[x86] Remove a couple of fairly pointless tests. These were merely
testing that we generated divps and divss but not in a very systematic
way. There are other tests for widening binary operations already that
make these unnecessary.
The second one seems mostly about testing Atom as well as normal X86,
but despite the comment claiming it is testing a different instruction
sequence, it then tests for exactly the same div instruction sequence!
(The sequence of instructions is actually quite different on Atom, but
not the sequence of div instructions....)
And then it has an "execution" test that simply isn't run? Very strange.
Anyways, none of this is really needed so clean this up.
[x86] Add triples to these tests so that we see fewer calling convention
differences and they're a bit easier to maintain. This should fix the
tests on cygwin bots, etc.
[x86] Regenerate precise checks for a couple of test cases and remove
a test case that was just grepping the debug stats output rather than
actually checking the generated code for anything useful.
[x86] Remove an over-reduced test case. This would need to be
intergrated much more fully into some logical part of the backend to
really understand what it is trying to accomplish and how to update it.
I suspect it no longer holds enough value to be worth having.
[x86] This is a terrible SSE1 test, but we should keep it. I've deleted
two functions that really didn't have any interesting assertions, and
generated more precise tests for one of the others.
[x86] Regenerate a number of FileCheck assertions with my script for
test cases that will change with the new vector shuffle lowering. This
gives us a nice baseline for deltas against. I've checked and removed
the cases where there were weird register usage being pinned down, and
all of these are extremely pin-pointed tests so fully checking them
seems very appropriate.
[x86] Remove a couple of other overly isolated tests that are low-value
at this point. We have lots of tests of peephole optimizations with
insert and extract on vectors.
[x86] Regenerate a bunch more avx512 test cases using my script to have
tighter, more strict FileCheck assertions. Some of these I really like
as they show case exactly what instruction sequences come out of these
microscopic functionality tests.
[x86] Regenerate an avx512 test with my script to provide a nice
baseline for updates from the new vector shuffle lowering.
I've inspected the results here, and I couldn't find any register
allocation decisions where there should be any realistic way to register
allocate things differently. The closest was the imul test case. If you
see something here you'd like register number variables on, just shout
and I'll add them.
[x86] Remove some of the --show-mc-encoding flags from avx512 tests that
need to be updated for the new vector shuffle lowering.
After talking to Adam Nemet, Tim Northover, etc., it seems that testing
MC encodings in the same suite as the basic codegen isn't the right
approach. Instead, we're going to want dedicated MC tests for the
encodings. These encodings are starting to get in my way so I wanted to
cut them out early. The total set of instructions that should have
encoding tests added is:
Hal Finkel [Thu, 2 Oct 2014 22:34:22 +0000 (22:34 +0000)]
[PowerPC] Modern Book-E cores support sync
Older Book-E cores, such as the PPC 440, support only msync (which has the same
encoding as sync 0), but not any of the other sync forms. Newer Book-E cores,
however, do support sync, and for performance reasons we should allow the use
of the more-general form.
This refactors msync use into its own feature group so that it applies by
default only to older Book-E cores (of the relevant cores, we only have
definitions for the PPC440/450 currently).
Robin Morisset [Thu, 2 Oct 2014 22:27:07 +0000 (22:27 +0000)]
[Power] Improve the expansion of atomic loads/stores
Summary:
Atomic loads and store of up to the native size (32 bits, or 64 for PPC64)
can be lowered to a simple load or store instruction (as the synchronization
is already handled by AtomicExpand, and the atomicity is guaranteed thanks to
the alignment requirements of atomic accesses). This is exactly what this patch
does. Previously, these were implemented by complex
load-linked/store-conditional loops.. an obvious performance problem.
For example, this patch turns
```
define void @store_i8_unordered(i8* %mem) {
store atomic i8 42, i8* %mem unordered, align 1
ret void
}
```
from
```
_store_i8_unordered: ; @store_i8_unordered
; BB#0:
rlwinm r2, r3, 3, 27, 28
li r4, 42
xori r5, r2, 24
rlwinm r2, r3, 0, 0, 29
li r3, 255
slw r4, r4, r5
slw r3, r3, r5
and r4, r4, r3
LBB4_1: ; =>This Inner Loop Header: Depth=1
lwarx r5, 0, r2
andc r5, r5, r3
or r5, r4, r5
stwcx. r5, 0, r2
bne cr0, LBB4_1
; BB#2:
blr
```
into
```
_store_i8_unordered: ; @store_i8_unordered
; BB#0:
li r2, 42
stb r2, 0(r3)
blr
```
which looks like a pretty clear win to me.
