Yonghong Song [Thu, 20 Dec 2018 17:40:23 +0000 (17:40 +0000)]
[BPF] Disable relocation for .BTF.ext section
Build llvm with assertion on, and then build bcc against this llvm.
Run any bcc tool with debug=8 (turning on -g for clang compilation),
you will get the following assertion errors,
/home/yhs/work/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp:888:
void llvm::RuntimeDyldELF::resolveBPFRelocation(const llvm::SectionEntry&, uint64_t,
uint64_t, uint32_t, int64_t): Assertion `Value <= (4294967295U)' failed.
The .BTF.ext ELF section uses Fixup's to get the instruction
offsets. The data width of the Fixup is 4 bytes since we only need
the insn offset within the section.
This caused the above error though since R_BPF_64_32 expects
4-byte value and the Runtime Dyld tried to resolve the actual
insn address which is 8 bytes.
Actually the offset within the section is all what we need.
Therefore, there is no need to perform any kind of relocation
for .BTF.ext section and such relocation will actually cause
incorrect result.
This patch changed BPFELFObjectWriter::getRelocType() such that
for Fixup Kind FK_Data_4, if the relocation Target is a temporary
symbol, let us skip the relocation (ELF::R_BPF_NONE).
Simon Pilgrim [Thu, 20 Dec 2018 14:56:44 +0000 (14:56 +0000)]
[SelectionDAGBuilder] Enable funnel shift building to custom rotates
This patch enables funnel shift -> rotate building for all ROTL/ROTR custom/legal operations.
AFAICT X86 was the last target that was missing modulo support (PR38243), but I've tried to CC stakeholders for every target that has ROTL/ROTR custom handling for their final OK.
Alex Bradbury [Thu, 20 Dec 2018 14:52:15 +0000 (14:52 +0000)]
[RISCV] Properly evaluate fixup_riscv_pcrel_lo12
This is a update to D43157 to correctly handle fixup_riscv_pcrel_lo12.
Notable changes:
Rebased onto trunk
Handle and test S-type
Test case pcrel-hilo.s is merged into relocations.s
D43157 description:
VK_RISCV_PCREL_LO has to be handled specially. The MCExpr inside is
actually the location of an auipc instruction with a VK_RISCV_PCREL_HI fixup
pointing to the real target.
Differential Revision: https://reviews.llvm.org/D54029
Patch by Chih-Mao Chen and Michael Spencer.
Ulrich Weigand [Thu, 20 Dec 2018 14:24:17 +0000 (14:24 +0000)]
[SystemZ] "Generic" vector assembler instructions shoud clobber CC
There are several vector instructions which may or may not set the
condition code register, depending on the value of an argument.
For codegen, we use two versions of the instruction, one that sets
CC and one that doesn't, which hard-code appropriate values of that
argument. But we also have a "generic" version of the instruction
that is used for the assembler/disassembler. These generic versions
should always be considered to clobber CC just to be safe.
Simon Pilgrim [Thu, 20 Dec 2018 13:50:12 +0000 (13:50 +0000)]
[InstCombine] Make x86 PADDS/PSUBS constant folding tests generic
As discussed on D55894, this replaces the existing PADDS/PSUBUS intrinsics with the the sadd/ssub.sat generic intrinsics and moves the tests out of the x86 subfolder.
PR40110 has been raised to fix the regression with constant folding vectors containing undef elements.
Ulrich Weigand [Thu, 20 Dec 2018 13:05:03 +0000 (13:05 +0000)]
[SystemZ] Make better use of VLLEZ
This patch fixes two deficiencies in current code that recognizes
the VLLEZ idiom:
- For the floating-point versions, we have ISel patterns that match
on a bitconvert as the top node. In more complex cases, that
bitconvert may already have been merged into something else.
Fix the patterns to match the inner nodes instead.
- For the 64-bit integer versions, depending on the surrounding code,
we may get either a DAG tree based on JOIN_DWORDS or one based on
INSERT_VECTOR_ELT. Use a PatFrags to simply match both variants.
