Summary:
This change achieves two things:
- Redefine the Custom Event handling instrumentation points emitted by
the compiler to not require dynamic relocation of references to the
__xray_CustomEvent trampoline.
- Remove the synthetic reference we emit at the end of a function that
we used to keep auxiliary sections alive in favour of SHF_LINK_ORDER
associated with the section where the function is defined.
To achieve the custom event handling change, we've had to introduce the
concept of sled versioning -- this will need to be supported by the
runtime to allow us to understand how to turn on/off the new version of
the custom event handling sleds. That change has to land first before we
change the way we write the sleds.
To remove the synthetic reference, we rely on a relatively new linker
feature that preserves the sections that are associated with each other.
This allows us to limit the effects on the .text section of ELF
binaries.
Because we're still using absolute references that are resolved at
runtime for the instrumentation map (and function index) maps, we mark
these sections write-able. In the future we can re-define the entries in
the map to use relative relocations instead that can be statically
determined by the linker. That change will be a bit more invasive so we
defer this for later.
Depends on D36816.
Reviewers: dblaikie, echristo, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36615
llvm-svn: 311525
This also changes the TailDuplicator to be configured explicitely
pre/post regalloc rather than relying on the isSSA() flag. This was
necessary to have `llc -run-pass` work reliably.
llvm-svn: 311520
Adds infrastructure to clone whole instruction bundles rather than just
single instructions. This fixes a bug where tail duplication would
unbundle instructions while cloning.
This should unbreak the "Clang Stage 1: cmake, RA, with expensive checks
enabled" build on greendragon. The bot broke with r311139 hitting this
pre-existing bug.
A proper testcase will come next.
llvm-svn: 311511
This partially reverts r311429 in favor of making ISD::isConstantSplatVector do something not confusing. Turns out the only other user of it was also having to deal with the weird property of it returning a smaller size.
So rather than continue to deal with this quirk everywhere, just make the interface do something sane.
Differential Revision: https://reviews.llvm.org/D37039
llvm-svn: 311510
I was contacted by Jesper Antonsson from Ericsson who ran into problems
with r311181 in their test suites with for an out-of-tree target.
Because of the latter I don't have a reproducer, but we definitely don't
want to modify the data structure on which we are iterating inside the
loop.
llvm-svn: 311466
When expanding a BRCOND into a BR_CC, do not create an AND 1
if one already exists.
Review: D36705
Patch by Joel Galenson <jgalenson@google.com>
llvm-svn: 311447
This adds debug messages to various functions that create new SDValue nodes.
This is e.g. useful to have during legalization, as otherwise it can prints
legalization info of nodes that did not appear in the dumps before.
Differential Revision: https://reviews.llvm.org/D36984
llvm-svn: 311444
ISD::isConstantSplatVector can shrink to the smallest splat width. But we don't check the size of the resulting APInt at all. This can cause us to misinterpret the results.
This patch just adds a flag to prevent the APInt from changing width.
Fixes PR34271.
Differential Revision: https://reviews.llvm.org/D36996
llvm-svn: 311429
When removing a live-range we used to not touch them making debug
prints harder to read because the IR was not matching what the
live-ranges information was saying.
This only affects debug printing and allows to put stronger asserts in
the code (see r308906 for instance).
llvm-svn: 311401
Summary:
If all the operands of a BUILD_VECTOR extract elements from same vector then split the
vector efficiently based on the maximum vector access index.
Reviewers: zvi, delena, RKSimon, thakis
Reviewed By: RKSimon
Subscribers: chandlerc, eladcohen, llvm-commits
Differential Revision: https://reviews.llvm.org/D35788
llvm-svn: 311255
They won't affect the DWARF output, but they will mess with the
sorting of the fragments. This fixes the crash reported in PR34159.
https://bugs.llvm.org/show_bug.cgi?id=34159
llvm-svn: 311217
This patch teaches the SDag type legalizer how to split up debug info for
integer values that are split into a hi and lo part.
(re-commit)
Differential Revision: https://reviews.llvm.org/D36805
llvm-svn: 311181
We see a modest performance improvement from this slightly higher tail dup threshold.
