Summary:
This patch could be treated as a rebase of D33960. It also fixes PR35547.
A fix for `llvm/test/Other/close-stderr.ll` is proposed in D68164. Seems
the consensus is that the test is passing by chance and I'm not
sure how important it is for us. So it is removed like in D33960 for now.
The rest of the test fixes are just adding `--crash` flag to `not` tool.
** The reason it fixes PR35547 is
`exit` does cleanup including calling class destructor whereas `abort`
does not do any cleanup. In multithreading environment such as ThinLTO or JIT,
threads may share states which mostly are ManagedStatic<>. If faulting thread
tearing down a class when another thread is using it, there are chances of
memory corruption. This is bad 1. It will stop error reporting like pretty
stack printer; 2. The memory corruption is distracting and nondeterministic in
terms of error message, and corruption type (depending one the timing, it
could be double free, heap free after use, etc.).
Reviewers: rnk, chandlerc, zturner, sepavloff, MaskRay, espindola
Reviewed By: rnk, MaskRay
Subscribers: wuzish, jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, arichardson, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, lenary, s.egerton, pzheng, cfe-commits, MaskRay, filcab, davide, MatzeB, mehdi_amini, hiraditya, steven_wu, dexonsmith, rupprecht, seiya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D67847
This flag was originally part of D70157, but was removed as we carved away pieces of the review. Since we have the nop support checked in, and it appears mature(*), I think it's time to add the master flag. For now, it will default to nop padding, but once the prefix padding support lands, we'll update the defaults.
(*) I can now confirm that downstream testing of the changes which have landed to date - nop padding and compiler support for suppressions - is passing all of the functional testing we've thrown at it. There might still be something lurking, but we've gotten enough coverage to be confident of the basic approach.
Note that the new flag can be used either when assembling an .s file, or when using the integrated assembler directly from the compiler. The later will use all of the suppression mechanism and should always generate correct code. We don't yet have assembly syntax for the suppressions, so passing this directly to the assembler w/a raw .s file may result in broken code. Use at your own risk.
Also note that this isn't the wiring for the clang option. I think the most recent review for that is D72227, but I've lost track, so that might be off.
Differential Revision: https://reviews.llvm.org/D72738
For a target symbol defined in the same section, currently we don't emit
a relocation if VariantKind is VK_None (with few exceptions like RISC-V
relaxation), while GNU as emits one. This causes program behavior
differences with and without -ffunction-sections, and can break intended
symbol interposition in a -shared link.
```
.globl foo
foo:
call foo # no relocation. On other targets, may be written as b foo, etc
call bar # a relocation if bar is in another section (e.g. -ffunction-sections)
call foo@plt # a relocation
```
Unify these cases by always emitting a relocation. If we ever want to
optimize `call foo` in -shared links, we should emit a STB_LOCAL alias
and call via the alias.
ARM/thumb2-beq-fixup.s: we now emit a relocation to global_thumb_fn as GNU as does.
X86/Inputs/align-branch-64-2.s: we now emit R_X86_64_PLT32 to foo as GNU does.
ELF/relax.s: rewrite the test as target-in-same-section.s .
We omitted relocations to `global` and now emit R_X86_64_PLT32.
Note, GNU as does not emit a relocation for `jmp global` (maybe its own
bug). Our new behavior is compatible except `jmp global`.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D72197
The primary motivation of this change is to bring the code more closely in sync behavior wise with the assembler's version of nop emission. I'd like to eventually factor them into one, but that's hard to do when one has features the other doesn't.
The longest encodeable nop on x86 is 15 bytes, but many processors - for instance all intel chips - can't decode the 15 byte form efficiently. On those processors, it's better to use either a 10 byte or 11 byte sequence depending.
The patch gives out the details of the znver2 scheduler model.
There are few improvements with respect to execution units, latencies and
throughput when compared with znver1.
The tests that were present for znver1 for llvm-mca tool were replicated.
The latencies, execution units, timeline and throughput information are updated for znver2.
Reviewers: craig.topper, Simon Pilgrim
Differential Revision: https://reviews.llvm.org/D66088
Summary:
Amend MS offset operator implementation, to more closely fit with its MS counterpart:
1. InlineAsm: evaluate non-local source entities to their (address) location
2. Provide a mean with which one may acquire the address of an assembly label via MS syntax, rather than yielding a memory reference (i.e. "offset asm_label" and "$asm_label" should be synonymous
3. address PR32530
Based on http://llvm.org/D37461
Fix broken test where the break appears unrelated.
- Set up appropriate memory-input rewrites for variable references.
- Intel-dialect assembly printing now correctly handles addresses by adding "offset".
- Pass offsets as immediate operands (using "r" constraint for offsets of locals).
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D71436
This is in the context of the automatic padding work for the jcc erratum mitigation. These are example cases we need to *not* pad for correctness. Exact mechanism to suppress is still TBD, but saving the tests which have come up.
WARNING: If you're looking at this patch because you're looking for a full
performace mitigation of the Intel JCC Erratum, this is not it!
