Commit Graph

330424 Commits

Author SHA1 Message Date
Simon Tatham ceeff95ca4 [ARM] Add some sample IR MVE intrinsics with C++ isel.
This adds some initial example IR intrinsics for MVE instructions that
deliver multiple output values, and hence, have to be instruction-
selected by custom C++ code instead of Tablegen patterns.

I've added the writeback gather load instructions (taking a vector of
base addresses and a single common offset, returning a vector of
loaded values and an updated vector of base addresses); one example
from the long shift family (taking and returning a 64-bit value in two
GPRs); and the VADC instruction (which propagates a carry bit from
each vector-lane addition to the next, taking an input carry flag in
FPSCR and outputting the final one in FPSCR as well).

To support the VPT-predicated forms of these instructions, I've
written some helper functions to add the cluster of MVE predicate
operands to the end of a MachineInstr. `AddMVEPredicateToOps` is used
when the instruction actually is predicated (so it takes a predicate
mask argument), and `AddEmptyMVEPredicateToOps` is for when the
instruction is unpredicated (so it fills in $noreg for the mask). Each
one comes in a form suitable for `vpred_n`, and one for `vpred_r`
which takes the extra 'inactive' parameter.

For VADC, the representation of the carry flag in the IR intrinsic is
a word intended to be moved directly to and from `FPSCR_nzcvqc`, i.e.
with the carry flag in bit 29 of the word. (The user-facing ACLE
intrinsic will want it to be in bit 0, but I'll do that on the clang
side.)

Reviewers: dmgreen, miyuki, ostannard

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68699
2019-10-24 16:33:13 +01:00
Simon Tatham 1b45297e01 [ARM] Begin adding IR intrinsics for MVE instructions.
This commit, together with the next few, will add a representative
sample of the kind of IR intrinsics that we'll need in order to
implement the user-facing ACLE intrinsics for MVE. Supporting all of
them will take more work; the intention of this initial series of
commits is to implement an intrinsic or two from lots of different
categories, as examples and proofs of concept.

This initial commit introduces a small number of IR intrinsics for
instructions simple enough that they can use Tablegen ISel patterns:
the predicated versions of the VADD and VSUB instructions (both
integer and FP), VMIN and VMAX, and the float->half VCVT instruction
(predicated and unpredicated).

When using VPT-predicated instructions in automatic code generation,
it will be convenient to specify the predicate value as a vector of
the appropriate number of i1. To make it easy to specify all sizes of
an instruction in one go and give each one the matching predicate
vector type, I've added a system of Tablegen informational records
describing MVE's vector types: each one gives the underlying LLVM IR
ValueType (which may not be the same if the MVE vector is of
explicitly signed or unsigned integers) and an appropriate vNi1 to use
as the predicate vector.

(Also, those info records include the usual encoding for the types, so
that as we add associations between each instruction encoding and one
of the new `MVEVectorVTInfo` records, we can remove some of the
existing template parameters and replace them with references to the
vector type info's fields.)

The user-facing ACLE intrinsics will receive a predicate mask as a
16-bit integer, so I've also provided a pair of intrinsics i2v and
v2i, to convert between an integer and a vector of i1 by just changing
the register class.

Reviewers: dmgreen, miyuki, ostannard

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67158
2019-10-24 16:33:13 +01:00
Michael Liao b2a65f0d70 [AMDGPU] Skip additional folding on the same operand.
Reviewers: rampitec, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69355
2019-10-24 11:30:22 -04:00
Michael Liao 950b800c45 Fix compilation warning on the trailing whitespace. NFC. 2019-10-24 09:55:06 -04:00
Ilya Biryukov ed913a2915 [clangd] Fix case of variables and functions in code complete tests. NFC 2019-10-24 15:41:50 +02:00
Simon Atanasyan fd77e578e9 [docs] Add Mips as a supported architecture in GettingStarted.rst
Patch by Miloš Stojanović

Differential Revision: https://reviews.llvm.org/D69380
2019-10-24 15:56:30 +03:00
Simon Atanasyan c84cfaf9bc [docs] Update link to the MIPS 64-bit ELF object file specification
Patch by Miloš Stojanović

Differential Revision: https://reviews.llvm.org/D69377
2019-10-24 15:56:30 +03:00
Petar Avramovic e3b49df50e [MIPS GlobalISel] Select MSA vector generic and builtin fabs
selectImpl is able to select G_FABS when we set bank for vector
operands to fprb. Add detailed tests.
Note: G_FABS is generated from llvm-ir intrinsics llvm.fabs.*,
and at the moment MIPS is not able to generate this intrinsic for
vector type (some targets generate vector llvm.fabs.* from calls
to a builtin function).
We can handle fabs using __builtin_msa_fmax_a_<format> and passing
same vector as both arguments. __builtin_msa_fmax_a_<format> will
be directly selected into FMAX_A_<format> in legalizeIntrinsic.

