[DebugInfo] Add comments to phi dbg.value tracking code, NFC
LLVM developers might be surprised to learn that there are blocks
without valid insertion points (catchswitch), so it seems worth calling
that out explicitly. Also add a FIXME about what we should really be
doing if we ever need to make optimized Windows EH code debuggable.
While I'm here, make auto usage more consistent with LLVM standards and
avoid an unecessary call to insertBefore.
[RDF] Special treatment of exception handling registers
A landing pad can have live-in registers that are defined by the runtime,
not the program (exception pointer register and exception selector
register). Make sure to recognize that case and not link these registers
with any defs in the program.
Each landing pad will have phi nodes added at the beginning to provide
definitions of these registers, but the uses of those phi nodes will not
have any reaching defs.
Chris Bieneman [Tue, 27 Sep 2016 18:08:40 +0000 (18:08 +0000)]
Improve CMake output of host and target triple
Summary:
The previous output was confusing as it would output "Taget triple:
x86_64-unknown-linux-gnu" even when LLVM_HOST_TRIPLE or
LLVM_DEFAULT_TARGET_TRIPLE were set on the CMake command line
Sanjoy Das [Tue, 27 Sep 2016 18:01:38 +0000 (18:01 +0000)]
[SCEV] Make PendingLoopPredicates more frugal; NFCI
I don't expect `PendingLoopPredicates` to have very many
elements (e.g. when -O3'ing the sqlite3 amalgamation,
`PendingLoopPredicates` has at most 3 elements). So now we use a
`SmallPtrSet` for it instead of the more heavyweight `DenseSet`.
Keith Walker [Tue, 27 Sep 2016 16:46:07 +0000 (16:46 +0000)]
Propagate DBG_VALUE entries when there are unvisited predecessors
Variables are sometimes missing their debug location information in
blocks in which the variables should be available. This would occur
when one or more predecessor blocks had not yet been visited by the
routine which propagated the information from predecessor blocks.
This is addressed by only considering predecessor blocks which have
already been visited.
The solution to this problem was suggested by Daniel Berlin on the
LLVM developer mailing list.
llvm::join_items is similar to llvm::join, which produces a string
by concatenating a sequence of values together separated by a
given separator. But it differs in that the arguments to
llvm::join() are same-type members of a container, whereas the
arguments to llvm::join_items are arbitrary types passed into
a variadic template. The only requirement on parameters to
llvm::join_items (including for the separator themselves) is
that they be implicitly convertible to std::string or have
an overload of std::string::operator+
Adam Nemet [Tue, 27 Sep 2016 16:15:16 +0000 (16:15 +0000)]
Output optimization remarks in YAML
This allows various presentation of this data using an external tool.
This was first recommended here[1].
As an example, consider this module:
1 int foo();
2 int bar();
3
4 int baz() {
5 return foo() + bar();
6 }
The inliner generates these missed-optimization remarks today (the
hotness information is pulled from PGO):
remark: /tmp/s.c:5:10: foo will not be inlined into baz (hotness: 30)
remark: /tmp/s.c:5:18: bar will not be inlined into baz (hotness: 30)
Now with -pass-remarks-output=<yaml-file>, we generate this YAML file:
--- !Missed
Pass: inline
Name: NotInlined
DebugLoc: { File: /tmp/s.c, Line: 5, Column: 10 }
Function: baz
Hotness: 30
Args:
- Callee: foo
- String: will not be inlined into
- Caller: baz
...
--- !Missed
Pass: inline
Name: NotInlined
DebugLoc: { File: /tmp/s.c, Line: 5, Column: 18 }
Function: baz
Hotness: 30
Args:
- Callee: bar
- String: will not be inlined into
- Caller: baz
...
This is a summary of the high-level decisions:
* There is a new streaming interface to emit optimization remarks.
E.g. for the inliner remark above:
ORE.emit(DiagnosticInfoOptimizationRemarkMissed(
DEBUG_TYPE, "NotInlined", &I)
<< NV("Callee", Callee) << " will not be inlined into "
<< NV("Caller", CS.getCaller()) << setIsVerbose());
NV stands for named value and allows the YAML client to process a remark
using its name (NotInlined) and the named arguments (Callee and Caller)
without parsing the text of the message.
Subsequent patches will update ORE users to use the new streaming API.
* I am using YAML I/O for writing the YAML file. YAML I/O requires you
to specify reading and writing at once but reading is highly non-trivial
for some of the more complex LLVM types. Since it's not clear that we
(ever) want to use LLVM to parse this YAML file, the code supports and
asserts that we're writing only.
On the other hand, I did experiment that the class hierarchy starting at
DiagnosticInfoOptimizationBase can be mapped back from YAML generated
here (see D24479).
