For historic reasons, the behavior of .align differs between targets.
Fortunately, there are alternatives, .p2align and .balign, which make the
interpretation of the parameter explicit, and which behave consistently across
targets.
This patch teaches MC to use .p2align instead of .align, so that people reading
code for multiple architectures don't have to remember which way each platform
does its .align directive.
Differential Revision: http://reviews.llvm.org/D16549
llvm-svn: 258750
Consolidate the code which handles string table offsets less than 999999
with the code for offsets less than 9999999. While we are here,
simplify the code by not using sprintf to generate the string.
llvm-svn: 258664
When a symbol S shows up in an expression in assembly there are two
possible interpretations
* The expression is referring to the value of S in this file.
* The expression is referring to the value after symbol resolution.
In the first case the assembler can reason about the value and try to
produce a relocation.
In the second case, that is only possible if the symbol cannot be
preempted.
Assemblers are not very consistent about which interpretation gets used.
This changes MC to agree with GAS in the case of an expression of the
form "Sym - WeakSym".
llvm-svn: 258329
The value size was always 1 or 0, so we don't need to store it.
In a no asserts build this takes the testcase of pr26208 from 11 to 10
seconds.
llvm-svn: 258141
WebAssembly's stack will never be executable by default, so it isn't
necessary to declare .note.GNU-stack sections to request a non-executable
stack.
Differential Revision: http://reviews.llvm.org/D15969
llvm-svn: 257962
This method has no callers.
Also remove X86ELFRelocationInfo.cpp and X86MachORelocationInfo.cpp
which only existed to provide an implementation of that method.
Ok'd by Rafael and Jim.
llvm-svn: 257859
Currently WebAssembly has two kinds of relocations; data addresses and
function addresses. This adds ELF relocations for them, as well as an
MC symbol kind to indicate which type of relocation is needed.
llvm-svn: 257416
LLVM_ENABLE_TIMESTAMPS controls if timestamps are embedded into llvm's
binaries. Turning it off is useful for deterministic builds.
r246905 made it so that the define suddenly also controls if the binaries that
the llvm binaries _create_ embed timestamps or not – but this shouldn't be a
configure-time option. r256203/r256204 added a driver option to toggle this on
and off, so this patch now passes this driver option in LLVM_ENABLE_TIMESTAMPS
builds so that if LLVM_ENABLE_TIMESTAMPS is set, the build of LLVM is
deterministic – but the built clang can still write timestamps into other
executables when requested.
This also allows removing some of the test machinery added in r292012 to work
around this problem.
See PR24740 for background.
http://reviews.llvm.org/D15783
llvm-svn: 256958
SubtargetFeatures::ApplyFeatureFlag to be static, so that
MCSubtargetInfo doesn't need to instantiate SubtargetFeatures
for nothing. Also change the return type to void, as it
wasn't ever used.
This is a partial commit of http://reviews.llvm.org/D15746
llvm-svn: 256823
of casting the integer '4' to such a pointer. There is no reason to
expect '4' to be a portable or reliable pointer of this form. The only
reason this ever worked is because the PointerIntPair that this actually
gets used with has an artificially *low* presumed alignment that allowed
it to work. When the alignment of PointerIntPair is derived from the
actual type's alignment, the asserts start firing on this pointer. I'm
amazed we never managed to do anything that triggered the alignment
sanitizer with it, as this is just flat out UB.
If folks dislike this approach to providing a sentinel fragment address,
there are a myriad of other alternatives, suggestions welcome. But this
one has the distinct advantage of not requiring the friend dance of
ilist's sentinel (which I'll point out is *also* in play for
MCFragment!) and seems to be using a nicely provided facility in
MCFragment to establish just such dummy nodes.
This is part of a series of patches to allow LLVM to check for complete
pointee types when computing its pointer traits. This is absolutely
necessary to get correct (or reproducible) results for things like how
many low bits are guaranteed to be zero.
llvm-svn: 256552
header to its own header, allowing users of fragments to have a narrower
header file, and avoid circular header dependencies when getting the
definition of MCSection prior to inspecting traits on MCSection
pointers.
This is part of a series of patches to allow LLVM to check for complete
pointee types when computing its pointer traits. This is absolutely
necessary to get correct (or reproducible) results for things like how
many low bits are guaranteed to be zero.
Note that this doesn't in any way change the design of MC, it is just
moving code around to allow the *header files* to be more fine grained.
Without this, it is impossible to get a complete type for MCSection
where it is needed.
If anyone would prefer a different slicing of the header files, I'm
happy to oblige of course. =]
llvm-svn: 256548
MCDwarf emits a canned abbreviation table, but was not emitting proper
forms for DWARF version 4, which is the default after r249655.
Differential Revision: http://reviews.llvm.org/D15732
llvm-svn: 256313
InitMCObjectFileInfo was trying to override the triple in awkward ways.
