We used to only emit static const data members in CodeView as
S_CONSTANTS when they were used; this patch makes it so they are always emitted.
This changes CodeViewDebug.cpp to find the static const members from the
class debug info instead of creating DIGlobalVariables in the IR
whenever a static const data member is used.
Bug: https://bugs.llvm.org/show_bug.cgi?id=47580
Differential Revision: https://reviews.llvm.org/D89072
This reverts commit 504615353f.
This is needed to support fortran assumed rank arrays which
have runtime rank.
Summary:
Fortran assumed rank arrays have dynamic rank. DWARF TAG
DW_TAG_generic_subrange is needed to support that.
Testing:
unit test cases added (hand-written)
check llvm
check debug-info
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D89218
Fix an out-of-bounds shift in emitLegacyZExt by using a slightly more
complicated dwarf expression to create the zext mask.
This addresses a UBSan diagnostic seen when compiling compiler-rt
(llvm.org/PR47927).
rdar://70307714
Differential Revision: https://reviews.llvm.org/D89838
Since Wasm comdat sections work similarly to ELF, we can use that mechanism
to eliminate duplicate dwarf type information in the same way.
Differential Revision: https://reviews.llvm.org/D88603
We used to only emit static const data members in CodeView as
S_CONSTANTS when they were used; this patch makes it so they are always emitted.
I changed CodeViewDebug.cpp to find the static const members from the
class debug info instead of creating DIGlobalVariables in the IR
whenever a static const data member is used.
Bug: https://bugs.llvm.org/show_bug.cgi?id=47580
Differential Revision: https://reviews.llvm.org/D89072
This patch enables emitting DWARF `DW_OP_implicit_value` opcode when
tuning debug information for LLDB (`-debugger-tune=lldb`).
This will also propagate to Darwin platforms, since they use LLDB tuning
as a default.
rdar://67406059
Differential Revision: https://reviews.llvm.org/D90001
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Deciding where to place debugging instructions when normal instructions
sink between blocks is difficult -- see PR44117. Dealing with this with
instruction-referencing variable locations is simple: we just tolerate
DBG_INSTR_REFs referring to values that haven't been computed yet. This
patch adds support into InstrRefBasedLDV to record when a variable value
appears in the middle of a block, and should have a DBG_VALUE added when it
appears (a debug use before def).
While described simply, this relies heavily on the value-propagation
algorithm in InstrRefBasedLDV. The implementation doesn't attempt to verify
the location of a value unless something non-trivial occurs to merge
variable values in vlocJoin. This means that a variable with a value that
has no location can retain it across all control flow (including loops).
It's only when another debug instruction specifies a different variable
value that we have to check, and find there's no location.
This property means that if a machine value is defined in a block dominated
by a DBG_INSTR_REF that refers to it, all the successor blocks can
automatically find a location for that value (if it's not clobbered). Thus
in a sense, InstrRefBasedLDV is already supporting and implementing
use-before-defs. This patch allows us to specify a variable location in the
block where it's defined.
When loading live-in variable locations, TransferTracker currently discards
those where it can't find a location for the variable value. However, we
can tell from the machine value number whether the value is defined in this
block. If it is, add it to a set of use-before-def records. Then, once the
relevant instruction has been processed, emit a DBG_VALUE immediately after
it.
Differential Revision: https://reviews.llvm.org/D85775
Handle DBG_INSTR_REF instructions in LiveDebugValues, to determine and
propagate variable locations. The logic is fairly straight forwards:
Collect a map of debug-instruction-number to the machine value numbers
generated in the first walk through the function. When building the
variable value transfer function and we see a DBG_INSTR_REF, look up the
instruction it refers to, and pick the machine value number it generates,
That's it; the rest of LiveDebugValues continues as normal.
Awkwardly, there are two kinds of instruction numbering happening here: the
offset into the block (which is how machine value numbers are determined),
and the numbers that we label instructions with when generating
DBG_INSTR_REFs.
I've also restructured the TransferTracker redefVar code a little, to
separate some DBG_VALUE specific operations into its own method. The
changes around redefVar should be largely NFC, while allowing
DBG_INSTR_REFs to specify a value number rather than just a location.
Differential Revision: https://reviews.llvm.org/D85771
This patch copies @vsk's fix to instcombine from D85555 over to mem2reg. The
motivation and rationale are exactly the same: When mem2reg removes an alloca,
it erases the dbg.{addr,declare} instructions which refer to the alloca. It
would be better to instead remove all debug intrinsics which describe the
contents of the dead alloca, namely all dbg.value(<dead alloca>, ...,
DW_OP_deref)'s.
