Commit Graph

1158 Commits

Author SHA1 Message Date
Dmitri Gribenko 8a4595199a Revert "Fix test failures after r371640"
This reverts commit r371645, because r371640 was reverted.

llvm-svn: 371824
2019-09-13 08:26:59 +00:00
Matt Arsenault f5c3bb60b3 Fix test failures after r371640
r371640 evidently fixed bug 39481

llvm-svn: 371645
2019-09-11 18:55:20 +00:00
Guillaume Chatelet 48904e9452 [Alignment] Use llvm::Align in MachineFunction and TargetLowering - fixes mir parsing
Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.llvm.org/D65945 for reference,

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

Reviewers: courbet

Subscribers: MatzeB, qcolombet, dschuff, arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67433

llvm-svn: 371608
2019-09-11 11:16:48 +00:00
David Stenberg 5a583665f4 [DebugInfo][X86] Describe call site values for zero-valued imms
Summary:
Add zero-materializing XORs to X86's describeLoadedValue() hook in order
to produce call site values.

I have had to change the defs logic in collectCallSiteParameters() a bit
to be able to describe the XORs. The XORs implicitly define $eflags,
which would cause them to never be considered, due to a guard condition
that I->getNumDefs() is one. I have changed that condition so that we
now only consider instructions where a forwarded register overlaps with
the instruction's single explicit define. We still need to collect the implicit
defines of other forwarded registers to remove them from the work list.
I'm not sure how to move towards supporting instructions with multiple
explicit defines, cases where forwarded register are implicitly defined,
and/or cases where an instruction produces values for multiple forwarded
registers. Perhaps the describeLoadedValue() hook should take a register
argument, and we then leave it up to the hook to describe the loaded
value in that register? I have not yet encountered a situation where
that would be necessary though.

Reviewers: aprantl, vsk, djtodoro, NikolaPrica

Reviewed By: vsk

Subscribers: ychen, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67225

llvm-svn: 371333
2019-09-08 14:22:06 +00:00
Bjorn Pettersson 2b698a13a1 [DwarfExpression] Disallow some rewrites to avoid undefined behavior
Summary:
The value operand in DW_OP_plus_uconst/DW_OP_constu value can be
large (it uses uint64_t as representation internally in LLVM).
This means that in the uint64_t to int conversions, previously done
by DwarfExpression::addMachineRegExpression, could lose information.
Also, the negation done in "-Offset" was undefined behavior in case
Offset was exactly INT_MIN.

To avoid the above problems, we now avoid transformation like
 [Reg, DW_OP_plus_uconst, Offset] --> [DW_OP_breg, Offset]
and
 [Reg, DW_OP_constu, Offset, DW_OP_plus]  --> [DW_OP_breg, Offset]
when Offset > INT_MAX.

And we avoid to transform
 [Reg, DW_OP_constu, Offset, DW_OP_minus] --> [DW_OP_breg,-Offset]
when Offset > INT_MAX+1.

The patch also adjusts DwarfCompileUnit::constructVariableDIEImpl
to make sure that "DW_OP_constu, Offset, DW_OP_minus" is used
instead of "DW_OP_plus_uconst, Offset" when creating DIExpressions
with negative frame index offsets.

Notice that this might just be the tip of the iceberg. There
are lots of fishy handling related to these constants. I think both
DIExpression::appendOffset and DIExpression::extractIfOffset may
trigger undefined behavior for certain values.

Reviewers: sdesmalen, rnk, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: jholewinski, aprantl, hiraditya, ychen, uabelho, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D67263

llvm-svn: 371304
2019-09-07 11:40:10 +00:00
Bjorn Pettersson e85acf946d [DebugInfo] Pre-commit of test case for DW_OP_breg/DW_OP_fbreg folds
This currently triggers undefined behavior if executed with an
ubsan build. It is just a precommit of the test case to show that
we got a problem.

Fix is proposed in https://reviews.llvm.org/D67263 and plan is to
commit the fix directly after this patch.

llvm-svn: 371303
2019-09-07 11:39:57 +00:00
Guillaume Chatelet aff45e4b23 [LLVM][Alignment] Make functions using log of alignment explicit
Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:

 - `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
 - `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
 - `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,

Reviewers: lattner, thegameg, courbet

Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65945

llvm-svn: 371045
2019-09-05 10:00:22 +00:00
Igor Kudrin e46639620d [DWARF] Fix referencing Range List Tables from CUs for DWARF64.
As DW_AT_rnglists_base points after the header and headers have
different sizes for DWARF32 and DWARF64, we have to use the format
of the CU to adjust the offset correctly in order to extract
the referenced range list table.

