[InstCombine] allow icmp+binop folds before min/max bailout (PR43310)
This has the potential to uncover missed analysis/folds as shown in the
min/max code comment/test, but fewer restrictions on icmp folds should
be better in general to solve cases like:
https://bugs.llvm.org/show_bug.cgi?id=43310
We were already doing this dyn_cast && isa<> && cast<> pattern for some add*Operands methods, just do this more consistently to stop clang static analyzer warning so much.
The static analyzer is warning about potential null dereference, but we should be able to use cast<ConstantFPSDNode> directly and if not assert will fire for us.
Simon Pilgrim [Sun, 22 Sep 2019 12:04:38 +0000 (12:04 +0000)]
[Cost][X86] Add v2i64 truncation costs
We are missing costs for a lot of truncation cases, I'm hoping to address all the 'zero cost' cases in trunc.ll
I thought this was a vector widening side effect, but even before this we had some interesting LV decisions (notably over indvars) being made due to these zero costs.
[Docs] Adds new page for Getting Involved articles
Adds a new page for existing Getting Involved, Development Process, and Community Proposals articles. Also moves Mailing Lists, Meetups and social events, and IRC sections.
Martin Storsjo [Sat, 21 Sep 2019 19:09:24 +0000 (19:09 +0000)]
[CodeView] Add pragma push/pop_macro for ARM64_FPSR to enum header
This fixes (one aspect of) compilation of LLDB with MSVC for ARM64.
LLDB source files include intrin.h, and the MSVC intrin.h transitively
includes arm64intr.h, which has an ARM64_FPSR define, which clashes
with the enum declaration.
While Promoting alloca instruction of Vector Type,
Check total size in bits of its slices too.
If they don't match, don't promote the alloca instruction.
Wei Mi [Sat, 21 Sep 2019 17:23:55 +0000 (17:23 +0000)]
Recommit [SampleFDO] Expose an interface to return the size of a section
or the size of the profile for profile in ExtBinary format.
Fix a test failure on Mac.
[SampleFDO] Expose an interface to return the size of a section or the
size of the profile for profile in ExtBinary format.
Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.
At the same time, add some dump facility to show the size of each section.
[Attributor] Implement "norecurse" function attribute deduction
Summary:
This patch introduces `norecurse` function attribute deduction.
`norecurse` will be deduced if the following conditions hold:
* The size of SCC in which the function belongs equals to 1.
* The function doesn't have self-recursion.
* We have `norecurse` for all call site.
To avoid a large change, SCC is calculated using scc_iterator in InfoCache initialization for now.
James Molloy [Sat, 21 Sep 2019 08:19:41 +0000 (08:19 +0000)]
[MachinePipeliner] Improve the TargetInstrInfo API analyzeLoop/reduceLoopCount
Recommit: fix asan errors.
The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).
This patch introduces a new API:
/// Analyze loop L, which must be a single-basic-block loop, and if the
/// conditions can be understood enough produce a PipelinerLoopInfo object.
virtual std::unique_ptr<PipelinerLoopInfo>
analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;
The return value is expected to be an implementation of the abstract class:
/// Object returned by analyzeLoopForPipelining. Allows software pipelining
/// implementations to query attributes of the loop being pipelined.
class PipelinerLoopInfo {
public:
virtual ~PipelinerLoopInfo();
/// Return true if the given instruction should not be pipelined and should
/// be ignored. An example could be a loop comparison, or induction variable
/// update with no users being pipelined.
virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;
/// Create a condition to determine if the trip count of the loop is greater
/// than TC.
///
/// If the trip count is statically known to be greater than TC, return
/// true. If the trip count is statically known to be not greater than TC,
/// return false. Otherwise return nullopt and fill out Cond with the test
/// condition.
virtual Optional<bool>
createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
SmallVectorImpl<MachineOperand> &Cond) = 0;
/// Modify the loop such that the trip count is
/// OriginalTC + TripCountAdjust.
virtual void adjustTripCount(int TripCountAdjust) = 0;
/// Called when the loop's preheader has been modified to NewPreheader.
virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;
/// Called when the loop is being removed.
virtual void disposed() = 0;
};
The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.