Ulrich Weigand [Thu, 20 Dec 2018 13:01:20 +0000 (13:01 +0000)]
[SystemZ] Make better use of VGEF/VGEG
Current code in SystemZDAGToDAGISel::tryGather refuses to perform
any transformation if the Load SDNode has more than one use. This
(erronously) counts uses of the chain result, which prevents the
optimization in many cases unnecessarily. Fixed by this patch.
Ulrich Weigand [Thu, 20 Dec 2018 12:59:05 +0000 (12:59 +0000)]
[SystemZ] Make better use of VLDEB
We already have special code (DAG combine support for FP_ROUND)
to recognize cases where we an use a vector version of VLEDB to
perform two floating-point truncates in parallel, but equivalent
support for VLEDB (vector floating-point extends) has been
missing so far. This patch adds corresponding DAG combine
support for FP_EXTEND.
Simon Pilgrim [Thu, 20 Dec 2018 10:54:59 +0000 (10:54 +0000)]
[X86] Change 'simple nonmem' intrinsic test to not use PADDSW
Those intrinsics will be autoupgraded soon to @llvm.sadd.sat generics (D55894), so to keep a x86-specific case I'm replacing it with @llvm.x86.sse2.pmulhu.w
LLVM treats void* pointers passed to assembly routines as pointers to
sized types.
We used to emit calls to __msan_instrument_asm_load() for every such
void*, which sometimes led to false positives.
A less error-prone (and truly "conservative") approach is to unpoison
only assembly output arguments.
Clement Courbet [Thu, 20 Dec 2018 09:13:47 +0000 (09:13 +0000)]
[CodeGen][ExpandMemcmp] Add an option for allowing overlapping loads.
Summary:
This allows expanding {7,11,13,14,15,21,22,23,25,26,27,28,29,30,31}-byte memcmp
in just two loads on X86. These were previously calling memcmp.
Kang Zhang [Thu, 20 Dec 2018 06:19:59 +0000 (06:19 +0000)]
[PowerPC] Implement the isSelectSupported() target hook
Summary:
PowerPC has scalar selects (isel) and vector mask selects (xxsel). But PowerPC
does not have vector CR selects, PowerPC does not support scalar condition
selects on vectors.
In addition to implementing this hook, isSelectSupported() should return false
when the SelectSupportKind is ScalarCondVectorVal, so that predictable selects
are converted into branch sequences.
Michael Kruse [Thu, 20 Dec 2018 04:58:07 +0000 (04:58 +0000)]
Introduce llvm.loop.parallel_accesses and llvm.access.group metadata.
The current llvm.mem.parallel_loop_access metadata has a problem in that
it uses LoopIDs. LoopID unfortunately is not loop identifier. It is
neither unique (there's even a regression test assigning the some LoopID
to multiple loops; can otherwise happen if passes such as LoopVersioning
make copies of entire loops) nor persistent (every time a property is
removed/added from a LoopID's MDNode, it will also receive a new LoopID;
this happens e.g. when calling Loop::setLoopAlreadyUnrolled()).
Since most loop transformation passes change the loop attributes (even
if it just to mark that a loop should not be processed again as
llvm.loop.isvectorized does, for the versioned and unversioned loop),
the parallel access information is lost for any subsequent pass.
This patch unlinks LoopIDs and parallel accesses.
llvm.mem.parallel_loop_access metadata on instruction is replaced by
llvm.access.group metadata. llvm.access.group points to a distinct
MDNode with no operands (avoiding the problem to ever need to add/remove
operands), called "access group". Alternatively, it can point to a list
of access groups. The LoopID then has an attribute
llvm.loop.parallel_accesses with all the access groups that are parallel
(no dependencies carries by this loop).
This intentionally avoid any kind of "ID". Loops that are clones/have
their attributes modifies retain the llvm.loop.parallel_accesses
attribute. Access instructions that a cloned point to the same access
group. It is not necessary for each access to have it's own "ID" MDNode,
but those memory access instructions with the same behavior can be
grouped together.
