[PATCH] D43962: [GlobalISel][utils] Adding the init version of Instruction Select Testgen

[Roman Tereshin via Phabricator via llvm-commits]

rtereshin added a comment.

Performance
===========

or why all the tests are in a single file?

F5866910: Screen Shot 2018-03-02 at 3.33.49 PM.png <https://reviews.llvm.org/F5866910>

in short, with test cases in separate test-files it takes at least ~30 times (or at least 2 minutes just for AArch64 and only for the rules currently imported by GlobalISel emitter) longer to update the tests, and at least 15 times (or at least 40 seconds just for AArch64 and only for the rules currently imported by GlobalISel emitter) longer to run the tests on 4-cores SSD-only iMac running macOS depending on a build type. In some cases, the difference reaches 130x / 5 minutes.

With all the tests in a single file it takes about 2 seconds to update them for AArch64 at the moment, and about 1.33 seconds to run them on the same machine as described above (both tests ran in parallel, where the test testing the Testgen itself takes ~1/3 of a second, and the test testing the Instruction Selector takes the full 1.33 seconds).


Repository:
  rL LLVM

https://reviews.llvm.org/D43962