As far as I can tell, prior to D80264 these `dbg.value+deref`s would have been
silently dropped instead of being made `undef`, so we're just returning to
previous behaviour with these patches.
Testing:
`llvm-lit llvm/test` and `ninja check-clang` gave no unexpected failures. Added
3 tests, each of which covers a dbg.value deletion path in mem2reg:
mem2reg-promote-alloca-1.ll
mem2reg-promote-alloca-2.ll
mem2reg-promote-alloca-3.ll
The first is based on the dexter test inlining.c from D89543. This patch also
improves the debugging experience for loop.c from D89543, which suffers
similarly after arg promotion instead of inlining.
When switching the register debug operands to $noreg in
setupDebugValueUndef() also clear the sub-register indices for virtual
registers. This is done when marking DBG_VALUEs undef in other cases,
e.g. in LiveDebugVariables. I have not found any cases where leaving the
sub-register index causes any issues, and the indices would eventually
get dropped when LiveDebugVariables reinserted the undef DBG_VALUEs
after register scheduling, but if nothing else it looked a bit weird in
printouts to have sub-register indices on $noreg, and I don't think the
sub-register index holds any meaningful information at that point.
I have not been able to find any source-level reproducer for this with
an upstream target, so I have just added an instrumented machine-sink
test.
Reviewed By: djtodoro, jmorse
Differential Revision: https://reviews.llvm.org/D89941
Testing reveals that lldb and gdb have some problems with supporting
DW_OP_convert - gdb with Split DWARF tries to resolve the CU-relative
DIE offset relative to the skeleton DIE. lldb tries to treat the offset
as absolute, which judging by the llvm-dsymutil support for
DW_OP_convert, I guess works OK in MachO? (though probably llvm-dsymutil
is producing invalid DWARF by resolving the relative reference to an
absolute one?).
Specifically this disables DW_OP_convert usage in DWARFv5 if:
* Tuning for GDB and using Split DWARF
* Tuning for LLDB and not targeting MachO
Both FastRegAlloc and LiveDebugVariables/greedy need to cope with
DBG_INSTR_REFs. None of them actually need to take any action, other than
passing DBG_INSTR_REFs through: variable location information doesn't refer
to any registers at this stage.
LiveDebugVariables stashes the instruction information in a tuple, then
re-creates it later. This is only necessary as the register allocator
doesn't expect to see any debug instructions while it's working. No
equivalence classes or interval splitting is required at all!
No changes are needed for the fast register allocator, as it just ignores
debug instructions. The test added checks that both of them preserve
DBG_INSTR_REFs.
This also expands ScheduleDAGInstrs.cpp to treat DBG_INSTR_REFs the same as
DBG_VALUEs when rescheduling instructions around. The current movement of
DBG_VALUEs around is less than ideal, but it's not a regression to make
DBG_INSTR_REFs subject to the same movement.
Differential Revision: https://reviews.llvm.org/D85757
The instruction referencing work currently only works on X86, and all the
tests for it will be X86 based for the time being. Configure the whole
directory to be X86-only, seeing how I keep on landing tests that don't
have the correct REQUIRES lines.
This patch touches two optimizations, TwoAddressInstruction and X86's
FixupLEAs pass, both of which optimize by re-creating instructions. For
LEAs, various bits of arithmetic are better represented as LEAs on X86,
while TwoAddressInstruction sometimes converts instrs into three address
instructions if it's profitable.
For debug instruction referencing, both of these require substitutions to
be created -- the old instruction number must be pointed to the new
instruction number, as illustrated in the added test. If this isn't done,
any variable locations based on the optimized instruction are
conservatively dropped.
Differential Revision: https://reviews.llvm.org/D85756
Seems users have enough different uses of the symbolizer where they
might have unknown binaries and offsets such that "best effort" behavior
is all that's expected of llvm-symbolizer - so even erroring on unknown
executables and out of bounds offsets might not be suitable.
This reverts commit 1de0199748.
This reverts commit a7b209a6d4.
This reverts commit 338dd138ea.
Create the LLVM / CodeView register mappings for the 32-bit ARM Window targets.