For example, a triple specifying COFF but not Windows was forced as ELF.
This makes it easy for internal invariants to get violated, such as
those which triggered PR25912.
This fixes PR25912.
llvm-svn: 256226
Today, we always take into account the possibility that object files
produced by MC may be consumed by an incremental linker. This results
in us initialing fields which vary with time (TimeDateStamp) which harms
hermetic builds (e.g. verifying a self-host went well) and produces
sub-optimal code because we cannot assume anything about the relative
position of functions within a section (call sites can get redirected
through incremental linker thunks).
Let's provide an MCTargetOption which controls this behavior so that we
can disable this functionality if we know a-priori that the build will
not rely on /incremental.
llvm-svn: 256203
Support for COFF timestamps was unintentionally broken in r246905 when
it was conditionally available depending on whether or not LLVM was
configured with LLVM_ENABLE_TIMESTAMPS. However, Config/config.h was
never included which essentially broke the feature. Due to lax testing,
the breakage was never identified until we observed strange failures
during incremental links of Chromium.
This issue is resolved by simply including Config/config.h in
WinCOFFObjectWriter and teaching lit that the MC/COFF/timestamp.s test
is conditionally supported depending on LLVM_ENABLE_TIMESTAMPS. With
this in place, we can strengthen the test to ensure that it will not
accidentally get broken in the future.
This fixes PR25891.
llvm-svn: 256137
These days relocations are created and stored in a deterministic way.
The order they are created is also suitable for the .o file, so we don't
need an explicit sort.
The last remaining exception is MIPS.
llvm-svn: 255902
The .even directive aligns content to an evan-numbered address.
In at&t syntax .even
In Microsoft syntax even (without the dot).
Differential Revision: http://reviews.llvm.org/D15413
llvm-svn: 255462
This is very rudimentary support for debug_cu_index, but it is enough to
allow llvm-dwarfdump to find the offsets for contributions and
correctly dump debug_info.
It will need to actually find the real signature of the unit and build
the real hash table with the right number of buckets, as per the DWP
specification.
It will also need to be expanded to cover the tu_index as well.
llvm-svn: 254489
The COFF object writer was previously adding unnecessary symbols to its
temporary data structures and cleaning them up later. This made the code
harder to understand and caused a bug (aliases classed as temporary symbols
would cause an assertion failure). A much simpler way of handling such
symbols is to ask the layout for their section-relative position when needed.
Tested with a bootstrap on Windows and by building Chrome.
Differential Revision: http://reviews.llvm.org/D14975
llvm-svn: 254183
Starting on an input stream that is not at offset 0 would trigger the
assert in WinCOFFObjectWriter.cpp:1065:
assert(getStream().tell() <= (*i)->Header.PointerToRawData &&
"Section::PointerToRawData is insane!");
llvm-svn: 253464
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.
It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.
There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
linker since it knowns where the dynamic relocations are.
llvm-svn: 253436
Currently, if the assembler encounters an error after parsing (such as an
out-of-range fixup), it reports this as a fatal error, and so stops after the
first error. However, for most of these there is an obvious way to recover
after emitting the error, such as emitting the fixup with a value of zero. This
means that we can report on all of the errors in a file, not just the first
one. MCContext::reportError records the fact that an error was encountered, so
we won't actually emit an object file with the incorrect contents.
Differential Revision: http://reviews.llvm.org/D14717
llvm-svn: 253328
This adds reportError to MCContext, which can be used as an alternative to
reportFatalError when the assembler wants to try to continue processing the
rest of the file after the error is reported, so that all of the errors ina
file can be reported. It records the fact that an error was encountered, so we
can avoid emitting an object file if any errors occurred.
This patch doesn't add any uses of this function (a later patch will convert
most uses of reportFatalError to use it), but there is a small functional
change: we use the SourceManager to print the error message, even if we have a
null SMLoc. This means that we get a SourceManager-style message, with the file
and line information shown as <unknown>, rather than the "LLVM ERROR" style
used by report_fatal_error.
llvm-svn: 253327
The way prelink used to work was
* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.
There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
implementation is pretty broken. It talks about relocations that are
"resolved by the static linker". If they are resolved, there are none
left for the prelinker. What one needs to track is if an expression
will require only dynamic relocations that point to the same DSO.
At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)
This patch removes support for it. That is, it stops printing the
".local" sections.
llvm-svn: 253280
Storing the source location of the expression that created a constant pool
entry allows us to emit better error messages if we later discover that the
expression cannot be represented by a relocation.
Differential Revision: http://reviews.llvm.org/D14646
llvm-svn: 253220
This allows for accurate architecture targeting as well as removing
duplicate information (hardcoded feature strings) from MCTargetDesc.
llvm-svn: 253196
MCRelaxableFragment previously kept a copy of MCSubtargetInfo and
MCInst to enable re-encoding the MCInst later during relaxation. A copy
of MCSubtargetInfo (instead of a reference or pointer) was needed
because the feature bits could be modified by the parser.
