Max Kazantsev [Tue, 28 Nov 2017 07:48:12 +0000 (07:48 +0000)]
[SCEV][NFC] More efficient caching in CompareSCEVComplexity
Currently, we use a set of pairs to cache responces like `CompareSCEVComplexity(X, Y) == 0`. If we had
proved that `CompareSCEVComplexity(S1, S2) == 0` and `CompareSCEVComplexity(S2, S3) == 0`,
this cache does not allow us to prove that `CompareSCEVComplexity(S1, S3)` is also `0`.
This patch replaces this set with `EquivalenceClasses` any two values from the same set are equal from
point of `CompareSCEVComplexity`. This, in particular, allows us to prove the fact from example above.
Max Kazantsev [Tue, 28 Nov 2017 07:07:55 +0000 (07:07 +0000)]
[GVN] Prevent ScalarPRE from hoisting across instructions that don't pass control flow to successors
This is to address a problem similar to those in D37460 for Scalar PRE. We should not
PRE across an instruction that may not pass execution to its successor unless it is safe
to speculatively execute it.
Simon Dardis [Tue, 28 Nov 2017 04:07:59 +0000 (04:07 +0000)]
[DAGCombine] Disable finding better chains for stores at O0
Unoptimized IR can have linear sequences of stores to an array, where the
initial GEP for the first store is formed from the pointer to the array, and the
GEP for each store after the first is formed from the previous GEP with some
offset in an inductive fashion.
The (large) resulting DAG when analyzed by DAGCombine undergoes an excessive
number of combines as each store node is examined every time its' offset node
is combined with any child of the offset. One of the transformations is
findBetterNeighborChains which assists MergeConsecutiveStores. The former
relies on repeated chain walking to do its' work, however MergeConsecutiveStores
is disabled at O0 which makes the transformation redundant.
Any optimization level other than O0 would invoke InstCombine which would
resolve the chain of GEPs into flat base + offset GEP for each store which
does not exhibit the repeated examination of each store to the array.
Disabling this optimization fixes an excessive compile time issue (30~ minutes
for the test case provided) at O0.
Matthias Braun [Tue, 28 Nov 2017 03:54:20 +0000 (03:54 +0000)]
MachineVerifier: Improve register operand checks
This fixes cases where we wouldn't perform various register operand
checks just because we didn't happen to have a definition in the
MCInstrDesc. This changes the code to only skip the tests that actually
depend on the MCInstrDesc definition.
This makes the machine verifier spot the problem from
https://llvm.org/PR33071 after the pass that actually caused it.
Matthias Braun [Tue, 28 Nov 2017 03:54:19 +0000 (03:54 +0000)]
MachineVerifier: Improve PHI operand checking
Additional checks for phi operands:
- first operand should be a virtual register def. It should not be
tied, implicit, internalread, earlyclobber or a read.
- The other operands should be register/mbb operands next to each other
- The register operands should not be implicit, internalread,
earlyclobber, debug or tied.
- We can perform most of the PHI checks even for unreachable blocks.
Reland r319090, "COFF: Do not create SectionChunks for discarded comdat sections." with a fix for debug sections.
If /debug was not specified, readSection will return a null
pointer for debug sections. If the debug section is associative with
another section, we need to make sure that the section returned from
readSection is not a null pointer before adding it as an associative
section.
Dan Gohman [Tue, 28 Nov 2017 01:13:40 +0000 (01:13 +0000)]
[WebAssembly] Fix trapping behavior in fptosi/fptoui.
This adds code to protect WebAssembly's `trunc_s` family of opcodes
from values outside their domain. Even though such conversions have
full undefined behavior in C/C++, LLVM IR's `fptosi` and `fptoui` do
not, and only return undef.
This also implements the proposed non-trapping float-to-int conversion
feature and uses that instead when available.
Craig Topper [Mon, 27 Nov 2017 22:56:10 +0000 (22:56 +0000)]
[X86] Teach getSetCCResultType to handle more than just SimpleVTs when looking at larger than 512-bit vectors.
Which VTs are considered simple is determined by the superset of the legal types of all targets in LLVM. If we're looking at VTs that are going to be split down to 512-bits we should allow any VT not just simple ones since the simple list changes over time as new targets are added.
Petr Hosek [Mon, 27 Nov 2017 22:31:11 +0000 (22:31 +0000)]
[CMake][runtimes] Support monorepo layout with runtimes build
We introduce a new variable LLVM_ENABLE_RUNTIMES which works
similarly to LLVM_ENABLE_PROJECTS and allows specifying runtimes
that will be enabled in the runtimes build.
