December 2019 - Pharo-dev - lists.pharo.org

[Pharo 8.0] Build #1073: Revert "5223-Remove-blueInk-packages-from-repository"
by ci-pharo-ci-jenkins2＠inria.fr Dec. 13, 2019

Dec. 13, 2019

There is a new Pharo build available! The status of the build #1073 was: SUCCESS. The Pull Request #5377 was integrated: "Revert "5223-Remove-blueInk-packages-from-repository"" Pull request url: https://github.com/pharo-project/pharo/pull/5377 Issue Url: https://github.com/pharo-project/pharo/issues/revert Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1072: Improving comments of ffiCall: and ffiLibrary.
by ci-pharo-ci-jenkins2＠inria.fr Dec. 13, 2019

Dec. 13, 2019

There is a new Pharo build available! The status of the build #1072 was: FAILURE. The Pull Request #5357 was integrated: "Improving comments of ffiCall: and ffiLibrary." Pull request url: https://github.com/pharo-project/pharo/pull/5357 Issue Url: https://github.com/pharo-project/pharo/issues/5352 Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1071: Revert "Revert "[Perfs] x10 on method compiling with #deferFlushDuring
by ci-pharo-ci-jenkins2＠inria.fr Dec. 13, 2019

Dec. 13, 2019

There is a new Pharo build available! The status of the build #1071 was: SUCCESS. The Pull Request #5374 was integrated: "Revert "Revert "[Perfs] x10 on method compiling with #deferFlushDuring" Pull request url: https://github.com/pharo-project/pharo/pull/5374 Issue Url: https://github.com/pharo-project/pharo/issues/5292 Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1070: Reword of ZnClient ifFail: method comment
by ci-pharo-ci-jenkins2＠inria.fr Dec. 13, 2019

Dec. 13, 2019

There is a new Pharo build available! The status of the build #1070 was: SUCCESS. The Pull Request #5371 was integrated: "Reword of ZnClient ifFail: method comment" Pull request url: https://github.com/pharo-project/pharo/pull/5371 Issue Url: https://github.com/pharo-project/pharo/issues/ZnClient Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1069: Announcements: Small Cleanup
by ci-pharo-ci-jenkins2＠inria.fr Dec. 12, 2019

Dec. 12, 2019

There is a new Pharo build available! The status of the build #1069 was: SUCCESS. The Pull Request #5367 was integrated: "Announcements: Small Cleanup" Pull request url: https://github.com/pharo-project/pharo/pull/5367 Issue Url: https://github.com/pharo-project/pharo/issues/AnnouncementsClean Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1068: [easyReview] slightly better DNU message
by ci-pharo-ci-jenkins2＠inria.fr Dec. 12, 2019

Dec. 12, 2019

There is a new Pharo build available! The status of the build #1068 was: SUCCESS. The Pull Request #5361 was integrated: "[easyReview] slightly better DNU message" Pull request url: https://github.com/pharo-project/pharo/pull/5361 Issue Url: https://github.com/pharo-project/pharo/issues/typo Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1067: Demeter's law: fix two cases
by ci-pharo-ci-jenkins2＠inria.fr Dec. 12, 2019

Dec. 12, 2019

There is a new Pharo build available! The status of the build #1067 was: FAILURE. The Pull Request #5366 was integrated: "Demeter's law: fix two cases" Pull request url: https://github.com/pharo-project/pharo/pull/5366 Issue Url: https://github.com/pharo-project/pharo/issues/Demeterslawfix Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 8.0] Build #1066: Change url in GoverApiTest >>testRepositoryErrors
by ci-pharo-ci-jenkins2＠inria.fr Dec. 12, 2019

Dec. 12, 2019

There is a new Pharo build available! The status of the build #1066 was: SUCCESS. The Pull Request #5363 was integrated: "Change url in GoverApiTest >>testRepositoryErrors" Pull request url: https://github.com/pharo-project/pharo/pull/5363 Issue Url: https://github.com/pharo-project/pharo/issues/GoferApiTestServerChange Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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Debugging GCC code generation
by tesonep＠gmail.com Dec. 11, 2019