This commit replaces the MCSubtargetInfo copy in MCRelaxableFragment
with a constant reference to MCSubtargetInfo. The copies of
MCSubtargetInfo are kept in MCContext, and the target parsers are now
responsible for asking MCContext to provide a copy whenever the feature
bits of MCSubtargetInfo have to be toggled.
With this patch, I saw a 4% reduction in peak memory usage when I
compiled verify-uselistorder.lto.bc using llc.
rdar://problem/21736951
Differential Revision: http://reviews.llvm.org/D14346
llvm-svn: 253127
MCSubtargetInfo in the subclasses into MCTargetAsmParser and define a
member function getSTI.
This is done in preparation for making changes to shrink the size of
MCRelaxableFragment. (see http://reviews.llvm.org/D14346).
llvm-svn: 253124
Summary:
Support for R_MIPS_NONE allows us to parse MIPS16's usage of .reloc.
R_MIPS_32 was included to be able to better test the directive.
Targets can add their relocations by overriding MCAsmBackend::getFixupKind().
Subscribers: grosbach, rafael, majnemer, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13659
llvm-svn: 252888
We now create the .eh_frame section early, just like every other special
section.
This means that the special flags are visible in code that explicitly
asks for ".eh_frame".
llvm-svn: 252313
These MachO file directives are used by linkers and other tools to provide
compatibility information, much like the existing .ios_version_min and
.macosx_version_min.
llvm-svn: 251569
The existing behavior was correct on Darwin, which is probably the
platform it was written for.
Before this change, we would rewrite "align 8" to ".align 3" and then
fail to make it through the integrated assembler because 3 is not a
power of 2.
Differential Revision: http://reviews.llvm.org/D14120
llvm-svn: 251418
This is a patch to improve StringTableBuilder's performance. That class'
finalize function is very hot particularly in LLD because the function
does tail-merge strings in string tables or SHF_MERGE sections.
Generic std::sort-style sorter is not efficient for sorting strings.
The function implemented in this patch seems to be more efficient.
Here's a benchmark of LLD to link Clang with or without this patch.
The numbers are medians of 50 runs.
-O0
real 0m0.455s
real 0m0.430s (5.5% faster)
-O3
real 0m0.487s
real 0m0.452s (7.2% faster)
Since that is a benchmark of the whole linker, the speedup of
StringTableBuilder itself is much more than that.
http://reviews.llvm.org/D14053
llvm-svn: 251337
In PIC mode we were previously computing global variable addresses (or GOT
entry addresses) by adding the PC, the PC-relative GOT displacement and
the GOT-relative symbol/GOT entry displacement. Because the latter two
displacements are fixed, we ended up performing one more addition than
necessary.
This change causes us to compute addresses using a single PC-relative
displacement, resulting in a shorter code sequence. This reduces code size
by about 4% in a recent build of Chromium for Android.
As a result of this change we no longer need to compute the GOT base address
in the ARM backend, which allows us to remove the Global Base Reg pass and
SDAG lowering for the GOT.
We also now no longer use the GOT when addressing a symbol which is known
to be defined in the same linkage unit. Specifically, the symbol must have
either hidden visibility or a strong definition in the current module in
order to not use the the GOT.
This is a change from the previous behaviour where we would use the GOT to
address externally visible symbols defined in the same module. I think the
only cases where this could matter are cases involving symbol interposition,
but we don't really support that well anyway.
Differential Revision: http://reviews.llvm.org/D13650
llvm-svn: 251322
GNU as and Darwin give the various binary operators different
precedence. LLVM's MC supported the Darwin semantics but not the GNU
semantics.
This fixes PR25311.
llvm-svn: 251271
In this mode it just tries to tail merge the strings without imposing any other
format constrains. It will not, for example, add a null byte between them.
Also add support for keeping a tentative size and offset if we decide to
not optimize after all.
This will be used shortly in lld for merging SHF_STRINGS sections.
llvm-svn: 251153
Crashing is bad, m'kay? Fixing a 4 year old bug of my own creation.
Adding the testcase now which I should have added then which would have
long since caught this.
The problem is that printMessage() will display the diagnostic but not
set HadError to true, resulting in the assembler continuing on its way
and trying to create relocations for things that may not allow them or
otherwise get itself into trouble. Using the Error() helper function
here rather than calling printMessage() directly resolves this.
rdar://23133240
llvm-svn: 250557
Recommit r250342: move coal-sections-powerpc.s to subdirectory for powerpc.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250370
Recommit r250342: add -arch=ppc32 to the RUN lines of powerpc tests.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250349
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250342
This was just forgotten when SectionSymbols was introduced and could cause
corruption if the MCContext was reused after Reset.