Michal Gorny [Mon, 27 Nov 2017 22:23:09 +0000 (22:23 +0000)]
[cmake] Pass -Wl,-z,nodelete on Linux to prevent unloading
Prevent unloading shared libraries on Linux when dlclose() is called.
This is necessary since command-line option parsing API relies on
registering the global option instances in the option parser instance
which can be loaded in a different shared library.
Given that we can't reliably remove those options when a library is
unloaded, the parser ends up containing dangling references. Since glibc
has relatively complex library unloading rules, some of the LLVM
libraries can be unloaded while others (including the Support library)
stay loaded causing quite a mayhem. To reliably prevent that, just
forbid unloading all libraries -- it's a very bad idea anyway.
While the issue arguably happens only with BUILD_SHARED_LIBS, it may
affect any library reusing llvm::cl interface.
Based on patch provided Ross Hayward on https://bugs.gentoo.org/617154.
Previously hit by Fedora back in Feb 2016:
https://lists.freedesktop.org/archives/mesa-dev/2016-February/107242.html
Greg Clayton [Mon, 27 Nov 2017 22:12:44 +0000 (22:12 +0000)]
Fixed the ability to recursively get an attribute value from a DWARFDie.
The previous implementation would only look 1 DW_AT_specification or DW_AT_abstract_origin deep. This means DWARFDie::getName() would fail in certain cases. I ran into such a case while creating a tool that used the LLVM DWARF parser to generate a symbolication format so I have seen this in the wild.
Craig Topper [Mon, 27 Nov 2017 22:01:17 +0000 (22:01 +0000)]
[X86] Remove lines that set v8f32 FP_ROUND/FP_EXTEND to Legal under AVX512. NFCI
We don't do this for narrow vectors under AVX or SSE features. We also don't set them to Expand like we do for many vectors op. Nor does TargetLoweringBase.cpp. This leads me to believe these default to Legal.
Davide Italiano [Mon, 27 Nov 2017 21:25:13 +0000 (21:25 +0000)]
[SROA] Propagate !range metadata when moving loads.
This tries to propagate !range metadata to a pre-existing load
when a load is optimized out. This is done instead of adding an
assume because converting loads to and from assumes creates a
lot of IR.
COFF: Do not create SectionChunks for discarded comdat sections.
With this change, instead of creating a SectionChunk for each section
in the object file, we only create them when we encounter a prevailing
comdat section.
Also change how symbol resolution occurs between comdat symbols. Now
only the comdat leader participates in comdat resolution, and not any
other external associated symbols. This is more in line with how COFF
semantics are defined, and should allow for a more straightforward
implementation of non-ANY comdat types.
On my machine, this change reduces our runtime linking a release
build of chrome_child.dll with /nopdb from 5.65s to 4.54s (median of
50 runs).
Petr Hosek [Mon, 27 Nov 2017 20:41:53 +0000 (20:41 +0000)]
Use LIST_SEPARATOR rather than escaping in ExternalProject_Add
Escaping ; in list arguments passed to ExternalProject_Add doesn't seem
to be working in newer versions of CMake (see
https://public.kitware.com/Bug/view.php?id=16137 for more details). Use
a custom LIST_SEPARATOR instead which is the officially supported way.
Zaara Syeda [Mon, 27 Nov 2017 20:26:36 +0000 (20:26 +0000)]
[PowerPC] Remove redundant TOC saves
This patch adds a peep hole optimization to remove any redundant toc save
instructions added as part of the call sequence for indirect calls. It removes
any toc saves within a function that are dominated by another toc save.
David Blaikie [Mon, 27 Nov 2017 19:43:58 +0000 (19:43 +0000)]
Rename CommandFlags.h -> CommandFlags.def
Since this isn't a real header - it includes static functions and had
external linkage variables (though this change makes them static, since
that's what they should be) so can't be included more than once in a
program.
Jake Ehrlich [Mon, 27 Nov 2017 18:56:01 +0000 (18:56 +0000)]
[llvm-objcopy] Add --strip-all-gnu and change --strip-all
GNU's --strip-all doesn't strip as aggressively as it could in general.
Currently llvm-objcopy copies the exact behavoir of GNU's --strip-all.
eu-strip is used as a drop in replacement for GNU strip/objcopy in many many
places without issue. eu-strip removes non-allocated sections and keeps
.gnu.warning* sections. Because --strip-all will likely be the most widely
used stripping option we should make --strip-all as aggressive as it can safely
be. Since we have evidence from eu-strip that this is a safe option we should
allow it. For those that might still have an issue afterwards I've added
--strip-all-gnu as an exact drop in replacement for GNU's --strip-all as well.