Reviewed By: compnerd
Differential Revision: https://reviews.llvm.org/D89622
LLVM rejects DWARF operator DW_OP_over. This DWARF operator is needed
for Flang to support assumed rank array.
Summary:
Currently LLVM rejects DWARF operator DW_OP_over. Below error is
produced when llvm finds this operator.
[..]
invalid expression
!DIExpression(151, 20, 16, 48, 30, 35, 80, 34, 6)
warning: ignoring invalid debug info in over.ll
[..]
There were some parts missing in support of this operator, which are
now completed.
Testing
-added a unit testcase
-check-debuginfo
-check-llvm
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D89208
Add a table recording "substitutions" between pairs of <instruction,
operand> numbers, from old pairs to new pairs. Post-isel optimizations are
able to record the outcome of an optimization in this way. For example, if
there were a divide instruction that generated the quotient and remainder,
and it were replaced by one that only generated the quotient:
$rax, $rcx = DIV-AND-REMAINDER $rdx, $rsi, debug-instr-num 1
DBG_INSTR_REF 1, 0
DBG_INSTR_REF 1, 1
Became:
$rax = DIV $rdx, $rsi, debug-instr-num 2
DBG_INSTR_REF 1, 0
DBG_INSTR_REF 1, 1
We could enter a substitution from <1, 0> to <2, 0>, and no substitution
for <1, 1> as it's no longer generated.
This approach means that if an instruction or value is deleted once we've
left SSA form, all variables that used the value implicitly become
"optimized out", something that isn't true of the current DBG_VALUE
approach.
Differential Revision: https://reviews.llvm.org/D85749
(this doesn't cover all cases - libDebugInfoDWARF has a default error
handler that prints errors without any exit code handling - I'll be
following up with a patch for that after this)
When given the -experimental-debug-variable-locations option (via -Xclang
or to llc), have SelectionDAG generate DBG_INSTR_REF instructions instead
of DBG_VALUE. For now, this only happens in a limited circumstance: when
the value referred to is not a PHI and is defined in the current block.
Other situations introduce interesting problems, addresed in later patches.
Practically, this patch hooks into InstrEmitter and if it can find a
defining instruction for a value, gives it an instruction number, and
points the DBG_INSTR_REF at that <instr, operand> pair.
Differential Revision: https://reviews.llvm.org/D85747
This patch defines the MIR format for debug instruction references: it's an
integer trailing an instruction, marked out by "debug-instr-number", much
like how "debug-location" identifies the DebugLoc metadata of an
instruction. The instruction number is stored directly in a MachineInstr.
Actually referring to an instruction comes in a later patch, but is done
using one of these instruction numbers.
I've added a round-trip test and two verifier checks: that we don't label
meta-instructions as generating values, and that there are no duplicates.
Differential Revision: https://reviews.llvm.org/D85746
This patch adds support for DWARF attribute DW_AT_rank.
Summary:
Fortran assumed rank arrays have dynamic rank. DWARF attribute
DW_AT_rank is needed to support that.
Testing:
unit test cases added (hand-written)
check llvm
check debug-info
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D89141
Use SCEV to salvage additional @llvm.dbg.value that have turned into
referencing undef after transformation (and traditional
salvageDebugInfo). Before transformation compute SCEV for each
@llvm.dbg.value in the loop body and store it (along side its current
DIExpression). After transformation update those @llvm.dbg.value now
referencing undef by comparing its stored SCEV to the SCEV of the
current loop-header PHI-nodes. Allow match with offset by inserting
compensation code in the DIExpression.
Includes fix for the nullptr deref that caused the original commit
to be reverted in 9d63029770.
Fixes : PR38815
Differential Revision: https://reviews.llvm.org/D87494
And another step towards transformss not introducing inttoptr and/or
ptrtoint casts that weren't there already.
In this case, when load/store uses have conflicting types,
instead of falling back to the iN, we can try to use allocated sub-type.
As disscussed, this isn't the best idea overall (we shouldn't rely on
allocated type), but it works fine as a temporary measure.
I've measured, and @ `-O3` as of vanilla llvm test-suite + RawSpeed,
this results in +0.05% more bitcasts, -5.51% less inttoptr
and -1.05% less ptrtoint (at the end of middle-end opt pipeline)
See https://bugs.llvm.org/show_bug.cgi?id=47592
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D88788
Register context information was already being passed into the DWARFDebugFrame code that dumps unwind information but it wasn't being used. This change adds the ability to dump registers names of a valid MC register context was passed in and if it knows about the register. Updated the tests to use the newly returned register names.
