This change will ease refactoring LowerFABS() and LowerFNEG()
since they have a lot of overlap.
Remove the creation of a floating point constant from an integer
because it's going to be used for a bitwise integer op anyway.
No change to codegen expected, but the verbose comment string
for asm output may change from float values to hex (integer),
depending on whether the constant already exists or not.
Differential Revision: http://reviews.llvm.org/D5052
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216889 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If a variadic function body contains a musttail call, then we copy all
of the remaining register parameters into virtual registers in the
function prologue. We track the virtual registers through the function
body, and add them as additional registers to pass to the call. Because
this is all done in virtual registers, the register allocator usually
gives us good code. If the function does a call, however, it will have
to spill and reload all argument registers (ew).
Forwarding regparms on x86_32 is not implemented because most compilers
don't support varargs in 32-bit with regparms.
Reviewers: majnemer
Subscribers: aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D5060
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216780 91177308-0d34-0410-b5e6-96231b3b80d8
We've rejected these kinds of functions since r28405 in 2006 because
it's impossible to lower the return of a callee cleanup varargs
function. However there are lots of legal ways to leave such a function
without returning, such as aborting. Today we can leave a function with
a musttail call to another function with the correct prototype, and
everything works out.
I'm removing the verifier check declaring that a normal return from such
a function is UB.
Reviewed By: nlewycky
Differential Revision: http://reviews.llvm.org/D5059
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216779 91177308-0d34-0410-b5e6-96231b3b80d8
The new solution is to not use this lowering if there are any dynamic
allocas in the current function. We know up front if there are dynamic
allocas, but we don't know if we'll need to create stack temporaries
with large alignment during lowering. Conservatively assume that we will
need such temporaries.
Reviewed By: hans
Differential Revision: http://reviews.llvm.org/D5128
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216775 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Mostly renaming the (not very explicit) variables Tmp0, .. Tmp4, and grouping
related statements together, along with a few lines of comments for the
surprising parts.
No functional change intended.
Test Plan: make check-all
Reviewers: jfb
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5088
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216768 91177308-0d34-0410-b5e6-96231b3b80d8
Added new types to Legalizer.
Fixed getSetCCResultType function
Added lowering tests.
Reviewed by Elena Demikhovsky.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216717 91177308-0d34-0410-b5e6-96231b3b80d8
a single early exit.
And factor the subsequent cast<> from all but one block into a single
variable.
No functionality changed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216645 91177308-0d34-0410-b5e6-96231b3b80d8
functionality changed.
Separating this into two functions wasn't helping. There was a decent
amount of boilerplate duplicated, and some subsequent refactorings here
will pull even more common code out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216644 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Introduce support::ulittleX_t::ref type to Support/Endian.h and use it in x86 JIT
to enforce correct endianness and fix unaligned accesses.
Test Plan: regression test suite
Reviewers: lhames
Subscribers: ributzka, llvm-commits
Differential Revision: http://reviews.llvm.org/D5011
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216631 91177308-0d34-0410-b5e6-96231b3b80d8
Instructions like 'fxsave' and control flow instructions like 'jne'
match any operand size. The loop I added to the Intel syntax matcher
assumed that using a different size would give a different instruction.
Now it handles the case where we get the same instruction for different
memory operand sizes.
This also allows us to remove the hack we had for unsized absolute
memory operands, because we can successfully match things like 'jnz'
without reporting ambiguity. Removing this hack uncovered test case
involving 'fadd' that was ambiguous. The memory operand could have been
single or double precision.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216604 91177308-0d34-0410-b5e6-96231b3b80d8
we stopped efficiently lowering sextload using the SSE41 instructions
for that operation.