The behavior of llvm.mem.parallel_loop_access is not changed by this
patch, but should be considered deprecated.
Thomas Lively [Thu, 20 Dec 2018 02:10:22 +0000 (02:10 +0000)]
[WebAssembly] Gate unimplemented SIMD ops on flag
Summary:
Gates v128.const, f32x4.sqrt, f32x4.div, i8x16.extract_lane_u, and
i16x8.extract_lane_u on the --wasm-enable-unimplemented-simd flag,
since these ops are not implemented yet in V8.
Amara Emerson [Thu, 20 Dec 2018 01:11:04 +0000 (01:11 +0000)]
[AArch64][GlobalISel] Implement selection og G_MERGE of two s32s into s64.
This code pattern is an unfortunate side effect of the way some types get split
at call lowering. Ideally we'd either not generate it at all or combine it away
in the legalizer artifact combiner.
Until then, add selection support anyway which is a significant proportion of
our current fallbacks on CTMark.
Vitaly Buka [Thu, 20 Dec 2018 00:30:18 +0000 (00:30 +0000)]
[asan] Prevent folding of globals with redzones
Summary:
ICF prevented by removing unnamed_addr and local_unnamed_addr for all sanitized
globals.
Also in general unnamed_addr is not valid here as address now is important for
ODR violation detector and redzone poisoning.
Before the patch ICF on globals caused:
1. false ODR reports when we register global on the same address more than once
2. globals buffer overflow if we fold variables of smaller type inside of large
type. Then the smaller one will poison redzone which overlaps with the larger one.
Nico Weber [Wed, 19 Dec 2018 23:52:16 +0000 (23:52 +0000)]
[gn build] Add check-lld target and make it work
Also add a build file for llvm-lit, which in turn needs llvm/tools/llvm-config.
With this, check-lld runs and passes all of lld's lit tests. It doesn't run any
of its unit tests yet.
Running just ninja -C out/gn will build all prerequisites needed to run tests,
but it won't run the tests (so that the build becomes clean after one build).
Running ninja -C out/gn check-lld will build prerequisites if needed and run
the tests. The check-lld target never becomes clean and runs tests every time.
llvm-config's build file is a bit gnarly: Everything not needed to run tests is
basically stubbed out. Also, to generate LibraryDependencies.inc we shell out
to llvm-build at build-time. It would be much nicer to get the library
dependencies by using the dependency data the GN build contains
(http://llvm-cs.pcc.me.uk/gen/tools/llvm-config/LibraryDependencies.inc#1).
Eli Friedman [Wed, 19 Dec 2018 22:52:04 +0000 (22:52 +0000)]
[CodeGenPrepare] Fix bad IR created by large offset GEP splitting.
Creating the IR builder, then modifying the CFG, leads to an IRBuilder
where the BB and insertion point are inconsistent, so new instructions
have the wrong parent.
Modified an existing test because the test wasn't covering anything
useful (the "invoke" was not actually an invoke by the time we hit the
code in question).
Nikita Popov [Wed, 19 Dec 2018 19:56:21 +0000 (19:56 +0000)]
[BDCE][DemandedBits] Detect dead uses of undead instructions
This (mostly) fixes https://bugs.llvm.org/show_bug.cgi?id=39771.
BDCE currently detects instructions that don't have any demanded bits
and replaces their uses with zero. However, if an instruction has
multiple uses, then some of the uses may be dead (have no demanded bits)
even though the instruction itself is still live. This patch extends
DemandedBits/BDCE to detect such uses and replace them with zero.
While this will not immediately render any instructions dead, it may
lead to simplifications (in the motivating case, by converting a rotate
into a simple shift), break dependencies, etc.
The implementation tries to strike a balance between analysis power and
complexity/memory usage. Originally I wanted to track demanded bits on
a per-use level, but ultimately we're only really interested in whether
a use is entirely dead or not. I'm using an extra set to track which uses
are dead. However, as initially all uses are dead, I'm not storing uses
those user is also dead. This case is checked separately instead.
