reversed in the function's original ordering, and we happened to
encounter it while handling an outer unnatural CFG structure.

Thanks to the test case reduced from GCC's source by Benjamin Kramer.
This may also fix a crasher in gzip that Duncan reduced for me, but
I haven't yet gotten to testing that one.

llvm-svn: 145094

llvm-svn: 145092

llvm-svn: 145079

llvm-svn: 145078

add basic PPC register-pressure feedback; adjust the vaarg test to match the new register-allocation pattern

llvm-svn: 145065

More fixes to the X86InstComments for shuffle instructions. In particular add AVX flavors of many instructions and fix the destination operand for some of the existing AVX entries.

llvm-svn: 145063

updateTerminator code didn't correctly handle EH terminators in one very
specific case. AnalyzeBranch would find no terminator instruction, and
so the fallback in updateTerminator is to assume fallthrough. This is
correct, but the destination of the fallthrough was assumed to be the
first successor.

This is *almost always* true, but in certain cases the loop
transformations will cause the landing pad to be the first successor!
Instead of this brittle logic, actually look through the successors for
a non-landing-pad accessor, and to assert if more than one is found.

This will hopefully fix some (if not all) of the self host miscompiles
with block placement. Thanks to Benjamin Kramer for reporting, Nick
Lewycky for an initial stab at a reduction, and Duncan for endless
advice on EH (which I know nothing about) as well as reviewing the
actual fix.

llvm-svn: 145062

llvm-svn: 145061

dropping weights on the floor for invokes. This was impeding my writing
further test cases for invoke when interacting with probabilities and
block placement.

No test case as there doesn't appear to be a way to test this stuff. =/
Suggestions for a test case of course welcome. I hope to be able to add
test cases that indirectly cover this eventually by adding probabilities
to the exceptional edge and reordering blocks as a result.

llvm-svn: 145060

This was put in because in a certain version of DragonFlyBSD stat(2) lied about the
size of some files. This was fixed a long time ago so we can remove the workaround.

llvm-svn: 145059

llvm-svn: 145057

before the clobber so that we copy the value if needed.

Fixes pr11415.

llvm-svn: 145056

Fix shuffle decoding logic to handle UNPCKLPS/UNPCKLPD on 256-bit vectors correctly. Add support for decoding UNPCKHPS/UNPCKHPD for AVX 128-bit and 256-bit forms.

llvm-svn: 145055

Add methods for querying minimum SSE version along with AVX. Simplifies all the places that had to check a version of SSE and AVX.

llvm-svn: 145053

llvm-svn: 145048

llvm-svn: 145047

llvm-svn: 145044

llvm-svn: 145028

llvm-svn: 145027

llvm-svn: 145026

llvm-svn: 145025

Make LowerSIGN_EXTEND_INREG split 256-bit vectors when AVX1 is enabled and use AVX2 shifts when AVX2 is enabled.

llvm-svn: 145022

llvm-svn: 145014

Suggested in code review by Eli.

That code in InstCombine looks kinda suspicious.

llvm-svn: 145013

llvm-svn: 145011

properly account for the *global* probability of the edge being taken.
This manifested as a very large number of unconditional branches to
blocks being merged against the CFG even though they weren't
particularly hot within the CFG.

The fix is to check whether the edge being merged is both locally hot
relative to other successors for the source block, and globally hot
compared to other (unmerged) predecessors of the destination block.

This introduces a new crasher on GCC single-source, but it's currently
behind a flag, and Ben has offered to work on the reduction. =]

llvm-svn: 145010

llvm-svn: 145009

llvm-svn: 145008

setFlags doesn't modify its arguments.

llvm-svn: 145007

is actually being tested. Also add some FileCheck goodness to much more
carefully ensure that the result is the desired result. Before this test
would only have failed through an assert failure if the underlying fix
were reverted.

Also, add some weight metadata and a comment explaining exactly what is
going on to a trick section of the test case. Originally, we were
getting very unlucky and trying to form a block chain that isn't
actually profitable. I'm working on a fix to avoid forming these
unprofitable chains, and that would also have masked any failure from
this test case. The easy solution is to add some metadata that makes it
*really* profitable to form the bad chain here.

llvm-svn: 145006

Add code for lowering v32i8 shifts by a splat to AVX2 immediate shift instructions. Remove 256-bit splat handling from LowerShift as it was already handled by PerformShiftCombine.

llvm-svn: 145005

llvm-svn: 145004

Remove some of the special classes that worked around an old tablegen limitation of not being able to remove redundant bitconverts from patterns.

llvm-svn: 145003

llvm-svn: 144999

formation phase and into the initial walk of the basic blocks. We
essentially pre-merge all blocks where unanalyzable fallthrough exists,
as we won't be able to update the terminators effectively after any
reorderings. This is quite a bit more principled as there may be CFGs
where the second half of the unanalyzable pair has some analyzable
predecessor that gets placed first. Then it may get placed next,
implicitly breaking the unanalyzable branch even though we never even
looked at the part that isn't analyzable. I've included a test case that
triggers this (thanks Benjamin yet again!), and I'm hoping to synthesize
some more general ones as I dig into related issues.

Also, to make this new scheme work we have to be able to handle branches
into the middle of a chain, so add this check. We always fallback on the
incoming ordering.

Finally, this starts to really underscore a known limitation of the
current implementation -- we don't consider broken predecessors when
merging successors. This can caused major missed opportunities, and is
something I'm planning on looking at next (modulo more bug reports).

llvm-svn: 144994

llvm-svn: 144990

Synthesize SSSE3/AVX 128-bit horizontal integer add/sub instructions from add/sub of appropriate shuffle vectors.

llvm-svn: 144989

llvm-svn: 144988

llvm-svn: 144987

llvm-svn: 144986