Differential Revision: https://reviews.llvm.org/D36775
llvm-svn: 311139
Two issues identified by buildbots were addressed:
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
Reviewers: qcolombet, javed.absar, MatzeB, jonpa
Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny
Differential Revision: https://reviews.llvm.org/D30751
llvm-svn: 311135
This patch teaches the SDag type legalizer how to split up debug info for
integer values that are split into a hi and lo part.
Differential Revision: https://reviews.llvm.org/D36805
llvm-svn: 311102
The SelectionDAGBuilder translates various conditional branches into
CaseBlocks which are then translated into SDNodes. If a conditional
branch results in multiple CaseBlocks only the first CaseBlock is
translated into SDNodes immediately, the rest of the CaseBlocks are
put in a queue and processed when all LLVM IR instructions in the
basic block have been processed.
When a CaseBlock is transformed into SDNodes the SelectionDAGBuilder
is queried for the current LLVM IR instruction and the resulting
SDNodes are annotated with the debug info of the current
instruction (if it exists and has debug metadata).
When the deferred CaseBlocks are processed, the SelectionDAGBuilder
does not have a current LLVM IR instruction, and the resulting SDNodes
will not have any debuginfo. As DwarfDebug::beginInstruction() outputs
a .loc directive for the first instruction in a labeled
block (typically the case for something coming from a CaseBlock) this
tends to produce a line-0 directive.
This patch changes the handling of CaseBlocks to store the current
instruction's debug info into the CaseBlock when it is created (and the
SelectionDAGBuilder knows the current instruction) and to always use
the stored debug info when translating a CaseBlock to SDNodes.
Patch by Frej Drejhammar!
Differential Revision: https://reviews.llvm.org/D36671
llvm-svn: 311097
The idea of this patch is to continue the scheduler state over an MBB boundary
in the case where the successor block has only one predecessor. This means
that the scheduler will continue in the successor block (after emitting any
branch instructions) with e.g. maintained processor resource counters.
Benchmarks have been confirmed to benefit from this.
The algorithm in MachineScheduler.cpp that extracts scheduling regions of an
MBB has been extended so that the strategy may optionally reverse the order
of processing the regions themselves. This is controlled by a new method
doMBBSchedRegionsTopDown(), which defaults to false.
Handling the top-most region of an MBB first also means that a top-down
scheduler can continue the scheduler state across any scheduling boundary
between to regions inside MBB.
Review: Ulrich Weigand, Matthias Braun, Andy Trick.
https://reviews.llvm.org/D35053
llvm-svn: 311072
When v1i1 is legal (e.g. AVX512) the legalizer can reach
a case where a v1i1 SETCC with an illgeal vector type operand
wasn't scalarized (since v1i1 is legal) but its operands does
have to be scalarized. This used to assert because SETCC was
missing from the vector operand scalarizer.
This patch attemps to teach the legalizer to handle these cases
by scalazring the operands, converting the node into a scalar
SETCC node.
Differential revision: https://reviews.llvm.org/D36651
llvm-svn: 311071
If we want to substitute the relocation of derived pointer with gep of base then
we must ensure that relocation of base dominates the relocation of derived pointer.
Currently only check for basic block is present. However it is possible that both
relocation are in the same basic block but relocation of derived pointer is defined
earlier.
The patch moves the relocation of base pointer right before relocation of derived
pointer in this case.
Reviewers: sanjoy,artagnon,igor-laevsky,reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36462
llvm-svn: 311067
This reverts commit r311038.
Several buildbots are breaking, and at least one appears to be due to
the forwarding of physical regs enabled by this change. Reverting while
I investigate further.
llvm-svn: 311062
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
Reviewers: qcolombet, javed.absar, MatzeB, jonpa
Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny
Differential Revision: https://reviews.llvm.org/D30751
llvm-svn: 311038
r310825 caused the clang-ppc64le-linux-lnt bot to go red
(http://lab.llvm.org:8011/builders/clang-ppc64le-linux-lnt/builds/5712)
because of a test-suite failure of
SingleSource/UnitTests/2003-07-09-SignedArgs
This reverts commit 0028f6a87224fb595a1c19c544cde9b003035996.
llvm-svn: 311008
Undef subreg definition means that the content of the super register
doesn't matter at this point. While that's true for virtual registers,
this may not hold when replacing them with actual physical registers.
