Commit Graph

361212 Commits

Author SHA1 Message Date
Fangrui Song 4e80c768c2 [ELF] Support -r --gc-sections
-r --gc-sections is usually not useful because it just makes intermediate output
smaller. https://bugs.llvm.org/show_bug.cgi?id=46700#c7 mentions a use case:
validating the absence of undefined symbols ealier than in the final link.

After D84129 (SHT_GROUP support in -r links), we can support -r
--gc-sections without extra code. So let's allow it.

Reviewed By: grimar, jhenderson

Differential Revision: https://reviews.llvm.org/D84131
2020-07-23 08:16:01 -07:00
LLVM GN Syncbot 23d1800433 [gn build] Port 92874d2866 2020-07-23 15:07:01 +00:00
Evgeny Leviant dc619f3d7a [CodeGen][TargetPassConfig] Add unreachable-mbb-elimination pass explicitly
Differential revision: https://reviews.llvm.org/D84228
2020-07-23 18:05:11 +03:00
Braedy Kuzma 24e41a34fe [Matrix] Add asserts for mismatched element types.
This patch clarifies the failing point of having input or output vectors
of differing types. Before, lowering would fail elsewhere (e.g. in
`fmul` creation) which may have been not immediately clear.

As a side effect, the `getElementType` and `getVectoryTy` functions
required the `const` qualifier to be added.

Reviewers: fhahn

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D84374
2020-07-23 16:02:48 +01:00
Sebastian Neubauer 896679733d [AMDGPU] Fix typo. NFC 2020-07-23 17:01:12 +02:00
Xing GUO 92874d2866 [DWARFYAML] Refactor emitDebugInfo() to make the length be inferred.
This patch refactors `emitDebugInfo()` to make the length field be
inferred from its content. Besides, the `Visitor` class is removed in
this patch. The original `Visitor` class helps us determine an
appropriate length and emit the .debug_info section. These two
processes can be merged into one process. Besides, the length field
should be inferred when it's missing rather than when it's zero.

Reviewed By: jhenderson, labath

Differential Revision: https://reviews.llvm.org/D84008
2020-07-23 23:00:19 +08:00
Xing GUO a997e6edb9 [DWARFYAML] Pull out common helper functions for rnglist and loclist tables. NFC.
This patch helps pull out some common helper functions for range list
and location list tables. NFC.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D84383
2020-07-23 22:57:30 +08:00
Kazuaki Ishizaki 06b90586a4 [mlir]: NFC: Fix trivial typo in documents and comments
Differential Revision: https://reviews.llvm.org/D84400
2020-07-23 23:40:57 +09:00
Simon Pilgrim d720ba1e4b [X86][SSE] SimplifyDemandedVectorEltsForTargetNode - add SSE shift multiple use handling
Add SimplifyMultipleUseDemandedVectorElts peek through for imm/var SSE shifts
2020-07-23 14:39:03 +01:00
Ulrich Weigand 68a80a4436 [SystemZ] Ensure -mno-vx disables any use of vector features
When passing the -vector feature to LLVM (or equivalently the
-mno-vx command line argument to clang), the intent is that
generated code must not use any vector features (in particular,
no vector registers must be used).

However, there are some cases where we still could generate
such uses; these are all related to some of the additional
vector features (like +vector-enhancements-1).  Since none
of those features are actually usable with -vector, just make
sure we disable them all if -vector is given.
2020-07-23 15:34:59 +02:00
Florian Hahn ecd3f853a8 [SCEVExpander] Use IRBuilderCallbackInserter to call rememberInstruction.
Currently there are plenty of instructions that SCEVExpander creates but
does not track as created. IRBuilder allows specifying a callback
whenever an instruction is inserted. Use this to call
rememberInstruction automatically for each created instruction.

There are still a few rememberInstruction calls remaining, because in
some cases Inst::Create functions are used to construct instructions.

Suggested by @lebedev.ri in D75980.

Reviewers: mkazantsev, reames, sanjoy.google, lebedev.ri

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D84326
2020-07-23 14:25:28 +01:00
Russell Gallop c798628fbd [docs] Fix TestSuiteGuide.md to mention scipy
This has been required since https://reviews.llvm.org/D57828.

Differential Revision: https://reviews.llvm.org/D82379
2020-07-23 14:21:59 +01:00
Mikhail Maltsev 2b89c34784 [libcxx] Adjust trivial_abi tests for C++03 and C++11 testing
This change replaces std::make_unique with manual construction of
std::unique_ptr to make the tests compatible with C++11
(std::make_unique is a C++14 feature).

libc++ supports std::unique_ptr and std::shared_ptr even in C++03 but
with some limitations: unique_ptr_array.pass.cpp and
shared_ptr_arg.pass.cpp fail to compile in C++03 mode and need to be
disabled.