The test case has a couple of cases that are not simplified yet. In
particular, we're only looking at uses of instructions right now. I think
it would make sense to also extend this to arguments. Furthermore
DemandedBits doesn't yet know some of the tricks that InstCombine does
for the demanded bits or bitwise or/and/xor in combination with known
bits information.
David Blaikie [Wed, 19 Dec 2018 19:34:24 +0000 (19:34 +0000)]
llvm-dwarfdump: Improve/fix pretty printing of array dimensions
This is to address post-commit feedback from Paul Robinson on r348954.
The original commit misinterprets count and upper bound as the same thing (I thought I saw GCC producing an upper bound the same as Clang's count, but GCC correctly produces an upper bound that's one less than the count (in C, that is, where arrays are zero indexed)).
I want to preserve the C-like output for the common case, so in the absence of a lower bound the count (or one greater than the upper bound) is rendered between []. In the trickier cases, where a lower bound is specified, a half-open range is used (eg: lower bound 1, count 2 would be "[1, 3)" and an unknown parts use a '?' (eg: "[1, ?)" or "[?, 7)" or "[?, ? + 3)").
Matthew Voss [Wed, 19 Dec 2018 19:07:45 +0000 (19:07 +0000)]
[ThinLTO] Remove dllimport attribute from locally defined symbols
Summary:
The LTO/ThinLTO driver currently creates invalid bitcode by setting
symbols marked dllimport as dso_local. The compiler often has access
to the definition (often dllexport) and the declaration (often
dllimport) of an object at link-time, leading to a conflicting
declaration. This patch resolves the inconsistency by removing the
dllimport attribute.
Jessica Paquette [Wed, 19 Dec 2018 19:01:36 +0000 (19:01 +0000)]
[GlobalISel][AArch64] Add support for @llvm.ceil
This adds a G_FCEIL generic instruction and uses it in AArch64. This adds
selection for floating point ceil where it has a supported, dedicated
instruction. Other cases aren't handled here.
It updates the relevant gisel tests and adds a select-ceil test. It also adds a
check to arm64-vcvt.ll which ensures that we don't fall back when we run into
one of the relevant cases.
Craig Topper [Wed, 19 Dec 2018 18:49:13 +0000 (18:49 +0000)]
[X86] Don't match TESTrr from (cmp (and X, Y), 0) during isel. Defer to post processing
The (cmp (and X, Y) 0) pattern is greedy and ends up forming a TESTrr and consuming the and when it might be better to use one of the BMI/TBM like BLSR or BLSI.
This patch moves removes the pattern from isel and adds a post processing check to combine TESTrr+ANDrr into just a TESTrr. With this patch we are able to select the BMI/TBM instructions, but we'll also emit a TESTrr when the result is compared to 0. In many cases the peephole pass will be able to use optimizeCompareInstr to remove the TEST, but its probably not perfect.
Craig Topper [Wed, 19 Dec 2018 18:45:57 +0000 (18:45 +0000)]
[X86] Fix assert fails in pass X86AvoidSFBPass
Fixes https://bugs.llvm.org/show_bug.cgi?id=38743
The function removeRedundantBlockingStores is supposed to remove any blocking stores contained in each other in lockingStoresDispSizeMap.
But it currently looks only at the previous one, which will miss some cases that result in assert.
This patch refine the function to check all previous layouts until find the uncontained one. So all redundant stores will be removed.
Yonghong Song [Wed, 19 Dec 2018 16:40:25 +0000 (16:40 +0000)]
[BPF] Generate BTF DebugInfo under BPF target
This patch implements BTF (BPF Type Format).
The BTF is the debug info format for BPF, introduced
in the below linux patch:
https://github.com/torvalds/linux/commit/69b693f0aefa0ed521e8bd02260523b5ae446ad7#diff-06fb1c8825f653d7e539058b72c83332
and further extended several times, e.g.,
https://www.spinics.net/lists/netdev/msg534640.html
https://www.spinics.net/lists/netdev/msg538464.html
https://www.spinics.net/lists/netdev/msg540246.html
The main advantage of implementing in LLVM is:
. better integration/deployment as no extra tools are needed.