Indeed, some part of the physical register may be coalesced with the
related virtual register and thus, the values for those parts matter and
must be live.
The fix consists in checking whether or not subregs of the physical register
being assigned to an undef subreg definition are live through that def and
insert an implicit use if they are. Doing so, will keep them alive until
that point like they should be.
E.g., let vreg14 being assigned to R0_R1 then
%vreg14:gsub_0<def,read-undef> = COPY %R0 ; <-- R1 is still live here
%vreg14:gsub_1<def> = COPY %R1
Before this changes, the rewriter would change the code into:
%R0<def> = KILL %R0, %R0_R1<imp-def> ; <-- this tells R1 is redefined
%R1<def> = KILL %R1, %R0_R1<imp-def>, %R0_R1<imp-use> ; this value of this R1
; is believed to come
; from the previous
; instruction
Because of this invalid liveness, later pass could make wrong choices and in
particular clobber live register as it happened with the register scavenger in
llvm.org/PR34107
Now we would generate:
%R0<def> = KILL %R0, %R0_R1<imp-def>, %R0_R1<imp-use> ; This tells R1 needs to
; reach this point
%R1<def> = KILL %R1, %R0_R1<imp-def>, %R0_R1<imp-use>
The bug has been here forever, it got exposed recently because the register
scavenger got smarter.
Fixes llvm.org/PR34107
llvm-svn: 310979
Since we don't factor in instruction lengths into outlining calculations
right now, it's never the case that a candidate could have length < 2.
Thus, we should quit early when we see such candidates.
llvm-svn: 310894
This was running immediately after isel, before
isel pseudos were even expanded which is really
unreasonable. Move this to before pre-reglloc
passes in case some other pre-regalloc pass wants to
use the updated regmask info.
Fixes one of the reasons IPRA doesn't do anything on
AMDGPU currently. Tests will be included with future
patch after a few more are fixed.
llvm-svn: 310875
Summary: It is creating useless work as the commuted nodes is the same as the node we are working on in that case.
Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33840
llvm-svn: 310832
into vextract(vNiX,Idx) when creating vextract with getNode().
This case appeared in AVX512 after fixing pr33349 in r310552.
Differential revision: https://reviews.llvm.org/D36571
llvm-svn: 310828
Summary:
Without the SrcVT its hard to know what is really being asked for. For example if your target has 128, 256, and 512 bit vectors. Maybe extracting 128 from 256 is cheap, but maybe extracting 128 from 512 is not.
For x86 we do support extracting a quarter of a 512-bit register. But for i1 vectors we don't have isel patterns for extracting arbitrary pieces. So we need this to have a correct implementation of isExtractSubvectorCheap for mask vectors.
Reviewers: RKSimon, zvi, efriedma
Reviewed By: RKSimon
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D36649
llvm-svn: 310793
If all the operands of a BUILD_VECTOR extract elements from same vector then split the vector efficiently based on the maximum vector access index.
Reapplied with fix to only work with simple value types.
Committed on behalf of @jbhateja (Jatin Bhateja)
Differential Revision: https://reviews.llvm.org/D35788
llvm-svn: 310782
The previous rev (r310208) failed to account for overflow when subtracting the
constants to see if they're suitable for shift/lea. This version add a check
for that and more test were added in r310490.
We can convert any select-of-constants to math ops:
http://rise4fun.com/Alive/d7d
For this patch, I'm enhancing an existing x86 transform that uses fake multiplies
(they always become shl/lea) to avoid cmov or branching. The current code misses
cases where we have a negative constant and a positive constant, so this is just
trying to plug that hole.
The DAGCombiner diff prevents us from hitting a terrible inefficiency: we can start
with a select in IR, create a select DAG node, convert it into a sext, convert it
back into a select, and then lower it to sext machine code.
Some notes about the test diffs:
1. 2010-08-04-MaskedSignedCompare.ll - We were creating control flow that didn't exist in the IR.