[X86] Add test case to show failure to fold load with getmantss due to isel pattern looking for Constant instead of TargetConstant
The intrinsic has an immarg so its gets created with a TargetConstant
instead of a Constant after r372338. The isel pattern was only
updated for the register form, but not the memory form.
Matt Arsenault [Sat, 21 Sep 2019 02:37:33 +0000 (02:37 +0000)]
AMDGPU/GlobalISel: Allow selection of scalar min/max
I believe all of the uniform/divergent pattern predicates are
redundant and can be removed. The uniformity bit already influences
the register class, and nothhing has broken when I've removed this and
others.
Artur Pilipenko [Sat, 21 Sep 2019 01:37:14 +0000 (01:37 +0000)]
Support for 64-bit PC-relative relocations for X86_64
ELF files generated for X86_64 targets may contain 64-bit PC-relative
relocations. For instance, an exception handler table entry contains the start
of exception-throwing frame relative to the start of exception handler. As these
two labels belong to different sections, their difference and so the relocation
is 64-bit.
An attempt to parse such file, i.e. in DWARFContext::create, results in "failed
to compute relocation" error.
This fix adds support for such relocations to RelocationResolver.cpp.
[GlobalISel] Defer setting HasCalls on MachineFrameInfo to selection time.
We currently always set the HasCalls on MFI during translation and legalization if
we're handling a call or legalizing to a libcall. However, if that call is later
optimized to a tail call then we don't need the flag. The flag being set to true
causes frame lowering to always save and restore FP/LR, which adds unnecessary code.
This change does the same thing as SelectionDAG and ports over some code that scans
instructions after selection, using TargetInstrInfo to determine if target opcodes
are known calls.
Teresa Johnson [Fri, 20 Sep 2019 23:29:17 +0000 (23:29 +0000)]
[Inliner] Remove incorrect early exit during switch cost computation
Summary:
The CallAnalyzer::visitSwitchInst has an early exit when the estimated
lower bound of the switch cost will put the overall cost of the inline
above the threshold. However, this code is not correctly estimating the
lower bound for switches that can be transformed into bit tests, leading
to unnecessary lost inlines, and also differing behavior with
optimization remarks enabled.
First, the early exit is controlled by whether ComputeFullInlineCost is
enabled or not, and that in turn is disabled by default but enabled when
enabling -pass-remarks=missed. This by itself wouldn't lead to a
problem, except that as described below, the lower bound can be above
the real lower bound, so we can sometimes get different inline decisions
with inline remarks enabled, which is problematic.
The early exit was added in along with a new switch cost model in D31085.
The reason why this early exit was added is due to a concern one reviewer
raised about compile time for large switches:
https://reviews.llvm.org/D31085?id=94559#inline-276200
However, the code just below there calls
getEstimatedNumberOfCaseClusters, which in turn immediately calls
BasicTTIImpl getEstimatedNumberOfCaseClusters, which in the worst case
does a linear scan of the cases to get the high and low values. The
bit test handling in particular is guarded by whether the number of
cases fits into the max bit width. There is no suggestion that anyone
measured a compile time issue, it appears to be theoretical.
The problem is that the reviewer's comment about the lower bound
calculation is incorrect, specifically in the case of a switch that can
be lowered to a bit test. This isn't followed up on the comment
thread, but the author does add a FIXME to that effect above the early
exit added when they subsequently revised the patch.
As a result, we were incorrectly early exiting and not inlining
functions with switch statements that would be lowered to bit tests in
cases where we were nearing the threshold. Combined with the fact that
this early exit was skipped with opt remarks enabled, this caused
different inlining decisions to be made when -pass-remarks=missed is
enabled to debug the missing inline.
Remove the early exit for the above reasons.
I also copied over an existing AArch64 inlining test to X86, and
adjusted the threshold so that the bit test inline only occurs with the
fix in this patch.
Wei Mi [Fri, 20 Sep 2019 23:24:50 +0000 (23:24 +0000)]
[SampleFDO] Expose an interface to return the size of a section or the size
of the profile for profile in ExtBinary format.
Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.
At the same time, add some dump facility to show the size of each section.
The recently announced IBM z15 processor implements the architecture
already supported as "arch13" in LLVM. This patch adds support for
"z15" as an alternate architecture name for arch13.
