Chandler Carruth [Fri, 20 Jan 2017 02:41:20 +0000 (02:41 +0000)]
[LoopInfo] Add helper methods to compute two useful orderings of the
loops in a function.
These are relatively confusing to talk about and compute correctly so it
seems really good to write down their implementation in one place. I've
replaced one place we needed this in the loop PM infrastructure and
I have another place in a pending patch that wants it.
We can't quite use this for the core loop PM walk because there we're
sometimes working on a sub-forest.
I'll add the expected unittests before committing this but wanted to
make sure folks were happy with these names / comments.
Credit goes to Richard Smith for the idea for naming the order where siblings
are in reverse program order but the tree traversal remains preorder.
[AMDGPU] Prevent spills before exec mask is restored
Inline spiller can decide to move a spill as early as possible in the basic block.
It will skip phis and label, but we also need to make sure it skips instructions
in the basic block prologue which restore exec mask.
Added isPositionLike callback in TargetInstrInfo to detect instructions which
shall be skipped in addition to common phis, labels etc.
Big functions with large vreg # are quite unwieldy to update. This test
also relied on legal s8 operations which we're considering removing.
Change it to have one function per test (it does increase boilerplate,
but makes the core hopefully more readable and maintanable), and use
100% legal operations throughout.
Kuba Mracek [Fri, 20 Jan 2017 00:24:32 +0000 (00:24 +0000)]
[lit] Limit parallelism of sanitizer tests on Darwin [llvm part, take 2]
Running lit tests and unit tests of ASan and TSan on macOS has very bad performance when running with a high number of threads. This is caused by xnu (the macOS kernel), which currently doesn't handle mapping and unmapping of sanitizer shadow regions (reserved VM which are several terabytes large) very well. The situation is so bad that increasing the number of threads actually makes the total testing time larger. The macOS buildbots are affected by this. Note that we can't easily limit the number of sanitizer testing threads without affecting the rest of the tests.
This patch adds a special "group" into lit, and limits the number of concurrently running tests in this group. This helps solve the contention problem, while still allowing other tests to run in full, that means running lit with -j8 will still with 8 threads, and parallelism is only limited in sanitizer tests.
Justin Bogner [Fri, 20 Jan 2017 00:24:30 +0000 (00:24 +0000)]
GlobalISel: Only set FailedISel on dropped dbg intrinsics when using fallback
It's easier to test the non-fallback path if we just drop these
intrinsics for now, like we did before we added the fallback path.
We'll obviously need to fix this properly, but the fixme for that is
already here.
Anna Thomas [Fri, 20 Jan 2017 00:21:33 +0000 (00:21 +0000)]
[AliasAnalysis] Fences do not modify constant memory location
Summary:
Fence instructions are currently marked as `ModRef` for all memory locations.
We can improve this for constant memory locations (such as constant globals),
since fence instructions cannot modify these locations.
This helps us to forward constant loads across fences (added test case in GVN).
There were no changes in behaviour for similar test cases in early-cse and licm.
Justin Bogner [Fri, 20 Jan 2017 00:16:19 +0000 (00:16 +0000)]
GlobalISel: Pass the MachineFunction in to reportSelectionError directly
Rather than trying to find MF based on the possibly-null MI we've
passed in here, just pass it in directly. It's already available at
all callers anyway.
Matthias Braun [Fri, 20 Jan 2017 00:16:14 +0000 (00:16 +0000)]
CodeGen: Add/Factor out LiveRegUnits class; NFCI
This is a set of register units intended to track register liveness, it
is similar in spirit to LivePhysRegs.
You can also think of this as the liveness tracking parts of the
RegisterScavenger factored out into an own class.
[PM] Make default pipeline test for the new PM strict
Use CHECK-NEXT to verify that a test breaks whenever unexpected passes,
analyses, or invalidations show up in default pipelines. The test case
is constructed so that we don't expect to invalidate anything, and needs
to be kept that way.
The test is slightly less strict than we'd like because of differences
in type pretty-printing.
(Right now it does show some invalidations - all of those are intentional
and temporary.)
Zachary Turner [Thu, 19 Jan 2017 23:31:24 +0000 (23:31 +0000)]
[pdb] Add HashTable data structure.
