV/* \\\; ls -al $RemoteRoot/VM.r$REV +ssh $RemoteUser chmod a-w $RemoteRoot/VM.r$REV/* \; ls -al $RemoteRoot/VM.r$REV + Property changes on: branches/Cog/scripts/uploadARMvms ___________________________________________________________________ Added: svn:executable + *

1 0

VM Maker: ImageFormat-dtl.19.mcz
by commits＠source.squeak.org 09 Nov '14

09 Nov '14

David T. Lewis uploaded a new version of ImageFormat to project VM Maker: http://source.squeak.org/VMMaker/ImageFormat-dtl.19.mcz ==================== Summary ==================== Name: ImageFormat-dtl.19 Author: dtl Time: 9 November 2014, 5:21:39.097 pm UUID: 5cc40fa2-9edb-414f-9421-4f3f59193818 Ancestors: ImageFormat-dtl.18 fix comment =============== Diff against ImageFormat-dtl.18 =============== Item was changed: ----- Method: ImageFileHeader>>readImageVersionFrom:startingAt: (in category 'reading') ----- readImageVersionFrom: aStream startingAt: imageOffset "Look for image format in the next 4 or 8 bytes and set imageFormat. Answer true if the header is written in little endian format." (aStream nextNumber: 4) caseOf: { [ 16r00001966 "6502" ] -> [ imageFormat := ImageFormat fromInteger: 6502. ^false ] . [ 16r66190000 "6502" ] -> [ imageFormat := ImageFormat fromInteger: 6502. ^true ] . [ 16r00001968 "6504" ] -> [ imageFormat := ImageFormat fromInteger: 6504. ^false ] . [ 16r68190000 "6504" ] -> [ imageFormat := ImageFormat fromInteger: 6504. ^true ] . [ 16r00001969 "6505" ] -> [ imageFormat := ImageFormat fromInteger: 6505. ^false ] . [ 16r69190000 "6505" ] -> [ imageFormat := ImageFormat fromInteger: 6505. ^true ] . [ 16r00001979 "6521" ] -> [ imageFormat := ImageFormat fromInteger: 6521. ^false ] . [ 16r79190000 "6521" ] -> [ imageFormat := ImageFormat fromInteger: 6521. ^true ] . [ 16rA0090100 "68000" ] -> [ imageFormat := ImageFormat fromInteger: 68000. aStream next: 4. ^true ] . [ 16rA2090100 "68002" ] -> [ imageFormat := ImageFormat fromInteger: 68002. aStream next: 4. ^true ] . [ 16rA3090100 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68003. aStream next: 4. ^true ] . + [ 16rB3090100 "68019" ] -> [ imageFormat := ImageFormat fromInteger: 68019. aStream next: 4. ^true ] . - [ 16rB3090100 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68019. aStream next: 4. ^true ] . [ 16r00000000 ] -> [ (aStream nextNumber: 4) caseOf: { [ 16r000109A0 "68000" ] -> [ imageFormat := ImageFormat fromInteger: 68000. ^false ] . [ 16r000109A2 "68002" ] -> [ imageFormat := ImageFormat fromInteger: 68002. ^false ] . [ 16r000109A3 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68003. ^false ] . [ 16r000109B3 "68019" ] -> [ imageFormat := ImageFormat fromInteger: 68019. ^false ] . } otherwise: [self error: self asString , ' unrecognized format number'] ] } otherwise: [self error: self asString , ' unrecognized format number'] "ImageFormat versionNumberByteArrays do: [:e | Transcript cr; show: e printString , ': ', (ImageFormat fromBytes: e) description] #[0 0 25 102]: A 32-bit image with no closure support and no native platform float word order requirement (6502) #[102 25 0 0]: A 32-bit image with no closure support and no native platform float word order requirement (6502) #[0 0 25 104]: A 32-bit image with closure support and no native platform float word order requirement (6504) #[104 25 0 0]: A 32-bit image with closure support and no native platform float word order requirement (6504) #[0 0 0 0 0 1 9 160]: A 64-bit image with no closure support and no native platform float word order requirement (68000) #[160 9 1 0 0 0 0 0]: A 64-bit image with no closure support and no native platform float word order requirement (68000) #[0 0 0 0 0 1 9 162]: A 64-bit image with closure support and no native platform float word order requirement (68002) #[162 9 1 0 0 0 0 0]: A 64-bit image with closure support and no native platform float word order requirement (68002) #[0 0 25 105]: A 32-bit image with closure support and float words stored in native platform order (6505) #[105 25 0 0]: A 32-bit image with closure support and float words stored in native platform order (6505) #[0 0 0 0 0 1 9 163]: A 64-bit mage with closure support and float words stored in native platform order (68003) #[163 9 1 0 0 0 0 0]: A 64-bit image with closure support and float words stored in native platform order (68003) " !