Differential Revision: https://reviews.llvm.org/D69346
2019-10-24 13:45:26 +02:00
evgeny 1ae8e8d25f Don't add -fsplit-lto-unit for thin LTO builds with PS4 and Darwin toolchains
These toolchains use legacy thin LTO API, which is not capable of unit splitting
Differential revision: https://reviews.llvm.org/D69173
2019-10-24 14:10:03 +03:00
David Tellenbach 6d11abfe35 [compiler-rt] Expose __hwasan_tag_mismatch_stub
Summary:
GCC would like to emit a function call to report a tag mismatch
rather than hard-code the `brk` instruction directly.

__hwasan_tag_mismatch_stub contains most of the functionality to do
this already, but requires exposure in the dynamic library.

This patch moves __hwasan_tag_mismatch_stub outside of the anonymous
namespace that it was defined in and declares it in
hwasan_interface_internal.h.

We also add the ability to pass sizes larger than 16 bytes to this
reporting function by providing a fourth parameter that is only looked
at when the size provided is not in the original accepted range.

This does not change the behaviour where it is already being called,
since the previous definition only accepted sizes up to 16 bytes and
hence the change in behaviour is not seen by existing users.
The change in declaration does not matter, since the only existing use
is in the __hwasan_tag_mismatch function written in assembly.

Reviewers: eugenis, kcc, pcc, #sanitizers

Reviewed By: eugenis, #sanitizers

Subscribers: kristof.beyls, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D69113

Patch by Matthew Malcomson <matthew.malcomson@arm.com>
2019-10-24 11:16:06 +01:00
David Tellenbach 93aec861f5 Revert "Expose __hwasan_tag_mismatch_stub"
Attribution to author of patch got lost.

This reverts commit 612eadb7bc.
2019-10-24 11:11:05 +01:00
David Tellenbach 612eadb7bc Expose __hwasan_tag_mismatch_stub
Summary:
GCC would like to emit a function call to report a tag mismatch
rather than hard-code the `brk` instruction directly.

__hwasan_tag_mismatch_stub contains most of the functionality to do
this already, but requires exposure in the dynamic library.

This patch moves __hwasan_tag_mismatch_stub outside of the anonymous
namespace that it was defined in and declares it in
hwasan_interface_internal.h.

We also add the ability to pass sizes larger than 16 bytes to this
reporting function by providing a fourth parameter that is only looked
at when the size provided is not in the original accepted range.

This does not change the behaviour where it is already being called,
since the previous definition only accepted sizes up to 16 bytes and
hence the change in behaviour is not seen by existing users.
The change in declaration does not matter, since the only existing use
is in the __hwasan_tag_mismatch function written in assembly.

Tested with gcc and clang on an AArch64 vm.

Reviewers: eugenis, kcc, pcc, #sanitizers

Reviewed By: eugenis, #sanitizers

Subscribers: kristof.beyls, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D69113
2019-10-24 11:05:39 +01:00
Marek Kurdej 73cebfe412 [libFuzzer] docs: update note to include REDUCE event. 2019-10-24 12:04:12 +02:00
Benjamin Kramer bfa3f0c316 Hide implementation details in anonymous namespaces. NFC. 2019-10-24 10:48:43 +02:00
Haojian Wu 13fc899cde [clangd] Handle the missing constructor initializers in findExplicitReferences.
Reviewers: ilya-biryukov

Subscribers: MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69241
2019-10-24 10:38:37 +02:00
Haojian Wu bf71e4fe0a [clangd] Collect name references in the index.
Summary:
This is used for cross-file rename. When renaming a class, we expect to
rename all related constructors/destructors.