This was being parsed / serialized ad-hoc inside the code
for a specific PDB stream. But this data structure is used
in multiple ways / places within the PDB format. To be able
to re-use it we need to raise this code out and make it more
generic. In doing so, a number of bugs are fixed in the
original implementation, and support is added for growing
the hash table and deleting items from the hash table,
which had either been omitted or incorrect implemented in
the initial version.
[PM] Make default pipeline test for the new PM strict
Use CHECK-NEXT to verify that a test breaks whenever unexpected passes,
analyses, or invalidations show up in default pipelines. The test case
is constructed so that we don't expect to invalidate anything, and needs
to be kept that way.
(Right now it does show some invalidations - all of those are intentional
and temporary.)
Simon Pilgrim [Thu, 19 Jan 2017 22:41:22 +0000 (22:41 +0000)]
[SelectionDAG] Improve knownbits handling of UMIN/UMAX (PR31293)
This patch improves the knownbits logic for unsigned integer min/max opcodes.
For UMIN we know that the result will have the maximum of the inputs' known leading zero bits in the result, similarly for UMAX the maximum of the inputs' leading one bits.
This is particularly useful for simplifying clamping patterns,. e.g. as SSE doesn't have a uitofp instruction we want to use sitofp instead where possible and for that we need to confirm that the top bit is not set.
Haicheng Wu [Thu, 19 Jan 2017 22:28:34 +0000 (22:28 +0000)]
[InlineCost] Use TTI to check if GEP is free.
Currently, a GEP is considered free only if its indices are all constant.
TTI::getGEPCost() can give target-specific more accurate analysis. TTI is
already used for the cost of many other instructions.
Serge Rogatch [Thu, 19 Jan 2017 20:24:23 +0000 (20:24 +0000)]
[XRay][Arm] Repair XRay table emission on Arm32 and add tests to identify such problem earlier
Summary:
Emission of XRay table was occasionally disabled for Arm32, but this bug was not then detected because earlier (also by mistake) testing of XRay was occasionally disabled on 32-bit Arm targets. This patch should fix that problem and detect such problems in the future.
This patch is one of a series, see also
- https://reviews.llvm.org/D28623
Xin Tong [Thu, 19 Jan 2017 19:31:40 +0000 (19:31 +0000)]
Improve what can be promoted in LICM.
Summary:
In case of non-alloca pointers, we check for whether it is a pointer
from malloc-like calls and it is not captured. In such case, we can
promote the pointer, as the caller will have no way to access this pointer
even if there is unwinding in middle of the loop.
Simon Pilgrim [Thu, 19 Jan 2017 16:25:02 +0000 (16:25 +0000)]
[X86][SSE] Attempt to pre-truncate arithmetic operations that have already been extended
As discussed on D28219 - it is profitable to combine trunc(binop (s/zext(x), s/zext(y)) to binop(trunc(s/zext(x)), trunc(s/zext(y))) assuming the trunc(ext()) will simplify further
Simon Pilgrim [Thu, 19 Jan 2017 15:03:00 +0000 (15:03 +0000)]
[X86][SSE] Added tests for pre-truncating arithmetic operations that have already been extended
As discussed on D28219 - it is profitable to combine trunc(binop (s/zext(x), s/zext(y)) to binop(trunc(s/zext(x)), trunc(s/zext(y))) assuming the trunc(ext()) will simplify further
Mikael Holmen [Thu, 19 Jan 2017 13:55:55 +0000 (13:55 +0000)]
[DAG] Don't increase SDNodeOrder for dbg.value/declare.
Summary:
The SDNodeOrder is saved in the IROrder field in the SDNode, and this
field may affects scheduling. Thus, letting dbg.value/declare increase
the order numbers may in turn affect scheduling.
Because of this change we also need to update the code deciding when
dbg values should be output, in ScheduleDAGSDNodes.cpp/ProcessSDDbgValues.
Dbg values now have the same order as the SDNode they are connected to,
not the following orders.