* The YAML stream is stored in the LLVM context.
* In the example, we can probably further specify the IR value used,
i.e. print "Function" rather than "Value".
* As before hotness is computed in the analysis pass instead of
DiganosticInfo. This avoids the layering problem since BFI is in
Analysis while DiagnosticInfo is in IR.
[docs] Make WritingAnLLVMPass.rst up-to-date with current state of things
This patch updates WritingAnLLVMPass.rst to make it in line with current state of things.
Specifically:
* Makefile instructions replaced with CMake ones
* Filenames replaced with correct ones
* Example reformatted a bit to make it less confusing and more conforming to LLVM Coding Standards
* opt tool output updated with what it actually prints nowdays
* "gcse" (which doesn't exist anymore) replaced with "gvn" (which still does)
[Power9] Builtins for ELF v.2 API conformance - back end portion
This patch corresponds to review:
https://reviews.llvm.org/D24396
This patch adds support for the "vector count trailing zeroes",
"vector compare not equal" and "vector compare not equal or zero instructions"
as well as "scalar count trailing zeroes" instructions. It also changes the
vector negation to use XXLNOR (when VSX is enabled) so as not to increase
register pressure (previously this was done with a splat immediate of all
ones followed by an XXLXOR). This was done because the altivec.h
builtins (patch to follow) use vector negation and the use of an additional
register for the splat immediate is not optimal.
[X86] Use std::max to calculate alignment instead of assuming RC->getSize() will not return a value greater than 32. I think it theoretically could be 64 for AVX-512.
Kevin Enderby [Mon, 26 Sep 2016 21:11:03 +0000 (21:11 +0000)]
Next set of additional error checks for invalid Mach-O files for the
other load commands that use the Mach::linkedit_data_command type
but not used in llvm libObject code but used in llvm tool code.
This includes LC_FUNCTION_STARTS, LC_SEGMENT_SPLIT_INFO
and LC_DYLIB_CODE_SIGN_DRS load commands.
Piotr Padlewski [Mon, 26 Sep 2016 20:37:32 +0000 (20:37 +0000)]
[thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.
I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.
I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.
Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.
Statistic: Only print statistics on exit for -stats
Previously enabling the statistics with EnableStatistics() would lead to
them getting printed to stderr/-info-output-file on exit. However
frontends may want a way to enable statistics and do the printing on
their own instead of the forced printing on exit.
This changes the code so that only the -stats option enables printing on
exit, EnableStatistics() only enables the tracking but requires invoking
one of the PrintStatistics() variants.
[llvm-cov] Silence a warning from the MSVC runtime (NFC)
Rework getLongestCommonPrefixLen() so that it doesn't access string null
terminators. The old version with std::mismatch would do this:
|
v
Strings[0] = ['a', nil]
Strings[1] = ['a', 'a', nil]
^
|
This should silence a warning from the MSVC runtime (PR30515). As
before, I tested this out by preparing a coverage report for FileCheck.
Thanks to Yaron Keren for the report!
Matthew Simpson [Mon, 26 Sep 2016 17:08:37 +0000 (17:08 +0000)]
[LV] Scalarize instructions marked scalar after vectorization
This patch ensures that we actually scalarize instructions marked scalar after
vectorization. Previously, such instructions may have been vectorized instead.
Gor Nishanov [Mon, 26 Sep 2016 15:49:28 +0000 (15:49 +0000)]
[Coroutines] Part14: Handle coroutines with no suspend points.
Summary:
If coroutine has no suspend points, remove heap allocation and turn a coroutine into a normal function.
Also, if a pattern is detected that coroutine resumes or destroys itself prior to coro.suspend call, turn the suspend point into a simple jump to resume or cleanup label. This pattern occurs when coroutines are used to propagate errors in functions that return expected<T>.
Don't match the UXTW extended reg forms of ADD/ADDS/SUB/SUBS if the
32-bit to 64-bit zero-extend can be done for free by taking advantage
of the 32-bit defining instruction zeroing the upper 32-bits of the X
register destination. This enables better instruction selection in a
few cases, such as:
sub x0, xzr, x8
instead of:
mov x8, xzr
sub x0, x8, w9, uxtw
Add support to optionally limit the size of jump tables.
Many high-performance processors have a dedicated branch predictor for
indirect branches, commonly used with jump tables. As sophisticated as such
branch predictors are, they tend to have well defined limits beyond which
their effectiveness is hampered or even nullified. One such limit is the
number of possible destinations for a given indirect branches that such
branch predictors can handle.
This patch considers a limit that a target may set to the number of
destination addresses in a jump table.
Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar
<aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>.