The patch also changes the type of RangeSectionBase because in DWARF64
it is 8-bytes long.

Differential Revision: https://reviews.llvm.org/D67098

llvm-svn: 371016
2019-09-05 07:02:28 +00:00
Alexey Lapshin cbf1f3b771 [Debuginfo][SROA] Need to handle dbg.value in SROA pass.
SROA pass processes debug info incorrecly if applied twice.
Specifically, after SROA works first time, instcombine converts dbg.declare
intrinsics into dbg.value. Inlining creates new opportunities for SROA,
so it is called again. This time it does not handle correctly previously
inserted dbg.value intrinsics.

Differential Revision: https://reviews.llvm.org/D64595

llvm-svn: 370906
2019-09-04 14:19:49 +00:00
Pavel Labath 98634c2e11 Fix address sizes in the dwarfdump-debug-loc-error-cases test
the test is building a 64-bit executable, so the addresses should be
64-bit too. The test was still passing even with smaller address size,
but it was hitting the "unexpected end of data" error sooner than it
should.

llvm-svn: 370882
2019-09-04 11:47:20 +00:00
Jeremy Morse 337a7cb55e [DebugInfo] LiveDebugValues: locations with different exprs should not be merged
When comparing variable locations, LiveDebugValues currently considers only
the machine location, ignoring any DIExpression applied to it. This is a
problem because that DIExpression can do pretty much anything to the machine
location, for example dereferencing it.

This patch adds DIExpressions to that comparison; now variables based on the
same register/memory-location but with different expressions will compare
differently, and be dropped if we attempt to merge them between blocks. This
reduces variable coverage-range a little, but only because we were producing
broken locations.

Differential Revision: https://reviews.llvm.org/D66942

llvm-svn: 370877
2019-09-04 11:09:05 +00:00
Pavel Labath 88b4e28a67 DWARF: Fix a regression in location list dumping
Summary:
While fixing the handling of some error cases, r370363 introduced new
problems -- assertion failures due to unchecked errors (my excuse is that a very
early version of that patch used Optional<T> instead of Expected).

This patch adds proper handling of parsing errors encountered when
dumping location lists from inside DWARF DIEs, and adds a bunch of
additional tests.

I reorder the arguments of the location list dumping functions to make
them consistent, and also be able to dump the two kinds of location
lists generically.

Reviewers: JDevlieghere, dblaikie, probinson

Subscribers: aprantl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67102

llvm-svn: 370868
2019-09-04 10:09:12 +00:00
Jordan Rupprecht f9f81289e6 Revert [MBP] Disable aggressive loop rotate in plain mode
This reverts r369664 (git commit 51f48295cb)

It causes many benchmark regressions, internally and in llvm's benchmark suite.

llvm-svn: 370398
2019-08-29 19:03:58 +00:00
Pavel Labath bd546e5902 DWARFDebugLoc: Make parsing and error reporting more robust
Summary:
While examining this class for possible use in lldb, I noticed two
things:
- it spits out parsing errors directly to stderr
- the loclists parser can incorrectly return valid location lists when
  parsing malformed (truncated) data

I improve the stderr situation by making the parseOneLocationList
functions return Expected<T>s. The errors are still dumped to stderr by
their callers, so this is only a partial fix, but it is enough for my
use case, as I intend to parse the locations lists one by one.

I fix the behavior in the truncated scenario by using the newly
introduced DataExtractor Cursor API.

I also add tests for handling the error cases, as they currently have no
coverage.

Reviewers: dblaikie, JDevlieghere, probinson

Subscribers: lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63591

llvm-svn: 370363
2019-08-29 14:26:05 +00:00
Jeremy Morse 313d2ce999 [DebugInfo] LiveDebugValues should always revisit backedges if it skips them
The "join" method in LiveDebugValues does not attempt to join unseen
predecessor blocks if their out-locations aren't yet initialized, instead
the block should be re-visited later to see if any locations have changed
validity. However, because the set of blocks were all being "process"'d
once before "join" saw them, that logic in "join" was actually ignoring
legitimate out-locations on the first pass through. This meant that some
invalidated locations were not removed from the head of loops, allowing
illegal locations to persist.

