LiveDebugValues propagates variable locations between blocks by creating
new DBG_VALUE insts in the successors, then interpreting them when it
passes back through the block at a later time. However, this flushes out
any extra information about the location that LiveDebugValues holds: for
example, connections between variable locations such as discussed in
D65368. And as reported in PR42772 this causes us to lose track of the
fact that a spill-location is actually a spill, not a register location.
This patch fixes that by deferring the creation of propagated DBG_VALUEs
until after propagation has completed: instead location propagation occurs
only by sharing location ID numbers between blocks.
Differential Revision: https://reviews.llvm.org/D66412
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369508 91177308-0d34-0410-b5e6-96231b3b80d8
Currently the machine instruction sinker identifies DBG_VALUE insts that
also need to sink by comparing register numbers. Unfortunately this isn't
safe, because (after register allocation) a DBG_VALUE may read a register
that aliases what's being sunk. To fix this, identify the DBG_VALUEs that
need to sink by recording & examining their register units. Register units
gives us the following guarantee:
"Two registers overlap if and only if they have a common register unit"
[MCRegisterInfo.h]
Thus we can always identify aliasing DBG_VALUEs if the set of register
units read by the DBG_VALUE, and the register units of the instruction
being sunk, intersect. (MachineSink already uses classes like
"LiveRegUnits" for determining sinking validity anyway).
The test added checks for super and subregister DBG_VALUE reads of a sunk
copy being sunk as well.
Differential Revision: https://reviews.llvm.org/D58191
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369247 91177308-0d34-0410-b5e6-96231b3b80d8
LiveDebugVariables can coalesce ranges of variable locations across
multiple basic blocks. However when it recreates DBG_VALUE instructions,
it has to recreate one DBG_VALUE per block, otherwise it doesn't
represent the pre-regalloc layout and variable assignments can go missing.
This feature works -- however while mucking around with LiveDebugVariables,
I commented the relevant code it out and no tests failed. Thus, here's a
test that checks LiveDebugVariables preserves DBG_VALUEs across block
boundaries.
Differential Revision: https://reviews.llvm.org/D66347
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369243 91177308-0d34-0410-b5e6-96231b3b80d8
In r369026 we disabled spill-recognition in LiveDebugValues for anything
that has a complex expression. This is because it's hard to recover the
complex expression once the spill location is baked into it.
This patch re-enables spill-recognition and slightly adjusts the DBG_VALUE
insts that LiveDebugValues tracks: instead of tracking the last DBG_VALUE
for a variable, it tracks the last _unspilt_ DBG_VALUE. The spill-restore
code is then able to access and copy the original complex expression; but
the rest of LiveDebugValues has to be aware of the slight semantic shift,
and produce a new spilt location if a spilt location is propagated between
blocks.
The test added produces an incorrect variable location (see FIXME), which
will be the subject of future work.
Differential Revision: https://reviews.llvm.org/D65368
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369092 91177308-0d34-0410-b5e6-96231b3b80d8
This patch avoids a crash caused by DW_OP_LLVM_fragments being dropped
from DIExpressions by LiveDebugValues spill-restore code. The appearance
of a previously unseen fragment configuration confuses LDV, as documented
in PR42773, and reproduced by the test function this patch adds (Crashes
on a x86_64 debug build).
To avoid this, on spill restore, we now use fragment information from the
spilt-location-expression.
In addition, when spilling, we now don't spill any DBG_VALUE with a complex
expression, as it can't be safely restored and will definitely lead to an
incorrect variable location. The discussion of this is in D65368.
Differential Revision: https://reviews.llvm.org/D66284
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369026 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: There are places where a case that debug label scope has an extra lexical block file is not considered properly. The modified test won't pass without this patch.
Reviewers: aprantl, HsiangKai
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66187
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368891 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368718 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368579 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When eliminating an unreachable block we must remove any call site
information for calls residing in the block.
This was originally found on a downstream target, and the attached x86
test case was produced by hand-modifying some MIR.
