39272 Commits

Author SHA1 Message Date
Andrea Di Biagio
fd503e5af3 [DAGcombiner] Fix incorrect sinking of a truncate into the operand of a shift.
This fixes a regression introduced by revision 268094.
Revision 268094 added the following dag combine rule:
// trunc (shl x, K) -> shl (trunc x), K => K < vt.size / 2

That rule converts a truncate of a shift-by-constant into a shift of a truncated
value. We do this only if the shift count is less than half the size in bits of
the truncated value (K < vt.size / 2).

The problem is that the constraint on the shift count is incorrect, so the rule
doesn't work well in some cases involving vector types. The combine rule should
have been written instead like this:
// trunc (shl x, K) -> shl (trunc x), K => K < vt.getScalarSizeInBits()

Basically, if K is smaller than the "scalar size in bits" of the truncated value
then we know that by "sinking" the truncate into the operand of the shift we
would never accidentally make the shift undefined.

This patch fixes the check on the shift count, and adds test cases to make sure
that we don't regress the behavior.

Differential Revision: https://reviews.llvm.org/D24154

llvm-svn: 280482
2016-09-02 11:29:09 +00:00
Alexey Bataev
ed27d69037 [InstCombine] Add test for insertelementinsts with constants.
Added a tests that shows that several insertelementinsts with constant
indexes/data are not folded into a single shuffleinst.

llvm-svn: 280474
2016-09-02 09:00:53 +00:00
George Rimar
d8a4ecac3b [llvm-readobj] - Teach readobj to print DT_AUXILIARY dynamic tag in human readable form.
Previously DT_AUXILIARY was unknown, patch fixes that.

Differential revision: https://reviews.llvm.org/D24138

llvm-svn: 280471
2016-09-02 07:35:19 +00:00
James Molloy
f3cf2a494b [SimplifyCFG] Add a workaround to fix PR30188
We're sinking stores, which is a good thing, but in the process creating selects for the store address operand, which SROA/Mem2Reg can't look through, which caused serious regressions.

The real fix is in SROA, which I'll be looking into.

llvm-svn: 280470
2016-09-02 07:29:00 +00:00
Craig Topper
ad79bf4712 [AVX-512] Move tests for masked floating point logical operations to avx512dqvl-intrinsics-upgrade.ll since they have now been autoupgraded.
llvm-svn: 280467
2016-09-02 06:11:31 +00:00
Craig Topper
45d6503089 [AVX-512] Add more patterns for masked and broadcasted logical operations where the select or broadcast has a floating point type.
These are needed in order to remove the masked floating point logical operation intrinsics and use native IR.

llvm-svn: 280465
2016-09-02 05:29:13 +00:00
Craig Topper
00aecd97bf [AVX-512] Add execution domain fixing for logical operations with broadcast loads. This builds on the handling of masked ops since we need to keep element size the same.
llvm-svn: 280464
2016-09-02 05:29:09 +00:00
Hal Finkel
5ef4b03106 [PowerPC] hasAndNotCompare should return true
As Sanjay suggested when he added the hook, PPC should return true from
hasAndNotCompare. We have an efficient negated 'and' on PPC (which can feed a
compare).

Fixes PR27203.

llvm-svn: 280457
2016-09-02 02:58:25 +00:00
Hal Finkel
a39fd4bc53 [PowerPC] Add a pattern for a runtime bit check
Following a suggestion by Sanjay, we should lower:

  %shl = shl i32 1, %y
  %and = and i32 %x, %shl
  %cmp = icmp eq i32 %and, %shl
  ret i1 %cmp

into:

  subfic r4, r4, 32
  rlwnm r3, r3, r4, 31, 31

Add this pattern and some associated patterns for the 64-bit case and the
not-equal case. Fixes PR27356.