Differential Revision: https://reviews.llvm.org/D88767
This reverts commit a3caf7f610.
The ReleaseLTO-g test-suite configuration has been failing
to build since this commit, because clang segfaults while
building 7zip.
Use SCEV to salvage additional @llvm.dbg.value that have turned into
referencing undef after transformation (and traditional
salvageDebugInfo). Before transformation compute SCEV for each
@llvm.dbg.value in the loop body and store it (along side its current
DIExpression). After transformation update those @llvm.dbg.value now
referencing undef by comparing its stored SCEV to the SCEV of the
current loop-header PHI-nodes. Allow match with offset by inserting
compensation code in the DIExpression.
Fixes : PR38815
Differential Revision: https://reviews.llvm.org/D87494
It's not possible to do this in complete generality - a CU using a
sec_offset DW_AT_ranges has no way of knowing where its rnglists
contribution starts, so should not attempt to parse any full rnglist
table/header to do so. And even using FORM_rnglistx there's no need to
parse the header - the offset can be computed using the CU's DWARF
format (32 or 64) to compute offset entry sizes, and then the list
parsed at that offset without ever trying to find a rnglist contribution
header immediately prior to the rnglists_base.
This allows LiveDebugValues to insert the proper DBG_VALUEs in live
out blocks if a spill is inserted before the use of a
register. Previously, this would see the register use as the last
DBG_VALUE, even though the stack slot should be treated as the live
out value.
This avoids an lldb test regression when D52010 is re-applied.
attachments. They would crash the backend, which expects all
DISubprograms that are not part of the type system to have a unit field.
Clang right before https://reviews.llvm.org/D79967 would generate this
kind of broken IR.
rdar://problem/69534688
Thanks to Fangrui for fixing an assembler test I had missed!
https://reviews.llvm.org/D88270
attachments. They would crash the backend, which expects all
DISubprograms that are not part of the type system to have a unit field.
Clang right before https://reviews.llvm.org/D79967 would generate this
kind of broken IR.
rdar://problem/69534688
Introduce a helper which can be used to update the debug location of an
Instruction after the instruction is hoisted. This can be used to safely
drop a source location as recommended by the docs.
For more context, see the discussion in https://reviews.llvm.org/D60913.
Differential Revision: https://reviews.llvm.org/D85670
Until then, this one line fix removes the assert fail with basic block sections
with debug info. Bug tracking this: #47549
This fix does not generate loc list or DW_AT_const_value if the argument is
mentioned in a different section than the start of the function.
Temporarily fixes bugzilla : https://bugs.llvm.org/show_bug.cgi?id=47549
Differential Revision: https://reviews.llvm.org/D87787
Flag DIEs that have DW_CHILDREN_yes set in their abbreviation but don't
actually have any children.
rdar://59809554
Differential revision: https://reviews.llvm.org/D88048
If we are going to write handler data (that is written as variable
length data following after the unwind info in .xdata), we need to
emit the handler data immediately, but for cases where no such
info is going to be written, skip emitting it right away. (Unwind
info for all remaining functions that hasn't gotten it emitted
directly is emitted at the end.)
This does slightly change the ordering of sections (triggering a
bunch of updates to DebugInfo/COFF tests), but the change should be
benign.
This also matches GCC's assembly output, which doesn't output
.seh_handlerdata unless it actually is needed.
For ARM64, the unwind info can be packed into the runtime function
entry itself (leaving no data in the .xdata section at all), but
that can only be done if there's no follow-on data in the .xdata
section. If emission of the unwind info is triggered via
EmitWinEHHandlerData (or the .seh_handlerdata directive), which
implicitly switches to the .xdata section, there's a chance of the
caller wanting to pass further data there, so the packed format
can't be used in that case.
Differential Revision: https://reviews.llvm.org/D87448
This rewrites big parts of the fast register allocator. The basic
strategy of doing block-local allocation hasn't changed but I tweaked
several details:
Track register state on register units instead of physical
registers. This simplifies and speeds up handling of register aliases.
Process basic blocks in reverse order: Definitions are known to end
register livetimes when walking backwards (contrary when walking
forward then uses may or may not be a kill so we need heuristics).
Check register mask operands (calls) instead of conservatively
assuming everything is clobbered. Enhance heuristics to detect
killing uses: In case of a small number of defs/uses check if they are
all in the same basic block and if so the last one is a killing use.