Fix this by removing the run of "process" before the main join/process loop
in ExtendRanges. Now the unseen predecessors that "join" skips truly are
uninitialized, and we come back to the block at a later time to re-run
"join", see the @baz function added.

This also fixes another fault where stack/register transfers in the entry
block (or any other before-any-loop-block) had their tranfers initially
ignored, and were then never revisited. The MIR test added tests for this
behaviour.

XFail a test that exposes another bug; a fix for this is coming in D66895.

Differential Revision: https://reviews.llvm.org/D66663

llvm-svn: 370328
2019-08-29 10:53:29 +00:00
Bjorn Pettersson 89846231f7 Fixup in test/DebugInfo/X86/live-debug-vars-discard-invalid.mir
The test case used invalid source operands as input
to BTS64rr instructions (feeding register operands with
immediates). This patch changes those instruction into
using BTS64ri8 instead, which seems to better match the
operand types.

Fixes problems seen in https://reviews.llvm.org/D63973.

llvm-svn: 369866
2019-08-25 10:54:44 +00:00
Jeremy Morse 0ae5498146 [DebugInfo] Remove invalidated locations during LiveDebugValues
LiveDebugValues gives variable locations to blocks, but it should also take
away. There are various circumstances where a variable location is known
until a loop backedge with a different location is detected. In those
circumstances, where there's no agreement on the variable location, it
should be undef / removed, otherwise we end up picking a location that's
valid on some loop iterations but not others.

However, LiveDebugValues doesn't currently do this, see the new testcase
attached. Without this patch, the location of  is assumed to be %bar
through the loop. Once it's added to the In-Locations list, it's never
removed, even though the later dbg.value(0... of  makes the location
un-knowable.

This patch checks during block-location-joining to see whether any
previously-present locations have been removed in a predecessor. If they
have, the live-ins have changed, and the block needs reprocessing.
Similarly, in transferTerminator, assign rather than |= the Out-Locations
after processing a block, as we may have deleted some previously valid
locations. This will mean that LiveDebugValues performs more propagation
 -- but that's necessary for it being correct.

Differential Revision: https://reviews.llvm.org/D66599

llvm-svn: 369778
2019-08-23 16:33:42 +00:00
Guozhi Wei 51f48295cb [MBP] Disable aggressive loop rotate in plain mode
Patch https://reviews.llvm.org/D43256 introduced more aggressive loop layout optimization which depends on profile information. If profile information is not available, the statically estimated profile information(generated by BranchProbabilityInfo.cpp) is used. If user program doesn't behave as BranchProbabilityInfo.cpp expected, the layout may be worse.

To be conservative this patch restores the original layout algorithm in plain mode. But user can still try the aggressive layout optimization with -force-precise-rotation-cost=true.

Differential Revision: https://reviews.llvm.org/D65673

llvm-svn: 369664
2019-08-22 16:21:32 +00:00
Jonas Devlieghere 57ae300562 [Dwarf] Complete the list of type tags.
An incorrect verification error revealed that the list of type tags was
incomplete. This patch adds the missing types by adding a tag kind to
the Dwarf.def file, which is used by the `isType` function.

A test was added for the original verification error.

Differential revision: https://reviews.llvm.org/D65914

llvm-svn: 368718
2019-08-13 17:00:54 +00:00
Hans Wennborg a45f301f7a Revert r368339 "[MBP] Disable aggressive loop rotate in plain mode"
It caused assertions to fire when building Chromium:

  lib/CodeGen/LiveDebugValues.cpp:331: bool
  {anonymous}::LiveDebugValues::OpenRangesSet::empty() const: Assertion
  `Vars.empty() == VarLocs.empty() && "open ranges are inconsistent"' failed.

See https://crbug.com/992871#c3 for how to reproduce.