Reviewers: kadircet, ilya-biryukov

Subscribers: MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69338
2019-10-24 10:25:16 +02:00
Petar Avramovic 914ce66413 [MIPS GlobalISel] MSA vector generic and builtin fadd, fsub, fmul, fdiv
Select vector G_FADD, G_FSUB, G_FMUL and G_FDIV for MIPS32 with MSA. We
have to set bank for vector operands to fprb and selectImpl will do the
rest. __builtin_msa_fadd_<format>, __builtin_msa_fsub_<format>,
__builtin_msa_fmul_<format> and __builtin_msa_fdiv_<format> will be
transformed into G_FADD, G_FSUB, G_FMUL and G_FDIV in legalizeIntrinsic
respectively and selected in the same way.

Differential Revision: https://reviews.llvm.org/D69340
2019-10-24 10:15:07 +02:00
Petar Avramovic 1d7f79c017 [MIPS GlobalISel] MSA vector generic and builtin sdiv, srem, udiv, urem
Select vector G_SDIV, G_SREM, G_UDIV and G_UREM for MIPS32 with MSA. We
have to set bank for vector operands to fprb and selectImpl will do the
rest. __builtin_msa_div_s_<format>, __builtin_msa_mod_s_<format>,
__builtin_msa_div_u_<format> and __builtin_msa_mod_u_<format> will be
transformed into G_SDIV, G_SREM, G_UDIV and G_UREM in legalizeIntrinsic
respectively and selected in the same way.

Differential Revision: https://reviews.llvm.org/D69333
2019-10-24 10:03:36 +02:00
Craig Topper 7f1ffef567 [X86] Replace some regular expressions in xray tests with explicit checks to show bad assembly.
We're print 16-bit or 32-bit registers in copy instructions to
64-bit registers. This code will not assemble if it were to be
parsed back in. Emitting to binary works because we'll encode
the register the same way no matter what the size is.
2019-10-23 23:05:09 -07:00
Stanislav Mekhanoshin 61e7a61bdc [AMDGPU] Allow folding of sgpr to vgpr copy
Potentially sgpr to sgpr copy should also be possible.
That is however trickier because we may end up with a
wrong register class at use because of xm0/xexec permutations.

Differential Revision: https://reviews.llvm.org/D69280
2019-10-23 18:42:48 -07:00
Shoaib Meenai e3d26b42b9 [Hexagon] Fix typo. NFC
Testing git push access.
2019-10-23 18:06:28 -07:00
Meike Baumgärtner da6384fbb9
Add beginning of LLVM's GettingStarted to GitHub readme
Reviewed and approved by chandlerc.

As GitHub is the canonical LLVM repository now, embrace GitHub's way of displaying basic build instructions in the top-level readme.md.
2019-10-23 18:03:37 -07:00
Chandler Carruth dc1499b90d Improve Clang's getting involved document and make it more inclusive in wording.
Summary: Working with Meike and others to improve the wording in this document.

Reviewers: klimek

Subscribers: mcrosier, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69351
2019-10-23 16:11:24 -07:00
David Tenty bf869683c3 Use portable flag with nm in extract_symbols.py
Summary:
nm is one of the tools that extract_symbols.py can use to extract
symbols from llvm libraries as part of the build process. This patch
updates the invocation of nm to use the -P POSIX option for "portable
output" so we get a consistently parsable output format on all
platforms.

A link to the relevant nm format: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/nm.html

Reviewers: hubert.reinterpretcast, stevewan, sfertile

Reviewed By: stevewan

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69004
2019-10-23 16:48:22 -04:00
Meike Baumgärtner 23fdd513a3
Improve language in GettingStarted.rst
This patch was reviewed and approved by chandlerc.

"Getting Started with the LLVM System" is the first point of contact for many newcomers in the LLVM community.
 * Make the first two paragraphs more welcoming
 * Use more inclusive language
2019-10-23 12:32:57 -07:00
Stephan T. Lavavej 7c9844b66e [libcxx][NFC] Strip trailing whitespace, fix typo. 2019-10-23 11:49:43 -07:00
Chandler Carruth bf2975eca0 Remove a no longer accurate sentence from the coding standards.
(And test my commit access. We're working on larger changes here.)
2019-10-23 11:40:45 -07:00
Louis Dionne 6b77ebdc91 [NFC] Strip trailing whitespace from libc++ 2019-10-23 11:19:19 -07:00
Hans Wennborg 684ebc605e Revert 4334892e7b "[DAGCombine][ARM] x ==/!= c -> (x - c) ==/!= 0 iff '-c' can be folded into the x node."
This broke various Windows builds, see comments on the Phabricator
review.