2. memcmp.ll - Choose -1 or 1 is the case that got me looking at this again. We could avoid the
push/pop in some cases if we used 'movzbl %al' instead of an xor on a different reg? That's a
post-DAG problem though.
3. mul-constant-result.ll - The trade-off between sbb+not vs. setne+neg could be addressed if
that's a regression, but those would always be nearly equivalent.
4. pr22338.ll and sext-i1.ll - These tests have undef operands, so we don't actually care about these diffs.
5. sbb.ll - This shows a win for what is likely a common case: choose -1 or 0.
6. select.ll - There's another borderline case here: cmp+sbb+or vs. test+set+lea? Also, sbb+not vs. setae+neg shows up again.
7. select_const.ll - These are motivating cases for the enhancement; replace cmov with cheaper ops.
Assembly differences between movzbl and xor to avoid a partial reg stall are caused later by the X86 Fixup SetCC pass.
Differential Revision: https://reviews.llvm.org/D35340
llvm-svn: 310717
Move store merge to happen after intrinsic lowering to allow lowered
stores to be merged.
Some regressions due in MergeConsecutiveStores to missing
insert_subvector that are addressed in follow up patch.
Reviewers: craig.topper, efriedma, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34559
llvm-svn: 310710
rL310372 enabled simplifyShuffleMask to support undef shuffle mask inputs, but its causing hangs.
Removing support until I can triage the problem
llvm-svn: 310699
Summary:
This fixes PR32721 in IfConvertTriangle and possible similar problems in
IfConvertSimple, IfConvertDiamond and IfConvertForkedDiamond.
In PR32721 we had a triangle
EBB
| \
| |
| TBB
| /
FBB
where FBB didn't have any successors at all since it ended with an
unconditional return. Then TBB and FBB were be merged into EBB, but EBB
would still keep its successors, and the use of analyzeBranch and
CorrectExtraCFGEdges wouldn't help to remove them since the return
instruction is not analyzable (at least not on ARM).
The edge updating code and branch probability updating code is now pushed
into MergeBlocks() which allows us to share the same update logic between
more callsites. This lets us remove several dependencies on analyzeBranch
and completely eliminate RemoveExtraEdges.
One thing that showed up with this patch was that IfConversion sometimes
left a successor with 0% probability even if there was no branch or
fallthrough to the successor.
One such example from the test case ifcvt_bad_zero_prob_succ.mir. The
indirect branch tBRIND can only jump to bb.1, but without the patch we
got:
bb.0:
successors: %bb.1(0x80000000)
bb.1:
successors: %bb.1(0x80000000), %bb.2(0x00000000)
tBRIND %r1, 1, %cpsr
B %bb.1
bb.2:
There is no way to jump from bb.1 to bb2, but still there is a 0% edge
from bb.1 to bb.2.
With the patch applied we instead get the expected:
bb.0:
successors: %bb.1(0x80000000)
bb.1:
successors: %bb.1(0x80000000)
tBRIND %r1, 1, %cpsr
B %bb.1
Since bb.2 had no predecessor at all, it was removed.
Several testcases had to be updated due to this since the removed
successor made the "Branch Probability Basic Block Placement" pass
sometimes place blocks in a different order.
Finally added a couple of new test cases:
* PR32721_ifcvt_triangle_unanalyzable.mir:
Regression test for the original problem dexcribed in PR 32721.
* ifcvt_triangleWoCvtToNextEdge.mir:
Regression test for problem that caused a revert of my first attempt
to solve PR 32721.
* ifcvt_simple_bad_zero_prob_succ.mir:
Test case showing the problem where a wrong successor with 0% probability
was previously left.
* ifcvt_[diamond|forked_diamond|simple]_unanalyzable.mir
Very simple test cases for the simple and (forked) diamond cases
involving unanalyzable branches that can be nice to have as a base if
wanting to write more complicated tests.
Reviewers: iteratee, MatzeB, grosser, kparzysz
Reviewed By: kparzysz
Subscribers: kbarton, davide, aemerson, nemanjai, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D34099
llvm-svn: 310697