llvm-svn: 280454
2016-09-02 02:34:44 +00:00
NAKAMURA Takumi
9aec5c3797 llvm/test/Transforms/GCOVProfiling/three-element-mdnode.ll: Use %/T instead of %T, not to emit backslashes.
llvm-svn: 280451
2016-09-02 01:33:00 +00:00
Hal Finkel
b54579fab6 [PowerPC] Don't apply the PPC64 address-formation peephole for offsets greater than 7
When applying our address-formation PPC64 peephole, we are reusing the @ha TOC
addis value with the low parts associated with different offsets (i.e.
different effective symbol addends). We were assuming this was okay so long as
the offsets were less than the alignment of the global variable being accessed.
This ignored the fact, however, that the TOC base pointer itself need only be
8-byte aligned. As a result, what we were doing is legal only for offsets less
than 8 regardless of the alignment of the object being accessed.

Fixes PR28727.

llvm-svn: 280441
2016-09-02 00:28:20 +00:00
Hal Finkel
1e8218cc09 [PowerPC] Don't consider fusion in PPC64 address-formation peephole
The logic in this function assumes that the P8 supports fusion of addis/addi,
but it does not. As a result, there is no advantage to restricting our peephole
application, merging addi instructions into dependent memory accesses, even
when the addi has multiple users, regardless of whether or not we're optimizing
for size.

We might need something like this again for the P9; I suspect we'll revisit
this code when we work on P9 tuning.

llvm-svn: 280440
2016-09-02 00:27:50 +00:00
Michael Kuperstein
7bc54cebea [Legalizer] Don't throw away false low half when expanding GT/LT SETCC
When expanding a SETCC for which the low half is known to evaluate to false,
we can only throw it away for LT/GT comparisons, not LE/GE.

This fixes PR29170.

Differential Revision: https://reviews.llvm.org/D24151

llvm-svn: 280424
2016-09-01 23:02:32 +00:00
Michael Kuperstein
5f17d08f49 [SelectionDAG] Generate vector_shuffle nodes for undersized result vector sizes
Prior to this, we could generate a vector_shuffle from an IR shuffle when the
size of the result was exactly the sum of the sizes of the input vectors.
If the output vector was narrower - e.g. a <12 x i8> being formed by a shuffle
with two <8 x i8> inputs - we would lower the shuffle to a sequence of extracts
and inserts.

Instead, we can form a larger vector_shuffle, and then extract a subvector
of the right size - e.g. shuffle the two <8 x i8> inputs into a <16 x i8>
and then extract a <12 x i8>.

This also includes a target-specific X86 combine that in the presence of
AVX2 combines:
(vector_shuffle <mask> (concat_vectors t1, undef)
                       (concat_vectors t2, undef))
into:
(vector_shuffle <mask> (concat_vectors t1, t2), undef)
in cases where this allows us to form VPERMD/VPERMQ.

(This is not a separate commit, as that pattern does not appear without
the DAGBuilder change.)

llvm-svn: 280418
2016-09-01 21:32:09 +00:00
Heejin Ahn
c0f18172f5 [WebAssembly] Add asm.js-style setjmp/longjmp handling for wasm (reland r280302)
Summary: This patch adds asm.js-style setjmp/longjmp handling support for WebAssembly. It also uses JavaScript's try and catch mechanism.

Reviewers: jpp, dschuff

Subscribers: jfb, dschuff

Differential Revision: https://reviews.llvm.org/D24121

llvm-svn: 280415
2016-09-01 21:05:15 +00:00
Tim Northover
8d8812c5d7 GlobalISel: add a G_PHI instruction to give phis a type.
They're another source of generic vregs, which are going to need a type on the
definition when we remove the register width from MachineRegisterInfo.

llvm-svn: 280412
2016-09-01 20:45:41 +00:00
Sanjay Patel
199a8e6a92 [InstCombine] add tests to show potential shuffle+insert folds
llvm-svn: 280403
2016-09-01 19:14:19 +00:00
Andrey Turetskiy
cde38b6a99 [X86] Loosen memory folding requirements for cvtdq2pd and cvtps2pd instructions.
According to spec cvtdq2pd and cvtps2pd instructions don't require memory operand to be aligned
to 16 bytes. This patch removes this requirement from the memory folding table.