The patch also uses z15 in a number of places where we used arch13
as long as the official name was not yet announced.
Michael Trent [Fri, 20 Sep 2019 19:13:24 +0000 (19:13 +0000)]
Can't pass .dSYM directory to llvm-objdump -dsym= (and error message is wrong)
Summary:
Allow users to pass the path to a .dSYM directory to llvm-objdump's -dsym
flag rather than requiring users to find the DWARF DSYM Mach-O within the
bundle structure by hand.
[SelectionDAG][Mips][Sparc] Don't allow SimplifyDemandedBits to constant fold TargetConstant nodes to a Constant.
Summary:
After the switch in SimplifyDemandedBits, it tries to create a
constant when possible. If the original node is a TargetConstant
the default in the switch will call computeKnownBits on the
TargetConstant which will succeed. This results in the
TargetConstant becoming a Constant. But TargetConstant exists to
avoid being changed.
I've fixed the two cases that relied on this in tree by explicitly
making the nodes constant instead of target constant. The Sparc
case is an old bug. The Mips case was recently introduced now that
ImmArg on intrinsics gets turned into a TargetConstant when the
SelectionDAG is created. I've removed the ImmArg since it lowers
to generic code.
Remove assert from MachineLoop::getLoopPredecessor()
According to the documentation method returns predecessor
if the given loop's header has exactly one unique predecessor
outside the loop. Otherwise return null.
In reality it asserts if there is no predecessor outside of
the loop.
The testcase has the loop where predecessors outside of the
loop were not identified as analyzeBranch() was unable to
process the mask branch and returned true. That is also not
correct to assert for the truly dead loops.
Summary:
This is a patch for updating TextAPI/Macho to read in targets as opposed to arch/platform.
This is because in previous versions tbd files only supported a single platform but that is no longer the case,
so, now its tracked by unique triples.
This precedes a seperate patch that will add the TBD-v4 format
[Alignment][NFC] migrate DataLayout internal struct to llvm::Align
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
With this patch the PointerAlignElem struct goes from 20B to 16B.
David Tellenbach [Fri, 20 Sep 2019 13:22:59 +0000 (13:22 +0000)]
[FastISel] Fix insertion of unconditional branches during FastISel
The insertion of an unconditional branch during FastISel can differ depending on
building with or without debug information. This happens because FastISel::fastEmitBranch
emits an unconditional branch depending on the size of the current basic block
without distinguishing between debug and non-debug instructions.
This patch fixes this issue by ignoring debug instructions when getting the size
of the basic block.
[IntrinsicEmitter] Add overloaded types for SVE intrinsics (Subdivide2 & Subdivide4)
Summary:
Both match the type of another intrinsic parameter of a vector type, but where each element is subdivided to form a vector with more elements of a smaller type.
Subdivide2Argument allows intrinsics such as the following to be defined:
- declare <vscale x 4 x i32> @llvm.something.nxv4i32(<vscale x 8 x i16>)
Subdivide4Argument allows intrinsics such as:
- declare <vscale x 4 x i32> @llvm.something.nxv4i32(<vscale x 16 x i8>)
Tests are included in follow up patches which add intrinsics using these types.
James Molloy [Fri, 20 Sep 2019 08:57:46 +0000 (08:57 +0000)]
[MachinePipeliner] Improve the TargetInstrInfo API analyzeLoop/reduceLoopCount
The way MachinePipeliner uses these target hooks is stateful - we reduce trip
count by one per call to reduceLoopCount. It's a little overfit for hardware
loops, where we don't have to worry about stitching a loop induction variable
across prologs and epilogs (the induction variable is implicit).
This patch introduces a new API:
/// Analyze loop L, which must be a single-basic-block loop, and if the
/// conditions can be understood enough produce a PipelinerLoopInfo object.
virtual std::unique_ptr<PipelinerLoopInfo>
analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const;
The return value is expected to be an implementation of the abstract class:
/// Object returned by analyzeLoopForPipelining. Allows software pipelining
/// implementations to query attributes of the loop being pipelined.
class PipelinerLoopInfo {
public:
virtual ~PipelinerLoopInfo();
/// Return true if the given instruction should not be pipelined and should
/// be ignored. An example could be a loop comparison, or induction variable
/// update with no users being pipelined.
virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;
/// Create a condition to determine if the trip count of the loop is greater
/// than TC.
