Coverage decreased (-0.009%) to 77.621% when pulling 4ac220f on uploadcare:fpi-resample into 12bd44a on python-pillow:master.

What are the units on the performance measurement?

Coverage increased (+0.05%) to 77.684% when pulling ba4a539 on uploadcare:fpi-resample into 12bd44a on python-pillow:master.

I split ImagingResampleHorizontal to two versions: for 8 bits per channel with int accumulators and for 32 bits per channel with double accumulator. I have tried to reduce code duplication and make separate ImagingPrecompute function.

New tests really good, because they check the consistency of result after manipulations: there should not be any shifts or dithering. And just for information, none of new tests are passed on master:

======================================================================
FAIL: CoreResampleConsistencyTest.test_32f
----------------------------------------------------------------------
AssertionError: 1.00000011921 != 1.0 for pixel (0, 1)
AssertionError: nan != 3.40282306074e+38 for pixel (0, 0)
AssertionError: 1.17549351004e-38 != 1.17549393043e-38 for pixel (0, 0)
AssertionError: 1.19209289551e-07 != 1.19209303762e-07 for pixel (0, 0)

======================================================================
FAIL: CoreResampleConsistencyTest.test_32i
----------------------------------------------------------------------
AssertionError: 11 != 12 for pixel (0, 0)
AssertionError: -2147483392 != 2147483647 for pixel (0, 0)
AssertionError: -11 != -12 for pixel (0, 0)
AssertionError: -2147483392 != -2147483648 for pixel (0, 0)

With the latest changes (separate ImagingPrecompute) new implementation is about 1% slower than initial for 8bpc and about 10% slower than master for 32bpc: this is a fee for the accuracy. Also, the bug with GCC 4.8 and below is still relevant for I mode, but I think this is the time then we can remove workaround: users who really faced with this problem can update compiler.

Could anyone help me with AppVeyor windows builds? Error message command 'link.exe' failed with exit status 1120 doesn't make any sense and I don't see any other errors.

I'll see what I can do on the windows builds. Probably a compile error, and for some reason we're not getting the traces. The usual compile error is from a declaration not being at the beginning of a block, but I'm not seeing that from a quick scan of the diff.

Error appears to be this: https://ci.appveyor.com/project/wiredfool/pillow/build/3.3.pre.290/job/n525alym7ebxiips#L1369

Resample.obj : error LNK2019: unresolved external symbol lround referenced in function ImagingResampleHorizontal_32bpc
build\lib.win-amd64-2.7\PIL\_imaging.pyd : fatal error LNK1120: 1 unresolved externals

If you rebase, you'll get the appveyor changes.

unresolved external symbol lround

ok, I'll check what we can use in Visual C

Changes Unknown when pulling b04e736 on uploadcare:fpi-resample into * on python-pillow:master*.

Changes Unknown when pulling c23e897 on uploadcare:fpi-resample into * on python-pillow:master*.

Changes Unknown when pulling 0da1564 on uploadcare:fpi-resample into * on python-pillow:master*.

Changes Unknown when pulling 233bbb6 on uploadcare:fpi-resample into * on python-pillow:master*.

Changes Unknown when pulling 8ca0a5d on uploadcare:fpi-resample into * on python-pillow:master*.

LOL, new problems with windows: build hangs up on test-installed.py.

I'm ok with all other changes.

Changes Unknown when pulling aaf51e4 on uploadcare:fpi-resample into * on python-pillow:master*.

@wiredfool Any thoughts about win builds?

I'll take a look, bot probably not tonight.

Looks like it's this test: https://github.com/python-pillow/Pillow/blob/master/Tests/test_image_filter.py#L39 that is hanging.

See: https://ci.appveyor.com/project/wiredfool/pillow/build/3.3.pre.295/job/wq9ms96g7w1amjvy

The code to change the way the tests run is in wiredfool@55b2c3b, which I'm planning to pr/commit shortly.

I found out that the problem is in replacing malloc with calloc. I have no idea why is it happens because calloc is already used in Pillow in many places. Moreover, as I understand, TestImageFilter.test_crash doesn't use resampling and don't call the code with calloc from this PR.

Changes Unknown when pulling 757a728 on uploadcare:fpi-resample into * on python-pillow:master*.

Returning malloc makes builds green again. I don't understand anything )

Coverage increased (+0.01%) to 77.708% when pulling 1c3def1 on uploadcare:fpi-resample into 73c8140 on python-pillow:master.

Coverage increased (+0.01%) to 77.708% when pulling 5ffd9e5 on uploadcare:fpi-resample into 73c8140 on python-pillow:master.

@wiredfool Done. Also rebased against master to pass the latest resampling accuracy tests.