. bpf JIT based compilation (like bcc, bpftrace, etc.) can get
BTF without much extra effort.
. BTF line_info needs selective source codes, which can be
easily retrieved when inside the compiler.
This patch implemented BTF generation by registering a BPF
specific DebugHandler in BPFAsmPrinter.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D55752
Peter Wu [Wed, 19 Dec 2018 16:15:05 +0000 (16:15 +0000)]
[Object] Deduplicate long archive member names
Summary:
Import libraries as created by llvm-dlltool always use the same archive
member name for every object file (namely, the DLL library name). Ensure
that long names are not repeatedly stored in the string table.
Simon Pilgrim [Wed, 19 Dec 2018 14:43:36 +0000 (14:43 +0000)]
[X86][SSE] Auto upgrade PADDUS/PSUBUS intrinsics to UADD_SAT/USUB_SAT generic intrinsics (llvm)
Now that we use the generic ISD opcodes, we can use the generic intrinsics directly as well. This fixes the poor fast-isel codegen by not expanding to an easily broken IR code sequence.
I'm intending to deal with the signed saturation equivalents as well.
Simon Pilgrim [Wed, 19 Dec 2018 13:37:59 +0000 (13:37 +0000)]
[TargetLowering] Fix propagation of undefs in zero extension ops (PR40091)
As described on PR40091, we have several places where zext (and zext_vector_inreg) fold an undef input into an undef output. For zero extensions this is incorrect as the output should guarantee to least have the new upper bits set to zero.
SimplifyDemandedVectorElts is the worst offender (and its the most likely to cause new undefs to appear) but DAGCombiner's tryToFoldExtendOfConstant has a similar issue.
Nico Weber [Wed, 19 Dec 2018 13:35:53 +0000 (13:35 +0000)]
Let TableGen write output only if it changed, instead of doing so in cmake, attempt 2
This relands r330742:
"""
Let TableGen write output only if it changed, instead of doing so in cmake.
Removes one subprocess and one temp file from the build for each tablegen
invocation.
No intended behavior change.
"""
In particular, if you see rebuilds after this change that you didn't see
before this change, that's unintended and it's fine to revert this change
again (but let me know).
r330742 got reverted because some people reported that llvm-tblgen ran on every
build after it. This could happen if the depfile output got deleted without
deleting the main .inc output. To fix, make TableGen always write the depfile,
but keep writing the main .inc output only if it has changed. This matches what
we did in cmake before.
Simon Pilgrim [Wed, 19 Dec 2018 10:39:14 +0000 (10:39 +0000)]
[X86][SSE] Remove SSE ADDUS/SUBUS saturation intrinsics from schedule/stack tests
These are already being autoupgraded, currently to an IR sequence, but best to replace them with generic llvm uadd_sat/usub_sat intrinsics (which D55855 will be doing shortly anyhow).
The avx512 masked cases need doing as well but require a bit of tidyup first.
Carl Ritson [Wed, 19 Dec 2018 10:17:49 +0000 (10:17 +0000)]
AMDGPU/InsertWaitcnts: Update VGPR/SGPR bounds when brackets are merged
Summary:
Fix an issue where VGPR/SGPR bounds are not properly extended when brackets are merged.
This manifests as missing waitcnt insertions when multiple brackets are forwarded to a successor block and the first forward has lower VGPR/SGPR bounds.
Irreducible loop test has been extended based on a CTS failure detected for GFX9.
Diana Picus [Wed, 19 Dec 2018 09:55:10 +0000 (09:55 +0000)]
[ARM GlobalISel] Support G_CONSTANT for Thumb2
All we have to do is mark it as legal.
This allows us to select a lot of new patterns handled by TableGen. This
patch adds tests for them and splits up the existing test file for
binary operators into 2 files, one for arithmetic ops and one for
logical ones.