Zachary Turner [Mon, 27 Nov 2017 18:48:37 +0000 (18:48 +0000)]
[BinaryStream] Support growable streams.
The existing library assumed that a stream's length would never
change. This makes some things simpler, but it's not flexible
enough for what we need, especially for writable streams where
what you really want is for each call to write to actually append.
Michal Gorny [Mon, 27 Nov 2017 18:34:52 +0000 (18:34 +0000)]
[cmake] Pass -Wl,-z,nodelete on Linux to prevent unloading
Prevent unloading shared libraries on Linux when dlclose() is called.
This is necessary since command-line option parsing API relies on
registering the global option instances in the option parser instance
which can be loaded in a different shared library.
Given that we can't reliably remove those options when a library is
unloaded, the parser ends up containing dangling references. Since glibc
has relatively complex library unloading rules, some of the LLVM
libraries can be unloaded while others (including the Support library)
stay loaded causing quite a mayhem. To reliably prevent that, just
forbid unloading all libraries -- it's a very bad idea anyway.
While the issue arguably happens only with BUILD_SHARED_LIBS, it may
affect any library reusing llvm::cl interface.
Based on patch provided Ross Hayward on https://bugs.gentoo.org/617154.
Previously hit by Fedora back in Feb 2016:
https://lists.freedesktop.org/archives/mesa-dev/2016-February/107242.html
Craig Topper [Mon, 27 Nov 2017 18:15:14 +0000 (18:15 +0000)]
[X86] Teach combineX86ShuffleChain that AllowIntDomain requires at least SSE2.
I don't have a good test case for this at the moment. I was playing around with a change in legalizing and triggered this code to produce a PSHUFD with sse1 only.
Craig Topper [Mon, 27 Nov 2017 17:51:55 +0000 (17:51 +0000)]
[X86] Make getSetCCResultType return vXi1 for any vXi32/vXi64 vector over 512 bits long when AVX512 is enabled.
Similar for vXi16/vXi8 with BWI.
Any vector larger than 512 bits will be split to 512 bits during legalization. But without this we will fold sexts with them before that making it difficult to recover leading to scalarization.
Zaara Syeda [Mon, 27 Nov 2017 17:11:03 +0000 (17:11 +0000)]
[Power9] Improvements to vector extract with variable index exploitation
This patch extends on to rL307174 to not use the power9 vector extract with
variable index instructions when extracting word element 1. For such cases,
the existing selection of MFVSRWZ provides a better sequence.
[llvm-dwarfdump] Display DW_AT_high_pc as absolute value
DWARF4 relative DW_AT_high_pc values are now displayed as absolute
addresses. The relative value is only shown when explicitly dumping the
forms, i.e. in show-form or verbose mode.
Nirav Dave [Mon, 27 Nov 2017 15:28:15 +0000 (15:28 +0000)]
[DAG] Do MergeConsecutiveStores again before Instruction Selection
Summary:
Now that store-merge is only generates type-safe stores, do a second
pass just before instruction selection to allow lowered intrinsics to
be merged as well.
Petar Jovanovic [Mon, 27 Nov 2017 14:25:36 +0000 (14:25 +0000)]
[mips] fix asmstring of Ext and Ins instructions and mips16 JALRC/JRC
Make the print format consistent with other assembler instructions.
Adding a tab character instead of space in asmstring of Ext and Ins
instructions.
Removing space around the tab character for JALRC and replacing space with
tab in JRC.
Vedran Miletic [Mon, 27 Nov 2017 13:26:38 +0000 (13:26 +0000)]
[AMDGPU] Add custom lowering for llvm.log{,10}.{f16,f32} intrinsics
AMDGPU backend errors with "unsupported call to function" upon
encountering a call to llvm.log{,10}.{f16,f32} intrinsics. This patch
adds custom lowering to avoid that error on both R600 and SI.
John Brawn [Mon, 27 Nov 2017 11:29:15 +0000 (11:29 +0000)]
[CGP] Fix handling of null pointer values in optimizeMemoryInst
The current way that trivial addressing modes are detected incorrectly thinks
that null pointers are non-trivial, leading to an infinite loop where we keep
duplicating the same select. Fix this by aware of null when deciding if an
addressing mode is trivial.
Simon Pilgrim [Mon, 27 Nov 2017 10:41:32 +0000 (10:41 +0000)]
[X86][FMA] Tag all FMA/FMA4 instructions with WriteFMA schedule class
As mentioned on PR17367, many instructions are missing scheduling tags preventing us from setting 'CompleteModel = 1' for better instruction analysis. This patch deals with FMA/FMA4 which is one of the bigger offenders (along with AVX512 in general).