1 0

VM Maker: ImageFormat-dtl.18.mcz
by commits＠source.squeak.org 09 Nov '14

09 Nov '14

David T. Lewis uploaded a new version of ImageFormat to project VM Maker: http://source.squeak.org/VMMaker/ImageFormat-dtl.18.mcz ==================== Summary ==================== Name: ImageFormat-dtl.18 Author: dtl Time: 9 November 2014, 5:14:48.61 pm UUID: 03405b51-1796-4492-8857-24051f1ce38a Ancestors: ImageFormat-dtl.17 Read Spur 32 and 64 bit image headers. =============== Diff against ImageFormat-dtl.17 =============== Item was changed: ----- Method: ImageFileHeader>>readImageVersionFrom:startingAt: (in category 'reading') ----- readImageVersionFrom: aStream startingAt: imageOffset "Look for image format in the next 4 or 8 bytes and set imageFormat. Answer true if the header is written in little endian format." (aStream nextNumber: 4) caseOf: { [ 16r00001966 "6502" ] -> [ imageFormat := ImageFormat fromInteger: 6502. ^false ] . [ 16r66190000 "6502" ] -> [ imageFormat := ImageFormat fromInteger: 6502. ^true ] . [ 16r00001968 "6504" ] -> [ imageFormat := ImageFormat fromInteger: 6504. ^false ] . [ 16r68190000 "6504" ] -> [ imageFormat := ImageFormat fromInteger: 6504. ^true ] . [ 16r00001969 "6505" ] -> [ imageFormat := ImageFormat fromInteger: 6505. ^false ] . [ 16r69190000 "6505" ] -> [ imageFormat := ImageFormat fromInteger: 6505. ^true ] . + [ 16r00001979 "6521" ] -> [ imageFormat := ImageFormat fromInteger: 6521. ^false ] . + [ 16r79190000 "6521" ] -> [ imageFormat := ImageFormat fromInteger: 6521. ^true ] . [ 16rA0090100 "68000" ] -> [ imageFormat := ImageFormat fromInteger: 68000. aStream next: 4. ^true ] . [ 16rA2090100 "68002" ] -> [ imageFormat := ImageFormat fromInteger: 68002. aStream next: 4. ^true ] . [ 16rA3090100 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68003. aStream next: 4. ^true ] . + [ 16rB3090100 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68019. aStream next: 4. ^true ] . [ 16r00000000 ] -> [ (aStream nextNumber: 4) caseOf: { [ 16r000109A0 "68000" ] -> [ imageFormat := ImageFormat fromInteger: 68000. ^false ] . [ 16r000109A2 "68002" ] -> [ imageFormat := ImageFormat fromInteger: 68002. ^false ] . [ 16r000109A3 "68003" ] -> [ imageFormat := ImageFormat fromInteger: 68003. ^false ] . + [ 16r000109B3 "68019" ] -> [ imageFormat := ImageFormat fromInteger: 68019. ^false ] . } otherwise: [self error: self asString , ' unrecognized format number'] ] } otherwise: [self error: self asString , ' unrecognized format number'] "ImageFormat versionNumberByteArrays do: [:e | Transcript cr; show: e printString , ': ', (ImageFormat fromBytes: e) description] #[0 0 25 102]: A 32-bit image with no closure support and no native platform float word order requirement (6502) #[102 25 0 0]: A 32-bit image with no closure support and no native platform float word order requirement (6502) #[0 0 25 104]: A 32-bit image with closure support and no native platform float word order requirement (6504) #[104 25 0 0]: A 32-bit image with closure support and no native platform float word order requirement (6504) #[0 0 0 0 0 1 9 160]: A 64-bit image with no closure support and no native platform float word order requirement (68000) #[160 9 1 0 0 0 0 0]: A 64-bit image with no closure support and no native platform float word order requirement (68000) #[0 0 0 0 0 1 9 162]: A 64-bit image with closure support and no native platform float word order requirement (68002) #[162 9 1 0 0 0 0 0]: A 64-bit image with closure support and no native platform float word order requirement (68002) #[0 0 25 105]: A 32-bit image with closure support and float words stored in native platform order (6505) #[105 25 0 0]: A 32-bit image with closure support and float words stored in native platform order (6505) #[0 0 0 0 0 1 9 163]: A 64-bit mage with closure support and float words stored in native platform order (68003) #[163 9 1 0 0 0 0 0]: A 64-bit image with closure support and float words stored in native platform order (68003) " !