Differential Revision: https://reviews.llvm.org/D23919

llvm-svn: 280402
2016-09-01 18:50:02 +00:00
Yaxun Liu
add05a8d95 AMDGPU: Add runtime metadata for pointee alignment of argument.
Add runtime metdata for pointee alignment of pointer type kernel argument. The key is KeyArgPointeeAlign and the value is a 32 bit unsigned integer.

Differential Revision: https://reviews.llvm.org/D24145

llvm-svn: 280399
2016-09-01 18:46:49 +00:00
Michael Kuperstein
65bc3c89ff [DAGCombine] Don't fold a trunc if it feeds an anyext
Legalization tends to create anyext(trunc) patterns. This should always be
combined - into either a single trunc, a single ext, or nothing if the
types match exactly. But if we happen to combine the trunc first, we may pull
the trunc away from the anyext or make it implicit (e.g. the truncate(extract)
-> extract(bitcast) fold).

To prevent this, we can avoid doing the fold, similarly to how we already handle
fpround(fpextend).

Differential Revision: https://reviews.llvm.org/D23893

llvm-svn: 280386
2016-09-01 17:59:24 +00:00
Simon Dardis
bd27154757 [mips] interAptiv based generic schedule model
This scheduler describes a processor which covers all MIPS ISAs based
around the interAptiv and P5600 timings.

Reviewers: vkalintiris, dsanders

Differential Revision: https://reviews.llvm.org/D23551

llvm-svn: 280374
2016-09-01 14:53:53 +00:00
Sanjay Patel
dd861964d1 [InstCombine] remove fold of an icmp pattern that should never happen
While removing a scalar shackle from an icmp fold, I noticed that I couldn't find any tests to trigger
this code path.

The 'and' shrinking transform should be handled by InstCombiner::foldCastedBitwiseLogic()
or eliminated with InstSimplify. The icmp narrowing is part of InstCombiner::foldICmpWithCastAndCast().

Differential Revision: https://reviews.llvm.org/D24031 

llvm-svn: 280370
2016-09-01 14:20:43 +00:00
Krzysztof Parzyszek
07d9f53b51 [Hexagon] Deal with undefs when extending live intervals
Reapply r280275, since MSVC accepts r280358.

llvm-svn: 280369
2016-09-01 13:59:35 +00:00
Elena Demikhovsky
4d7738dfde Optimized FMA intrinsic + FNEG , like
-(a*b+c)

and FNEG + FMA, like
a*b-c or (-a)*b+c.

The bug description is here :  https://llvm.org/bugs/show_bug.cgi?id=28892

Differential revision: https://reviews.llvm.org/D23313

llvm-svn: 280368
2016-09-01 13:58:53 +00:00
James Molloy
88cad7e5cf [SimplifyCFG] Handle tail-sinking of more than 2 incoming branches
This was a real restriction in the original version of SinkIfThenCodeToEnd. Now it's been rewritten, the restriction can be lifted.

As part of this, we handle a very common and useful case where one of the incoming branches is actually conditional. Consider:

   if (a)
     x(1);
   else if (b)
     x(2);

This produces the following CFG:

         [if]
        /    \
      [x(1)] [if]
        |     | \
        |     |  \
        |  [x(2)] |
         \    |  /
          [ end ]

[end] has two unconditional predecessor arcs and one conditional. The conditional refers to the implicit empty 'else' arc. This same pattern can also be caused by an empty default block in a switch.

We can't sink the call to x() down to end because no call to x() happens on the third incoming arc (assume that x() has sideeffects for the sake of argument; if something is safe to speculate we could indeed sink nevertheless but this cannot happen in the general case and causes many extra selects).