Reviewers: rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13547
llvm-svn: 249854
Stop using `getNextNode()` to get an iterator to a fragment (at least,
in this one place). Instead, use iterator logic directly.
The `getNextNode()` interface isn't actually supposed to work for
creating iterators; it's supposed to return `nullptr` (not a real
iterator) if this is the last node. It's currently broken and will
"happen" to work, but if we ever fix the function, we'll get some
strange failures in places like this.
llvm-svn: 249763
When outgoing function arguments are passed using push instructions, and EH
is enabled, we may need to indicate to the stack unwinder that the stack
pointer was adjusted before the call.
This should fix the exception handling issues in PR24792.
Differential Revision: http://reviews.llvm.org/D13132
llvm-svn: 249522
This extends the work done in r233995 so that now getFragment (in addition to
getSection) also works for variable symbols.
With that the existing logic to decide if a-b can be computed works even if
a or b are variables. Given that, the expression evaluation can avoid expanding
variables as aggressively and that in turn lets the relocation code see the
original variable.
In order for this to work with the asm streamer, there is now a dummy fragment
per section. It is used to assign a section to a symbol when no other fragment
exists.
This patch is a joint work by Maxim Ostapenko andy myself.
llvm-svn: 249303
Summary:
The default behavior is to omit the .section directive for .text, .data,
and sometimes .bss, but some targets may want to omit this directive for
other sections too.
The AMDGPU backend will uses this to emit a simplified syntax for section
switches. For example if the section directive is not omitted (current
behavior), section switches to .hsatext will be printed like this:
.section .hsatext,#alloc,#execinstr,#write
This is actually wrong, because .hsatext has some custom STT_* flags,
which MC doesn't know how to print or parse.
If the section directive is omitted (made possible by this commit),
section switches will be printed like this:
.hsatext
The motivation for this patch is to make it possible to emit sections
with custom STT_* flags without having to teach MC about all the target
specific STT_* flags.
Reviewers: rafael, grosbach
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12423
llvm-svn: 248618
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).
For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.
This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.
This commit also contains a trivial patch to clang to account for the C++ API
change. Thanks go to Pavel Labath for fixing LLDB for me.
Reviewers: rengolin
Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10969
llvm-svn: 247692
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).
For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.
This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.
This commit also contains a trivial patch to clang to account for the C++ API
change.
Reviewers: rengolin
Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10969
llvm-svn: 247683
.align directive refuses alignment 0 -- a comment in the code hints this is
done for GNU as compatibility, but it seems GNU as accepts .align 0
(and silently rounds up alignment to 1).
Differential Revision: http://reviews.llvm.org/D12682
llvm-svn: 247048
Casting to unsigned long can cause the time to get truncated to 32-bits,
making it appear to be a valid timestamp. Just use isUInt<32> instead.
llvm-svn: 246840
This prevents MC clients from getting COFF.h, which conflicts with
winnt.h macros. Also a minor IWYU cleanup. Now the only public headers
including COFF.h are in Object, and they actually need it.
llvm-svn: 246784
The MS incremental linker seems to inspect the timestamp written into
the object file to determine whether or not it's contents need to be
considered. Failing to set the timestamp to a date newer than the
executable will result in the object file not participating in
subsequent links. To ameliorate this, write the current time into the
object file's TimeDateStamp field.
llvm-svn: 246607
We can just ask the ObjectWriter for it's stream instead of caching
around our own reference to it. No functionality change is intended.
llvm-svn: 246604
COFF sections are accompanied with an auxiliary symbol which includes a
checksum. This checksum used to be filled with just zero but this seems
to upset LINK.exe when it is processing a /INCREMENTAL link job.
Instead, fill the CheckSum field with the JamCRC of the section
contents. This matches MSVC's behavior.
This fixes PR19666.
N.B. A rather simple implementation of JamCRC is given. It implements
a byte-wise calculation using the method given by Sarwate. There are
implementations with higher throughput like slice-by-eight and making
use of PCLMULQDQ. We can switch to one of those techniques if it turns
out to be a significant use of time.
llvm-svn: 246590
There are occasions where it is useful to consider the entirety of the
contents of a section. For example, compressed debug info needs the
entire section available before it can compress it and write it out.
The compressed debug info scenario was previously implemented by
mirroring the implementation of writeSectionData in the ELFObjectWriter.
Instead, allow the output stream to be swapped on demand. This lets
callers redirect the output stream to a more convenient location before
it hits the object file.
No functionality change is intended.
Differential Revision: http://reviews.llvm.org/D12509
llvm-svn: 246554
Avoid marking some MCSymbols as used in MC/AsmParser.cpp when no uses
exist. This fixes a bug in parseAssignmentExpression() which
inadvertently sets IsUsed, thereby triggering:
"invalid re-assignment of non-absolute variable"
on otherwise valid code. No other functionality change intended.