1 0

Re: goto instruction with Cog VM
by Ralph Boland 09 Nov '14

09 Nov '14

> Hi Ralph, ... > > > > I was aware of caseOf: in Squeak. I always found it awkward to use and > > felt a true case statement would be simpler. Alas, it's impossible to > > have a true case statement added to Smalltalk now I think. > So what's a "true" case statement? For me, at least, the Squeak one *is*, > and is more general than one limited to purely integer keys, as for example > is C's switch statement. A number of languages provide case statements > that are like Squeak's. What do you consider a "true" case statement? I mean that: caseOf: is not part of the language itself but rather part of the standard library or set of packages that one finds in the IDE. To be part of the language it would need to be something the compiler is aware of. That is to day the Smalltalk language is not very much. Smalltalk (Squeak) the language would not include Sets or Dictionaries but would include (some) Array classes because some aspects of Arrays are dealt with directly by the compiler. Selectors such as ifTrue: and to:do: are part of the language because they are inlined by the compiler. Put another way, if I could get my doBlockAt: method incorporated into the Squeak IDE it would nevertheless NOT be part of Squeak the language. The consequence of caseOf: not being part of the language is that the compiler/VM cannot perform optimizations when caseOf: is run into but must treat it as user written code. Squeak's caseOf: is more general than C's switch statement but it could be more general in that there is a hard coded message (=). I would like to be able to replace the '=' message by an arbitrary binary operator such as includes: or '>'. I have to backtrack here: I looked at the code and it looks like the compiler inlines caseOf: and caseOf:otherwise. If so then these selectors are part of the language by my definition. ... > > But I wouldn't want to be forced to implement my FSMs this way. > > It might be acceptable for small FSMs. > > I want to avoid sequential search and > > even binary search might be rather expensive. > > I look at computed gotos as the solution but, > > as you pointed out, computed gotos pose problems for JIT. > > Admittedly, for large FSM's, it might be best or necessary to > > use a FSM simulator anyway, as I do now. > Nah. One should always be able to map it down somehow. Tis will be easier > with the Spur instruction set which lifts number of literals and length of > branches limits. Good to hear. > > Again, for my FSM, case this would often be considered to be good. > > But if the state transition tables are sparse then Dictionaries > > might be preferable to Arrays. > > Yes, but getting to the limit of what the VM can reasonably interpret. > Better would be an Array of value. pc pairs, where the keys are the values > the switch bytecode compares top of stack against, and the pcs are where to > jump to on a match. The JIT can therefore implement the table as it sees > fit, whereas the interpreter can just do a linear search through the Array. I am looking at this from the point of view of a compiler writer/generator and consider your proposal as inadequate for my needs. You, I think, are looking at this from the point of view of a VM writer and what can reasonably be delivered. I don't think what I want is overly difficult for the interpreter to deliver but as you pointed out, and you know much better than I, what I want causes serious problems for the VM. > > My expection is that at: be sent to the collection object > > to get the address to go to. Knowing that the collection > > is an array though makes it easier for the compiler/VM to > > ensure that the addresses stored in the collection are valid. > > Actually, the compiler will be generating the addresses. > > Does the VM have absolute trust in the compiler to generate valid > > addresses? > Yes. Generate bad bytecode and the VM crashes. This is what I expected to hear but wanted it to be clear for compilers generated by my parser generator tool as you did. Ralph