Test Plan:
fixed the tests + new test for indexed accesses + make check-all
Fix the threshold added in r186434 (a re-apply of r185393) and updaated
to be a ManagedStatic in r218163 to not be a global variable written and
read to from within the innards of SpillPlacement.
This will fix a really scary race condition for anyone that has two
copies of LLVM running spill placement concurrently. Yikes!
This will also fix a really significant compile time hit that r218163
caused because the spill placement threshold read is actually in the
*very* hot path of this code. The memory fence on each read was showing
up as huge compile time regressions when spilling is responsible for
most of the compile time. For example, optimizing sanitized code showed
over 50% compile time regressions here. =/
Rui Ueyama [Thu, 2 Oct 2014 22:05:29 +0000 (22:05 +0000)]
llvm-readobj: print COFF imported symbols
This patch defines a new iterator for the imported symbols.
Make a change to COFFDumper to use that iterator to print
out imported symbols and its ordinals.
DI: Fold constant arguments into a single MDString
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString. Integers are stringified and
a `\0` character is used as a separator.
Part of PR17891.
Note: I've attached my testcases upgrade scripts to the PR. If I've
just broken your out-of-tree testcases, they might help.
[x86] Teach the new vector shuffle lowering to widen floating point
elements as well as integer elements in order to form simpler shuffle
patterns.
This is the primary reason why we were failing to match some of the
2-and-2 floating point shuffles such as PR21140. Even after fixing this
we need to support some extra patterns in the backend in order to match
the resulting X86ISD::UNPCKL nodes into the correct instructions. This
commit should fix PR21140 and includes more comprehensive testing of
insertion patterns in v4 shuffles.
Not all of the added tests are beautiful. For example, we don't have
clever instructions to insert-via-load in the integer domain. There are
also some places where we aren't sufficiently cunning with our use of
movq and movd, but that's future work.
Justin Bogner [Thu, 2 Oct 2014 17:14:18 +0000 (17:14 +0000)]
InstrProf: Avoid linear search in a hot loop
Every time we were adding or removing an expression when generating a
coverage mapping we were doing a linear search to try and deduplicate
the list. The indices in the list are important, so we can't just
replace it by a DenseMap entirely, but an auxilliary DenseMap for fast
lookup massively improves the performance issues I was seeing here.
Justin Bogner [Thu, 2 Oct 2014 16:04:03 +0000 (16:04 +0000)]
InstrProf: Don't keep a large sparse list around just to zero it
The Terms vector here represented a polynomial of of all possible
counters, and is used to simplify expressions when generating coverage
mapping. There are a few problems with this:
1. Keeping the vector as a member is wasteful, since we clear it every
time we use it.
2. Most expressions refer to a subset of the counters, so we end up
iterating over a large number of zeros doing nothing a lot of the
time.
This updates the user of the vector to store the terms locally, and
uses a sort and combine approach so that we only operate on counters
that are actually used in a given expression. For small cases this
makes very little difference, but in cases with a very large number of
counted regions this is a significant performance fix.
Zinovy Nis [Thu, 2 Oct 2014 13:01:15 +0000 (13:01 +0000)]
[BUG][INDVAR] Fix for PR21014: wrong SCEV operands commuting for non-commutative instructions
My commit rL216160 introduced a bug PR21014: IndVars widens code 'for (i = ; i < ...; i++) arr[ CONST - i]' into 'for (i = ; i < ...; i++) arr[ i - CONST]'
thus inverting index expression. This patch fixes it.
Thanks to Jörg Sonnenberger for pointing.
This file isn't really doing anything useful. Many of the tests that
seem to be combined are also repeats from other test files. Many of the
other tests, despite the comment that they should be combined into
a single shuffle... well... aren't combined into a single shuffle.
=/
[x86] Merge still more combine tests into the common file. These at
least seem *slightly* more interesting test wise, although given how
spotily we actually combine anything, I remain somewhat suspicious.