Annoyingly all scheduler models need to define WriteFMA (now that its actually used), even for older targets without FMA/FMA4 support, but that is an existing problem shared by other schedule classes.
Momchil Velikov [Mon, 27 Nov 2017 10:13:14 +0000 (10:13 +0000)]
[ARM] Fix an off-by-one error when restoring LR for 16-bit Thumb
The commit https://reviews.llvm.org/rL318143 computes incorrectly to offset to
restore LR from.
The number of tPOP operands is 2 (condition) + 2 (implicit def and use of SP) +
count of the popped registers. We need to load LR from just past the last
register, hence the correct offset should be either getNumOperands() - 4 and
getNumExplicitOperands() - 2 (multiplied by 4).
Jatin Bhateja [Sun, 26 Nov 2017 15:08:41 +0000 (15:08 +0000)]
[SCEV] Adding a check on outgoing branches of a terminator instr for SCEVBackedgeConditionFolder, NFC.
Summary:
For a given loop, getLoopLatch returns a non-null value
when a loop has only one latch block. In the modified
context adding an assertion to check that both the outgoing branches of
a terminator instruction (of latch) does not target same header.
+
few minor code reorganization.
Oren Ben Simhon [Sun, 26 Nov 2017 13:02:45 +0000 (13:02 +0000)]
Control-Flow Enforcement Technology - Shadow Stack support (LLVM side)
Shadow stack solution introduces a new stack for return addresses only.
The HW has a Shadow Stack Pointer (SSP) that points to the next return address.
If we return to a different address, an exception is triggered.
The shadow stack is managed using a series of intrinsics that are introduced in this patch as well as the new register (SSP).
The intrinsics are mapped to new instruction set that implements CET mechanism.
The patch also includes initial infrastructure support for IBT.
For more information, please see the following:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf
Jatin Bhateja [Sun, 26 Nov 2017 02:01:01 +0000 (02:01 +0000)]
[SCEV] NFC : Removing unnecessary check on outgoing branches of a branch instr.
Summary:
For a given loop, getLoopLatch returns a non-null value
when a loop has only one latch block. In the modified
context a check on both the outgoing branches of a terminator instruction (of latch) to same header is redundant.
David Blaikie [Sat, 25 Nov 2017 20:06:04 +0000 (20:06 +0000)]
Remove dead code
(this header is not fully implemented (the out of line function
writeTypeRecordKind is called in an inline function but never
implemented - this fails to link under modular code generation) and not
included anywhere)
Craig Topper [Sat, 25 Nov 2017 18:32:43 +0000 (18:32 +0000)]
[X86] Add separate intrinsics for scalar FMA4 instructions.
Summary:
These instructions zero the non-scalar part of the lower 128-bits which makes them different than the FMA3 instructions which pass through the non-scalar part of the lower 128-bits.
I've only added fmadd because we should be able to derive all other variants using operand negation in the intrinsic header like we do for AVX512.
I think there are still some missed negate folding opportunities with the FMA4 instructions in light of this behavior difference that I hadn't noticed before.
I've split the tests so that we can use different intrinsics for scalar testing between the two. I just copied the tests split the RUN lines and changed out the scalar intrinsics.
fma4-fneg-combine.ll is a new test to make sure we negate the fma4 intrinsics correctly though there are a couple TODOs in it.
Craig Topper [Sat, 25 Nov 2017 18:09:37 +0000 (18:09 +0000)]
[X86] Don't report gather is legal on Skylake CPUs when AVX2/AVX512 is disabled. Allow gather on SKX/CNL/ICL when AVX512 is disabled by using AVX2 instructions.
Summary:
This adds a new fast gather feature bit to cover all CPUs that support fast gather that we can use independent of whether the AVX512 feature is enabled. I'm only using this new bit to qualify AVX2 codegen. AVX512 is still implicitly assuming fast gather to keep tests working and to match the scatter behavior.
Test command lines have been added for these two cases.
Craig Topper [Sat, 25 Nov 2017 17:59:00 +0000 (17:59 +0000)]
[SelectionDAG] Remove some dead code from vector scalaring
Summary:
Currently ScalarizeVecRes_SETCC checks for the result type being a vector and jumps to ScalarizeVecRes_VSETCC. But if we're scalarizing a vector result, aren't we guaranteed to be looking at a vector type?
This patch deletes the current ScalarizeVecRes_SETCC and renames ScalarizeVecRes_VSETCC to ScalarizeVecRes_SETCC.
projects / llvm / log