Matt Arsenault [Wed, 19 Apr 2017 18:29:07 +0000 (18:29 +0000)]
StructurizeCFG: Directly invert cmp instructions
The most common case for a branch condition is
a single use compare. Directly invert the branch
predicate rather than adding a lot of xor i1 true
which the DAG will have to fold later.
This produces nicer to read structurizer output.
This produces some random changes in codegen
due to the DAG swapping branch conditions itself,
and then does a poor job of dealing with those
inverts.
Sanjoy Das [Wed, 19 Apr 2017 18:21:09 +0000 (18:21 +0000)]
[GVN] Don't coerce non-integral pointers to integers or vice versa
Summary:
See http://llvm.org/docs/LangRef.html#non-integral-pointer-type
The NewGVN test does not fail without these changes (perhaps it does
try to coerce pointers <-> integers to begin with?), but I added the
test case anyway.
[DAG] add splat vector support for 'and' in SimplifyDemandedBits
The patch itself is simple: stop discriminating against vectors in visitAnd() and again in
SimplifyDemandedBits().
Some notes for reference:
1. We're not consistent about calls to SimplifyDemandedBits in the various visitXXX functions.
Sometimes, we check if the RHS is a constant first. Other times (like here), we just dive in.
2. I'd like to break the vector shackles in steps for the sake of risk minimization, but we could
make similar simultaneous changes in other places if we think that would be better.
3. I don't know what the intent of the changed tests in this patch was supposed to be, but since
they wiggled in a positive way, I'm just going with that. :)
4. In the rotate tests, note that we can see through non-splat constants. This is a result of D24253.
5. My motivation for being here now is to make D31944 look better, so this is step 1 of N towards
improving the vector codegen in that patch without writing any actual new code.
Prefer addAttr(Attribute::AttrKind) over the AttributeList overload
This should simplify the call sites, which typically want to tweak one
attribute at a time. It should also avoid creating ephemeral
AttributeLists that live forever.
[APInt] Move the 'return *this' from the slow cases of assignment operators inline. We should let the compiler see that the fast/slow cases both return *this.
I don't think we chain assignments together very often so this shouldn't matter much.
[InstSimplify] fold identity shuffles (recursing if needed)
This patch simplifies the examples from D31509 and D31927 (PR30630) and catches
the basic identity shuffle tests that Zvi recently added.
I'm not sure if we have something like this in DAGCombiner, but we should?
It's worth noting that "MaxRecurse / RecursionLimit" is only 3 on entry at the moment.
We might want to bump that up if there are longer shuffle chains like this in the wild.
For now, we're ignoring shuffles that have undef mask elements because it's not
clear how those should be handled.
but using this function you cannot produce a word with every
bit set to 1 (i.e. leadingBitMask<uint8_t>(8)) because left
shift is undefined when N is greater than or equal to the
number of bits in the word.
This patch provides an efficient, branch-free implementation
that works for all values of N in [0, CHAR_BIT*sizeof(T)]
Also, make a few changes to allow using the pass in .mir testcases.
Among other things, change the abbreviation from opt-amode to amode-opt,
because otherwise lit would expand the "opt" part to the full path to
the opt binary.
Using address range map to speedup finding inline stack for address.
Summary:
In the current implementation, to find inline stack for an address incurs expensive linear search in 2 places:
* linear search for the top-level DIE
* recursive linear traverse the DIE tree to find the path to the leaf DIE
In this patch, a map is built from address to its corresponding leaf DIE. The inline stack is built by traversing from the leaf DIE up to the root DIE. This speeds up batch symbolization by ~10X without noticible memory overhead.
Davide Italiano [Wed, 19 Apr 2017 14:23:42 +0000 (14:23 +0000)]
[InstSimplify] Deduce correct type for vector GEP.
InstSimplify returned the wrong type when simplifying a vector GEP
and we ended up crashing when trying to replace all uses with the
new value. Fixes PR32697.
Igor Breger [Wed, 19 Apr 2017 11:34:59 +0000 (11:34 +0000)]
[GlobalIsel][X86] support G_TRUNC selection.
Summary:
[GlobalIsel][X86] support G_TRUNC selection.
Add regbank-select and legalizer tests. Currently legalization of trunc i64 on 32bit platform not supported.
Support G_MUL, very similar to G_ADD and G_SUB. The only difference is
in the instruction selector, where we have to select either MUL or MULv5
depending on the target.