[x86] Merge the third combining test into the generic one and add proper
checks for all the ISA variants.
If the SSE2 checks here terrify you, good. This is (in large part) the
kind of amazingly bad code that is holding LLVM back when vectorizing on
older ISAs.
At the same time, these tests seem increasingly dubious to me. There are
a very large number of tests and it isn't clear that they are
systematically covering a specific set of functionality. Anyways,
I don't want to reduce testing during the transition, I just want to
consolidate it to where it is easier to manage.
[x86] Merge the second set of vector combining tests into a common test
file.
Some of these really don't make sense to test -- we're testing for the
*lack* of combining two shuffles into one, presumably because the two
would generate better shuffles in the end. But if you look at the
generated code shown here, in many cases the generated code is, frankly,
terrible. Or we combine any two generated shuffles back into a single
instruction! I've left a FIXME to revisit these decisions.
[x86] Minimize the parameters to this test for clarity.
The test has to do with DAG combines, and so it doesn't need the new
vector shuffle lowering to be effective. Also, it has a nice in-IR
triple string which we should really be using rather than command line
flags (unless it varies form RUN-line to RUN-line). Finally, I much
prefer letting LLVM synthesize the correct datalayout string from the
triple rather than baking one in here that will just become stale.
Lang Hames [Thu, 2 Oct 2014 04:17:36 +0000 (04:17 +0000)]
[PBQP] Add support for graph-level metadata to the PBQP graph. This will be used
in the future to attach useful information about the PBQP graph (e.g. the
associated MachineFunction, pointers to regalloc passes) to the graph itself,
making that information accessible to the solver. This should also allow the
PBQPBuilder interface to be simplified.
Justin Bogner [Thu, 2 Oct 2014 00:31:00 +0000 (00:31 +0000)]
InstrProf: Simplify counting a file's regions when writing coverage (NFC)
When writing a coverage mapping we iterate through the mapping regions
in order of FileID, but we were then repeatedly searching from the
beginning of the list to count the number of regions with a given
FileID.
It is simpler and more efficient to search forward from the current
iterator to find the number of regions.
[x86] Improve and correct how the new vector shuffle lowering was
matching and lowering 64-bit insertions.
The first problem was that we weren't looking through bitcasts to
discover that we *could* lower as insertions. Once fixed, we in turn
weren't looking through bitcasts to discover that we could fold a load
into the lowering. Once fixed, we weren't forming a SCALAR_TO_VECTOR
node around the inserted element and instead were passing a scalar to
a DAG node that expected a vector. It turns out there are some patterns
that will "lower" this into the correct asm, but the rest of the X86
backend is very unhappy with such antics.
This should fix a few more edge case regressions I've spotted going
through the regression test suite to enable the new vector shuffle
lowering.
Bob Wilson [Wed, 1 Oct 2014 22:44:01 +0000 (22:44 +0000)]
PR21101: tablegen's FastISel emitter should filter out unused functions.
FastISel has a fixed set of virtual functions that are overridden by the
tablegen-generated code for each target. These functions are distinguished by
the kinds of operands, e.g., register + immediate = "ri". The FastISel emitter
has been blindly emitting functions with different combinations of operand
kinds, even for combinations that are completely unused by FastISel, e.g.,
"fastEmit_rrr". Change to filter out functions that will be irrelevant for
FastISel and do not bother generating the code for them. Also add explicit
"override" keywords for the virtual functions that are overridden.
Negative FABS of either a scalar or vector should be handled the same way
on x86 with SSE/AVX: a single OR instruction of the FP operand with a
constant to light up the sign bit(s).
I neglected to update `DIBuilder::createPieceExpression()` in r218797,
which I noticed while rebasing a patch for PR17891. On closer
inspection, it looks like dead code.
If there are any downstream users of this, you should transition to the
more general `createExpression()`. Or, we can add this back, but then
it should just forward to `createExpression()`.
[x86] Add a 32-bit run to the sext test, and remove a sad vec_sext.ll
test file.
This old test had a bunch of functions that were never even checked. =/
The only thing it really did was to make sure that we did something
reasonable in 32-bit mode with SSE4.1. Adding another run line to the
main vector-sext.ll test seems a better way to do that.
[x86] Teach both sext and zext vector tests to cover a nice wide range
of architectures: SSE2, SSSE3, SSE4.1, AVX, and AVX2.