3 5

Squeak on Android
by Carlos Crosetti 08 Nov '14

08 Nov '14

Hi, I instaelled from the storeow I can open Squeak ad the nd run commands from menus and the world pop up menu too. I am on an Asus Memopad tablet, Android 4.2 I also can select an expression from within a workspace, how I do evaluate (do it, print it)? Thanks, Carlos

1 0

Re: Spur-3126 problem with #instVarAt:
by Eliot Miranda 08 Nov '14

08 Nov '14

HiChris, Hi All, Chris, forgive me for replying to vm-dev, but I want to canvas responses to the solutions I'm proposing, (and I want to spread this good news) so I'm begging forgiveness instead of asking permission ;-) On Thu, Nov 6, 2014 at 7:31 PM, Chris Muller <ma.chris.m(a)gmail.com> wrote: > Hi Eliot. The good news is, with a minor tweak to a timeout delay, > the Magma test suite actually *finished to completion*! > Yeeeeeaaaaahhh!!! > Fantastic news. Your's is a great test of the system. Thanks for your efforts in getting us this far! But its that required minor tweak that exposes the bad news, though -- > there seems to be some sort of performance issue when accessing via > #instVarAt:. > > In the following script, Cog reports 18M per second where Spur reports > 120K per second. > > | arr| arr := Array new: 1000. > [arr instVarAt: 1000] bench > > Also, observe changing the Array size to 1 and instVarAt: 1 speeds up > dramatically. This makes me think there is some sort of enumerating / > looping going on in #instVarAt: primitive. > Actually it is going on in the primitive failure machinery, not the primitive itself, but ok... this performance is to be expected. Here's the definition of instVarAt: instVarAt: index "Primitive. Answer a fixed variable in an object. The numbering of the variables corresponds to the named instance variables. Fail if the index is not an Integer or is not the index of a fixed variable. Essential. See Object documentation whatIsAPrimitive." <primitive: 73> "Access beyond fixed variables." ^self basicAt: index - self class instSize You see that the primitive is defined to access /only/ named inst vars, and to fail if access is attempted beyond the named inst vars. Now Array has no named inst vars, and so the primtiive will always fail. Now Spur provides transparent forwarding (and hence fast become with direct pointers) by checking for forwarding on message send (see your second issue) /and/ on primitive failure. So whenever the instVarAt: primitive fails the VM scans the receiver and arguments to the primitive's "accessor depth" (in this case 1, 0 comprising stack references to the arguments, 1 comprising inst vars of the receiver and arguments), looking for forwarding pointers, and if it finds any, eliminating them by following them and updating the reference, and then retrying the primitive. If none are found, or the primitive fails a second time, execution proceeds, failing the primitive and activating its method. The accessor depth for a primitive is computed by analysing the primitive's parse tree (actually the closure of the primitive's parse tree over any calls it makes). In this case the analysis concludes the depth is 1, whereas a depth of 0 would be ok in cases where there are no forwarded references in the Array; if the primitive were to answer a forwarded object, the forwarding pointer would be followed when it was sent a message. Lots of accesses to the same slot in the ARray. if it yielded a forwarding object, would push forwarding costs to where that result was used. So there's a toss up between eagerly following or not. The reason why changing the size of the array makes such a difference is that the VM has to scan the entire array and so does ~ 1000 times as much work when it has length 1000 than when it has length 1. The assumption behind my architecture here is that primitive failure is relatively rare. That's clearly not true in this case. Fortunately there are a number of solutions I can think of here: 1. in Magma you can implement a new method for accessing slots, lets call it slotAt:, and it would be defined like this: Object>>slotAt: index "Access the nth slot of an object. Use the instVarAt: primitive for speed with fixed, non-variable objects." <primitive: 73> "Access beyond fixed variables." ^self basicAt: index - self class instSize Array>>slotAt: index "Access the nth slot of an object. Use the basicAt:: primitive for speed with variable objects." <primitive: 60> index isInteger ifTrue: [self class isVariable ifTrue: [self