This is a consequence of a bad predicate I used thinking of the memory
access needs. The code actually handles the cases where the predicate
doesn't apply, and handles them much better. =] Simple fix and a test
case added. Fixes PR20767.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216538 91177308-0d34-0410-b5e6-96231b3b80d8
This combine is essentially combining target-specific nodes back into target
independent nodes that it "knows" will be combined yet again by a target
independent DAG combine into a different set of target-independent nodes that
are legal (not custom though!) and thus "ok". This seems... deeply flawed. The
crux of the problem is that we don't combine un-legalized shuffles that are
introduced by legalizing other operations, and thus we don't see a very
profitable combine opportunity. So the backend just forces the input to that
combine to re-appear.
However, for this to work, the conditions detected to re-form the unlegalized
nodes must be *exactly* right. Previously, failing this would have caused poor
code (if you're lucky) or a crasher when we failed to select instructions.
After r215611 we would fall back into the legalizer. In some cases, this just
"fixed" the crasher by produces bad code. But in the test case added it caused
the legalizer and the dag combiner to iterate forever.
The fix is to make the alignment checking in the x86 side of things match the
alignment checking in the generic DAG combine exactly. This isn't really a
satisfying or principled fix, but it at least make the code work as intended.
It also highlights that it would be nice to detect the availability of under
aligned loads for a given type rather than bailing on this optimization. I've
left a FIXME to document this.
Original commit message for r215611 which covers the rest of the chang:
[SDAG] Fix a case where we would iteratively legalize a node during
combining by replacing it with something else but not re-process the
node afterward to remove it.
In a truly remarkable stroke of bad luck, this would (in the test case
attached) end up getting some other node combined into it without ever
getting re-processed. By adding it back on to the worklist, in addition
to deleting the dead nodes more quickly we also ensure that if it
*stops* being dead for any reason it makes it back through the
legalizer. Without this, the test case will end up failing during
instruction selection due to an and node with a type we don't have an
instruction pattern for.
It took many million runs of the shuffle fuzz tester to find this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216537 91177308-0d34-0410-b5e6-96231b3b80d8
The existing matcher has lots of AT&T assembly dialect assumptions baked
into it. In particular, the hack for resolving the size of a memory
operand by appending the four most common suffixes doesn't work at all.
The Intel assembly dialect mnemonic table has ambiguous entries, so we
need to try matching multiple times with different operand sizes, since
that's the only way to choose different instruction variants.
This makes us more compatible with gas's implementation of Intel
assembly syntax. MSVC assumes you want byte-sized operations for the
instructions that we reject as ambiguous.
Reviewed By: grosbach
Differential Revision: http://reviews.llvm.org/D4747
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216481 91177308-0d34-0410-b5e6-96231b3b80d8
This actually was caught by existing tests but those tests were disabled
with an XFAIL because of PR20736. While working on fixing that,
I noticed the test failure, and tracked it down to this.
We even have a really nice Clang warning that would have caught this but
it isn't enabled in LLVM! =[ I may look at enabling it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216391 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support to recognize division by uniform power of 2 and modifies the cost table to vectorize division by uniform power of 2 whenever possible.
Updates Cost model for Loop and SLP Vectorizer.The cost table is currently only updated for X86 backend.
Thanks to Hal, Andrea, Sanjay for the review. (http://reviews.llvm.org/D4971)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216371 91177308-0d34-0410-b5e6-96231b3b80d8
these DAG combines.
The DAG auto-CSE thing is truly terrible. Due to it, when RAUW-ing
a node with its operand, you can cause its uses to CSE to itself, which
then causes their uses to become your uses which causes them to be
picked up by the RAUW. For nodes that are determined to be "no-ops",
this is "fine". But if the RAUW is one of several steps to enact
a transformation, this causes the DAG to really silently eat an discard
nodes that you would never expect. It took days for me to actually
pinpoint a test case triggering this and a really frustrating amount of
time to even comprehend the bug because I never even thought about the
ability of RAUW to iteratively consume nodes due to CSE-ing them into
itself.