Reviewers: aprantl, asowda, NikolaPrica, djtodoro, ivanbaev, vsk
Reviewed By: NikolaPrica, vsk
Subscribers: vsk, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D64500
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368566 91177308-0d34-0410-b5e6-96231b3b80d8
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)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368377 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368339 91177308-0d34-0410-b5e6-96231b3b80d8
Prevent the LoadStoreOptimizer from pairing any load/store instructions with
instructions from the prologue/epilogue if the CFI information has encoded the
operations as separate instructions. This would otherwise lead to a mismatch
of the actual prologue size from the size as recorded in the Windows CFI.
Reviewers: efriedma, mstorsjo, ssijaric
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D65817
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368164 91177308-0d34-0410-b5e6-96231b3b80d8
In debug frame information, some fields, e.g., Length in CIE/FDE and
Offset in FDE are attributes to describe the structure of CIE/FDE. They
are not related to the relaxed code. However, these attributes are
symbol differences. So, in current design, these attributes will be
filled as zero and LLVM generates relocations for them.
We only need to generate relocations for symbols in executable sections.
So, if the symbols are not located in executable sections, we still
evaluate their values under relaxation.
Differential Revision: https://reviews.llvm.org/D61584
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366531 91177308-0d34-0410-b5e6-96231b3b80d8
It is necessary to generate fixups in .debug_frame or .eh_frame as
relaxation is enabled due to the address delta may be changed after
relaxation.
There is an opcode with 6-bits data in debug frame encoding. So, we
also need 6-bits fixup types.
Differential Revision: https://reviews.llvm.org/D58335
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366524 91177308-0d34-0410-b5e6-96231b3b80d8
It is necessary to generate fixups in .debug_frame or .eh_frame as
relaxation is enabled due to the address delta may be changed after
relaxation.
There is an opcode with 6-bits data in debug frame encoding. So, we
also need 6-bits fixup types.
Differential Revision: https://reviews.llvm.org/D58335
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366442 91177308-0d34-0410-b5e6-96231b3b80d8
Windows sees DW_AT_decl_file (".\dwarf-riscv-relocs.c") while Linux sees
DW_AT_decl_file ("./dwarf-riscv-relocs.c").
This fixes a failure introduced in rL366402.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366410 91177308-0d34-0410-b5e6-96231b3b80d8
When code relaxation is enabled many RISC-V fixups are not resolved but
instead relocations are emitted. This happens even for DWARF debug
sections. Therefore, to properly support the parsing of DWARF debug info
we need to be able to resolve RISC-V relocations. This patch adds:
* Support for RISC-V relocations in RelocationResolver
* DWARF support for two relocations per object file offset
* DWARF changes to support relocations in more DIE fields
The two relocations per offset change is needed because some RISC-V
relocations (used for label differences) come in pairs.
Relocations can also be emitted for DWARF fields where relocations were
not yet evaluated. Adding relocation support for some of these fields is
essencial. On the other hand, LLVM currently emits RISC-V relocations
for fixups that could be safely evaluated, since they can never be
affected by code relaxations. This patch also adds relocation support
for the fields affected by those extraneous relocations (the DWARF unit
entry Length, and the DWARF debug line entry TotalLength and
PrologueLength), for testing purposes.
Differential Revision: https://reviews.llvm.org/D62062
Patch by Luís Marques.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366402 91177308-0d34-0410-b5e6-96231b3b80d8
Items which are known to be wrong/different vs GCC are marked as TODO and will
be address in follow-up patches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366326 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366264 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365945 91177308-0d34-0410-b5e6-96231b3b80d8
A build failure was found on the SystemZ platform.
This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365886 91177308-0d34-0410-b5e6-96231b3b80d8
- The test had extension .yaml, which lit doesn't execute in this
directory. Rename to .test to make it run, and move the yaml bits
into a dedicated file, like with all other tests in this dir.
- llvm-pdbdump got renamed to llvm-pdbutil long ago, update test.
- -dbi-module-info got renamed in r305032, update test for this too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365514 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365467 91177308-0d34-0410-b5e6-96231b3b80d8
Jordan reports on llvm-commits a performance regression with r364515,
backing the patch out while it's investigated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365448 91177308-0d34-0410-b5e6-96231b3b80d8
Emit replacements for clobbered parameters location if the parameter
has unmodified value throughout the funciton. This is basic scenario
where we can use the debug entry values.