Differential Revision: https://reviews.llvm.org/D84394
2020-07-23 14:20:49 +01:00
Jay Foad b35833b84e [GlobalISel][AMDGPU] Legalize saturating add/subtract
Add support in LegalizerHelper for lowering G_SADDSAT etc. either
using add/subtract-with-overflow or using max/min instructions.

Enable this lowering for AMDGPU so it can be tested. The legalization
rules are still approximate and skips out on using the clamp bit to
treat these as legal, which has never been used before. This also
doesn't yet try to deal with expanding SALU cases.
2020-07-23 09:06:42 -04:00
Florian Hahn 82e35197e6 [LSR] Re-generate check lines for test.
The test is quite frafile, as the check lines match IR numbers and it is
not obvious why only a very small subset is checked.

Re-generate check lines, so further changes are more obvious.
2020-07-23 13:53:53 +01:00
Florian Hahn 09c96a31ef [LoopIdiom] Add additional test cases. 2020-07-23 13:53:26 +01:00
Erich Keane 7bf9e22049 Update make_cxx_dr_status and cxx_dr_status.html for the new release.
Our latest release is now 11, so update the make_cxx_dr_status and
regenerate the cxx_dr_status.html document.
2020-07-23 05:50:10 -07:00
Sanjay Patel 7485e92412 [InstSimplify] reduce code duplication for binop expansion; NFC
D84250 proposes to extend this code, so the duplication for
the commuted case would continue to grow.
2020-07-23 08:35:21 -04:00
Simon Pilgrim 1003113ef0 Fix -Wparentheses warning - add missing brackets around the entire assertion condition 2020-07-23 13:33:24 +01:00
Pavel Labath 9cdd68e7c1 Recommit "[lldb/API] Overwrite variables with SBLaunchInfo::SetEnvironment(append=true)"
The patch was reverted 27d52cd86a because of failures in
TestWeakSymbols.py. These have now been addressed in D83552.

The original commit message was:
This function was documented to overwrite entries with D76111, which was
adding a couple of similar functions. However, this function (unlike the
functions added in that patch) was/is not actually overwriting variables
-- any pre-existing variables would get ignored.

This behavior does not seem to be intentional. In fact, before the refactor in
D41359, this function could introduce duplicate entries, which could
have very surprising effects both inside lldb and on other applications
(some applications would take the first value, some the second one; in
lldb, attempting to unset a variable could make the second variable
become active, etc.).

Overwriting seems to be the most reasonable behavior here, so change the
code to match documentation.

Differential Revision: https://reviews.llvm.org/D83306
2020-07-23 14:17:57 +02:00
Shinji Okumura 697c6d8907 [Attributor] Cache query results for isPotentiallyReachable in AAReachability
Summary:
This is the next patch of [[ https://reviews.llvm.org/D76210 | D76210 ]].
This patch made a map in `InformationCache` for caching results.

Reviewers: jdoerfert, sstefan1, uenoku, homerdin, baziotis

Reviewed By: jdoerfert

Subscribers: hiraditya, uenoku, kuter, bbn, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83246
2020-07-23 20:49:28 +09:00
Konstantin Schwarz 931488779f [GlobalISel][InlineAsm] Add register class ID to the flags of register input operands
Summary: We do this already for output operands, but missed it for (non-tied) input operands.

Reviewers: arsenm, Petar.Avramovic

Reviewed By: arsenm

Subscribers: jvesely, wdng, nhaehnle, rovka, hiraditya, llvm-commits, kerbowa

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83763
2020-07-23 13:35:01 +02:00
Simon Pilgrim 18b453390c Fix implicit dependency on CommandLine.h 2020-07-23 12:33:14 +01:00
Simon Pilgrim 5b20c14525 ValueProfileCollector.h - remove unnecessary includes. NFC. 2020-07-23 12:33:13 +01:00
Med Ismail Bennani e605994bb3 [lldb/test] Fix TestHistoryRecall failure (NFC)
This patch fixes a test failure in TestHistoryRecall caused by the move
of the `history` subcommand to the `session` command.

This change was introduced by commit 85fbb08fa2.