Enhance heuristic for copy-coalescing through hinting: We check the
first k defs of a register for COPYs rather than relying on there just
being a single definition. When testing this on the full llvm
test-suite including SPEC externals I measured:
average 5.1% reduction in code size for X86, 4.9% reduction in code on
aarch64. (ranging between 0% and 20% depending on the test) 0.5%
faster compiletime (some analysis suggests the pass is slightly slower
than before, but we more than make up for it because later passes are
faster with the reduced instruction count)
Also adds a few testcases that were broken without this patch, in
particular bug 47278.
Patch mostly by Matthias Braun
Initial support for dwarf fission sections (-gsplit-dwarf) on wasm.
The most interesting change is support for writing 2 files (.o and .dwo) in the
wasm object writer. My approach moves object-writing logic into its own function
and calls it twice, swapping out the endian::Writer (W) in between calls.
It also splits the import-preparation step into its own function (and skips it when writing a dwo).
Differential Revision: https://reviews.llvm.org/D85685
This is needed to support assumed size array of fortran which can have missing upperBound/count
, contrary to current DISubrange support.
Example:
subroutine sub (array1, array2)
integer :: array1 (*)
integer :: array2 (4:9, 10:*)
array1(7:8) = 9
array2(5, 10) = 10
end subroutine
Now the validation check is relaxed for fortran.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D87500
This seems to have caused incorrect register allocation in some cases,
breaking tests in the Zig standard library (PR47278).
As discussed on the bug, revert back to green for now.
> Record internal state based on register units. This is often more
> efficient as there are typically fewer register units to update
> compared to iterating over all the aliases of a register.
>
> Original patch by Matthias Braun, but I've been rebasing and fixing it
> for almost 2 years and fixed a few bugs causing intermediate failures
> to make this patch independent of the changes in
> https://reviews.llvm.org/D52010.
This reverts commit 66251f7e1d, and
follow-ups 931a68f26b
and 0671a4c508. It also adjust some
test expectations.
The patch fixes emitting flags and the debug_line_offset field in
the header, as well as the reference to the macro string for
a pre-standard GNU .debug_macro extension.
Differential Revision: https://reviews.llvm.org/D87024
The patch fixes emitting the unit length field in the header of
the table and offsets to the entry pool. Note that while the patch
changes the common method to emit offsets, in fact, nothing is changed
for Apple accelerator tables, because we do not yet support DWARF64 for
those targets.
Differential Revision: https://reviews.llvm.org/D87023
The patch fixes emitting the header of the table. The content is
independent of the DWARF format.
Differential Revision: https://reviews.llvm.org/D87022
The transition is done by using methods of AsmPrinter which
automatically emit values in compliance with the selected DWARF format.
Differential Revision: https://reviews.llvm.org/D87013
The patch fixes calculating the size of the table and emitting
the fields which depend on the DWARF format by using methods that
choose appropriate sizes automatically.
Differential Revision: https://reviews.llvm.org/D87012
The patch fixes emitting the offset to the type DIE. All other fields
are already fixed in previous patches.
Differential Revision: https://reviews.llvm.org/D87021
These two fixes are better to go together because llvm-dwarfdump is
unable to dump a table when another one is malformed.
Differential Revision: https://reviews.llvm.org/D87018
The patch uses a common method to determine the appropriate form for
the value of the attribute.
Differential Revision: https://reviews.llvm.org/D87016
The patch also adds a method to choose an appropriate DWARF form
to represent section offsets according to the version and the format
of producing debug info.
Differential Revision: https://reviews.llvm.org/D87014
The patch adds a switch to enable emitting debug info in the 64-bit
DWARF format. Most emitter for sections will be updated in the subsequent
patches, whereas for .debug_line and .debug_frame the emitters are in
the MC library, which is already updated.
For now, the switch is enabled only for 64-bit ELF targets.
Differential Revision: https://reviews.llvm.org/D87011
This was landed but reverted in 5b9c2b1bea due to asan picking up a memory
leak. This is fixed in the change to InstrRefBasedImpl.cpp. Original
commit message follows:
[LiveDebugValues][NFC] Add instr-ref tests, adapt old tests
This patch adds a few tests in DebugInfo/MIR/InstrRef/ of interesting
behaviour that the instruction referencing implementation of
LiveDebugValues has. Mostly, these tests exist to ensure that if you
give the "-experimental-debug-variable-locations" command line switch,
the right implementation runs; and to ensure it behaves the same way as
the VarLoc LiveDebugValues implementation.
