[PATCH][X86] SSE2 cvtsd2ss instruction expects two operands

[Cameron McInally]

On Tue, Oct 22, 2013 at 11:11 PM, Craig Topper <craig.topper at gmail.com> wrote:
> For this case you can probably copy the avx-intrinsics.ll test case for this
> intrinsic and create an sse2-intrinsics.ll. There appear to be several more
> intrinsics that aren't being tested on sse2 so if you want to add tests for
> them that would be awesome.

Ah, interesting. Thanks, Craig.

This looks like it needs a good bit of work. I notice that the SSE
intrinsic test cases are not as well organized as the AVX, FMA, and
XOP intrinsics. It would be nice to bring SSE up to par.

Ideally, here is what I would like to do:

1) Replicate the intrinsic tests covered in avx-intinsics-x86.ll for
their SSE equivalents. To do this, I suggest adding several new .ll
files. One for each subclass of the SSE intrinsics.

sse-intrinsics-x86.ll
sse2-intrinsics-x86.ll
sse3-intrinsics-x86.ll
ssse3-intrinsics-x86.ll
sse41-intrinsics-x86.ll
sse42-intrinsics-x86.ll

This would organize the SSE intrinsic tests a bit better, but is not
without issue. I suspect that there would be some immediate
double-coverage in the test base. Cleaning this up would need some
future care.

2) Add more robust CHECKs to these intrinsic tests, including those in
avx-intrinsics-x86.ll and friends. Currently, these CHECKs look for
the instruction name, but ignore the operand classes and count.

Quentin mentioned using a CHECK-NOT for the issue at hand:

define @fct(<some args>) {
; CHECK-NOT: <expected instruction> <regex op1>, <regex op2>, <regex op3>
<simple use of your instrinsic>
}

This is a good solution for our current problem. But, it is not so
clear that it would scale well. Ideally, it would be nice to check for
the case we really want, instead of one-of-many cases that we do not
want. Of course, this depends on the expressiveness of the CHECK
mechanism, which is something I have no intuition built around. So, I
do not have a good solution right now. It is something that I would
have to think about.

In the meantime, please advise if you would like to go ahead with the
SSE test clean-up.

-Cameron