Daniel Sanders [Thu, 19 Jan 2017 11:15:55 +0000 (11:15 +0000)]
Re-commit: [globalisel] Tablegen-erate current Register Bank Information
Summary:
Adds a RegisterBank tablegen class that can be used to declare the register
banks and an associated tablegen pass to generate the necessary code.
Changes since first commit attempt:
* Added missing guards
* Added more missing guards
* Found and fixed a use-after-free bug involving Twine locals
Craig Topper [Thu, 19 Jan 2017 07:37:45 +0000 (07:37 +0000)]
[AVX-512] Add test cases that show where we are using two subvector inserts to broadcast a 128-bit subvector into a 512-bit vector. We'd be better off using something like SHUFF32X4.
If the subvector comes from a load, we convert to SUBV_BROADCAST and use a broadcast instruction. But if there is no load we keep the inserts. I think we should create the SUBV_BROADCAST even without the load and let isel use the fallback patterns that are used if the load can't be folded. This will use the SHUFF32X4 or similar instruction for the 128-bit into 512-bit case and a single insert for 128 into 256 or 256 into 512.
This should be fixed so subvector broadcast intrinsics can be replaced with native IR since some of those currently lower directly to SHUFF32X4.
Matt Arsenault [Thu, 19 Jan 2017 06:35:27 +0000 (06:35 +0000)]
AMDGPU: Disable some fneg combines unless nsz
For -(x + y) -> (-x) + (-y), if x == -y, this would
change the result from -0.0 to 0.0. Since the fma/fmad
combine is an extension of this problem it also
applies there.
fmul should be fine, and I don't think any of the unary
operators or conversions should be a problem either.
c++filt does not attempt to demangle symbols which do not match its
expected format. This means that the symbol must start with _Z or ___Z
(block invocation function extension). Any other symbols are returned
as is. Note that this is different from the behaviour of __cxa_demangle
which will demangle fragments.
LowerTypeTests: Implement exporting of type identifiers.
Type identifiers are exported by:
- Adding coarse-grained information about how to test the type
identifier to the summary.
- Creating symbols in the object file (aliases and absolute symbols)
containing fine-grained information about the type identifier.
Dehao Chen [Thu, 19 Jan 2017 00:44:11 +0000 (00:44 +0000)]
Add -debug-info-for-profiling to emit more debug info for sample pgo profile collection
Summary:
SamplePGO binaries built with -gmlt to collect profile. The current -gmlt debug info is limited, and we need some additional info:
* start line of all subprograms
* linkage name of all subprograms
* standalone subprograms (functions that has neither inlined nor been inlined)
This patch adds these information to the -gmlt binary. The impact on speccpu2006 binary size (size increase comparing with -g0 binary, also includes data for -g binary, which does not change with this patch):
Eli Friedman [Wed, 18 Jan 2017 23:56:42 +0000 (23:56 +0000)]
[SCEV] Make getUDivExactExpr handle non-nuw multiplies correctly.
To avoid regressions, make ScalarEvolution::createSCEV a bit more
clever.
Also get rid of some useless code in ScalarEvolution::howFarToZero
which was hiding this bug.
No new testcase because it's impossible to actually expose this bug:
we don't have any in-tree users of getUDivExactExpr besides the two
functions I just mentioned, and they both dodged the problem. I'll
try to add some interesting users in a followup.
Eli Friedman [Wed, 18 Jan 2017 23:26:37 +0000 (23:26 +0000)]
Preserve domtree and loop-simplify for runtime unrolling.
Mostly straightforward changes; we just didn't do the computation before.
One sort of interesting change in LoopUnroll.cpp: we weren't handling
dominance for children of the loop latch correctly, but
foldBlockIntoPredecessor hid the problem for complete unrolling.
Currently punting on loop peeling; made some minor changes to isolate
that problem to LoopUnrollPeel.cpp.
Adds a flag -unroll-verify-domtree; it verifies the domtree immediately
after we finish updating it. This is on by default for +Asserts builds.
Mehdi Amini [Wed, 18 Jan 2017 21:37:11 +0000 (21:37 +0000)]
Improve the `-filter-print-funcs` option to skip the banner for CGSCC pass when nothing is to be printed
Before, it would print a sequence of:
*** IR Dump After Function Integration/Inlining ******
*** IR Dump After Function Integration/Inlining ******
*** IR Dump After Function Integration/Inlining ******
...