This also reverts the follow-up 20bf0cf.

> Summary:
> This fold, helps recover from the rest of the D62266 ARM regressions.
> https://rise4fun.com/Alive/TvpC
>
> Note that while the fold is quite flexible, i've restricted it
> to the single interesting pattern at the moment.
>
> Reviewers: efriedma, craig.topper, spatel, RKSimon, deadalnix
>
> Reviewed By: deadalnix
>
> Subscribers: javed.absar, kristof.beyls, llvm-commits
>
> Tags: #llvm
>
> Differential Revision: https://reviews.llvm.org/D62450
2019-10-23 19:52:02 +02:00
Raphael Isemann d01fd2f35a [lldb] Add nodebug attribute to import-std-module/sysroot test
Summary:
So far we rely on the default argument and the fact that we don't call this
inline function in our actual `main.cpp` to make sure that this function can only
be called if LLDB loads this header as a C++ module. This patch just adds
the nodebug attribute as yet another measure to make sure LLDB can't call this
function without the standard module loaded. Note that the test is already
requiring clang for the sysroot setup, so its fine that this is a Clang specific attribute.

Reviewers: friss, labath

Subscribers: JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D68861
2019-10-23 09:26:57 -07:00
Kevin P. Neal b689cc640f Minor movement of one function with now-correct strictfp attribute to pass
against the latest version of D68233.
2019-10-23 12:23:03 -04:00
Sam McCall 8bda5f2067 [clangd] abort if shutdown takes more than a minute.
Summary:
A certain class of bug (e.g. infloop on an AST worker thread) currently means
clangd never terminates, even if the editor shuts down the protocol and closes
our stdin, and the main thread recognizes that.

Instead, let's wait 60 seconds for threads to finish cleanly, and then crash
if they haven't.

(Obviously, we should still fix these bugs).

Reviewers: kadircet

Subscribers: MaskRay, jkorous, arphaman, jfb, usaxena95, cfe-commits, ilya-biryukov

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69329
2019-10-23 17:52:59 +02:00
Roman Lebedev 60286818ff
[Analysis] Update Analysis/LazyValueAnalysis/lvi-after-jumpthreading.ll
I should have updated it in 1f665046fb
but i didn't even realize those tests were there.
2019-10-23 18:39:10 +03:00
stevewan 342c02d0ad Fix non-portable GNU diff option
Summary: This is a fix to revision D68839 and rL375023. This patch substitutes POSIX option "-b" for the non-portable GNU option "--strip-trailing-cr".

Reviewers: daltenty, hubert.reinterpretcast

Reviewed By: daltenty

Subscribers: mehdi_amini, hiraditya, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69342
2019-10-23 11:19:01 -04:00
Roman Lebedev 8eda8f8ce8
[LVI][NFC] Factor solveBlockValueSaturatingIntrinsic() out of solveBlockValueIntrinsic()
Now that there's SaturatingInst class, this is cleaner.
2019-10-23 18:17:33 +03:00
Roman Lebedev 1f665046fb
[LVI][CVP] LazyValueInfoImpl::solveBlockValueBinaryOp(): use no-wrap flags from `add` op
Summary:
This was suggested in https://reviews.llvm.org/D69277#1717210
In this form (this is what was suggested, right?), the results aren't staggering
(especially since given LVI cross-block focus)
this does catch some things (as per test-suite), but not too much:

