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author | Renato Golin <renato.golin@linaro.org> | 2013-07-03 20:56:33 +0000 |
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committer | Renato Golin <renato.golin@linaro.org> | 2013-07-03 20:56:33 +0000 |
commit | f0126ea0a1a574b6b45c93a1a56a24d0ce30de87 (patch) | |
tree | 7dc5480c71aec3420ac680b79e7f7eae2807e2a9 /docs/TestingGuide.rst | |
parent | 79c163d6ddeb84ea1743eca0644688951bfc5a97 (diff) | |
download | external_llvm-f0126ea0a1a574b6b45c93a1a56a24d0ce30de87.zip external_llvm-f0126ea0a1a574b6b45c93a1a56a24d0ce30de87.tar.gz external_llvm-f0126ea0a1a574b6b45c93a1a56a24d0ce30de87.tar.bz2 |
Add platform specific tests doc
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185581 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/TestingGuide.rst')
-rw-r--r-- | docs/TestingGuide.rst | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/docs/TestingGuide.rst b/docs/TestingGuide.rst index 79cedee..3cfbb21 100644 --- a/docs/TestingGuide.rst +++ b/docs/TestingGuide.rst @@ -275,6 +275,66 @@ This test will fail if placed into a ``download`` directory. To make your tests robust, always use ``opt ... < %s`` in the RUN line. :program:`opt` does not output a ``ModuleID`` when input comes from stdin. +Platform-Specific Tests +----------------------- + +Whenever adding tests that require the knowledge of a specific platform, +either related to code generated, specific output or back-end features, +you must make sure to isolate the features, so that buildbots that +run on different architectures (and don't even compile all back-ends), +don't fail. + +The first problem is to check for target-specific output, for example sizes +of structures, paths and architecture names, for example: + +* Tests containing Windows paths will fail on Linux and vice-versa. +* Tests that check for ``x86_64`` somewhere in the text will fail anywhere else. +* Tests where the debug information calculates the size of types and structures. + +Also, if the test rely on any behaviour that is coded in any back-end, it must +go in its own directory. So, for instance, code generator tests for ARM go +into ``test/CodeGen/ARM`` and so on. Those directories contain a special +``lit`` configuration file that ensure all tests in that directory will +only run if a specific back-end is compiled and available. + +For instance, on ``test/CodeGen/ARM``, the ``lit.local.cfg`` is: + +.. code-block:: python + + config.suffixes = ['.ll', '.c', '.cpp', '.test'] + targets = set(config.root.targets_to_build.split()) + if not 'ARM' in targets: + config.unsupported = True + +Other platform-specific tests are those that depend on a specific feature +of a specific sub-architecture, for example only to Intel chips that support ``AVX2``. + +For instance, ``test/CodeGen/X86/psubus.ll`` tests three sub-architecture +variants: + +.. code-block:: llvm + + ; RUN: llc -mcpu=core2 < %s | FileCheck %s -check-prefix=SSE2 + ; RUN: llc -mcpu=corei7-avx < %s | FileCheck %s -check-prefix=AVX1 + ; RUN: llc -mcpu=core-avx2 < %s | FileCheck %s -check-prefix=AVX2 + +And the checks are different: + +.. code-block:: llvm + + ; SSE2: @test1 + ; SSE2: psubusw LCPI0_0(%rip), %xmm0 + ; AVX1: @test1 + ; AVX1: vpsubusw LCPI0_0(%rip), %xmm0, %xmm0 + ; AVX2: @test1 + ; AVX2: vpsubusw LCPI0_0(%rip), %xmm0, %xmm0 + +So, if you're testing for a behaviour that you know is platform-specific or +depends on special features of sub-architectures, you must add the specific +triple, test with the specific FileCheck and put it into the specific +directory that will filter out all other architectures. + + Variables and substitutions --------------------------- |