I've also touched roughly 30 other tests, purely to make the tests less
rigid about what output to accept. DBG_VALUE instructions are usually
printed with a trailing !debug-location indicating its scope:
!debug-location !1234
However InstrRefBasedLDV produces new DebugLoc instances on the fly,
meaning there sometimes isn't a numbered node when they're printed,
making the output:
!debug-location !DILocation(line: 0, blah blah)
Which causes a ton of these tests to fail. This patch removes checks for
that final part of each DBG_VALUE instruction. None of them appear to
be actually checking the scope is correct, just that it's present, so
I don't believe there's any loss in coverage here.
Differential Revision: https://reviews.llvm.org/D83054
As discussed in D86843, -earlycse-debug-hash should be used in more regression
tests to catch inconsistency between the hashing and the equivalence check.
Differential Revision: https://reviews.llvm.org/D86863
As stated in section 6.1.1.2, DWARFv5, p. 142,
| The last entry for each name is followed by a zero byte that
| terminates the list. There may be gaps between the lists.
The patch changes emitting a 4-byte zero value to a 1-byte one, which
effectively removes the gap between entry lists, and thus saves
approximately 3 bytes per name; the calculation is not exact because
the total size of the table is aligned to 4.
Differential Revision: https://reviews.llvm.org/D86927
This reverts commit b9d977b0ca.
This cutoff is no longer required. The commit 34ffa7fc501 (D86153) introduces a
performance improvement which was tested against the motivating case for this
patch.
Discussed in differential revision: https://reviews.llvm.org/D86153
Almost NFC (see end).
The backwards scan in validThroughout significantly contributed to compile time
for a pathological case, causing the 'X86 Assembly Printer' pass to account for
roughly 70% of the run time. This patch guards the loop against running
unnecessarily, bringing the pass contribution down to 4%.
Almost NFC: There is a hack in validThroughout which promotes single constant
value DBG_VALUEs in the prologue to be live throughout the function. We're more
likely to hit this code path with this patch applied. Similarly to the parent
patches there is a small coverage change reported in the order of 10s of bytes.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D86153
With the changes introduced in D86151 we can now check for single locations
which span multiple blocks for inlined scopes and blocks.
D86151 introduced the InstructionOrdering parameter, replacing a scan through
MBB instructions. The functionality to compare instruction positions across
blocks was add there, and this patch just removes the exit checks that were
previously (but no longer) required.
CTMark shows a geomean binary size reduction of 2.2% for RelWithDebInfo builds.
llvm-locstats (using D85636) shows a very small variable location coverage
change in 5 of 10 binaries, but just like in D86151 it is only in the order of
10s of bytes.
Reviewed By: djtodoro
Differential Revision: https://reviews.llvm.org/D86152
With this patch we're now accounting for two more cases which should be
considered 'valid throughout': First, where RangeEnd is ScopeEnd. Second, where
RangeEnd comes before ScopeEnd when including meta instructions, but are both
preceded by the same non-meta instruction.
CTMark shows a geomean binary size reduction of 1.5% for RelWithDebInfo builds.
`llvm-locstats` (using D85636) shows a very small variable location coverage
change in 2 of 10 binaries, but it is in the order of 10s of bytes which lines
up with my expectations.
I've added a test which checks both of these new cases. The first check in the
test isn't strictly necessary for this patch. But I'm not sure that it is
explicitly tested anywhere else, and is useful for the final patch in the
series.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D86151
This patch adds type information for SVE ACLE vector types,
by describing them as vectors, with a lower bound of 0, and
an upper bound described by a DWARF expression using the
AArch64 Vector Granule register (VG), which contains the
runtime multiple of 64bit granules in an SVE vector.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D86101
Fix the ARM backend's analyzeBranch so it doesn't ignore predicated
return instructions, and make the MachineVerifier rule more strict.
Differential Revision: https://reviews.llvm.org/D40061
This patch adds a few tests in DebugInfo/MIR/InstrRef/ of interesting
behaviour that the instruction referencing implementation of
LiveDebugValues has. Mostly, these tests exist to ensure that if you
give the "-experimental-debug-variable-locations" command line switch,
the right implementation runs; and to ensure it behaves the same way as
the VarLoc LiveDebugValues implementation.