| statistic                                        |       old |       new | delta | % change |
| correlated-value-propagation.NumAddNSW           |      4981 |      4982 |     1 |  0.0201% |
| correlated-value-propagation.NumAddNW            |     12125 |     12126 |     1 |  0.0082% |
| correlated-value-propagation.NumCmps             |      1199 |      1202 |     3 |  0.2502% |
| correlated-value-propagation.NumDeadCases        |       112 |       111 |    -1 | -0.8929% |
| correlated-value-propagation.NumMulNSW           |       275 |       278 |     3 |  1.0909% |
| correlated-value-propagation.NumMulNUW           |      1323 |      1326 |     3 |  0.2268% |
| correlated-value-propagation.NumMulNW            |      1598 |      1604 |     6 |  0.3755% |
| correlated-value-propagation.NumNSW              |      7158 |      7167 |     9 |  0.1257% |
| correlated-value-propagation.NumNUW              |     13304 |     13310 |     6 |  0.0451% |
| correlated-value-propagation.NumNW               |     20462 |     20477 |    15 |  0.0733% |
| correlated-value-propagation.NumOverflows        |         4 |         7 |     3 | 75.0000% |
| correlated-value-propagation.NumPhis             |     15366 |     15381 |    15 |  0.0976% |
| correlated-value-propagation.NumSExt             |      6273 |      6277 |     4 |  0.0638% |
| correlated-value-propagation.NumShlNSW           |      1172 |      1171 |    -1 | -0.0853% |
| correlated-value-propagation.NumShlNUW           |      2793 |      2794 |     1 |  0.0358% |
| correlated-value-propagation.NumSubNSW           |       730 |       736 |     6 |  0.8219% |
| correlated-value-propagation.NumSubNUW           |      2044 |      2046 |     2 |  0.0978% |
| correlated-value-propagation.NumSubNW            |      2774 |      2782 |     8 |  0.2884% |
| instcount.NumAddInst                             |    277586 |    277569 |   -17 | -0.0061% |
| instcount.NumAndInst                             |     66056 |     66054 |    -2 | -0.0030% |
| instcount.NumBrInst                              |    709147 |    709146 |    -1 | -0.0001% |
| instcount.NumCallInst                            |    528579 |    528576 |    -3 | -0.0006% |
| instcount.NumExtractValueInst                    |     18307 |     18301 |    -6 | -0.0328% |
| instcount.NumOrInst                              |    102660 |    102665 |     5 |  0.0049% |
| instcount.NumPHIInst                             |    318008 |    318007 |    -1 | -0.0003% |
| instcount.NumSelectInst                          |     46373 |     46370 |    -3 | -0.0065% |
| instcount.NumSExtInst                            |     79496 |     79488 |    -8 | -0.0101% |
| instcount.NumShlInst                             |     40654 |     40657 |     3 |  0.0074% |
| instcount.NumTruncInst                           |     62251 |     62249 |    -2 | -0.0032% |
| instcount.NumZExtInst                            |     68211 |     68221 |    10 |  0.0147% |
| instcount.TotalBlocks                            |    843910 |    843909 |    -1 | -0.0001% |
| instcount.TotalInsts                             |   7387448 |   7387423 |   -25 | -0.0003% |

Reviewers: nikic, reames

Reviewed By: nikic

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69321
2019-10-23 18:17:32 +03:00
Artem Dergachev be86fdb86e [analyzer] Fix off-by-one in operator call parameter binding.
Member operator declarations and member operator expressions
have different numbering of parameters and arguments respectively:
one of them includes "this", the other does not.

Account for this inconsistency when figuring out whether
the parameter needs to be manually rebound from the Environment
to the Store when entering a stack frame of an operator call,
as opposed to being constructed with a constructor and as such
already having the necessary Store bindings.

Differential Revision: https://reviews.llvm.org/D69155
2019-10-23 08:17:02 -07:00
Casey Carter 689ce81059
[libc++][NFC] Remove excess trailing newlines from most files
Testing git commit access.
2019-10-23 08:08:57 -07:00
Simon Atanasyan 8e574e56c6 [mips] Use `expandLoadAddress` for JAL expansion
- Reduce code duplication
- Get partial support of JAL expansion for XGOT.
2019-10-23 17:36:34 +03:00
Simon Atanasyan c470a9b586 [mips] Implement `la` macro expansion for N32 ABI 2019-10-23 17:36:34 +03:00
Simon Atanasyan 263abc6761 [mips] Add tests to check `la / dla` expansion in XGOT cases. NFC 2019-10-23 17:36:33 +03:00
Simon Atanasyan 82b1b39b36 [mips] Reformat `la / dla` expansion test cases. NFC 2019-10-23 17:36:33 +03:00
Simon Pilgrim a4d55a2c36 [X86] combineX86ShufflesRecursively - assert the root mask is legal. NFCI. 2019-10-23 07:33:29 -07:00
Sam McCall a9c3c176ad Reland "[Support] Add a way to run a function on a detached thread""
This reverts commit 7bc7fe6b78.
The immediate callers have been fixed to pass nullopt where appropriate.
2019-10-23 15:51:44 +02:00
Kadir Cetinkaya 10c8dbcb84 [clangd] Propogate context in TUScheduler::run
Reviewers: sammccall

Subscribers: ilya-biryukov, javed.absar, MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69328
2019-10-23 15:31:24 +02:00
Sam Elliott 977205b595 [Sanitizers] Add support for RISC-V 64-bit
Summary:
This has been tested with gcc trunk on openSUSE Tumbleweed on the HiFive Unleashed.