To fix this, we have to build up a brand-new chain of operations any
time we are combining across (potentially) intervening nodes. But once
the logic is added to do this, another issue surfaces: CombineTo eagerly
deletes the one node combined, *but no others*. This is... really
frustrating. If deleting it makes its operands become dead, those
operand nodes often won't go onto the worklist in the
order you would want -- they're already on it and not near the top. That
means things higher on the worklist will get combined prior to these
dead nodes being GCed out of the worklist, and if the chain is long, the
immediate users won't be enough to re-detect where the root of the chain
is that became single-use again after deleting the dead nodes. The
better way to do this is to never immediately delete nodes, and instead
to just enqueue them so we can recursively delete them. The
combined-from node is typically not on the worklist anyways by virtue of
having been popped off.... But that in turn breaks other tests that
*require* CombineTo to delete unused nodes. :: sigh ::
Fortunately, there is a better way. This whole routine should have been
returning the replacement rather than using CombineTo which is quite
hacky. Switch to that, and all the pieces fall together.
I suspect the same kind of miscompile is possible in the half-shuffle
folding code, and potentially the recursive folding code. I'll be
switching those over to a pattern more like this one for safety's sake
even though I don't immediately have any test cases for them. Note that
the only way I got a test case for this instance was with *heavily* DAG
combined 256-bit shuffle sequences generated by my fuzzer. ;]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216319 91177308-0d34-0410-b5e6-96231b3b80d8
There's no need to do this if the user doesn't call va_start. In the
future, we're going to have thunks that forward these register
parameters with musttail calls, and they won't need these spills for
handling va_start.
Most of the test suite changes are adding va_start calls to existing
tests to keep things working.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216294 91177308-0d34-0410-b5e6-96231b3b80d8
This (mostly) reverts commit r216119.
Somewhere during the review Reid committed r214980 which fixed this
another way, and I neglected to check that the testcase still failed
before committing.
I've left test/CodeGen/X86/aligned-variadic.ll around in case it adds
extra coverage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216246 91177308-0d34-0410-b5e6-96231b3b80d8
We discussed the issue of generality vs. readability of the AVX512 classes
recently. I proposed this approach to try to hide and centralize the mappings
we commonly perform based on the vector type. A new class X86VectorVTInfo
captures these.
The idea is to pass an instance of this class to classes/multiclasses instead
of the corresponding ValueType. Then the class/multiclass can use its field
for things that derive from the type rather than passing all those as separate
arguments.
I modified avx512_valign to demonstrate this new approach. As you can see
instead of 7 related template parameters we now have one. The downside is
that we have to refer to fields for the derived values. I named the argument
'_' in order to make this as invisible as possible. Please let me know if you
absolutely hate this. (Also once we allow local initializations in
multiclasses we can recover the original version by assigning the fields to
local variables.)
Another possible use-case for this class is to directly map things, e.g.:
RegisterClass KRC = X86VectorVTInfo<32, i16>.KRC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216209 91177308-0d34-0410-b5e6-96231b3b80d8
Fix for PR20648 - http://llvm.org/bugs/show_bug.cgi?id=20648
This patch checks the operands of a vselect to see if all values are constants.
If yes, bail out of any further attempts to create a blend or shuffle because
SelectionDAGLegalize knows how to turn this kind of vselect into a single load.
This already happens for machines without SSE4.1, so the added checks just send
more targets down that path.
Differential Revision: http://reviews.llvm.org/D4934
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216121 91177308-0d34-0410-b5e6-96231b3b80d8
The goal of the patch is to implement section 3.2.3 of the AMD64 ABI
correctly. The controlling sentence is, "The size of each argument gets
rounded up to eightbytes. Therefore the stack will always be eightbyte
aligned." The equivalent sentence in the i386 ABI page 37 says, "At all
times, the stack pointer should point to a word-aligned area." For both
architectures, the stack pointer is not being rounded up to the nearest
eightbyte or word between the last normal argument and the first
variadic argument.
Patch by Thomas Jablin!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216119 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This fixes http://llvm.org/bugs/show_bug.cgi?id=19530.
The problem is that X86ISelLowering erroneously thought the third call
was eligible for tail call elimination.
It would have been if it's return value was actually the one returned
by the calling function, but here that is not the case and
additional values are being returned.