Unfortunately, this exposses the absolute horror of the code we generate
for many of these patterns. Anyone wanting to familiarize themselves
with the x86 backend and improve performance could do a lot of good
sitting down and making these test cases not look so terrible. While the
new vector shuffle code I'm working on well help some, it won't fix all
of the crimes here.
Sanjay Patel [Wed, 1 Oct 2014 20:36:33 +0000 (20:36 +0000)]
Make the sqrt intrinsic return undef for a negative input.
As discussed here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140609/220598.html
And again here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-September/077168.html
The sqrt of a negative number when using the llvm intrinsic is undefined.
We should return undef rather than 0.0 to match the definition in the LLVM IR lang ref.
This change should not affect any code that isn't using "no-nans-fp-math";
ie, no-nans is a requirement for generating the llvm intrinsic in place of a sqrt function call.
Unfortunately, the behavior introduced by this patch will not match current gcc, xlc, icc, and
possibly other compilers. The current clang/llvm behavior of returning 0.0 doesn't either.
We knowingly approve of this difference with the other compilers in an attempt to flag code
that is invoking undefined behavior.
A front-end warning should also try to convince the user that the program will fail:
http://llvm.org/bugs/show_bug.cgi?id=21093
[x86] Sort the ISA-specific RUN lines for vector-sext.ll to go from
oldest to newest. This makes more sense to me and is more consistent
with other tests.
[x86] Rename avx-{s,z}ext.ll to vector-{s,z}ext.ll.
These tests are far and away the best sext and zext tests we have for
vectors. I'm going to merge the other similar tests into them and expand
the ISA coverage.
DIBuilder: Encapsulate DIExpression's element type
`DIExpression`'s elements are 64-bit integers that are stored as
`ConstantInt`. The accessors already encapsulate the storage. This
commit updates the `DIBuilder` API to also encapsulate that.
[x86] Generate the FileCheck assertions for avx-blend.ll with my new
script to make them nice and predictable. This will ease updating them
for the new vector shuffle lowering and seeing the delta if any.
[x86] Clean up and generate detailed FileCheck assertions for
avx-sext.ll using my new script.
Also add an AVX2 mode to this test.
Part of cleaning up the test suite before enabling the new vector
shuffle lowering. This also highlights some of the abysmal failures of
the old shuffle lowering. Check out those 'pinsrw' and 'pextrw'
sequences!
- Problem
One program takes ~3min to compile under -O2. This happens after a certain
function A is inlined ~700 times in a function B, inserting thousands of new
BBs. This leads to 80% of the compilation time spent in
GVN::processNonLocalLoad and
MemoryDependenceAnalysis::getNonLocalPointerDependency, while searching for
nonlocal information for basic blocks.
Usually, to avoid spending a long time to process nonlocal loads, GVN bails out
if it gets more than 100 deps as a result from
MD->getNonLocalPointerDependency. However this only happens *after* all
nonlocal information for BBs have been computed, which is the bottleneck in
this scenario. For instance, there are 8280 times where
getNonLocalPointerDependency returns deps with more than 100 bbs and from
those, 600 times it returns more than 1000 blocks.
- Solution
Bail out early during the nonlocal info computation whenever we reach a
specified threshold. This patch proposes a 100 BBs threshold, it also
reduces the compile time from 3min to 23s.
- Testing
The test-suite presented no compile nor execution time regressions.
Some numbers from my machine (x86_64 darwin):
- 17s under -Oz (which avoids inlining).
- 1.3s under -O1.
- 2m51s under -O2 ToT
*** 23s under -O2 w/ Result.size() > 100
- 1m54s under -O2 w/ Result.size() > 500
With NumResultsLimit = 100, GVN yields the same outcome as in the
unlimited 3min version.
Adam Nemet [Wed, 1 Oct 2014 19:28:11 +0000 (19:28 +0000)]
[X86 disasm tblegen backend] Clean up numPhysicalOperands asserts
No functionality change intended.
This implements Elena's idea to put the new additionalOperand outside the
switch to cover all cases
(http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140929/237763.html).
Note only nontrivial change is in MRMSrcMemFrm. This requires an inclusive
interval of [2, 4] because we have prefix-dependent *optional* immediate
operand.
projects / llvm / log