The original version of this patch touched many calls to MCSymbol
accessors. On rafael's advice, I have stripped this patch down a bit.
As a follow-up, I intend to find the call sites which intentionally set
IsUsed and force them to do so explicitly.
Differential Revision: http://reviews.llvm.org/D12347
llvm-svn: 246457
Split a MCAssembler::layout() method out of MCAssembler::finish(). This allows
running the MCSections layout separately from the streaming of the output
file. This way if a client wants to use MC to generate section contents, but
emit something different than the standard relocatable object files it is
possible (llvm-dsymutil is such a client).
llvm-svn: 246008
Hardcode less values in some mach-o header writing routines and pass them
as argument. Doing so will allow reusing this code in llvm-dsymutil.
llvm-svn: 246007
This commit adds a virtual `peekTokens()` function to `MCAsmLexer`
which can peek forward an arbitrary number of tokens.
It also makes the `peekTok()` method call `peekTokens()` method, but
only requesting one token.
The idea is to better support targets which more more ambiguous
assembly syntaxes.
Patch by Dylan McKay!
llvm-svn: 245221
This reverts commit r245047.
It was failing on the darwin bots. The problem was that when running
./bin/llc -march=msp430
llc gets to
if (TheTriple.getTriple().empty())
TheTriple.setTriple(sys::getDefaultTargetTriple());
Which means that we go with an arch of msp430 but a triple of
x86_64-apple-darwin14.4.0 which fails badly.
That code has to be updated to select a triple based on the value of
march, but that is not a trivial fix.
llvm-svn: 245062
Other than some places that were handling unknown as ELF, this should
have no change. The test updates are because we were detecting
arm-coff or x86_64-win64-coff as ELF targets before.
It is not clear if the enum should live on the Triple. At least now it lives
in a single location and should be easier to move somewhere else.
llvm-svn: 245047
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
NFC patch for current users, but llvm-dsymutil will use the new
functionality to adapt to the input linetable.
Based on a patch by Adrian Prantl.
llvm-svn: 244318
On Darwin, it is required to stamp the object file with VERSION_MIN load
command. This commit will provide a VERSRION_MIN load command to the
MachO file that doesn't specify the version itself by inferring from
Target Triple.
llvm-svn: 244059
Disallow all mutation of `MCSubtargetInfo` expect the feature bits.
Besides deleting the assignment operators -- which were dead "code" --
this restricts `InitMCProcessorInfo()` to subclass initialization
sequences, and exposes a new more limited function called
`setDefaultFeatures()` for use by the ARMAsmParser `.cpu` directive.
There's a small functional change here: ARMAsmParser used to adjust
`MCSubtargetInfo::CPUSchedModel` as a side effect of calling
`InitMCProcessorInfo()`, but I've removed that suspicious behaviour.
Since the AsmParser shouldn't be doing any scheduling, there shouldn't
be any observable change...
llvm-svn: 241961
Force all creators of `MCSubtargetInfo` to immediately initialize it,
merging the default constructor and the initializer into an initializing
constructor. Besides cleaning up the code a little, this makes it clear
that the initializer is never called again later.
Out-of-tree backends need a trivial change: instead of calling:
auto *X = new MCSubtargetInfo();
InitXYZMCSubtargetInfo(X, ...);
return X;
they should call:
return createXYZMCSubtargetInfoImpl(...);
There's no real functionality change here.
llvm-svn: 241957
Remove all calls to `MCSubtargetInfo::InitCPUSched()` and merge its body
into the only relevant caller, `MCSubtargetInfo::InitMCProcessorInfo()`.
We were only calling the former after explicitly calling the latter with
the same CPU; it's confusing to have both methods exposed.
Besides a minor (surely unmeasurable) speedup in ARM and X86 from
avoiding running the logic twice, no functionality change.
llvm-svn: 241956
`MCSchedModel` is large. Make `MCSchedModel::GetDefaultSchedModel()`
return by-reference instead of by-value, so we can store a pointer in
`MCSubtargetInfo::CPUSchedModel` instead of a copy.
Note: since `MCSchedModel` is POD, this doesn't create a static
constructor.
llvm-svn: 241947
Summary:
This concludes the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
At this point, the StringRef-form of GNU Triples should only be used in the
public API (including IR serialization) and a couple objects that directly
interact with the API (most notably the Module class). The next step is to
replace these Triple objects with the TargetTuple object that will represent
our authoratative/unambiguous internal equivalent to GNU Triples.
Reviewers: rengolin
Subscribers: llvm-commits, jholewinski, ted, rengolin
Differential Revision: http://reviews.llvm.org/D10962
llvm-svn: 241472
All file formats only needed 16-bits right now which is enough to fit
in to the padding with other fields.