Test Plan: Test case from the original bug report is included.
Reviewers: rafael
Reviewed By: rafael
Subscribers: rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D4968
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216117 91177308-0d34-0410-b5e6-96231b3b80d8
Note: This was originally reverted to track down a buildbot error. Reapply
without any modifications.
Original commit message:
In the large code model for X86 floating-point constants are placed in the
constant pool and materialized by loading from it. Since the constant pool
could be far away, a PC relative load might not work. Therefore we first
materialize the address of the constant pool with a movabsq and then load
from there the floating-point value.
Fixes <rdar://problem/17674628>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216012 91177308-0d34-0410-b5e6-96231b3b80d8
Note: This was originally reverted to track down a buildbot error. Reapply
without any modifications.
Original commit message:
This mostly affects the i64 value type, which always resulted in an 15byte
mobavsq instruction to materialize any constant. The custom code checks the
value of the immediate and tries to use a different and smaller mov
instruction when possible.
This fixes <rdar://problem/17420988>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216010 91177308-0d34-0410-b5e6-96231b3b80d8
Group: Floating Point XMM and YMM instructions.
Sub-group: Other instructions.
<rdar://problem/15607571>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215923 91177308-0d34-0410-b5e6-96231b3b80d8
Group: Floating Point XMM and YMM instructions.
Sub-group: Math instructions.
<rdar://problem/15607571>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215921 91177308-0d34-0410-b5e6-96231b3b80d8
ARM in particular is getting dangerously close to exceeding 32 bits worth of
possible subtarget features. When this happens, various parts of MC start to
fail inexplicably as masks get truncated to "unsigned".
Mostly just refactoring at present, and there's probably no way to test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215887 91177308-0d34-0410-b5e6-96231b3b80d8
It should remove dosens of lines in handling instrinsics (in a huge switch) and give an easy way to add new intrinsics.
I did not completed to move al intrnsics to the table, I'll do this in the upcomming commits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215826 91177308-0d34-0410-b5e6-96231b3b80d8
MSVC gives this awesome diagnostic:
..\lib\Target\X86\X86ISelLowering.cpp(7085) : error C2971: 'llvm::VariadicFunction1' : template parameter 'Func' : 'isShuffleEquivalentImpl' : a local variable cannot be used as a non-type argument
..\include\llvm/ADT/VariadicFunction.h(153) : see declaration of 'llvm::VariadicFunction1'
..\lib\Target\X86\X86ISelLowering.cpp(7061) : see declaration of 'isShuffleEquivalentImpl'
Using an anonymous namespace makes the problem go away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215744 91177308-0d34-0410-b5e6-96231b3b80d8
the new shuffle lowering and an implementation for v4 shuffles.
This allows us to handle non-half-crossing shuffles directly for v4
shuffles, both integer and floating point. This currently misses places
where we could perform the blend via UNPCK instructions, but otherwise
generates equally good or better code for the test cases included to the
existing vector shuffle lowering. There are a few cases that are
entertainingly better. ;]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215702 91177308-0d34-0410-b5e6-96231b3b80d8
BLENDPS, BLENDPD, and PBLENDW instructions into pretty shuffle comments.
These will be used in my next commit as part of test cases for AVX
shuffles which can directly use blend in more places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215701 91177308-0d34-0410-b5e6-96231b3b80d8
elements of a shuffle mask and simplify how it works. No functionality
changed now that the bug that was here has been fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215696 91177308-0d34-0410-b5e6-96231b3b80d8
target-specific shuffl DAG combines.
We were recognizing the paired shuffles backwards. This code needs to be
replaced anyways as we have the same functionality elsewhere, but I'll
do the refactoring in a follow-up, this is the minimal fix to the
behavior.
In addition to fixing miscompiles with the new vector shuffle lowering,
it also causes the canonicalization to kick in much better, selecting
the smaller encoding variants in lots of places in the new AVX path.