([12/13] 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/D58042
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365444 91177308-0d34-0410-b5e6-96231b3b80d8
This patch addresses PR41675, where a stack-pointer variable is dereferenced
too many times by its location expression, presenting a value on the stack as
the pointer to the stack.
The difference between a stack *pointer* DBG_VALUE and one that refers to a
value on the stack, is currently the indirect flag. However the DWARF backend
will also try to guess whether something is a memory location or not, based
on whether there is any computation in the location expression. By simply
prepending the stack offset to existing expressions, we can accidentally
convert a register location into a memory location, which introduces a
suprise (and unintended) dereference.
The solution is to add DW_OP_stack_value whenever we add a DIExpression
computation to a stack *pointer*. It's an implicit location computed on the
expression stack, thus needs to be flagged as a stack_value.
For the edge case where the offset is zero and the location could be a register
location, DIExpression::prepend will still generate opcodes, and thus
DW_OP_stack_value must still be added.
Differential Revision: https://reviews.llvm.org/D63429
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364736 91177308-0d34-0410-b5e6-96231b3b80d8
Appears that the 'test/DebugInfo/MIR/X86/dbginfo-entryvals.mir'
does not pass on Windows.
This reverts commit rL364553.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364571 91177308-0d34-0410-b5e6-96231b3b80d8
Emit replacements for clobbered parameters location if the parameter
has unmodified value throughout the funciton. This is basic scenario
where we can use the debug entry values.
([12/13] 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/D58042
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364553 91177308-0d34-0410-b5e6-96231b3b80d8
Once MIR code leaves SSA form and the liveness of a vreg is considered,
DBG_VALUE insts are able to refer to non-live vregs, because their
debug-uses do not contribute to liveness. This non-liveness becomes
problematic for optimizations like register coalescing, as they can't
``see'' the debug uses in the liveness analyses.
As a result registers get coalesced regardless of debug uses, and that can
lead to invalid variable locations containing unexpected values. In the
added test case, the first vreg operand of ADD32rr is merged with various
copies of the vreg (great for performance), but a DBG_VALUE of the
unmodified operand is blindly updated to the modified operand. This changes
what value the variable will appear to have in a debugger.
Fix this by changing any DBG_VALUE whose operand will be resurrected by
register coalescing to be a $noreg DBG_VALUE, i.e. give the variable no
location. This is an overapproximation as some coalesced locations are
safe (others are not) -- an extra domination analysis would be required to
work out which, and it would be better if we just don't generate non-live
DBG_VALUEs.
This fixes PR40010.
Differential Revision: https://reviews.llvm.org/D56151
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364515 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Implements direct and indirect tail calls enabled by the 'tail-call'
feature in both DAG ISel and FastISel. Updates existing call tests and
adds new tests including a binary encoding test.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62877
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364445 91177308-0d34-0410-b5e6-96231b3b80d8
The test only checks the existence of the `Types CU list` line.
Unfortunately I can't make a better test because
{gcc,clang} -fuse-ld={lld,gold} --gdb-index do not give me a non-empty types CU list.
Reviewed By: ikudrin
Differential Revision: https://reviews.llvm.org/D63537
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363800 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Bug: https://bugs.llvm.org/show_bug.cgi?id=39024
The bug reports that a vectorized loop is stepped through 4 times and each step through the loop seemed to show a different path. I found two problems here:
A) An incorrect line number on a preheader block (for.body.preheader) instruction causes a step into the loop before it begins.
B) Instructions in the middle block have different line numbers which give the impression of another iteration.
In this patch I give all of the middle block instructions the line number of the scalar loop latch terminator branch. This seems to provide the smoothest debugging experience because the vectorized loops will always end on this line before dropping into the scalar loop. To solve problem A I have altered llvm::SplitBlockPredecessors to accommodate loop header blocks.
I have set up a separate review D61933 for a fix which is required for this patch.
Reviewers: samsonov, vsk, aprantl, probinson, anemet, hfinkel, jmorse
Reviewed By: hfinkel, jmorse
Subscribers: jmorse, javed.absar, eraman, kcc, bjope, jmellorcrummey, hfinkel, gbedwell, hiraditya, zzheng, llvm-commits
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D60831
llvm-svn: 363046
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363786 91177308-0d34-0410-b5e6-96231b3b80d8