As comment 10 on that bug report highlights
(https://bugs.llvm.org//show_bug.cgi?id=32471#c10), there are quite a
few different defendable design tradeoffs that could be made, including
not representing pointers at all in LLT.
I decided to go for representing vector-of-pointer as a concept in LLT,
while keeping the size of the LLT type 64 bits (this is an increase from
48 bits before). My rationale for keeping pointers explicit is that on
some targets probably it's very handy to have the distinction between
pointer and non-pointer (e.g. 68K has a different register bank for
pointers IIRC). If we keep a scalar pointer, it probably is easiest to
also have a vector-of-pointers to keep LLT relatively conceptually clean
and orthogonal, while we don't have a very strong reason to break that
orthogonality. Once we gain more experience on the use of LLT, we can
of course reconsider this direction.
Rejecting vector-of-pointer types in the IRTranslator is also an option
to avoid the crash reported in PR32471, but that is only a very
short-term solution; also needs quite a bit of code tweaks in places,
and is probably fragile. Therefore I didn't consider this the best
option.
[GlobalISel] Remove non-determinism from IRTranslator.
This showed up in r300535/r300537, which were reverted in r300538 due to
some of the introduced tests in there failing on some bots, due to the
non-determinism fixed in this commit.
Re-committing r300535/r300537 will add 2 tests for the change in this
commit.
Revert r300657 due to crashes in stage2 of bootstraps:
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/2476/steps/build-stage2-LLVMgold.so/logs/stdio
http://bb.pgr.jp/builders/clang-3stage-x86_64-linux/builds/15036/steps/build_llvmclang/logs/stdio
I've updated the commit thread, reverting to get the bots back to green.
Original commit summary:
[JumpThread] We want to fold (not thread) when all predecessor go to single BB's successor.
Tim Shen [Wed, 19 Apr 2017 03:22:50 +0000 (03:22 +0000)]
Cleanup some GraphTraits iteration code
Use children<> and nodes<> in appropriate places to cleanup the code.
Also, as part of the cleanup,
change the signature of DominatorTreeBase's Split.
It is a protected non-virtual member function called only twice,
both from within the class,
and the removed passed argument in both cases is '*this'.
The reason for the existence of that argument seems to be that
back before r43115 Split was a free function,
so an argument to get '*this' was needed - but now that is no longer the
case.
ARM: Use methods to access data stored with frame instructions
In r300196 several methods were added to TarfetInstrInfo to access
data stored with call frame setup/destroy instructions. This change
replaces calls to getOperand with calls to such special methods in
ARM target.
ARMFrameLowering: Reserve emergency spill slot for large arguments
We need to reserve an emergency spill slot in cases with large argument
types that could overflow immediate offsets for FP relative address
calculations.
[DataLayout] Removed default value from a variable that isn't used without being overwritten. Make variable an enum instead of an int to avoid a cast later. NFC
Allow suppressing host and target info in VersionPrinter
Summary:
VersionPrinter by default outputs information about the Host CPU
and Default target. Printing this information requires linking in
a large amount of data, such as supported target triples as C
strings, which in turn bloats the binary size.
Enable a new CMake option LLVM_VERSION_PRINTER_SHOW_HOST_TARGET_INFO
which controls printing of the host and target info. This allows
the target triple names to be dead-code stripped. This is a nice
win for LLVM clients that wish to minimize their binary size, such
as graphics drivers.
By default this is ON, so there is no change in the default behavior.
Clients who wish to suppress this printing can do so by setting this
option to off via CMake.
A test app on Linux that uses ParseCommandLineOptions() shows a binary
size reduction of 23KB (from 149K to 126K) for a Release build, and 24KB
(from 135K to 111K) in a MinSizeRel build.
[ConstantRange] Optimize APInt creation in getSignedMax/getSignedMin.
We were creating an APInt at the top of these methods that isn't always returned. For ranges wider than 64-bits this results in an allocation and deallocation when its not used.
In getSignedMax we were creating Upper-1 to use in a compare and then creating it again for a return value. The compiler is unable to determine that these can be shared. So help it out and create the Upper-1 in a temporary that can be reused.
[MemoryBuiltins] Add isMallocOrCallocLikeFn so BasicAA can check for both at the same time
BasicAA wants to know if a function is either a malloc or calloc like function. Currently we have to check both separately. This means both calls check if its an intrinsic, query TLI, check the nobuiltin attribute, scan the AllocationFnData, etc.
This patch adds a isMallocOrCallocLikeFn so we can go through all of the checks once per call.