This reduces the size of MCSymbol to 24-bytes on a 64-bit system. The
layout is now
0 | class llvm::MCSymbol
0 | class llvm::PointerIntPair SectionOrFragmentAndHasName
0 | intptr_t Value
| [sizeof=8, dsize=8, align=8
| nvsize=8, nvalign=8]
8 | unsigned int IsTemporary
8 | unsigned int IsRedefinable
8 | unsigned int IsUsed
8 | _Bool IsRegistered
8 | unsigned int IsExternal
8 | unsigned int IsPrivateExtern
8 | unsigned int Kind
9 | unsigned int IsUsedInReloc
9 | unsigned int SymbolContents
9 | unsigned int CommonAlignLog2
10 | uint32_t Flags
12 | uint32_t Index
16 | union
16 | uint64_t Offset
16 | uint64_t CommonSize
16 | const class llvm::MCExpr * Value
| [sizeof=8, dsize=8, align=8
| nvsize=8, nvalign=8]
| [sizeof=24, dsize=24, align=8
| nvsize=24, nvalign=8]
llvm-svn: 241196
Given that alignments are always powers of 2, just encode it this way.
This matches how we encode alignment on IR GlobalValue's for example.
This compresses the CommonAlign member down to 5 bits which allows it
to pack better with the surrounding fields.
Reviewed by Duncan Exon Smith.
llvm-svn: 241189
The AArch32 assembler parses the '@' as a comment symbol, so the error message shouldn't suggest
that '@<type>' is a valid replacement when assembling for AArch32 target.
Differential Revision: http://reviews.llvm.org/D10651
llvm-svn: 241149
This is part of an effort to pack the average MCSymbol down to 24 bytes.
The HasName bit was pushing the size of the bitfield over to another word,
so this change uses a PointerIntPair to fit in it to unused bits of a
PointerUnion.
Reviewed by Rafael Espíndola
llvm-svn: 241115
represented by uint64_t, this patch replaces these
usages with the FeatureBitset (std::bitset) type.
Differential Revision: http://reviews.llvm.org/D10542
llvm-svn: 241058
Summary:
The current implementation doesn't always flush all pending labels
beforeemitting data which can result in an incorrectly placed labels in
case when when instruction bundling is enabled and -mc-relax-all flag is
being used. To address this issue, we always flush pending labels before
emitting data.
The change was tested by running PNaCl toolchain trybots with
-mc-relax-all flag set.
Fixes https://code.google.com/p/nativeclient/issues/detail?id=4063
Test Plan: Regression test attached
Reviewers: mseaborn
Subscribers: jfb, llvm-commits
Differential Revision: http://reviews.llvm.org/D10325
llvm-svn: 240870
Summary:
Ensure that fragments are bundle aligned when instruction bundling
is enabled and the -mc-relax-all flag is set. This is implicitly
assumed by the bundle padding implementation but this assumption
does not hold when custom alignment is being used.
The change was tested by running PNaCl toolchain trybots with
-mc-relax-all flag set.
Fixes https://code.google.com/p/nativeclient/issues/detail?id=4063
Test Plan: Regression test attached
Reviewers: mseaborn
Subscribers: jfb, llvm-commits
Differential Revision: http://reviews.llvm.org/D10044
llvm-svn: 240869
r224810 fixed the handling of macro debug locations in AsmParser. This patch
fixes the logic to actually do what was intended: it uses the first macro of
the macro stack instead of the last one. The updated testcase shows that the
current scheme doesn't work when macro instanciations are nested and multiple
files are used.
Reviewers: compnerd
Differential Revision: http://reviews.llvm.org/D10463
llvm-svn: 240705
Summary:
In an expression such as "(((a+b)+c)+d)", parseParenExpression() would only parse the "a+b)+c", which would result in an error later on in the parser.
This means that we can only parse one level of inner parentheses.
In order to fix this, I added a new function called parseParenExprOfDepth(), which parses a specified number of trailing parenthesis expressions
(except for the outermost parenthesis), and changed MipsAsmParser to use it in parseMemOffset instead of parseParenExpression().
Reviewers: dsanders, rafael
Reviewed By: dsanders, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9742
llvm-svn: 240625
Summary
This change turns on the emission of
__LLVM_Stackmaps section when generating COFF binaries.
Test Plan
Added a scenario to the test case:
test\CodeGen\X86\statepoint-stackmap-format.ll.
Code Review:
http://reviews.llvm.org/D10680
llvm-svn: 240613
This causes errors like:
ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
may overflow at runtime; recompile with -fPIC
blah.cc:function f(): error: undefined reference to ''
blah.o:g(): error: undefined reference to ''
I have not yet come up with an appropriate reproduction.
llvm-svn: 240394
We hit undefined behaviour in some MCExpr tests when the LHS of a left
shift is -1. Twos-complement semantics are completely reasonable here,
so we should just do the shift in unsigned.
llvm-svn: 240385
This is a reapplication of r239440 which was reverted in r239441.
