[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Mark Dickinson added the comment: > Closing this as out of date. SGTM. Thanks. -- ___ Python tracker ___ ___ Python-bugs-list mail

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: I no longer have access to ICC, and the ICC buildbots have been mothballed some years ago. Closing this as out of date; the issue might not be, but the information about it here probably is :) -- resolution: -> out of date stage: -> resolved status:

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: I closed this prematurely: I successfully added /fp:strict to ICC builds, but it didn't fix the underlying issue. -- resolution: fixed -> stage: resolved -> status: closed -> open ___ Python tracker

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: With the buildbots not angry over this, I'm closing the issue. I opened #26262 to follow the possibility of changing the initializers to allow /fp:strict with MSVC. -- assignee: -> zach.ware resolution: -> fixed stage: -> resolved status: open -> clo

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Roundup Robot added the comment: New changeset 296fb7c10a7d by Zachary Ware in branch '2.7': Issue #25934: Default to /fp:strict for ICC builds https://hg.python.org/cpython/rev/296fb7c10a7d New changeset 747b415e96c4 by Zachary Ware in branch '3.5': Issue #25934: Default to /fp:strict for ICC b

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: Here's a patch that specifies /fp:strict if it looks like ICC is being used for the build. It also adds a convenient property for checking whether it's an ICC build ($(ICCBuild)). This doesn't change anything for MSVC builds but allows ICC builds to pass test_

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Mark Dickinson added the comment: The dtoa.c occurrence is also straightforward to fix. It's coming from this declaration: static const double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128, 9007199254740992.*9007199254740992.e-256}; We need to be a tiny bit careful here,

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Steve Dower added the comment: I'm -0 on changing the universal default (and want to call out that it's a relevant porting note for 3.6, not appropriate for 3.5), but we can presumably fix those in case someone wants to use strict for their own build. -- __

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Mark Dickinson added the comment: Thanks. The offending lines in the math module are: static const double degToRad = Py_MATH_PI / 180.0; static const double radToDeg = 180.0 / Py_MATH_PI; It would be trivial to replace these with suitable constants. --

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: Ah, it's been a while since I tested that, so my reporting was inaccurate. The problem is actually that the compile fails: ..\Modules\mathmodule.c(1924): error C2099: initializer is not a constant [C:\cpython\PCbuild\pythoncore.vcxproj] ..\Modules\mathmodule.c(

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Mark Dickinson added the comment: Which tests fail with MSVC /fp:strict? It's surprising that making behaviour stricter causes tests to fail that wouldn't have done otherwise. :-) -- ___ Python tracker ___

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Zachary Ware added the comment: I've looked into this a bit, and tests won't pass with MSVC /fp:strict, so it would need to be ICC specific. UNIX ICC builds do unconditionally use -fp-model strict now, though, so I think Windows ICC builds should as well. -- _

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

Changes by Serhiy Storchaka : -- components: +Build, Windows type: -> crash versions: +Python 3.5, Python 3.6 ___ Python tracker ___

[issue25934] ICC compiler: ICC treats denormal floating point numbers as 0.0

New submission from Stefan Krah: Zachary in #24999: "If that's the case, would anyone (in particular, Steve, Tim or Tim) mind if we just made the default (for MSVC as well as ICC) /fp:strict? It would be much easier to just change the global default than to try to either make it settable or