> Patch https://reviews.llvm.org/D43256 introduced more aggressive loop layout optimization which depends on profile information. If profile information is not available, the statically estimated profile information(generated by BranchProbabilityInfo.cpp) is used. If user program doesn't behave as BranchProbabilityInfo.cpp expected, the layout may be worse.
>
> To be conservative this patch restores the original layout algorithm in plain mode. But user can still try the aggressive layout optimization with -force-precise-rotation-cost=true.
>
> Differential Revision: https://reviews.llvm.org/D65673

llvm-svn: 368579
2019-08-12 14:23:13 +00:00
David Blaikie 0fcc1f7bac DebugInfo/DWARF: Provide some (pretty half-hearted) error handling access when parsing units
This isn't the most robust error handling API, but does allow clients to
opt-in to getting Errors they can handle. I suspect the long-term
solution would be to move away from the lazy unit parsing and have an
explicit step that parses the unit and then allows access to the other
APIs that require a parsed unit.

llvm-dwarfdump could be expanded to use this (or newer/better API) to
demonstrate the benefit of it - but for now lld will use this in a
follow-up cl which ensures lld can exit non-zero on errors like this (&
provide more descriptive diagnostics including which object file the
error came from).

(error access to later errors when parsing nested DIEs would be good too
- but, again, exposing that without it being a hassle for every consumer
may be tricky)

llvm-svn: 368377
2019-08-09 01:14:33 +00:00
Guozhi Wei 80347c3acc [MBP] Disable aggressive loop rotate in plain mode
Patch https://reviews.llvm.org/D43256 introduced more aggressive loop layout optimization which depends on profile information. If profile information is not available, the statically estimated profile information(generated by BranchProbabilityInfo.cpp) is used. If user program doesn't behave as BranchProbabilityInfo.cpp expected, the layout may be worse.

To be conservative this patch restores the original layout algorithm in plain mode. But user can still try the aggressive layout optimization with -force-precise-rotation-cost=true.

Differential Revision: https://reviews.llvm.org/D65673

llvm-svn: 368339
2019-08-08 20:25:23 +00:00
Djordje Todorovic b9973f87c6 Reland "[DwarfDebug] Dump call site debug info"
The build failure found after the rL365467 has been
resolved.

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 367446
2019-07-31 16:51:28 +00:00
David Blaikie 40580d36c4 DWARF: Skip zero column for inline call sites
D64033 <https://reviews.llvm.org/D64033> added DW_AT_call_column for
inline sites. However, that change wasn't aware of "-gno-column-info".
To avoid adding column info when "-gno-column-info" is used, now
DW_AT_call_column is only added when we have non-zero column (when
"-gno-column-info" is used, column will be zero).

Patch by Wenlei He!

Differential Revision: https://reviews.llvm.org/D64784

llvm-svn: 366264
2019-07-16 21:15:19 +00:00
Jonas Devlieghere 83264b3580 [DebugInfo] Add column info for inline sites
The column field is missing for all inline sites, currently it's always
zero. This changes populates DW_AT_call_column field for inline sites.
Test case modified to cover this change.

Patch by: Wenlei He

Differential revision: https://reviews.llvm.org/D64033

llvm-svn: 365945
2019-07-12 19:25:45 +00:00
Djordje Todorovic 0739ccd3b5 Revert "[DwarfDebug] Dump call site debug info"
A build failure was found on the SystemZ platform.

This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.

llvm-svn: 365886
2019-07-12 09:45:12 +00:00
Djordje Todorovic 01eaae6dd1 [DwarfDebug] Dump call site debug info
Dump the DWARF information about call sites and call site parameters into
debug info sections.

The patch also provides an interface for the interpretation of instructions
that could load values of a call site parameters in order to generate DWARF
about the call site parameters.

([13/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 365467
2019-07-09 11:33:56 +00:00
Paul Robinson a5f3e278c8 Use --defsym instead of sed in a test. NFC
llvm-svn: 364929
2019-07-02 14:47:49 +00:00
Matt Arsenault 9cac4e6d14 Rename ExpandISelPseudo->FinalizeISel, delay register reservation
This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.

Patch by Matthias Braun

llvm-svn: 363757
2019-06-19 00:25:39 +00:00
Sander de Smalen 5d6ee76c16 Describe stack-id as an enum
This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.

This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.