The index of the new insertelement instruction was evaluated in the
wrong way, it was considered as the index of the inserted value instead
of index of the position, where the value should be inserted.
Andrea Di Biagio [Mon, 26 Sep 2016 12:07:23 +0000 (12:07 +0000)]
[InstCombine] Teach the udiv folding logic how to handle constant expressions.
This patch fixes PR30366.
Function foldUDivShl() worked under the assumption that one of the values
in input to the function was always an instance of llvm::Instruction.
However, function visitUDivOperand() (the only user of foldUDivShl) was
clearly violating that precondition; internally, visitUDivOperand() uses pattern
matches to check the operands of a udiv. Pattern matchers for binary operators
know how to handle both Instruction and ConstantExpr values.
This patch fixes the problem in foldUDivShl(). Now we use pattern matchers
instead of explicit casts to Instruction. The reduced test case from PR30366
has been added to test file InstCombine/udiv-simplify.ll.
James Molloy [Mon, 26 Sep 2016 07:26:24 +0000 (07:26 +0000)]
[ARM] Promote small global constants to constant pools
If a constant is unamed_addr and is only used within one function, we can save
on the code size and runtime cost of an indirection by changing the global's storage
to inside the constant pool. For example, instead of:
This can cause significant code size savings when many small strings are used in one
function (4 bytes per string).
This recommit contains fixes for a nasty bug related to fast-isel fallback - because
fast-isel doesn't know about this optimization, if it runs and emits references to
a string that we inline (because fast-isel fell back to SDAG) we will end up
with an inlined string and also an out-of-line string, and we won't emit the
out-of-line string, causing backend failures.
It also contains fixes for emitting .text relocations which made the sanitizer
bots unhappy.
[X86] Optimization for replacing LEA with MOV at frame index elimination time
Summary:
Replace a LEA instruction of the form 'lea (%esp), %ebx' --> 'mov %esp, %ebx'
MOV is preferable over LEA because usually there are more issue-slots available to execute MOVs than LEAs. Latest processors also support zero-latency MOVs.
[PM] Refactor this unittest a bit to remove duplicated code. This was
suggested at one point during code review and I deferred it to
a follow-up commit.
[PM] Add a unittest for invalidating module analyses with an SCC pass.
This reinstates r280447. Original commit log:
This wasn't really well explicitly tested with a nice unittest before.
It seems good to have reasonably broken out unittests for this kind of
functionality as I'm workin go other invalidation features to make sure
none of the existing ones regress.
This still has too much duplicated code, I plan to factor that out in
a subsequent commit to use common helpers for repeated parts of this.
Sanjoy Das [Mon, 26 Sep 2016 02:44:10 +0000 (02:44 +0000)]
[SCEV] Assign LoopPropertiesCache in the move constructor
In a previous change I collapsed two different caches into one. When
doing that I noticed that ScalarEvolution's move constructor was not
moving those caches.
To keep the previous change simple, I've moved that bugfix into this
separate change.
Sanjoy Das [Mon, 26 Sep 2016 02:44:07 +0000 (02:44 +0000)]
[SCEV] Combine two predicates into one; NFC
Both `loopHasNoSideEffects` and `loopHasNoAbnormalExits` involve walking
the loop and maintaining similar sorts of caches. This commit changes
SCEV to compute both the predicates via a single walk, and maintain a
single cache instead of two.
[AVX-512] Remove duplicate instructions for converting integer to scalar floating point. We can use patterns to point to the other instructions instead.
Add some predicated searching functions to StringRef.
This adds 4 new functions to StringRef, which can be used to
take or drop characters while a certain condition is met, or
until a certain condition is met. They are:
take_while - Return characters until a condition is not met.
take_until - Return characters until a condition is met.
drop_while - Remove characters until a condition is not met.
drop_until - Remove characters until a condition is met.
Internally, all of these functions delegate to two additional
helper functions which can be used to search for the position
of a character meeting or not meeting a condition, which are:
find_if - Find the first character matching a predicate.
find_if_not - Find the first character not matching a predicate.
[AVX-512] Don't use two opcodes for INTR_TYPE_SCALAR_MASK_RM. The handling was such that if the second opcode was present the first was ingored, so we can just have one opcode.
[X86] Teach combineShuffle to avoid creating floating point operations with integer types and integer operations with floating point types. Seems isOperationLegal lies for mismatched types and operations.
Stop looking at users of UndefValue and ConstantPointerNull in the
objective C ARC optimizers. The other users aren't actually
interesting, since they're not pointing at a particular object. I
imagine these calls could be optimized through -instcombine... maybe
they already are?
These early returns will be required at some point in the future, with a
WIP patch that asserts when someone accesses a use-list on ConstantData.
projects / llvm / log