There are no changes to this patch from then, but this had instead exposed
a bug in .thumb_set which was fixed in r240318. Having fixed that bug, it
is now safe to re-apply this code.
Original commit message below:
It wasn't possible to have a variable Symbol with offset or 'isCommon' so
this just enables better packing of the MCSymbol class.
Reviewed by Rafael Espindola.
llvm-svn: 240320
According to the documentation, .thumb_set is 'the equivalent of a .set directive'.
We didn't have equivalent behaviour in terms of all the errors we could throw, for
example, when a symbol is redefined.
This change refactors parseAssignment so that it can be used by .set and .thumb_set
and implements tests for .thumb_set for all the errors thrown by that method.
Reviewed by Rafael Espíndola.
llvm-svn: 240318
Now that pr23900 is fixed, we can bring it back with no changes.
Original message:
Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.
Some of these symbols still show up in the symbol table, but we can just
make them unnamed.
In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.
Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.
llvm-svn: 240302
The ADDITIONAL_HEADER_DIRS command can be used to tell UIs that a given library
owns certain headers. The path for MCParser was missing MC/ in it.
llvm-svn: 240175
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.
Some of these symbols still show up in the symbol table, but we can just
make them unnamed.
In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.
Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.
llvm-svn: 240130
MCFragment didn't really need vtables. The majority of virtual methods were just getters and setters.
This removes the vtables and uses dispatch on the kind to do things like delete which needs to
get the appropriate class.
This reduces memory on the verify use list order test case by about 2MB out of 800MB.
Reviewed by Rafael Espíndola
llvm-svn: 239952
Directional labels can show up in symbol tables (and we have a llvm-mc test for
that). Given that, we need to make sure they are named.
With that out of the way, use setUseNamesOnTempLabels in llvm-mc so that it
too benefits from the memory saving.
llvm-svn: 239914
Summary:
This affects other tools so the previous C++ API has been retained as a
deprecated function for the moment. Clang has been updated with a trivial
patch (not covered by the pre-commit review) to avoid breaking -Werror builds.
Other in-tree tools will be fixed with similar patches.
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
The first time this was committed it accidentally fixed an inconsistency in
triples in llvm-mc and this caused a failure. This inconsistency was fixed in
r239808.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10366
llvm-svn: 239812
Summary:
This instruction encodes a loading operation that may fault, and a label
to branch to if the load page-faults. The locations of potentially
faulting loads and their "handler" destinations are recorded in a
FaultMap section, meant to be consumed by LLVM's clients.
Nothing generates FAULTING_LOAD_OP instructions yet, but they will be
used in a future change.
The documentation (FaultMaps.rst) needs improvement and I will update
this diff with a more expanded version shortly.
Depends on D10196
Reviewers: rnk, reames, AndyAyers, ab, atrick, pgavlin
Reviewed By: atrick, pgavlin
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10197
llvm-svn: 239740
Summary:
This affects other tools so the previous C++ API has been retained as a
deprecated function for the moment. Clang has been updated with a trivial
patch (not covered by the pre-commit review) to avoid breaking -Werror builds.
Other in-tree tools will be fixed with similar trivial patches.
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10366
llvm-svn: 239721
This intrinsic is like framerecover plus a load. It recovers the EH
registration stack allocation from the parent frame and loads the
exception information field out of it, giving back a pointer to an
EXCEPTION_POINTERS struct. It's designed for clang to use in SEH filter
expressions instead of accessing the EXCEPTION_POINTERS parameter that
is available on x64.
This required a minor change to MC to allow defining a label variable to
another absolute framerecover label variable.
llvm-svn: 239567
This makes emitAbsoluteSymbolDiff always succeed and moves logic from the asm
printer to it.
The object one now also works on ELF. If two symbols are in the same fragment,
we will never move them apart.
llvm-svn: 239552
Summary:
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
Reviewers: rafael
Reviewed By: rafael
Subscribers: rafael, ted, jfb, llvm-commits, rengolin, jholewinski
Differential Revision: http://reviews.llvm.org/D10311
llvm-svn: 239467
Summary:
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
Reviewers: rafael
Reviewed By: rafael
Subscribers: rafael, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10307
llvm-svn: 239465
Use a "safeseh" string attribute to do this. You would think we chould
just accumulate the set of personalities like we do on dwarf, but this
fails to account for the LSDA-loading thunks we use for
__CxxFrameHandler3. Each of those needs to make it into .sxdata as well.
The string attribute seemed like the most straightforward approach.
llvm-svn: 239448
This reverts commit 2e449ec5bcdf67b52b315b16c2128aaf25d5b73c.
This was svn r239440. Its currently failing an ARM test so reverting while I work out
what to do next.
llvm-svn: 239441
It wasn't possible to have a variable Symbol with offset or 'isCommon' so
this just enables better packing of the MCSymbol class.