Reviewers: arsenm, thegameg, qcolombet

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D60137

llvm-svn: 363533
2019-06-17 09:13:29 +00:00
Guozhi Wei d2210af332 [MBP] Move a latch block with conditional exit and multi predecessors to top of loop
Current findBestLoopTop can find and move one kind of block to top, a latch block has one successor. Another common case is:

    * a latch block
    * it has two successors, one is loop header, another is exit
    * it has more than one predecessors

If it is below one of its predecessors P, only P can fall through to it, all other predecessors need a jump to it, and another conditional jump to loop header. If it is moved before loop header, all its predecessors jump to it, then fall through to loop header. So all its predecessors except P can reduce one taken branch.

Differential Revision: https://reviews.llvm.org/D43256

llvm-svn: 363471
2019-06-14 23:08:59 +00:00
David Blaikie 4129e3e0f8 DebugInfo: Include enumerators in pubnames
This is consistent with GCC's behavior (which is the defacto standard
for pubnames). Though I find the presence of enumerators from enum
classes to be a bit confusing, possibly a bug on GCC's end (since they
can't be named unqualified, unlike the other names - and names nested in
classes don't go in pubnames, for instance - presumably because one must
name the class first & that's enough to limit the scope of the search)

llvm-svn: 363349
2019-06-14 01:58:56 +00:00
Jeremy Morse 181bf0cefb [DebugInfo] Use FrameDestroy to extend stack locations to end-of-function
We aim to ignore changes in variable locations during the prologue and
epilogue of functions, to avoid using space documenting location changes
that aren't visible. However in D61940 / r362951 this got ripped out as
the previous implementation was unsound.

Instead, use the FrameDestroy flag to identify when we're in the epilogue
of a function, and ignore variable location changes accordingly. This fits
in with existing code that examines the FrameSetup flag.

Some variable locations get shuffled in modified tests as they now cover
greater ranges, which is what would be expected. Some additional
single-location variables are generated too. Two tests are un-xfailed,
they were only xfailed due to r362951 deleting functionality they depended
on.

Apparently some out-of-tree backends don't accurately maintain FrameDestroy
flags -- if you're an out-of-tree maintainer and see changes in variable
locations disappear due to a faulty FrameDestroy flag, it's safe to back
this change out. The impact is just slightly more debug info than necessary.

Differential Revision: https://reviews.llvm.org/D62314

llvm-svn: 363245
2019-06-13 10:03:17 +00:00
Jeremy Morse e2f94974df [DebugInfo] Add a test that fell out of an earlier commit
r362951 was supposed to contain this test, however it didn't get committed
due to operator error. This was originally part of D59431.

llvm-svn: 363161
2019-06-12 13:41:56 +00:00
Francis Visoiu Mistrih a438432acc [FastISel] Skip creating unnecessary vregs for arguments
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.

This re-enables it for FastISel with the corresponding fix.

This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.

FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.

This fix moves the replacement of registers before the emission of
copies for the live-ins.

The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).

A few tests are affected by this:

* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed

Differential Revision: https://reviews.llvm.org/D62361

llvm-svn: 362963
2019-06-10 16:53:37 +00:00
Jeremy Morse bcff417292 [DebugInfo] Terminate all location-lists at end of block
This commit reapplies r359426 (which was reverted in r360301 due to
performance problems) and rolls in D61940 to address the performance problem.
I've combined the two to avoid creating a span of slow-performance, and to
ease reverting if more problems crop up.

The summary of D61940: This patch removes the "ChangingRegs" facility in
DbgEntityHistoryCalculator, as its overapproximate nature can produce incorrect
variable locations. An unchanging register doesn't mean a variable doesn't
change its location.

The patch kills off everything that calculates the ChangingRegs vector.
Previously ChangingRegs spotted epilogues and marked registers as unchanging if
they weren't modified outside the epilogue, increasing the chance that we can
emit a single-location variable record. Without this feature,
debug-loc-offset.mir and pr19307.mir become temporarily XFAIL. They'll be
re-enabled by D62314, using the FrameDestroy flag to identify epilogues, I've
split this into two steps as FrameDestroy isn't necessarily supported by all
backends.

The logic for terminating variable locations at the end of a basic block now
becomes much more enjoyably simple: we just terminate them all.