This is a preliminary patch on the patch towards mitigating the performance
regressions caused by Intel's microcode update for Jump Conditional Code
Erratum. For context, see:
https://www.intel.com/content/www/us/en/support/articles/000055650.html
The patch adds the required assembler infrastructure and command line options
needed to exercise the logic for INTERNAL TESTING. These are NOT public flags,
and should not be used for anything other than LLVM's own testing/debugging
purposes. They are likely to change both in spelling and meaning.
WARNING: This patch is knowingly incorrect in some cornercases. We need, and
do not yet provide, a mechanism to selective enable/disable the padding.
Conversation on this will continue in parellel with work on extending this
infrastructure to support prefix padding.
The goal here is to have the assembler align specific instructions such that
they neither cross or end at a 32 byte boundary. The impacted instructions are:
a. Conditional jump.
b. Fused conditional jump.
c. Unconditional jump.
d. Indirect jump.
e. Ret.
f. Call.
The new options for llvm-mc are:
-x86-align-branch-boundary=NUM aligns branches within NUM byte boundary.
-x86-align-branch=TYPE[+TYPE...] specifies types of branches to align.
A new MCFragment type, MCBoundaryAlignFragment, is added, which may emit
NOP to align the fused/unfused branch.
alignBranchesBegin inserts MCBoundaryAlignFragment before instructions,
alignBranchesEnd marks the end of the branch to be aligned,
relaxBoundaryAlign grows or shrinks sizes of NOP to align the target branch.
Nop padding is disabled when the instruction may be rewritten by the linker,
such as TLS Call.
Process Note: I am landing a patch by skan as it has been LGTMed, and
continuing to iterate on the review is simply slowing us down at this point.
We can and will continue to iterate in tree.
Patch By: skan
Differential Revision: https://reviews.llvm.org/D70157
Fix for PR24072:
X86 instructions jrcxz/jecxz/jcxz performs short jumps if rcx/ecx/cx register is 0
The maximum relative offset for a forward short jump is 127 Bytes (0x7F).
The maximum relative offset for a backward short jump is 128 Bytes (0x80).
Gnu assembler warns when the distance of the jump exceeds the maximum but llvm-as does not.
Patch by Konstantin Belochapka and Alexey Lapshin
Differential Revision: https://reviews.llvm.org/D70652
DwarfExpression::addMachineReg() knows how to build a larger register
that isn't expressible in DWARF by combining multiple
subregisters. However, if the entire value fits into just one
subregister, it would still emit the other subregisters, leading to
all sorts of inconsistencies down the line.
This patch fixes that by moving an already existing(!) check whether
the subregister's offset is before the end of the value to the right
place.
rdar://problem/57294211
Differential Revision: https://reviews.llvm.org/D70508
Summary: Matches GNU objdump. Makes debugging easier for me as I'm working out addresses from symbol+addend, so it would be good to be calculating in a single format.
Reviewers: MaskRay, grimar, jhenderson, bd1976llvm
Reviewed By: jhenderson
Subscribers: sdardis, jrtc27, atanasyan, rupprecht, seiya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69997
We need to encode bit 4 into the EVEX.V' bit. We do this right
for regular gather/scatter which use either MRMSrcMem or MRMDestMem
formats. The prefetches use MRM*m formats.
Fixes an issue recently added to PR36202.
llvm-svn: 374849
These flags should simply be passed through to the target, which will do
the right thing. Add an MC/X86 test that uses these directives with the
three primary object file formats and shows that they disassemble the
same everywhere.
There is a missing test for .code32 on Windows ARM, since I'm not sure
exactly how to construct one.
Fixes PR43203
llvm-svn: 370805
Summary:
There is no reason to differ in assembler behavior here between -msvc
and -gnu targets. Without this setting, the text after the '@' is
interpreted as a symbol variable, like foo@IMGREL.
Reviewers: mstorsjo
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66974
llvm-svn: 370408
We have aliases that disambiguate memory forms of bt/btc/btr/bts
without suffixes to the 32-bit form. These aliases should have
been updated when the instructions were updated in r356413.
llvm-svn: 368127
The upper 4 bits of the immediate byte are used to encode a
register. We need to limit the explicit immediate to fit in the
remaining 4 bits.
Fixes PR42899.
llvm-svn: 368123
D18885 emitted 5 bytes for call *foo@tlsdesc(%rax). It should use the
2-byte form instead and let R_X86_64_TLSDESC_CALL apply to the beginning
of the call instruction.
The 2-byte form was deliberately chosen to make ->LE and ->IE relaxation work:
0: 48 8d 05 00 00 00 00 lea 0x0(%rip),%rax # 7 <.text+0x7>
3: R_X86_64_GOTPC32_TLSDESC a-0x4
7: ff 10 callq *(%rax)
7: R_X86_64_TLSDESC_CALL a
=>
0: 48 c7 c0 fc ff ff ff mov $0xfffffffffffffffc,%rax
7: 66 90 xchg %ax,%ax
Also change the symbol type to STT_TLS when VK_TLSCALL or VK_TLSDESC is
seen.