///
/// If the trip count is statically known to be greater than TC, return
/// true. If the trip count is statically known to be not greater than TC,
/// return false. Otherwise return nullopt and fill out Cond with the test
/// condition.
virtual Optional<bool>
createTripCountGreaterCondition(int TC, MachineBasicBlock &MBB,
SmallVectorImpl<MachineOperand> &Cond) = 0;
/// Modify the loop such that the trip count is
/// OriginalTC + TripCountAdjust.
virtual void adjustTripCount(int TripCountAdjust) = 0;
/// Called when the loop's preheader has been modified to NewPreheader.
virtual void setPreheader(MachineBasicBlock *NewPreheader) = 0;
/// Called when the loop is being removed.
virtual void disposed() = 0;
};
The Pipeliner (ModuloSchedule.cpp) can use this object to modify the loop while
allowing the target to hold its own state across all calls. This API, in
particular the disjunction of creating a trip count check condition and
adjusting the loop, improves the code quality in ModuloSchedule.cpp.
[X86] Convert tbm_bextri_u32/tbm_bextri_u64 intrinsics TargetConstant argument to a regular Constant during lowering.
We reuse an ISD opcode here that can be reached from BMI that
doesn't require it to be an immediate. Our isel patterns to match
the TBM immediate form require a Constant and not a TargetConstant.
We were accidentally getting the Constant due to a quirk of
combineBEXTR calling SimplifyDemandedBits. The call to
SimplifyDemandedBits ended up constant folding the TargetConstant
to a regular Constant. But we should probably instead be asserting
if SimplifyDemandedBits on a TargetConstant so we shouldn't rely
on this behavior.
[X86] Remove the special isBuildVectorOfConstantSDNodes handling from LowerBUILD_VECTORvXi1.
The later code that generates a constant when there are
some non-const elements works basically the same and doesn't
require there to be any non-const elements.
Matt Arsenault [Fri, 20 Sep 2019 00:09:15 +0000 (00:09 +0000)]
MachineScheduler: Fix missing dependency with multiple subreg defs
If an instruction had multiple subregister defs, and one of them was
undef, this would improperly conclude all other lanes are
killed. There could still be other defs of those read-undef lanes in
other operands. This would improperly remove register uses from
CurrentVRegUses, so the visitation of later operands would not find
the necessary register dependency. This would also mean this would
fail or not depending on how different subregister def operands were
ordered.
On an undef subregister def, scan the instruction for other
subregister defs and avoid killing those.
This possibly should be deferring removing anything from
CurrentVRegUses until the entire instruction has been processed
instead.
Jakub Kuderski [Thu, 19 Sep 2019 19:39:42 +0000 (19:39 +0000)]
Don't use invalidated iterators in FlattenCFGPass
Summary:
FlattenCFG may erase unnecessary blocks, which also invalidates iterators to those erased blocks.
Before this patch, `iterativelyFlattenCFG` could try to increment a BB iterator after that BB has been removed and crash.
This patch makes FlattenCFGPass use `WeakVH` to skip over erased blocks.
[Analysis] Allow -scalar-evolution-max-iterations more than once
At present, `-scalar-evolution-max-iterations` is a `cl::Optional`
option, which means it demands to be passed exactly zero or one times.
Our build system makes it pretty tricky to guarantee this. We often
accidentally pass the flag more than once (but always with the same
value) which results in an error, after which compilation fails:
```
clang (LLVM option parsing): for the -scalar-evolution-max-iterations option: may only occur zero or one times!
```
It seems reasonable to allow -scalar-evolution-max-iterations to be
passed more than once. Quoting the [[ http://llvm.org/docs/CommandLine.html#controlling-the-number-of-occurrences-required-and-allowed | documentation ]]:
> The cl::ZeroOrMore modifier ... indicates that your program will allow the option to be specified zero or more times.
> ...
> If an option is specified multiple times for an option of the cl::opt class, only the last value will be retained.
Original patch by: Enrico Bern Hardy Tanuwidjaja <etanuwid@fb.com>
projects / llvm / log