[PATCH] D16726: [Profiling] Speed up unittests by ~5x

[Xinliang David Li via llvm-commits]

On Mon, Feb 8, 2016 at 3:12 PM, David Blaikie <dblaikie at gmail.com> wrote:
>
>
> On Mon, Feb 8, 2016 at 3:08 PM, Xinliang David Li <davidxl at google.com>
> wrote:
>>
>> On Mon, Feb 1, 2016 at 10:44 AM, David Blaikie <dblaikie at gmail.com> wrote:
>> >
>> >
>> > On Fri, Jan 29, 2016 at 5:58 PM, Xinliang David Li <davidxl at google.com>
>> > wrote:
>> >>
>> >> To clarify, it is not 128 iterations, but creating a symbol table with
>> >> 128 entries -- which is a reasonable size.
>> >
>> >
>> > We don't generally test on "realistic" sized inputs in the regression
>> > suite.
>> > We write targeted tests for functionality. Broad testing is done in the
>> > test-suite and other integration level testing.
>> >
>> >>
>> >> Test coverage wise, it is probably the same as a 3-entry symtab.
>> >
>> >
>> > Then let's use a 3-entry symtab.
>> >
>> > (why 3? Because it tests the boundaries (first and last) and one
>> > "normal"
>> > case of a non-boundary value - while the boundaries probably aren't
>> > interesting in this algorithm, it's cheap enough to just follow that
>> > common
>> > practice in test case design)
>>
>> Will update it to 3.
>>
>> >
>> > I'm also curious about the padding parameter - what does it do? Choose
>> > how
>> > many null characters go between each value? What effect does that
>> > have/why
>> > is that a tuning parameter? (understanding what it's for can help us
>> > choose
>> > appropriate test cases/coverage for that functionality)
>>
>> Internal padding bytes (for alignment to 4 bytes) can be zero to 3.
>
>
> Any idea what's particularly useful to test here? (does it just assert that
> the parameter is [0,3] ? Or does it have well defined behavior (returning an
> error code? doing something else?) outside that range? is any case more
> interesting than any other - or just a simple loop for [0,Padding] done at
> some point in the algorithm? Does anything test that the algorithm emitted
> the right padding?)

It tests that the reader is (flexible) and capable of handing padding
bytes not produced by the writer.  How many paddings should be emitted
is not specified. For instance, if some producer forces 8 byte
alignment, it should be handled too.

David