errorSubscriptBounds: index] ifFalse: [self errorNotIndexable]]. index isNumber ifTrue: [^self slotAt: index asInteger] ifFalse: [self errorNonIntegerIndex] This only works if Array has no subclasses with named inst vars, or at least, if there are any Magma makes no use of them. 2. I can add a slotAt: primitive that does not fail when access is made beyond the named inst vars, but provides useful, flat access to all the slots. This will be very fast, but requires a little work. 3. re the point about what the forwarding depth should be, I could provide a "manual override" of the depth for specific primtiives, so that the depth for instVarAt: would be 0. This is a little work but might have more uses beyond instVarAt:. I'm leaning to 2. But want to hear waht others think, including any additional solutions. Anyway, interesting. A behaviour wonderous strange, no doubt :-) (Problem #2) -- Now, here's something weird that I could not begin to > guess at. Switching to plain #at: (instead of #instVarAt:), and then > compare the output with vs. without become: > > "without become" > | arr| arr := Array new: 1000. > [arr at: 1000] bench > > '56,600,000 per second.' > > to same measurement after becomed: to the same. > > | arr| arr := Object new. > arr becomeForward: (Array new: 1000). > [arr at: 1000] bench > > '4,060,000 per second.' > > So my reified Proxy's are operating much more slowly. This > degradation does not exist in Cog. > So what's happening here is that when the become occurs, the Object new version of arr is changed to a forwarder to an (Array new: 1000). When the message is sent to arr, the send fails, the send failure code scans the temp vars of the stack frame, updates arr to point directly to the (Array new: 1000) version of arr, completing the become: operation, and the send is retried. If you change the benchmarks to | arr| arr := Array new: 1000. [1 to: 1000 do: [:i| arr at: i]] bench | arr| arr := Object new. arr becomeForward: (Array new: 1000). [1 to: 1000 do: [:i| arr at: i]] bench you should see much less difference: | arr| arr := Array new: 1000. [1 to: 1000 do: [:i| arr at: i]] bench '163,000 per second.' | arr| arr := Object new. arr becomeForward: (Array new: 1000). [1 to: 1000 do: [:i| arr at: i]] bench '161,000 per second.' So how common is it that you become an object and send a message to it only once from a reference? Do you have any macro benchmarks? If the macro benchmarks show substantial speedups even though micro-benchmarks show slow-downs there's no issue. The costs in the micro operations are being paid to gain substantial advantages at the macro level. PS -- Why is #instVarAt: so much slower than #at:? Is there any way > to make it just as fast? > See above. > PPS -- that line-ending problem when using the Clipboard that Levente > mentioned the other day has dogged me all year as well. Would it be > possible to include the -textenc UTF8 by default in the squeak script > that you release? > Yes. I think I can just make this the default in all VMs and/or just the Spur ones. IIRC I found out what the name to use for the defalt was just the other day. I'm going to go find it again, but yes, I'll make this the default. I'd prefer to make it the only choice. Is that OK with folks? > Thank you for this (soon-to-be) awesome piece of software.. > sigh ;-) -- best, Eliot

2 1

Re: [squeak-dev] Scratch plugins 1.4
by David T. Lewis 08 Nov '14

08 Nov '14

Javier, Thank you! I have also copied your updates to http://squeakvm.org/~lewis/MacOS-test-Javier/ Mac Squeakers: Please try this VM and let us know if it works for you. It should work for Etoys and Scratch, as well as for the latest Squeak trunk image. Dave On Fri, Nov 07, 2014 at 04:11:38PM -0500, Javier Diaz-Reinoso wrote: > I find here: > > > http://www.mobilewikiserver.com/Scratch.html > > the plugins CameraPlugin, ScratchPlugin and UnicodePlugin; so I compile in my old mac mini PPC and tested CameraPlugin using CameraPlugin>>videoTest from CameraPlugin.st, also from that site. > > I tested with the VM I compiled (Squeak 4.2.5beta2U) in an old iBook G4 with an USB webcam, also in a iMac intel (internal camera) and work OK, then I tested in Squeak 4.2.5beta1U and in Cog 4.0.3114 and also works. > > If you want to test download from: > > > https://copy.com/WdM4ygDwxAhZ314Z > > I don't tested the other plugins because I don't know what they do.

1 0

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

Vm-dev November 2014