Other test changes: inlined-argument.ll becomes XFAIL, but for a longer term.
The current algorithm for detecting that a variable has a single-location
doesn't work in this scenario (inlined function in multiple blocks), only other
bugs were making this test work. fission-ranges.ll gets slightly refreshed too,
as the location of "p" is now correctly determined to be a single location.

Differential Revision: https://reviews.llvm.org/D61940

llvm-svn: 362951
2019-06-10 15:23:46 +00:00
Nikola Prica abc1dff7e4 [DebugInfo] More strict debug range for stack variables
Variable's stack location can stretch longer than it should. If a
variable is placed at the stack in a some nested basic block its range
can be calculated to be up to the next occurrence of the variable's
DBG_VALUE, or up to the end of the function, thus covering a basic
blocks that should not be included in the variable’s location range.
This happens because the DbgEntityHistoryCalculator ends register
locations at the end of a basic block only if the variable’s location
register has been changed throughout the function, which is not the
case for the register used to reference stack objects.

This patch also tries to produce a single value location if the location
list builder managed to merge all the locations into one.

Reviewers: aprantl, dstenb, jmorse

Reviewed By: aprantl, dstenb, jmorse

Subscribers: djtodoro, ivanbaev, asowda

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D61600

llvm-svn: 362923
2019-06-10 08:41:06 +00:00
Alexey Lapshin b9f1e7b16e [DebugInfo] Incorrect debug info record generated for loop counter.
Incorrect Debug Variable Range was calculated while "COMPUTING LIVE DEBUG VARIABLES" stage.
Range for Debug Variable("i") computed according to current state of instructions
inside of basic block. But Register Allocator creates new instructions which were not taken
into account when Live Debug Variables computed. In the result DBG_VALUE instruction for
the "i" variable was put after these newly inserted instructions. This is incorrect.
Debug Value for the loop counter should be inserted before any loop instruction.

Differential Revision: https://reviews.llvm.org/D62650

llvm-svn: 362750
2019-06-06 21:19:39 +00:00
Nikola Prica 2d0106a110 [LiveDebugValues] Close range for previous variable's location when adding newly deduced location
When LiveDebugValues deduces new variable's location from spill, restore or
register copy instruction it should close old variable's location. Otherwise
we can have multiple block output locations for same variable. That could lead
to inserting two DBG_VALUEs for same variable to the beginning of the successor
block which results to ignoring of first DBG_VALUE.

Reviewers: aprantl, jmorse, wolfgangp, dstenb

Reviewed By: aprantl

Subscribers: probinson, asowda, ivanbaev, petarj, djtodoro

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D62196

llvm-svn: 362373
2019-06-03 09:48:29 +00:00
David Stenberg 5d0e6b6755 Stop undef fragments from closing non-overlapping fragments
Summary:
When DwarfDebug::buildLocationList() encountered an undef debug value,
it would truncate all open values, regardless if they were overlapping or
not. This patch fixes so that it only does that for overlapping fragments.

This change unearthed a bug that I had introduced in D57511,
which I have fixed in this patch. The code in DebugHandlerBase that
changes labels for parameter debug values could break DwarfDebug's
assumption that the labels for the entries in the debug value history
are monotonically increasing. Before this patch, that bug could result
in location list entries whose ending address was lower than the
beginning address, and with the changes for undef debug values that this
patch introduces it could trigger an assertion, due to attempting to
emit location list entries with empty ranges. A reproducer for the bug
is added in param-reg-const-mix.mir.

Reviewers: aprantl, jmorse, probinson

Reviewed By: aprantl

Subscribers: javed.absar, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D62379

llvm-svn: 361820
2019-05-28 13:23:25 +00:00
David Blaikie a17564c2f1 llvm-dwarfdump: Don't error on mixed units using/not using str_offsets
This lead to errors when dumping binaries with v4 and v5 units linked
together (but could've also errored on v5 units that did/didn't use
str_offsets).

Also improves error handling and messages around invalid str_offsets
contributions.

llvm-svn: 361683
2019-05-25 00:07:22 +00:00
David Blaikie fc302c2b7f dwarfdump: Deterministically... determine whether parsing a DWARF32 or DWARF64 str_offsets header
Rather than trying one and then the other - use the kind of the CU to
select which kind of header to parse.

llvm-svn: 361589
2019-05-24 01:41:58 +00:00
David Blaikie 79872a88a0 dwarfdump: Add a bit more DWARF64 support
This test case was incorrect because it mixed DWARF32 and DWARF64 for a
single unit (DWARF32 unit referencing a DWARF64 str_offsets section). So
fix enough of the unit parsing for DWARF64 and make the test valid.