We are now able to detect this case and split off the unconditional arcs to a common successor:

         [if]
        /    \
      [x(1)] [if]
        |     | \
        |     |  \
        |  [x(2)] |
         \   /    |
     [sink.split] |
           \     /
           [ end ]

Now we can sink the call to x() into %sink.split. This can cause significant code simplification in many testcases.

llvm-svn: 280364
2016-09-01 12:58:13 +00:00
James Molloy
eec6df3193 [SimplifyCFG] Change the algorithm in SinkThenElseCodeToEnd
r279460 rewrote this function to be able to handle more than two incoming edges and took pains to ensure this didn't regress anything.

This time we change the logic for determining if an instruction should be sunk. Previously we used a single pass greedy algorithm - sink instructions until one requires more than one PHI node or we run out of instructions to sink.

This had the problem that sinking instructions that had non-identical but trivially the same operands needed extra logic so we sunk them aggressively. For example:

    %a = load i32* %b          %d = load i32* %b
    %c = gep i32* %a, i32 0    %e = gep i32* %d, i32 1

Sinking %c and %e would naively require two PHI merges as %a != %d. But the loads are obviously equivalent (and maybe can't be hoisted because there is no common predecessor).

This is why we implemented the fairly complex function areValuesTriviallySame(), to look through trivial differences like this. However it's just not clever enough.

Instead, throw areValuesTriviallySame away, use pointer equality to check equivalence of operands and switch to a two-stage algorithm.

In the "scan" stage, we look at every sinkable instruction in isolation from end of block to front. If it's sinkable, we keep track of all operands that required PHI merging.

In the "sink" stage, we iteratively sink the last non-terminator in the source blocks. But when calculating how many PHIs are actually required to be inserted (to work out if we should stop or not) we remove any values that have already been sunk from the set of PHI-merges required, which allows us to be more aggressive.

This turns an algorithm with potentially recursive lookahead (looking through GEPs, casts, loads and any other instruction potentially not CSE'd) to two linear scans.

llvm-svn: 280351
2016-09-01 10:44:35 +00:00
Hal Finkel
5081ac27c7 Add ISD::EH_DWARF_CFA, simplify @llvm.eh.dwarf.cfa on Mips, fix on PowerPC
LLVM has an @llvm.eh.dwarf.cfa intrinsic, used to lower the GCC-compatible
__builtin_dwarf_cfa() builtin. As pointed out in PR26761, this is currently
broken on PowerPC (and likely on ARM as well). Currently, @llvm.eh.dwarf.cfa is
lowered using:

  ADD(FRAMEADDR, FRAME_TO_ARGS_OFFSET)

where FRAME_TO_ARGS_OFFSET defaults to the constant zero. On x86,
FRAME_TO_ARGS_OFFSET is lowered to 2*SlotSize. This setup, however, does not
work for PowerPC. Because of the way that the stack layout works, the canonical
frame address is not exactly (FRAMEADDR + FRAME_TO_ARGS_OFFSET) on PowerPC
(there is a lower save-area offset as well), so it is not just a matter of
implementing FRAME_TO_ARGS_OFFSET for PowerPC (unless we redefine its
semantics -- We can do that, since it is currently used only for
@llvm.eh.dwarf.cfa lowering, but the better to directly lower the CFA construct
itself (since it can be easily represented as a fixed-offset FrameIndex)). Mips
currently does this, but by using a custom lowering for ADD that specifically
recognizes the (FRAMEADDR, FRAME_TO_ARGS_OFFSET) pattern.

This change introduces a ISD::EH_DWARF_CFA node, which by default expands using
the existing logic, but can be directly lowered by the target. Mips is updated
to use this method (which simplifies its implementation, and I suspect makes it
more robust), and updates PowerPC to do the same.

Fixes PR26761.