This also changes the one other location I saw that called both together.
[X86] Keep EXTRACT_VECTOR_ELT result type as f128 for Android x86_64.
Android x86_64 target uses f128 type and stores f128 values in %xmm* registers.
SoftenFloatRes_EXTRACT_VECTOR_ELT should not convert result value
from f128 to i128.
[SLP vectorizer] Allow phi node reordering in tryToVectorizeList.
In tryToVectorizeList, under a very limited circumstance (when entered
from tryToVectorizePair), the values may be reordered (swapped) and the
SLP tree is built with the new order. This extends that to the case when
starting from phis in vectorizeChainsInBlock when there are exactly two
phis. The textual order of phi nodes shouldn't really matter. Without
this change, the loop body in the accompnaying test case is fully vectorized
when we swap the orde of the phis but not with this order. While this
doesn't solve the phi-ordering problem in a general way (for more than 2
phis), this is simple fix that piggybacks on an existing mechanism and
is useful in cases like multiplying two complex numbers.
Nirav Dave [Tue, 18 Apr 2017 15:36:34 +0000 (15:36 +0000)]
[DAG] Improve store merge candidate pruning.
Remove non-consecutive stores from store merge candidate search as
they cannot be merged and will prevent us from finding subsequent
mergeable store cases.
Gil Rapaport [Tue, 18 Apr 2017 14:43:43 +0000 (14:43 +0000)]
[LV] Cache block mask values
This patch is part of D28975's breakdown.
Add caching for block masks similar to the cache already used for edge masks,
replacing generation per user with reusing the first generated value which
dominates all uses.
Nikolai Bozhenov [Tue, 18 Apr 2017 13:29:26 +0000 (13:29 +0000)]
Make globalaa-retained.ll test catching more cases.
Summary:
* Add checks for store. That is needed because GlobalsAA is called
twice in the current pipeline with different sets of Function passes
following it. However, the loads are eliminated using instcombine
which happens everywhere. On the other hand, DeadStoreElimination is
performed only once so by checking for store we'll be able to catch
more cases when GlobalsAA is invalidated unintentionally.
* Add empty function above/below the test so that we don't depend on
the relative order of instcombine/dead-store-elimination and the
pass that invalidates the analysis (inside the same
FunctionPassManager).
Reviewers: kristof.beyls
Reviewed By: kristof.beyls
Subscribers: llvm-commits, n.bozhenov
Differential Revision: https://reviews.llvm.org/D32015
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Oliver Stannard [Tue, 18 Apr 2017 12:52:35 +0000 (12:52 +0000)]
[ARM] Add hardware build attributes in assembler
In the assembler, we should emit build attributes based on the target
selected with command-line options. This matches the GNU assembler's
behaviour. We only do this for build attributes which describe the
hardware that is expected to be available, not the ones that describe
ABI compatibility.
This is done by moving some of the attribute emission code to
ARMTargetStreamer, so that it can be shared between the assembly and
code-generation code paths. Since the assembler only creates a
MCSubtargetInfo, not an ARMSubtarget, the code had to be changed to
check raw features, and not use the convenience functions in
ARMSubtarget.
If different attributes are later specified using the .eabi_attribute
directive, then they will take precedence, as happens when the same
.eabi_attribute is specified twice.
This must be enabled by an option, because we don't want to do this when
parsing inline assembly. The attributes would match the ones emitted at
the start of the file, so wouldn't actually change the emitted object
file, but the extra directives would be added to every inline assembly
block when emitting assembly, which we'd like to avoid.
The majority of the changes in the build-attributes.ll test are just
re-ordering the directives, because the hardware attributes are now
emitted before the ABI ones. However, I did fix one bug which I spotted:
Tag_CPU_arch_profile was not being emitted for v6M.
Andrea Di Biagio [Tue, 18 Apr 2017 10:08:53 +0000 (10:08 +0000)]
[SampleProfile] Skip intrinsic calls when visiting callsites in InlineHotFunctions.
Before this patch, we always called method 'findCalleeFunctionSamples()' on
intrinsic calls. However, intrinsic calls like llvm.dbg.value() are not viable
candidates for obvious reasons.
Revert "[GlobalISel] Support vector-of-pointers in LLT"
This reverts r300535 and r300537.
The newly added tests in test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
produces slightly different code between LLVM versions being built with different compilers.