This still isn't quite ideal as we don't need both the shufpd and the
punpck instructions, but that'll get fixed in a follow-up patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215690 91177308-0d34-0410-b5e6-96231b3b80d8
broken logic for merging shuffle masks in the face of SM_SentinelZero
mask operands.
While these are '-1' they don't mean 'undef' the way '-1' means in the
pre-legalized shuffle masks. Instead, they mean that the shuffle
operation is forcibly zeroing that lane. Reflect this and explicitly
handle it in a bunch of places. In one place the effect is equivalent
but much more clear. In the rest it was really weirdly broken.
Also, rewrite the entire merging thing to be a more directy operation
with a single loop and just doing math to map the indices through the
various masks.
Also add a bunch of asserts to try to make in extremely clear what the
different masks can possibly look like.
Finally, add some comments to clarify that we're merging shuffle masks
*up* here rather than *down* as we do everywhere else, and thus the
logic is quite confusing.
Thanks to several different people for sending test cases, and for
Robert Khasanov for an initial attempt at fixing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215687 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts:
r215595 "[FastISel][X86] Add large code model support for materializing floating-point constants."
r215594 "[FastISel][X86] Use XOR to materialize the "0" value."
r215593 "[FastISel][X86] Emit more efficient instructions for integer constant materialization."
r215591 "[FastISel][AArch64] Make use of the zero register when possible."
r215588 "[FastISel] Let the target decide first if it wants to materialize a constant."
r215582 "[FastISel][AArch64] Cleanup constant materialization code. NFCI."
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215673 91177308-0d34-0410-b5e6-96231b3b80d8
No functional change. This will be used by the new FMA intrinsic lowering
code.
We can probably add NO_EXC here as well, I am just not too familiar with this
part of AVX512 yet. We can add that later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215662 91177308-0d34-0410-b5e6-96231b3b80d8
This change further evolves the base class AVX512_masking in order to make it
suitable for the masking variants of the FMA instructions.
Besides AVX512_masking there is now a new base class that instructions
including FMAs can use: AVX512_masking_3src. With three-source (destructive)
instructions one of the sources is already tied to the destination. This
difference from AVX512_masking is captured by this new class. The common bits
between _masking and _masking_3src are broken out into a new super class
called AVX512_masking_common.
As with valign, there is some corresponding restructuring of the underlying
format classes. The idea is the same we want to derive from two classes
essentially: one providing the format bits and another format-independent
multiclass supplying the various masking and non-masking instruction variants.
Existing fma tests in avx512-fma*.ll provide coverage here for the non-masking
variants. For masking, the next patches in the series will add intrinsics and
intrinsic tests.
For AVX512_masking_3src to work, the (ins ...) dag has to be passed *without*
the leading source operand that is tied to dst ($src1). This is necessary to
properly construct the (ins ...) for the different variants. For the record,
I did check that if $src is mistakenly included, you do get a fairly intuitive
error message from the tablegen backend.
Part of <rdar://problem/17688758>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215660 91177308-0d34-0410-b5e6-96231b3b80d8
lowering scheme.
Currently, this just directly bails to the fallback path of splitting
the 256-bit vector into two 128-bit vectors, operating there, and then
joining the results back together. While the results are far from
perfect, they are *shockingly* good for what we're doing here. I'll be
layering the rest of the functionality on top of this piece by piece and
updating tests as I go.
Note that 256-bit vectors in this mode are still somewhat WIP. While
I think the code paths that I'm adding here are clean and good-to-go,
there are still a lot of 128-bit assumptions that I'll need to stomp out
as I march through the functional spread here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215637 91177308-0d34-0410-b5e6-96231b3b80d8
In the large code model for X86 floating-point constants are placed in the
constant pool and materialized by loading from it. Since the constant pool
could be far away, a PC relative load might not work. Therefore we first
materialize the address of the constant pool with a movabsq and then load
from there the floating-point value.
Fixes <rdar://problem/17674628>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215595 91177308-0d34-0410-b5e6-96231b3b80d8