(not sure if anyone needs DWARF64 support though - support in
libDebugInfoDWARF has been added piecemeal and LLVM doesn't produce it
at all)

llvm-svn: 361582
2019-05-24 01:05:52 +00:00
Paul Robinson 0a16ba856b [DebugInfo] Fix tests missed by r362148
llvm-svn: 361251
2019-05-21 12:48:46 +00:00
Paul Robinson 116e8d4876 [DebugInfo] Handle -main-file-name correctly for asm source.
This option provides only the base filename, not a full relative path.

Part of the fix for PR41839.

Differential Revision: https://reviews.llvm.org/D62071

llvm-svn: 361245
2019-05-21 11:52:27 +00:00
Matt Arsenault 828b685ebe RegAllocFast: Improve hinting heuristic
Trace through multiple COPYs when looking for a physreg source. Add
hinting for vregs that will be copied into physregs (we only hinted
for vregs getting copied to a physreg previously).  Give hinted a
register a bonus when deciding which value to spill.  This is part of
my rewrite regallocfast series. In fact this one doesn't even have an
effect unless you also flip the allocation to happen from back to
front of a basic block. Nonetheless it helps to split this up to ease
review of D52010

Patch by Matthias Braun

llvm-svn: 360887
2019-05-16 12:50:39 +00:00
Fangrui Song f4dfd63c74 [IR] Disallow llvm.global_ctors and llvm.global_dtors of the 2-field form in textual format
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0

For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.

For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).

Reviewed By: rnk, dexonsmith

Differential Revision: https://reviews.llvm.org/D61547

llvm-svn: 360742
2019-05-15 02:35:32 +00:00
Fangrui Song 2f6ef2fc92 DWARF v5: emit DW_AT_addr_base if DW_AT_low_pc references .debug_addr
The condition !AddrPool.empty() is tested before attachRangesOrLowHighPC(), which may add an entry to AddrPool. We emit DW_AT_low_pc (DW_FORM_addrx) but may incorrectly omit DW_AT_addr_base for LineTablesOnly. This can be easily reproduced:

clang -gdwarf-5 -gmlt -c a.cc

Fix this by moving !AddrPool.empty() below.

This was discovered while investigating an lld crash (fixed by D61889) on such object files: ld.lld --gdb-index a.o

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D61891

llvm-svn: 360678
2019-05-14 14:37:26 +00:00
David Blaikie 7598b71488 DebugInfo: Only move types out of type units if they're named or type united
Follow up to r359122, after a bug was reported in it - the original
change too aggressively tried to move related types out of type units,
which included unnamed types (like array types) which can't reasonably
be declared-but-not-defined.

A step beyond that is that some types in type units can be anonymous, if
they are types with a name for linkage purposes (eg: "typedef struct { }
x;"). So ensure those don't get turned into plain declarations (without
signatures) because, lacking names, they can't be resolved to the
definition.

[Also include a fix for llvm-dwarfdump/libDebugInfoDWARF to pretty print
types in type units]

llvm-svn: 360458
2019-05-10 19:15:29 +00:00
Jeremy Morse a2b780b731 [DebugInfo] Use zero linenos for debug intrinsics when promoting dbg.declare
In certain circumstances, optimizations pick line numbers from debug
intrinsic instructions as the new location for altered instructions. This
is problematic because the line number of a debugging intrinsic is
meaningless (it doesn't produce any machine instruction), only the scope
information is valid. The result can be the line number of a variable
declaration "leaking" into real code from debugging intrinsics, making the
line table un-necessarily jumpy, and potentially different with / without
variable locations.

Fix this by using zero line numbers when promoting dbg.declare intrinsics
into dbg.values: this is safe for debug intrinsics as their line numbers
are meaningless, and reduces the scope for damage / misleading stepping
when optimizations pick locations from the wrong place.

Differential Revision: https://reviews.llvm.org/D59272

llvm-svn: 360415
2019-05-10 10:03:41 +00:00