Reviewed by Rafael Espindola.
llvm-svn: 239440
Based on feedback to r239428 by David Blaikie, use const_cast to reduce
duplication of the const and non-const versions of getNameEntryPtr.
Also have that method return the pointer to the name directly instead
of users having to then get the name from the union.
Finally, add a FIXME that we should use a static_assert once available in
the new operator.
llvm-svn: 239429
This should hopefully fix the 32-bit bots which were allocating space for a pointer
but needed to be aligned to 64-bits.
Now we allocate enough space for a uint64_t and a pointer and cast to the appropriate storage
llvm-svn: 239428
Similarly to User which allocates a number of Use's prior to the this pointer,
allocate space for the Name* for MCSymbol only when we need a name.
Given that an MCSymbol is 48-bytes on 64-bit systems, this saves a decent % of space.
Given the verify_uselistorder test case with debug info and llc, 50k symbols have names
out of 700k so this optimises for the common case of temporary unnamed symbols.
Reviewed by David Blaikie.
llvm-svn: 239423
Also delete the now unused MCMachOSymbolFlags.h header as the only enum in there was moved to MCSymbolMachO.
Similarly to ELF and COFF, manipulating the flags is now done via helpers instead of spread
throughout the codebase.
Reviewed by Rafael Espíndola.
llvm-svn: 239316
All flags setting/getting is now done in the class with helper methods instead
of users having to get the bits in the correct order.
Reviewed by Rafael Espíndola.
llvm-svn: 239314
Add getFPUFeatures to TargetParser, which gets the list of subtarget features
that are enabled/disabled for each FPU, and use it when handling the .fpu
directive.
No functional change in this commit, though clang will start behaving
differently once it starts using this.
Differential Revision: http://reviews.llvm.org/D10237
llvm-svn: 239150
Fix the FIXME and remove this old as(1) compat option. It was useful for
bringup of the integrated assembler to diff object files, but now it's
just causing more relocations than strictly necessary to be generated.
rdar://21201804
llvm-svn: 239084
Section symbols exist as an optimization: instead of having multiple relocations
point to different symbols, many of them can point to a single section symbol.
When that optimization is unused, a section symbol is also unused and adds no
extra information to the object file.
This saves a bit of space on the object files and makes the output of
llvm-objdump -t easier to read and consequently some tests get quite a bit
simpler.
llvm-svn: 239045
The fix is just that getOther had not been updated for packing the st_other
values in fewer bits and could return spurious values:
- unsigned Other = (getFlags() & (0x3f << ELF_STO_Shift)) >> ELF_STO_Shift;
+ unsigned Other = (getFlags() & (0x7 << ELF_STO_Shift)) >> ELF_STO_Shift;
Original message:
Pack the MCSymbolELF bit fields into MCSymbol's Flags.
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
llvm-svn: 239012
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
llvm-svn: 239006
This avoids yet another last minute patching of the binding.
While at it, also simplify the weakref implementation a bit by not walking
past it in the expression evaluation.
llvm-svn: 238982
With this getBinging can now return the correct answer for all cases not
involving a .symver and the elf writer doesn't need to patch it last minute.
llvm-svn: 238980
Some temporary symbols are created by MC itself. These symbols are never used
for lookup and are never included in the object symbol table, so we can
avoid creating a name for them.
Other temporaries are created by CodeGen or by the user by explicitly asking
for a name starting with .L (or L on MachO).
These temporaries behave like regular symbols, we just try to avoid including
them in the object symbol table, but sometimes they end up there:
const char *foo() {
return "abc" + 3;
}
will have a relocation pointing to a .L symbol.
It just so happens that almost all MC created temporary has the AlwaysAddSuffix
option and CodeGen/user created ones don't.
One interesting future optimization would be to use unnamed symbols for
all temporaries, but that would require use an st_name of 0 or
having the object writer create the names if a symbol does end up in the
symbol table.
No testcase since this just avoid creating a few extra names for MC created
temporaries.
llvm-svn: 238887
Summary:
Following on from r209907 which made personality encodings indirect, do the
same for TType encodings. This fixes the case where a try/catch block needs
to generate references to, for example, std::exception in the
.gcc_except_table.
Previous attempts at committing this broke the buildbots due to bugs in IAS.
These bugs have now been fixed so trying again.
Reviewers: petarj
Reviewed By: petarj
Subscribers: srhines, joerg, tberghammer, llvm-commits
Differential Revision: http://reviews.llvm.org/D9669
llvm-svn: 238863
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.
This reduces the size of MCSymbol from 56 to 48 bytes.
llvm-svn: 238801
There is no MCSectionData, so the old name is now meaningless.
Also remove some asserts/checks that were there just because the information
they used was in MCSectionData.
llvm-svn: 238708
Dan Gohman