Differential Revision: https://reviews.llvm.org/D24038

llvm-svn: 280350
2016-09-01 10:28:47 +00:00
Hal Finkel
40d7f5c277 Add a counter-function insertion pass
As discussed in https://reviews.llvm.org/D22666, our current mechanism to
support -pg profiling, where we insert calls to mcount(), or some similar
function, is fundamentally broken. We insert these calls in the frontend, which
means they get duplicated when inlining, and so the accumulated execution
counts for the inlined-into functions are wrong.

Because we don't want the presence of these functions to affect optimizaton,
they should be inserted in the backend. Here's a pass which would do just that.
The knowledge of the name of the counting function lives in the frontend, so
we're passing it here as a function attribute. Clang will be updated to use
this mechanism.

Differential Revision: https://reviews.llvm.org/D22825

llvm-svn: 280347
2016-09-01 09:42:39 +00:00
Dean Michael Berris
e8ae5baaf7 [XRay] Detect and emit sleds for sibling/tail calls
Summary:
This change promotes the 'isTailCall(...)' member function to
TargetInstrInfo as a query interface for determining on a per-target
basis whether a given MachineInstr is a tail call instruction. We build
upon this in the XRay instrumentation pass to emit special sleds for
tail call optimisations, where we emit the correct kind of sled.

The tail call sleds look like a mix between the function entry and
function exit sleds. Form-wise, the sled comes before the "jmp"
instruction that implements the tail call similar to how we do it for
the function entry sled. Functionally, because we know this is a tail
call, it behaves much like an exit sled -- i.e. at runtime we may use
the exit trampolines instead of a different kind of trampoline.

A follow-up change to recognise these sleds will be done in compiler-rt,
so that we can start intercepting these initially as exits, but also
have the option to have different log entries to more accurately reflect
that this is actually a tail call.

Reviewers: echristo, rSerge, majnemer

Subscribers: mehdi_amini, dberris, llvm-commits

Differential Revision: https://reviews.llvm.org/D23986

llvm-svn: 280334
2016-09-01 01:29:13 +00:00
Heejin Ahn
10a7086700 Revert "Add asm.js-style setjmp/longjmp handling for wasm"
This reverts commit r280302, it broke the integration tests.

llvm-svn: 280329
2016-09-01 00:44:37 +00:00
Nick Lewycky
97e49ac59e Add -fprofile-dir= to clang.
-fprofile-dir=path allows the user to specify where .gcda files should be
emitted when the program is run. In particular, this is the first flag that
causes the .gcno and .o files to have different paths, LLVM is extended to
support this. -fprofile-dir= does not change the file name in the .gcno (and
thus where lcov looks for the source) but it does change the name in the .gcda
(and thus where the runtime library writes the .gcda file). It's different from
a GCOV_PREFIX because a user can observe that the GCOV_PREFIX_STRIP will strip
paths off of -fprofile-dir= but not off of a supplied GCOV_PREFIX.

To implement this we split -coverage-file into -coverage-data-file and
-coverage-notes-file to specify the two different names. The !llvm.gcov
metadata node grows from a 2-element form {string coverage-file, node dbg.cu}
to 3-elements, {string coverage-notes-file, string coverage-data-file, node
dbg.cu}. In the 3-element form, the file name is already "mangled" with
.gcno/.gcda suffixes, while the 2-element form left that to the middle end
pass.

llvm-svn: 280306
2016-08-31 23:04:32 +00:00
Heejin Ahn
23d57103a4 Add asm.js-style setjmp/longjmp handling for wasm
Summary: This patch adds asm.js-style setjmp/longjmp handling support for WebAssembly. It also uses JavaScript's try and catch mechanism.

Reviewers: jpp, dschuff

Subscribers: jfb, dschuff

Differential Revision: https://reviews.llvm.org/D23928

llvm-svn: 280302
2016-08-31 22:40:34 +00:00
Reid Kleckner
109448ee81 Revert "Add an optional parameter with a list of undefs to extendToIndices"
This reverts commit r280268, it causes all MSVC 2013 to ICE. This
appears to have been fixed in a later MSVC 2013 update, because I cannot
reproduce it locally. That said, all upstream LLVM bots are broken right
now, so I am reverting.