E.g., dependent on the compiler LLVM is built with, either one of the following
can be produced:
remark: <unknown>:0:0: unable to legalize instruction: %vreg0<def>(p0) = G_EXTRACT_VECTOR_ELT %vreg1, %vreg2; (in function: vector_of_pointers_extractelement)
remark: <unknown>:0:0: unable to legalize instruction: %vreg2<def>(p0) = G_EXTRACT_VECTOR_ELT %vreg1, %vreg0; (in function: vector_of_pointers_extractelement)
Non-determinism like this is clearly a bad thing, so reverting this until
I can find and fix the root cause of the non-determinism.
[ARM] Check for correct HW div when lowering divmod
For subtargets that use the custom lowering for divmod, e.g. gnueabi,
we used to check if the subtarget has hardware divide and then lower to
a div-mul-sub sequence if true, or to a libcall if false.
However, judging by the usage of hasDivide vs hasDivideInARMMode, it
seems that hasDivide only refers to Thumb. For instance, in the
ARMTargetLowering constructor, the code that specifies whether to use
libcalls for (S|U)DIV looks like this:
In the case of divmod for arm-gnueabi, using only hasDivide() to
determine what to do means that instead of lowering to __aeabi_idivmod
to get the remainder, we lower to div-mul-sub and then further lower the
div to __aeabi_idiv. Even worse, if we have hardware divide in ARM but
not in Thumb, we generate a libcall instead of using it (this is not an
issue in practice since AFAICT none of the cores that we support have
hardware divide in ARM but not Thumb).
This patch fixes the code dealing with custom lowering to take into
account the mode (Thumb or ARM) when deciding whether or not hardware
division is available.
As comment 10 on that bug report highlights
(https://bugs.llvm.org//show_bug.cgi?id=32471#c10), there are quite a
few different defendable design tradeoffs that could be made, including
not representing pointers at all in LLT.
I decided to go for representing vector-of-pointer as a concept in LLT,
while keeping the size of the LLT type 64 bits (this is an increase from
48 bits before). My rationale for keeping pointers explicit is that on
some targets probably it's very handy to have the distinction between
pointer and non-pointer (e.g. 68K has a different register bank for
pointers IIRC). If we keep a scalar pointer, it probably is easiest to
also have a vector-of-pointers to keep LLT relatively conceptually clean
and orthogonal, while we don't have a very strong reason to break that
orthogonality. Once we gain more experience on the use of LLT, we can
of course reconsider this direction.
Rejecting vector-of-pointer types in the IRTranslator is also an option
to avoid the crash reported in PR32471, but that is only a very
short-term solution; also needs quite a bit of code tweaks in places,
and is probably fragile. Therefore I didn't consider this the best
option.
Adrian Prantl [Tue, 18 Apr 2017 01:21:53 +0000 (01:21 +0000)]
PR32382: Fix emitting complex DWARF expressions.
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
- describe a variable in a register
- consist of only a DW_OP_reg
2. Memory location descriptions
- describe the address of a variable
3. Implicit location descriptions
- describe the value of a variable
- end with DW_OP_stack_value & friends
The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident. This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.
This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.
There are two major changes in this patch:
I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.
When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
DBG_VALUE, [RBP-8] --> DW_OP_fbreg -8
DBG_VALUE, RAX --> DW_OP_reg0 +0
DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0
All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.
Object: Shrink the size of irsymtab::Symbol by a word. NFCI.
Instead of storing an UncommonIndex on the Symbol, use a flag bit to store
whether the Symbol has an Uncommon. This shrinks Chromium's .bc files (after
D32061) by about 1%.
Build SymbolMap in SampleProfileLoader to help matchin function names with suffix.
Summary: If there is suffix added in the function name (e.g. module hash added by thinLTO), we will not be able to find a match in profile as the suffix does not exist in profile. This patch build a map from function name to Function *. The map includes the entry for the stripped function name so that inlineHotFunctions can find the corresponding function to promote/inline.
[SimplifyCFG] Use hasNUses instead of comparing getNumUses to a constant."
The use list is a linked list so getNumUses requires a linear scan through the whole list. hasNUses will stop scanning at N and see if that is the end.
[APInt] Merge the multiword code from lshrInPlace and tcShiftRight into a single implementation
This merges the two different multiword shift right implementations into a single version located in tcShiftRight. lshrInPlace now calls tcShiftRight for the multiword case.
I retained the memmove fast path from lshrInPlace and used a memset for the zeroing. The for loop is basically tcShiftRight's implementation with the zeroing and the intra-shift of 0 removed.
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