Dec. 11, 2019

Hi, this mail is related to Pharo because it is knowledge I found debugging the build of the VM, but the rest is to document it and perhaps someone will found it interesting (also I couldn't find it easily using Google). Sorry for the long mail! The problem ========== The following code does not produce good code in 8.3 when using optimizations: long __attribute__ ((noinline)) myFunc(long i, int index){ long v; long x = i >> 3; v = x; return ((int*)(&v))[index]; } #include <stdio.h> int main(){ long i; int x; scanf("%ld", &i); scanf("%d", &x); printf("%ld",myFunc(i,x)); } Basically, with -02, it generates the following code: myFunc: movslq %esi, %rsi movslq -8(%rsp,%rsi,4), %rax ret And with -01 it generates the following code: myFunc: sarq $3, %rdi movq %rdi, -8(%rsp) movslq %esi, %rsi movslq -8(%rsp,%rsi,4), %rax ret As you can see, the more optimized version is losing the bit shift (or any other operation). To detect the problem it was not easy, basically, I have used the Pharo Tests to detect the failing function and then to understand the generation of code in GCC, we need to debug its generation. The first snippet is generated using: gcc -O2 prb.c -S -o prb.s -Wall and the second using: gcc -O1 prb.c -S -o prb.s -Wall The GCC pipeline has different steps, I have centered my self in the tree optimizations. GCC dumps each of the intermediate states of the compilation, working with C like trees. For example to get the optimized version of the program, before generating the Assembler we have to do: gcc -O2 prb.c -S -o prb.s -Wall -fdump-tree-optimized=/dev/stdout This will generate: __attribute__((noinline)) myFunc (long int i, int index) { long int v; long unsigned int _1; long unsigned int _2; int * _3; int _4; long int _8; <bb 2> [local count: 1073741825]: _1 = (long unsigned int) index_7(D); _2 = _1 * 4; _3 = &v + _2; _4 = *_3; _8 = (long int) _4; v ={v} {CLOBBER}; return _8; } This is the optimized SSA (static single assign) version of the function (https://gcc.gnu.org/onlinedocs/gccint/SSA.html) As you can see in this version the code is already optimized, and our operations not correctly generated. We expect to see something like: __attribute__((noinline)) myFunc (long int i, int index) { long int x; long int v; long unsigned int _1; long unsigned int _2; int * _3; int _4; long int _10; <bb 2> [local count: 1073741825]: x_6 = i_5(D) >> 3; v = x_6; _1 = (long unsigned int) index_9(D); _2 = _1 * 4; _3 = &v + _2; _4 = *_3; _10 = (long int) _4; v ={v} {CLOBBER}; return _10; } In the first SSA version, we are lacking the shift operation: x_6 = i_5(D) >> 3; v = x_6; So, we need to see in which of the optimizations and transformations our code is lost: To see all the steps we should execute: gcc -O2 prb.c -S -o prb.s -Wall -fdump-tree-all This will generate a lot, really a lot, of files in the same directory. They have the name: prb.c.xxx.yyyy Where xxx is the number of the step, and yyyy is the name of the step. Each of the files contains the result of applying the changes, so what I have done is looking in binary search where my code was lost. I have found that the problem was in the first dead code elimination step (prb.c.041t.cddce1) GCC does not like the crap code that we are writing, as we are copying a stack variable and then accessing directly to the memory: v = x; return ((int*)(&v))[index]; So, basically, it was assuming that we were only using v and not x, so all the code modifying x is described (this optimization is called "dead store code deletion"). Basically tries to remove all the code that is affecting stack (temporary) variables that are never used. I am not sure if this is a bug in GCC, so I will report it. But I have fixed the problem writing the code in a proper way. Sorry again for the long mail, I wanted to store the knowledge and propagate it before I eventually will flush it. I like these things, but I am not debugging the GCC optimization pipeline all the days. -- Pablo Tesone. tesonep(a)gmail.com

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[Pharo 8.0] Build #1065: Revert "[Perfs] x10 on method compiling with #deferFlushDuring:"
by ci-pharo-ci-jenkins2＠inria.fr Dec. 11, 2019

Dec. 11, 2019

There is a new Pharo build available! The status of the build #1065 was: SUCCESS. The Pull Request #5359 was integrated: "Revert "[Perfs] x10 on method compiling with #deferFlushDuring:"" Pull request url: https://github.com/pharo-project/pharo/pull/5359 Issue Url: https://github.com/pharo-project/pharo/issues/revert Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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