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-07-23 13:27:12 +02:00
Simon Pilgrim 910506fdde Fix implicit dependency on CommandLine.h 2020-07-23 12:15:17 +01:00
Med Ismail Bennani 85fbb08fa2 [lldb/interpreter] Move the history subcommand to session (NFCI)
This patch moves the `history` subcommand from the `command` to `session`
command. I think it makes more sense to have it there because as the `command`
usage suggests, it should be used to manage custom LLDB commands.

However, `history` is essentially tied to a debugging session and holds
all the commands (not specifically custom ones).

This also makes it more discoverable by adding an alias for it (mimicking
the shell builtin).

Differential Revision: https://reviews.llvm.org/D84307

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-07-23 13:05:45 +02:00
Simon Pilgrim f758d72eb8 Speculation.h - remove unnecessary includes. NFC. 2020-07-23 11:58:23 +01:00
Florian Hahn 6c9da995fc [ScheduleDAGRRList] Pacify overload mismatch in std::min.
On systems where size() doesn't return unsigned long, this leads to an
overloading mismatch. Convert the constant to whatever type is used for
Q.size() on the system.
2020-07-23 11:56:50 +01:00
Florian Hahn 2f8e6b5f3c [ScheduleDAGRRList] Limit number of candidates to explore.
Currently popFromQueueImpl iterates over all candidates to find the best
one. While the candidate queue is small, this is not a problem. But it
becomes a problem once the queue gets larger. For example, the snippet
below takes 330s to compile with llc -O0, but completes in 3s with this
patch.

define void @test(i4000000* %ptr) {
entry:
  store i4000000 0, i4000000* %ptr, align 4
  ret void
}

This patch limits the number of candidates to check to 1000. This limit
ensures that it never triggers for test-suite/SPEC2000/SPEC2006 on X86
and AArch64 with -O3, while still drastically limiting the compile-time
in case of very large queues.

It would be even better to use a binary heap to manage to queue
(D83335), but some heuristics change the score of a node in the queue
after another node has been scheduled. I plan to address this for
backends that use the MachineScheduler in the future, but that requires
a more careful evaluation. In the meantime, the limit should help users
impacted by this issue.

The patch includes a slightly smaller version of the motivating example
as test case, to guard against the issue.

Reviewers: efriedma, paquette, niravd

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D84328
2020-07-23 11:35:33 +01:00
Jakub Lichman 20c3386f4a [mlir][Linalg] emitLoopRanges and emitLoopRangesWithSymbols merged into one
Right now there is a branching for 2 functions based on whether target map has
symbols or not. In this commit these functions are merged into one.
Furthermore, emitting does not require inverse and map applying as it computes
the correct Range in a single step and thus reduces unnecessary overhead.

Differential Revision: https://reviews.llvm.org/D83756
2020-07-23 12:33:46 +02:00
Jakub Lichman 919922b0c2 [mlir] Added verification check for linalg.conv to ensure memrefs are of rank > 2
linalg.conv does not support memrefs with rank smaller than 3 as stated here:
https://www.tensorflow.org/versions/r2.0/api_docs/python/tf/nn/convolution

However it does not verify it and thus crashes with "LLVM ERROR: out of memory"
error for 1D case and "nWin > 0 && "expected at least one window dimension"" assertion
for 2D case. This commit adds check for that in the verification method.

Differential Revision: https://reviews.llvm.org/D84317
2020-07-23 12:27:05 +02:00
Alex Richardson 722e5d6aae [lit] Include total elapsed time in xunit output
The time= attribute can also be used for the testsuites tag. While this
attribute appears to be ignored by Jenkins (bab34bcc96/src/main/java/hudson/tasks/junit/SuiteResult.java (L202)),
it is still useful if you manually inspect the xml file.

Reviewed By: yln

Differential Revision: https://reviews.llvm.org/D84230
2020-07-23 11:19:18 +01:00
Alex Richardson 9020d28688 [libcxx][lit] Fix incorrect lambda capture in hasLocale checks
The lambda being used to check whether locales are supported was always
passing the value of alts from the last loop iteration due to the way that
python lambda captures work. Fix this by using a default argument capture.

To help debug future similar issues I also added a prefix to the config
test binary indicating which locale is being tested.
I originally found this issue when implementing a new executor that simply
collects test binaries in a given directory and was surprised to see many
additional executables other than the expected test binaries. I therefore
added the locale prefix to the test binaries and noticed that they were all
checking for cs_CZ.ISO8859-2.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D84040
2020-07-23 11:19:18 +01:00
Georgii Rymar 1162ffe8f4 [llvm-readelf] - Simplify the implementation of getSectionTypeString() helper. NFCI.
It is used for printing section headers in the GNU style
and the implementation can be simplified.