Reviewed By: compnerd
Differential Revision: https://reviews.llvm.org/D62512
llvm-svn: 361910
This can be used to create references among sections. When --gc-sections
is used, the referenced section will be retained if the origin section
is retained.
See R_MIPS_NONE (D13659), R_ARM_NONE (D61992), R_AARCH64_NONE (D61973) for similar changes.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D62014
llvm-svn: 360983
In Intel syntax, it's not uncommon to see a "short" modifier on Jcc conditional
jumps, which indicates the offset should be a "short jump" (8-bit immediate
offset from EIP, -128 to +127). This patch expands to all recognized Jcc
condition codes, and removes the inline restriction.
Clang already ignores "jmp short" in inline assembly. However, only "jmp" and a
couple of Jcc are actually checked, and only inline (i.e., not when using the
integrated assembler for asm sources). A quick search through asm-containing
libraries at hand shows a pretty broad range of Jcc conditions spelled with
"short."
GAS ignores the "short" modifier, and instead uses an encoding based on the
given immediate. MS inline seems to do the same, and I suspect MASM does, too.
NASM will yield an error if presented with an out-of-range immediate value.
Example of GCC 9.1 and MSVC v19.20, "jmp short" with offsets that do and do not
fit within 8 bits: https://gcc.godbolt.org/z/aFZmjY
Differential Revision: https://reviews.llvm.org/D61990
llvm-svn: 360954
We require d/q suffixes on the memory form of these instructions to disambiguate the memory size.
We don't require it on the register forms, but need to support parsing both with and without it.
Previously we always printed the d/q suffix on the register forms, but it's redundant and
inconsistent with gcc and objdump.
After this patch we should support the d/q for parsing, but not print it when its unneeded.
llvm-svn: 360085
The x/y/z suffix is needed to disambiguate the memory form in at&t syntax since no xmm/ymm/zmm register is mentioned.
But we should also allow it for the register and broadcast forms where its not needed for consistency. This matches gas.
The printing code will still only use the suffix for the memory form where it is needed.
llvm-svn: 359903
The broadcasting variant for instruction vfpclassp[d,s] shouldn't use suffix q/l. So remove them from the template.
Patch by Pengfei Wang
Differential Revision: https://reviews.llvm.org/D61295
llvm-svn: 359753
This improves readability and the behavior is consistent with GNU objdump.
The new test test/tools/llvm-objdump/X86/disassemble-section-name.s
checks we print newlines before and after "Disassembly of section ...:"
Differential Revision: https://reviews.llvm.org/D61127
llvm-svn: 359668
-t is --symbols in llvm-readobj but --section-details (unimplemented) in readelf.
The confusing option should not be used since we aim for improving
compatibility.
Keep just one llvm-readobj -t use case in test/tools/llvm-readobj/symbols.test
llvm-svn: 359661
We use both -long-option and --long-option in tests. Switch to --long-option for consistency.
In the "llvm-readelf" mode, -long-option is discouraged as it conflicts with grouped short options and it is not accepted by GNU readelf.
While updating the tests, change llvm-readobj -s to llvm-readobj -S to reduce confusion ("s" is --section-headers in llvm-readobj but --symbols in llvm-readelf).
llvm-svn: 359649
The 128/256 bit version of these instructions require an 'x' or 'y' suffix to
disambiguate the memory form in att syntax.
We were allowing the same suffix in intel syntax, but it appears gas does not
do that.
gas does allow the 'x' and 'y' suffix on register and broadcast forms even
though its not needed. We were allowing it on unmasked register form, but not on
masked versions or on masked or unmasked broadcast form.
While there fix some test coverage holes so they can be extended with the 'x'
and 'y' suffix tests.
llvm-svn: 359418
Years ago I moved this to an InstAlias using VR128H/VR128L. But now that we support {vex3} pseudo prefix, we need to block the optimization when it is set to match gas behavior.
llvm-svn: 358046
The EVEX versions are ambiguous with the VEX versions based on operands alone so we had explicitly dropped
them from the AsmMatcher table. Unfortunately, when we add them they incorrectly show in the table before
their VEX counterparts. This is different how the prioritization normally works.
To fix this we have to explicitly reject the instructions unless the {evex} prefix has been seen.
llvm-svn: 358041
These can be used to force the encoding used for instructions.
{vex2} will fail if the instruction is not VEX encoded, but otherwise won't do anything since we prefer vex2 when possible. Might need to skip use of the _REV MOV instructions for this too, but I haven't done that yet.
{vex3} will force the instruction to use the 3 byte VEX encoding or fail if there is no VEX form.
{evex} will force the instruction to use the EVEX version or fail if there is no EVEX version.
Differential Revision: https://reviews.llvm.org/D59266
llvm-svn: 358029
This error can only happen if an unfinished operation is at Eof.
Patch by Brandon Jones
Differential Revision: https://reviews.llvm.org/D57379
llvm-svn: 356972
Nothing prevents entries from being bigger than the 16 bit size field in
Dwarf < 5. For entries that are too big, just emit an empty entry
instead of crashing.
This fixes PR41038.
Reviewers: probinson, aprantl, davide
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D59518
llvm-svn: 356514
Yuanfang Chen