Sumanth Gundapaneni via llvm-dev
2015-Sep-23 21:44 UTC
[llvm-dev] Codegen difference between Asserts and No-Asserts mode
Hi, What is the guarantee that the codegen is same across Release and Release+Asserts build (except the known differences)? I assume there is no guarantee and it is possible to drop a bug like this. Personally I feel it is very expensive to debug and it depends on each scenario. Most of the bots test the Release+Asserts mode and any thoughts on how we can catch this sort of a problem with minimal set of changes to build infrastructure? --Sumanth G -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150923/26661e98/attachment.html>
Hal Finkel via llvm-dev
2015-Sep-23 21:48 UTC
[llvm-dev] Codegen difference between Asserts and No-Asserts mode
Hi Sumanth, I don't know to what you're referring, but the output from Release vs. Release+Asserts should be identical. There might be differences in the IR value names, but if that is affecting the final result, that's a bug. -Hal ----- Original Message -----> From: "Sumanth Gundapaneni via llvm-dev" <llvm-dev at lists.llvm.org> > To: llvmdev at cs.uiuc.edu, llvm-dev at lists.llvm.org > Sent: Wednesday, September 23, 2015 4:44:05 PM > Subject: [llvm-dev] Codegen difference between Asserts and No-Asserts mode > > Hi, > > What is the guarantee that the codegen is same across Release and > Release+Asserts build (except the known differences)? > > I assume there is no guarantee and it is possible to drop a bug like > this. Personally I feel it is very expensive to debug and it depends > on each scenario. > > Most of the bots test the Release+Asserts mode and any thoughts on > how we can catch this sort of a problem with minimal set of changes > to build infrastructure? > > --Sumanth G > > > > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-- Hal Finkel Assistant Computational Scientist Leadership Computing Facility Argonne National Laboratory
Greg Bedwell via llvm-dev
2015-Sep-28 12:01 UTC
[llvm-dev] Codegen difference between Asserts and No-Asserts mode
I imagine that the Clang "Check Compile Flow Consistency" tool (tools/clang/utils/check_cfc) would be a good fit for this sort of testing. It's currently used to verify that adding -g does not affect codegen or that compiling via a .s file produces the same codegen as a directly emitted object, so it may not be too much of a stretch to use it to verify that two different sets of compiler binaries produce identical codegen. Obviously you'd need a bot that was building both sets of executables first. Unfortunately, I don't have any time to look at doing this myself but I expect it would be worthwhile thing to do if someone wanted to pick this up. -Greg On 23 September 2015 at 22:48, Hal Finkel via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Hi Sumanth, > > I don't know to what you're referring, but the output from Release vs. > Release+Asserts should be identical. There might be differences in the IR > value names, but if that is affecting the final result, that's a bug. > > -Hal > > ----- Original Message ----- > > From: "Sumanth Gundapaneni via llvm-dev" <llvm-dev at lists.llvm.org> > > To: llvmdev at cs.uiuc.edu, llvm-dev at lists.llvm.org > > Sent: Wednesday, September 23, 2015 4:44:05 PM > > Subject: [llvm-dev] Codegen difference between Asserts and No-Asserts > mode > > > > Hi, > > > > What is the guarantee that the codegen is same across Release and > > Release+Asserts build (except the known differences)? > > > > I assume there is no guarantee and it is possible to drop a bug like > > this. Personally I feel it is very expensive to debug and it depends > > on each scenario. > > > > Most of the bots test the Release+Asserts mode and any thoughts on > > how we can catch this sort of a problem with minimal set of changes > > to build infrastructure? > > > > --Sumanth G > > > > > > > > > > _______________________________________________ > > LLVM Developers mailing list > > llvm-dev at lists.llvm.org > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > > > > -- > Hal Finkel > Assistant Computational Scientist > Leadership Computing Facility > Argonne National Laboratory > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150928/e797a6a4/attachment.html>