Differential revision: https://reviews.llvm.org/D84330
2020-07-23 13:04:42 +03:00
Balázs Kéri 65fd651980 [Analyzer][StreamChecker] Use BugType::SuppressOnSink at resource leak report.
Summary:
Use the built-in functionality BugType::SuppressOnSink
instead of a manual solution in StreamChecker.

Differential Revision: https://reviews.llvm.org/D83120
2020-07-23 11:53:25 +02:00
Sourabh Singh Tomar 8998f8ab66 [DebugInfo] Attempt to fix regression test failure after 59a76d957a
Test case `test/CodeGen/WebAssembly/stackified-debug.ll`
was failing due to malformed DwarfExpression.

This failure has been seen in lot of bots, for instance in:
http://lab.llvm.org:8011/builders/lld-x86_64-ubuntu-fast/builds/18794

: 'RUN: at line 1'
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/build/bin/llc
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/build/bin/FileCheck /home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/test/CodeGen/WebAssembly/stackified-debug.ll
home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/test/CodeGen/WebAssembly/stackified-debug.ll:26:10: error: CHECK: expected string not found in input
 CHECK: .int16 4 # Loc expr size
         ^
<stdin>:34:2: note: scanning from here
 .int16 3 # Loc expr size

Differential Revision: https://reviews.llvm.org/D83560
2020-07-23 14:55:30 +05:30
Jakub Lichman e4dd964df0 [mlir] Loop bounds inference in linalg.generic op improved to support bounds for convolution
Loop bound inference is right now very limited as it supports only permutation maps and thus
it is impossible to implement convolution with linalg.generic as it requires more advanced
loop bound inference. This commits solves it for the convolution case.

Depends On D83158

Differential Revision: https://reviews.llvm.org/D83191
2020-07-23 11:01:54 +02:00
Sourabh Singh Tomar 59a76d957a Re-apply:" Emit DW_OP_implicit_value for Floating point constants"
This patch was reverted in 9d2da6759b due to assertion failure seen
in `test/DebugInfo/Sparc/subreg.ll`. Assertion failure was happening
due to malformed/unhandeled DwarfExpression.

Differential Revision: https://reviews.llvm.org/D83560
2020-07-23 13:56:20 +05:30
Roman Lebedev 469cb724ee
[Reduce] Rewrite runDeltaPass() workloop: do reduce a single and/or last target
Summary:
If there was a single target to begin with, because a single target
can only occupy a single chunk, we couldn't increase granularity.
and would immediately give up.

Likewise, if we had multiple targets, if by the end we'd end up with
a single target, we wouldn't finish reducing it, it would always
end up being "interesting"

Reviewers: dblaikie, nickdesaulniers, diegotf

Reviewed By: dblaikie

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D84318
2020-07-23 10:51:46 +03:00
Eric Christopher 3a75466f41 Temporarily Revert "Reland [lldb] Unify type name matching in FormattersContainer"
as it breaks bots with due to m_valid being an unused class member
except in assert builds.

This reverts commit 074b121642.
2020-07-23 00:47:05 -07:00
Rainer Orth 55c0f12a86 [compiler-rt][sanitizers] Fix Solaris madvise declaration
A last-minute silent change in  D84046 <https://reviews.llvm.org/D84046> broke the Solaris buildbots (Solaris/sparcv9 <http://lab.llvm.org:8014/builders/clang-solaris11-sparcv9/builds/6772>, Solaris/amd64 <http://lab.llvm.org:8014/builders/clang-solaris11-amd64/builds/5434>):

  [2/3679] Building CXX object projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.sparc.dir/sanitizer_posix_libcdep.cpp.o
  FAILED: projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.sparc.dir/sanitizer_posix_libcdep.cpp.o
  /opt/llvm-buildbot/bin/c++  -DHAVE_RPC_XDR_H=1 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iprojects/compiler-rt/lib/sanitizer_common -I/opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/compiler-rt/lib/sanitizer_common -Iinclude -I/opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/llvm/include -I/opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/llvm/include/llvm/Support/Solaris -I/opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/compiler-rt/lib/sanitizer_common/.. -fPIC -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -std=c++14 -Wno-unused-parameter -O3     -m32 -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fvisibility=hidden -fno-lto -O3 -g -Wno-variadic-macros -Wno-non-virtual-dtor -fno-rtti -Wframe-larger-than=570 -UNDEBUG -std=c++14 -MD -MT projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.sparc.dir/sanitizer_posix_libcdep.cpp.o -MF projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.sparc.dir/sanitizer_posix_libcdep.cpp.o.d -o projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.sparc.dir/sanitizer_posix_libcdep.cpp.o -c /opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp
  /opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp:50:16: error: conflicting declaration of C function ‘int madvise(caddr_t, std::size_t, int)’
   extern "C" int madvise(caddr_t, size_t, int);
                  ^~~~~~~
  In file included from /opt/llvm-buildbot/home/solaris11-sparcv9/clang-solaris11-sparcv9/llvm/compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp:32:0:
  /usr/include/sys/mman.h:232:12: note: previous declaration ‘int madvise(void*, std::size_t, int)’
   extern int madvise(void *, size_t, int);
              ^~~~~~~