Also reverts dependent change r280275, "[Hexagon] Deal with undefs when
extending live intervals".

llvm-svn: 280301
2016-08-31 22:36:02 +00:00
Sanjay Patel
0d70831d73 [InstCombine] allow icmp (shr exact X, C2), C fold for splat constant vectors
The enhancement to foldICmpDivConstant ( http://llvm.org/viewvc/llvm-project?view=revision&revision=280299 )
allows us to remove the ConstantInt check; no other changes needed.

llvm-svn: 280300
2016-08-31 22:18:43 +00:00
Sanjay Patel
541aef4661 [InstCombine] allow icmp (div X, Y), C folds for splat constant vectors
Converting all of the overflow ops to APInt looked risky, so I've left that as a TODO.

llvm-svn: 280299
2016-08-31 21:57:21 +00:00
Matt Arsenault
b50eb8dc2b AMDGPU: Fix introducing stack access on unaligned v16i8
llvm-svn: 280298
2016-08-31 21:52:27 +00:00
Tim Northover
11a2354670 GlobalISel: use G_TYPE to annotate physregs with a type.
More preparation for dropping source types from MachineInstrs: regsters coming
out of already-selected code (i.e. non-generic instructions) don't have a type,
but that information is needed so we must add it manually.

This is done via a new G_TYPE instruction.

llvm-svn: 280292
2016-08-31 21:24:02 +00:00
Derek Schuff
1b258d313c [WebAssembly] Disable folding of GA+reg into load/store constant offsets
Summary:
If the register has a negative value then unsigned overflow will occur;
this case is sometimes even created intentionally by LSR. For now
disable GA+reg folding. Fixes PR29127

Differential Revision: https://reviews.llvm.org/D24053

llvm-svn: 280285
2016-08-31 20:27:20 +00:00
Geoff Berry
8d84605f25 [EarlyCSE] Optionally use MemorySSA. NFC.
Summary:
Use MemorySSA, if requested, to do less conservative memory dependency
checking.

This change doesn't enable the MemorySSA enhanced EarlyCSE in the
default pipelines, so should be NFC.

Reviewers: dberlin, sanjoy, reames, majnemer

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19821

llvm-svn: 280279
2016-08-31 19:24:10 +00:00
Quentin Colombet
bd850f4185 Actually check for the diagnostic to be emitted!
This makes the test case in r280273 actually useful!

llvm-svn: 280276
2016-08-31 18:53:32 +00:00
Krzysztof Parzyszek
e21a0b3b9f [Hexagon] Deal with undefs when extending live intervals
llvm-svn: 280275
2016-08-31 18:52:09 +00:00
Tom Stellard
ba5730884b AMDGPU/SI: Make sure llvm.amdgcn.implicitarg.ptr() is at least 4-byte aligned
Summary: This fixes some OpenCV tests that were broken by libclc commit r276443.

Reviewers: arsenm, jvesely

Subscribers: arsenm, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D24051

llvm-svn: 280274
2016-08-31 18:46:07 +00:00
Quentin Colombet
1c06a73a7c [TargetPassConfig] Add a hook to tell whether GlobalISel should warm on fallback.
Thanks to this patch, we know have a way to easly see if GlobalISel
failed.

llvm-svn: 280273
2016-08-31 18:43:04 +00:00
Kevin Enderby
9d0c945ad6 Next set of additional error checks for invalid Mach-O files for bad load commands
that use the Mach::linkedit_data_command type for the load commands that are
currently used in the MachOObjectFile constructor.

This contains the missing checks for LC_DATA_IN_CODE and
LC_LINKER_OPTIMIZATION_HINT load commands and the fields for the
Mach::linkedit_data_command type.  Checking for other load commands that
use this type will be added later.

