Commit Graph

10 Commits

Author SHA1 Message Date
Chandler Carruth 71f4187dbb [x86] Merge still more combine tests into the common file. These at
least seem *slightly* more interesting test wise, although given how
spotily we actually combine anything, I remain somewhat suspicious.

llvm-svn: 218861
2014-10-02 08:02:34 +00:00
Chandler Carruth 782b0a72ac [x86] Merge the third combining test into the generic one and add proper
checks for all the ISA variants.

If the SSE2 checks here terrify you, good. This is (in large part) the
kind of amazingly bad code that is holding LLVM back when vectorizing on
older ISAs.

At the same time, these tests seem increasingly dubious to me. There are
a very large number of tests and it isn't clear that they are
systematically covering a specific set of functionality. Anyways,
I don't want to reduce testing during the transition, I just want to
consolidate it to where it is easier to manage.

llvm-svn: 218860
2014-10-02 07:56:47 +00:00
Chandler Carruth b2941e2693 [x86] Merge the second set of vector combining tests into a common test
file.

Some of these really don't make sense to test -- we're testing for the
*lack* of combining two shuffles into one, presumably because the two
would generate better shuffles in the end. But if you look at the
generated code shown here, in many cases the generated code is, frankly,
terrible. Or we combine any two generated shuffles back into a single
instruction! I've left a FIXME to revisit these decisions.

llvm-svn: 218859
2014-10-02 07:42:58 +00:00
Chandler Carruth 2110501822 [x86] Merge the bitwise operation shuffle combining into the common test
file, adding assertions across the ISA variants for it.

llvm-svn: 218858
2014-10-02 07:30:24 +00:00
Chandler Carruth 3c7bf04c87 [x86] Update this test to run a full complement of the ISA extensions,
and use the new grouped FileCheck patterns to match them.

No interesting changes yet, but this test is now in proper form to have
the other shuffle combining tests merged into it.

llvm-svn: 218857
2014-10-02 07:22:26 +00:00
Chandler Carruth 11a5ae0880 [x86] Minimize the parameters to this test for clarity.
The test has to do with DAG combines, and so it doesn't need the new
vector shuffle lowering to be effective. Also, it has a nice in-IR
triple string which we should really be using rather than command line
flags (unless it varies form RUN-line to RUN-line). Finally, I much
prefer letting LLVM synthesize the correct datalayout string from the
triple rather than baking one in here that will just become stale.

llvm-svn: 218856
2014-10-02 07:17:15 +00:00
Chandler Carruth 7b2706726e [x86] Add a comment clarifying that this test should span all manners of
generic DAG combining of shuffles relevant to x86.

My plan is to fold a bunch of the other DAG combining test cases into
this one, while converting them to use the nice new FileCheck assertion
syntax.

llvm-svn: 218855
2014-10-02 07:13:25 +00:00
Benjamin Kramer e739cf3eb5 X86: When combining shuffles just remove shuffles that are completely redundant.
CombineTo doesn't allow replacing a node with itself so this would crash if the
combined shuffle is the same as the input shuffle.

llvm-svn: 212181
2014-07-02 15:09:44 +00:00
Chandler Carruth 688001f042 [x86] Teach the target combine step to aggressively fold pshufd insturcions.
Summary:
This allows it to fold pshufd instructions across intervening
half-shuffles and other noise. This pattern actually shows up in the
generic lowering tests, but I've also added direct tests using
intrinsics to make sure that the specific desired functionality is
working even if the lowering stuff changes in the future.

Differential Revision: http://reviews.llvm.org/D4292

llvm-svn: 211892
2014-06-27 11:40:13 +00:00
Chandler Carruth 0d6d1f2b17 [x86] Teach the target-specific combining how to aggressively fold
half-shuffles, even looking through intervening instructions in a chain.

Summary:
This doesn't happen to show up with any test cases I've found for the current
shuffle lowering, but previous attempts would benefit from this and it seems
generally useful. I've tested it directly using intrinsics, which also shows
that it will work with hand vectorized code as well.

Note that even though pshufd isn't directly used in these tests, it gets
exercised because we combine some of the half shuffles into a pshufd
first, and then merge them.

Differential Revision: http://reviews.llvm.org/D4291

llvm-svn: 211890
2014-06-27 11:34:40 +00:00