This patch undoes that change.

Tested on `amd64-pc-solaris2.11` (Solaris 11.4 and OpenIndiana).

Differential Revision: https://reviews.llvm.org/D84388
2020-07-23 09:37:14 +02:00
aartbik 1485fd295b [mlir] [VectorOps] Improve scatter/gather CPU performance
Replaced the linearized address with the proper LLVM way of
defining vector of base + indices in SIMD style. This yields
much better code. Some prototype results with microbencmarking
sparse matrix x vector with 50% sparsity (about 2-3x faster):

         LINEARIZED     IMPROVED
GFLOPS  sdot  saxpy     sdot saxpy
16x16    1.6   1.4       4.4  2.1
32x32    1.7   1.6       5.8  5.9
64x64    1.7   1.7       6.4  6.4
128x128  1.7   1.7       5.9  5.9
256x256  1.6   1.6       6.1  6.0
512x512  1.4   1.4       4.9  4.7

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D84368
2020-07-22 23:47:36 -07:00
Serge Pavlov dab898f9ab [Windows] Fix limit on command line size
This reapplies commit d4020ef7c4, reverted in ac0edc5588 because it
broke build of LLDB. This commit contains appropriate changes for LLDB.
The original commit message is below.

Documentation on CreateProcessW states that maximal size of command line
is 32767 characters including ternimation null character. In the
function llvm::sys::commandLineFitsWithinSystemLimits this limit was set
to 32768. As a result if command line was exactly 32768 characters long,
a response file was not created and CreateProcessW was called with
too long command line.

Differential Revision: https://reviews.llvm.org/D83772
2020-07-23 11:39:42 +07:00
Hiroshi Yamauchi 557db6f8aa Reland D84057 [PGO][PGSO] Remove a temporary flag used for gradual rollout.
The revert was a misfire.

Remove the temporary flag PGSOIRPassOrTestOnly and the guard code which was used
for the staged rollout. This is a cleanup (NFC) as it's now false by default.

Differential Revision: https://reviews.llvm.org/D84057
2020-07-22 20:57:25 -07:00
Sourabh Singh Tomar 9d2da6759b Revert "[DebugInfo] Emit DW_OP_implicit_value for Floating point constants"
This reverts commit 6b55a95898.
Temporal revert due to a failing/assertion in test case in Sparc backend.
`test/DebugInfo/Sparc/subreg.ll`
Seen in lot of bots, for instance in:
`http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/24679`
2020-07-23 08:50:01 +05:30
Shilei Tian c0185dc7df Revert "[OpenMP] Wait for kernel prior to memory deallocation"
This reverts commit 9b2832c089.
2020-07-22 23:03:36 -04:00
Shilei Tian 9b2832c089 [OpenMP] Wait for kernel prior to memory deallocation
Summary:
In the function `target`, memory deallocation and `target_data_end` is called
immediately returning from launching kernel. This might cause a race condition
that the corresponding memory is still being used by the kernel and a potential
issue that when the kernel starts to execute, its required data have already
been deallocated, especially when multiple kernels running concurrently. Since
nevertheless, we will block the thread issuing the target offloading at the end
of the target, we just move the synchronization ahead a little bit to make sure
the correctness.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: yaxunl, guansong, sstefan1, openmp-commits

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D84381
2020-07-22 22:55:34 -04:00
Xing GUO c4cf250c5b [DWARFYAML] Refactor range list table to hold more data structure.
This patch refactors the range list table to hold both the range list
table and the location list table.

Reviewed By: jhenderson, labath

Differential Revision: https://reviews.llvm.org/D84239
2020-07-23 10:25:01 +08:00
Sourabh Singh Tomar 6b55a95898 [DebugInfo] Emit DW_OP_implicit_value for Floating point constants
Summary:
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
2020-07-23 07:21:49 +05:30