Also fixed a couple of places that was using sizeof(MachOObjectFile::LoadCommandInfo)
that should have been using sizeof(MachO::load_command).

llvm-svn: 280267
2016-08-31 17:57:46 +00:00
Geoff Berry
64f5ed172a [EarlyCSE] Allow forwarding a non-invariant load into an invariant load.
Reviewers: sanjoy

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23935

llvm-svn: 280265
2016-08-31 17:45:31 +00:00
Teresa Johnson
8068cc68f7 [LTO] Fix common test to reflect r279911 and move to X86 subdirectory
Adjust the test to reflect the changes to common handling in r279911.
This test wasn't running due to an incorrect REQUIRES and thus missed
being modified for r279911 before. It was changed to XFAIL when the
bad REQUIRES was discovered.

Remove the XFAIL and move to a new X86 subdirectory that will properly
disable on non-X86.

llvm-svn: 280256
2016-08-31 16:15:39 +00:00
Reid Kleckner
9dac47319d [codeview] Emit vtable shape information
The shape of the vtable is passed down as the size of the
__vtbl_ptr_type. This special pointer type appears both as the pointee
type of the vptr type, and by itself in every dynamic class. For classes
with multiple vtables, only the shape of the primary vftable is
included, as the shape of all secondary vftables will be the same as in
the base class.

Fixes PR28150

llvm-svn: 280254
2016-08-31 15:59:30 +00:00
Philip Reames
2b1084ac93 [statepoints][experimental] Add support for live-in semantics of values in deopt bundles
This is a first step towards supporting deopt value lowering and reporting entirely with the register allocator. I hope to build on this in the near future to support live-on-return semantics, but I have a use case which allows me to test and investigate code quality with just the live-in semantics so I've chosen to start there. For those curious, my use cases is our implementation of the "__llvm_deoptimize" function we bind to @llvm.deoptimize. I'm choosing not to hard code that fact in the patch and instead make it configurable via function attributes.

The basic approach here is modelled on what is done for the "Live In" values on stackmaps and patchpoints. (A secondary goal here is to remove one of the last barriers to merging the pseudo instructions.) We start by adding the operands directly to the STATEPOINT SDNode. Once we've lowered to MI, we extend the remat logic used by the register allocator to fold virtual register uses into StackMap::Indirect entries as needed. This does rely on the fact that the register allocator rematerializes. If it didn't along some code path, we could end up with more vregs than physical registers and fail to allocate.

Today, we *only* fold in the register allocator. This can create some weird effects when combined with arguments passed on the stack because we don't fold them appropriately. I have an idea how to fix that, but it needs this patch in place to work on that effectively. (There's some weird interaction with the scheduler as well, more investigation needed.)

My near term plan is to land this patch off-by-default, experiment in my local tree to identify any correctness issues and then start fixing codegen problems one by one as I find them. Once I have the live-in lowering fully working (both correctness and code quality), I'm hoping to move on to the live-on-return semantics. Note: I don't have any *known* miscompiles with this patch enabled, but I'm pretty sure I'll find at least a couple. Thus, the "experimental" tag and the fact it's off by default.

Differential Revision: https://reviews.llvm.org/D24000

llvm-svn: 280250
2016-08-31 15:12:17 +00:00
Simon Pilgrim
6199b4fd49 [X86][SSE] Improve awareness of (v)cvtpd2ps implicit zeroing of upper 64-bits of xmm result
Associate x86_sse2_cvtpd2ps with X86ISD::VFPROUND to avoid inserting unnecessary zeroing shuffles.

Differential Revision: https://reviews.llvm.org/D23797

llvm-svn: 280249
2016-08-31 15:09:34 +00:00
Sjoerd Meijer
46b5b88387 Clang patch r280064 introduced ways to set the FP exceptions and denormal
types. This is the LLVM counterpart and it adds options that map onto FP
exceptions and denormal build attributes allowing better fp math library
selections.

Differential Revision: https://reviews.llvm.org/D24070

llvm-svn: 280246
2016-08-31 14:17:38 +00:00