I've also touched roughly 30 other tests, purely to make the tests less
rigid about what output to accept. DBG_VALUE instructions are usually
printed with a trailing !debug-location indicating its scope:
!debug-location !1234
However InstrRefBasedLDV produces new DebugLoc instances on the fly,
meaning there sometimes isn't a numbered node when they're printed,
making the output:
!debug-location !DILocation(line: 0, blah blah)
Which causes a ton of these tests to fail. This patch removes checks for
that final part of each DBG_VALUE instruction. None of them appear to
be actually checking the scope is correct, just that it's present, so
I don't believe there's any loss in coverage here.
Differential Revision: https://reviews.llvm.org/D83054
llc doesn't seem to automatically pick default `--triple`.
using `%llc_dwarf` should fix this.
Builder:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-quick/builds/20310
Error log:
bin/llc: error: : error: unable to get target for 'x86_64-unknown-linux-gnu', see --version and --triple.
This patch adds support for representing Fortran `character(n)`.
Primarily patch is based out of D54114 with appropriate modifications.
Test case IR is generated using our downstream classic-flang. We're in process
of upstreaming flang PR's but classic-flang has dependencies on llvm, so
this has to get in first.
Patch includes functional test case for both IR and corresponding
dwarf, furthermore it has been manually tested as well using GDB.
Source snippet:
```
program assumedLength
call sub('Hello')
call sub('Goodbye')
contains
subroutine sub(string)
implicit none
character(len=*), intent(in) :: string
print *, string
end subroutine sub
end program assumedLength
```
GDB:
```
(gdb) ptype string
type = character (5)
(gdb) p string
$1 = 'Hello'
```
Reviewed By: aprantl, schweitz
Differential Revision: https://reviews.llvm.org/D86305
This patch was reverted in 7c182663a8 due to some failures
observed on PCC based machines. Failures were due to Endianness issue and
long double representation issues.
Patch is revised to address Endianness issue. Furthermore, support
for emission of `DW_OP_implicit_value` for `long double` has been removed
(since it was unclean at the moment). Planning to handle this in
a clean way soon!
For more context, please refer to following review link.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D83560
llvm is missing support for DW_OP_implicit_value operation.
DW_OP_implicit_value op is indispensable for cases such as
optimized out long double variables.
For intro refer: DWARFv5 Spec Pg: 40 2.6.1.1.4 Implicit Location Descriptions
Consider the following example:
```
int main() {
long double ld = 3.14;
printf("dummy\n");
ld *= ld;
return 0;
}
```
when compiled with tunk `clang` as
`clang test.c -g -O1` produces following location description
of variable `ld`:
```
DW_AT_location (0x00000000:
[0x0000000000201691, 0x000000000020169b): DW_OP_constu 0xc8f5c28f5c28f800, DW_OP_stack_value, DW_OP_piece 0x8, DW_OP_constu 0x4000, DW_OP_stack_value, DW_OP_bit_piece 0x10 0x40, DW_OP_stack_value)
DW_AT_name ("ld")
```
Here one may notice that this representation is incorrect(DWARF4
stack could only hold integers(and only up to the size of address)).
Here the variable size itself is `128` bit.
GDB and LLDB confirms this:
```
(gdb) p ld
$1 = <invalid float value>
(lldb) frame variable ld
(long double) ld = <extracting data from value failed>
```
GCC represents/uses DW_OP_implicit_value in these sort of situations.
Based on the discussion with Jakub Jelinek regarding GCC's motivation
for using this, I concluded that DW_OP_implicit_value is most appropriate
in this case.
Link: https://gcc.gnu.org/pipermail/gcc/2020-July/233057.html
GDB seems happy after this patch:(LLDB doesn't have support
for DW_OP_implicit_value)
```
(gdb) p ld
p ld
$1 = 3.14000000000000012434
```
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D83560
Theory was that we should never reach a non-type unit (eg: type in an
anonymous namespace) when we're already in the invalid "encountered an
address-use, so stop emitting types for now, until we throw out the
whole type tree to restart emitting in non-type unit" state. But that's
not the case (prior commit cleaned up one reason this wasn't exposed
sooner - but also makes it easier to test/demonstrate this issue)
This reads more like what you'd expect the DWARF to look like (from the
lexical order of C++ - template parameters come before members, etc),
and also happens to make it easier to tickle (& thus test) a bug related
to type units and Split DWARF I'm about to fix.
Amy Huang