[LV] Allow reductions that have several uses outside the loop
We currently check whether a reduction has a single outside user. We don't
really need to require that - we just need to make sure a single value is
used externally. The number of external users of that value shouldn't actually
matter.
Justin Bogner [Wed, 18 Jan 2017 19:01:58 +0000 (19:01 +0000)]
cmake: Only sanitize use-after-scope if the host compiler supports it
In r292256, we started adding -fsanitize-use-after-scope when using
the address sanitizer, but that flag wasn't always available. This
fixes the config to only add the flag if the host compiler supports
it.
Evandro Menezes [Wed, 18 Jan 2017 18:57:08 +0000 (18:57 +0000)]
[AArch64] Generate literals by the little end
ARM seems to prefer that long literals be formed from their little end in
order to promote the fusion of the instrs pairs MOV/MOVK and MOVK/MOVK on
Cortex A57 and others (v. "Cortex A57 Software Optimisation Guide", section
4.14).
Mehdi Amini [Wed, 18 Jan 2017 18:36:21 +0000 (18:36 +0000)]
[ThinLTO] Add a recursive step in Metadata lazy-loading
Summary:
Without this, we're stressing the RAUW of unique nodes,
which is a costly operation. This is intended to limit
the number of RAUW, and is very effective on the total
link-time of opt with ThinLTO, before:
Graydon Hoare [Wed, 18 Jan 2017 18:12:20 +0000 (18:12 +0000)]
[lit] Support sharding testsuites, for parallel execution.
Summary:
This change equips lit.py with two new options, --num-shards=M and
--run-shard=N (set by default from env vars LIT_NUM_SHARDS and LIT_RUN_SHARD).
The options must be used together, and N must be in 1..M.
Together these options effect only test selection: they partition the testsuite
into M equal-sized "shards", then select only the Nth shard. They can be used
in a cluster of test machines to achieve a very crude (static) form of
parallelism, with minimal configuration work.
[AMDGPU] Do not allow register coalescer to create big superregs
Limit register coalescer by not allowing it to artificially increase
size of registers beyond dword. Such super-registers are in fact
register sequences and not distinct HW registers.
With more super-regs we would need to allocate adjacent registers
and constraint regalloc more than needed. Moreover, our super
registers are overlapping. For instance we have VGPR0_VGPR1_VGPR2,
VGPR1_VGPR2_VGPR3, VGPR2_VGPR3_VGPR4 etc, which complicates registers
allocation even more, resulting in excessive spilling.
Teresa Johnson [Wed, 18 Jan 2017 16:58:43 +0000 (16:58 +0000)]
Don't create a comdat group for a dropped def with initializer
Non-prevailing weak/linkonce odr symbols will be dropped by ThinLTO to
available_externally when possible. If they had an initializer in the
global_ctors list, a comdat group was being created. This code
already had logic to skip available_externally defs, but now the
EliminateAvailableExternally pass will drop these symbols to
declarations earlier. Change the check to skip all declarations for
linker (which includes available_externally along with declarations).
Sam Parker [Wed, 18 Jan 2017 15:52:11 +0000 (15:52 +0000)]
[ARM] Create SubtargetFeatures from build attrs
An ELFObjectFile can now create SubtargetFeatures from the available
ARM build attributes, in a similar manner to MIPS. I've moved the
MIPS code into its own function and the ARM handler also has a
separate function.
Florian Hahn [Wed, 18 Jan 2017 15:01:22 +0000 (15:01 +0000)]
[thumb,framelowering] Reset NoVRegs in Thumb1FrameLowering::emitPrologue.
Summary:
In this function, virtual registers can be introduced (for example
through calls to emitThumbRegPlusImmInReg). doScavengeFrameVirtualRegs
will replace those virtual registers with concrete registers later on
in PrologEpilogInserter, which sets NoVRegs again.
This patch fixes the Codegen/Thumb/segmented-stacks.ll test case which
failed with expensive checks.
https://llvm.org/bugs/show_bug.cgi?id=27484