Patch by Andreas Schwab (schwab)

Reviewers: luismarques

Reviewed By: luismarques

Subscribers: mhorne, emaste, luismarques, asb, mgorny, fedor.sergeev, simoncook, kito-cheng, shiva0217, rogfer01, rkruppe, lenary, s.egerton, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D66870
2019-10-23 14:12:52 +01:00
Sam McCall 7bc7fe6b78 Revert "[Support] Add a way to run a function on a detached thread"
This reverts commit 40668abca4.
This causes clang tests to fail, as stacksize=0 is being explicitly passed and
is no longer a no-op.
2019-10-23 15:10:35 +02:00
Sam McCall 40668abca4 [Support] Add a way to run a function on a detached thread
This roughly mimics `std::thread(...).detach()` except it allows to
customize the stack size. Required for https://reviews.llvm.org/D50993.

I've decided against reusing the existing `llvm_execute_on_thread` because
it's not obvious what to do with the ownership of the passed
function/arguments:

1. If we pass possibly owning functions data to `llvm_execute_on_thread`,
   we'll lose the ability to pass small non-owning non-allocating functions
   for the joining case (as it's used now). Is it important enough?
2. If we use the non-owning interface in the new use case, we'll force
   clients to transfer ownership to the spawned thread manually, but
   similar code would still have to exist inside
   `llvm_execute_on_thread(_async)` anyway (as we can't just pass the same
   non-owning pointer to pthreads and Windows implementations, and would be
   forced to wrap it in some structure, and deal with its ownership.

Patch by Dmitry Kozhevnikov!

Differential Revision: https://reviews.llvm.org/D51103
2019-10-23 12:48:38 +02:00
Mirko Brkusanin 4b63ca1379 [Mips] Use appropriate private label prefix based on Mips ABI
MipsMCAsmInfo was using '$' prefix for Mips32 and '.L' for Mips64
regardless of -target-abi option. By passing MCTargetOptions to MCAsmInfo
we can find out Mips ABI and pick appropriate prefix.

Tags: #llvm, #clang, #lldb

Differential Revision: https://reviews.llvm.org/D66795
2019-10-23 12:24:35 +02:00
David Stenberg 74a72e6848 [DebugInfo] Stop describing imms in TargetInstrInfo's describeLoadedValue() impl
Summary:
The default implementation of the describeLoadedValue() hook uses the
MoveImm property to determine if an instruction moves an immediate. If
an instruction has that property the function returns the second
operand, assuming that that is the immediate value the instruction
moves. As far as I can tell, the MoveImm property does not imply that
the second operand is the immediate value, nor that any other operand
necessarily holds the immediate value; it just means that the
instruction moves some immediate value.

One example where the second operand is not the immediate is SystemZ's
LZER instruction, which moves a zero immediate implicitly: $f0S = LZER.

That case triggered an out-of-bound assertion when getting the operand.
I have added a test case for that instruction.

Another example is ARM's MVN instruction, which holds the logical
bitwise NOT'd value of the immediate that is moved. For the following
reproducer:

  extern void foo(int);
  int main() { foo(-11); }

an incorrect call site value would be emitted:

  $ clang --target=arm foo.c -O1 -g -Xclang -femit-debug-entry-values \
      -c -o - | ./build/bin/llvm-dwarfdump  - | \
      grep -A2 call_site_parameter

  0x00000058:       DW_TAG_GNU_call_site_parameter
                      DW_AT_location (DW_OP_reg0 R0)
                      DW_AT_GNU_call_site_value (DW_OP_lit10)

Another example is the A2_combineii instruction on Hexagon which moves
two immediates to a super-register: $d0 = A2_combineii 20, 10.

Perhaps these are rare exceptions, and most MoveImm instructions hold
the immediate in the second operand, but in my opinion the default
implementation of the hook should only describe values that it can, by
some contract, guarantee are safe to describe, rather than leaving it up
to the targets to override the exceptions, as that can silently result
in incorrect call site values.

This patch adds X86's relevant move immediate instructions to the
target's hook implementation, so this commit should be a NFC for that
target. We need to do the same for ARM and AArch64.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: vsk

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D69109
2019-10-23 11:41:29 +02:00