Summary:
There seems to have been a misunderstanding as to the meaning of 'offset' in
the rules laid down by our ABI. The previous code believed that 'offset' meant
the offset within the section that the relocation is applied to. However, it
should have meant the offset from the symbol used in the relocation expression.
This patch adds two fields to ELFRelocationEntry and uses them to correct the
order of relocations for MIPS. These fields contain:
* The original symbol before shouldRelocateWithSymbol() is considered. This
ensures that R_MIPS_GOT16 is able to correctly distinguish between local and
external symbols, allowing us to tell whether %got() requires a matching
%lo() or not (local symbols require one, external symbols don't). It also
prevents confusing cases where the fuzzy matching rules cause things like
%hi(foo)/%lo(foo+3) and %hi(bar)/%lo(bar+1) to swap their %lo()'s.
* The original offset before shouldRelocateWithSymbol() is considered. The
existing Addend field is always zero when the object uses in place addends
(because it's already moved it to the encoding) but MIPS needs to use the
original offset to ensure that the linker correctly calculates the carry-in
bit for %hi() and %got().
IAS ensures that unmatchable %hi()/%got() relocations are placed at the end of
the table to ensure that the linker rejects the table (we're unable to report
such errors directly). The alternatives to this risk accidental matching
against inappropriate relocations which may silently compute incorrect values
due to an incorrect carry bit between the %lo() and %hi()/%got().
Reviewers: sdardis
Subscribers: dsanders, sdardis, rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D19718
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268733 91177308-0d34-0410-b5e6-96231b3b80d8
This change seems to speed up LLD a bit if it has a lot of mergeable
sections. The number is below. It's not too bad for a small patch.
Time to link Clang (debug build):
w/o patch 6.3696 seconds
w/patch 6.2746 seconds (-1.5%)
Differential Revision: http://reviews.llvm.org/D19933
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268698 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is much closer to the way MIPS relocation expressions work
(%hi(foo + 2) rather than %hi(foo) + 2) and removes the need for the
various bodges in MipsAsmParser::evaluateRelocExpr().
Removing those bodges ensures that the constant stored in MCValue is the
full 32 or 64-bit (depending on ABI) offset from the symbol. This will be used
to correct the %hi/%lo matching needed to sort the relocation table correctly.
As part of this:
* Gave MCExpr::print() the ability to omit parenthesis when emitting a
symbol reference inside a MipsMCExpr operator like %hi(X). Without this
we print things like %lo(($L1)).
* %hi(%neg(%gprel(X))) is now three MipsMCExpr's instead of one. Most of
the related special cases have been removed or moved to MipsMCExpr. We
can remove the rest as we gain support for the less common relocations
when they are not part of this specific combination.
* Renamed MipsMCExpr::VariantKind and the enum prefix ('VK_') to avoid confusion
with MCSymbolRefExpr::VariantKind and its prefix (also 'VK_').
* fixup_Mips_GOT_Local and fixup_Mips_GOT_Global were found to be identical
and merged into fixup_Mips_GOT.
* MO_GOT16 and MO_GOT turned out to be identical and have been merged into
MO_GOT.
* VK_Mips_GOT and VK_Mips_GOT16 turned out to be the same thing so they
have been merged into MEK_GOT
Reviewers: sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D19716
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268379 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This adds a unique ID to the COFF section uniquing map, similar to the
one we have for ELF. The unique id is not currently exposed via the
assembler because we don't have a use case for it yet. Users generally
create .pdata with the .seh_* family of directives, and the assembler
internally needs to produce .pdata and .xdata sections corresponding to
the code section.
The association between .text sections and the assembler-created .xdata
and .pdata sections is maintained as an ID field of MCSectionCOFF. The
CFI-related sections are created with the given unique ID, so if more
code is added to the same text section, we can find and reuse the CFI
sections that were already created.
Reviewers: majnemer, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D19376
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268331 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is the follow-up patch for http://reviews.llvm.org/D19436
* Update the discriminator reading algorithm to match the assignment algorithm.
* Add test to cover the new algorithm.
Reviewers: dnovillo, echristo, dblaikie
Subscribers: danielcdh, dblaikie, echristo, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D19522
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267945 91177308-0d34-0410-b5e6-96231b3b80d8
A latent bug in llvm-objdump used the wrong format specifier on 32-bit
targets, causing the test to fail. This fixes the issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267582 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The clang assembler assumes that the discriminator remains the same when there is source line change. The correct behavior is that when there is line change, discriminator will automatically reset to 0.
Reviewers: dnovillo, davidxl, echristo
Subscribers: echristo, llvm-commits
Differential Revision: http://reviews.llvm.org/D19436
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267226 91177308-0d34-0410-b5e6-96231b3b80d8
We'd disabled them on x86 because back in the early days some host tools
couldn't handle the new load commands. This no longer holds: anyone capable of
deploying Clang should be able to deploy its copies of ar/ranlib/etc.
rdar://25254790
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267075 91177308-0d34-0410-b5e6-96231b3b80d8
Since we can't emit diagnostics for missing "jmp 1f" labels until the end of
the file, we need to be able to restore the context used to calculate
file/line. This is basically the "# line file" directive that's being used at
the time the expression is seen.
rdar://25706972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266238 91177308-0d34-0410-b5e6-96231b3b80d8
Before, ELF at least managed a diagnostic but it was a completely untraceable
"undefined symbol" error. MachO had a variety of even worse behaviours: crash,
emit corrupt file, or an equally bad message.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265984 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fix for PR26941.
When there is both a section and a global definition with the same
name, the global wins.
Section symbols are not added to the symbol table; section references
are left undefined and fixed up in the object writer unless they've
been satisfied by some other definition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264649 91177308-0d34-0410-b5e6-96231b3b80d8
MCContext shouldn't be accessing the filesystem - that's a gross
layering violation and makes it awkward to use as a library or in a
daemon where it may not even be allowed filesystem access.
The CWD lookup here is normally redundant anyway, since the calling
context either also looks up the CWD or sets this to something more
specific. Here, we fix up the one caller that doesn't already set up a
debug compilation dir and make it clear that the responsibility for
such set up is in the users of MCContext.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264109 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support for the MachO .alt_entry assembly directive, and uses
it for global aliases with non-zero GEP offsets. The alt_entry flag indicates
that a symbol should be layed out immediately after the preceding symbol.
Conceptually it introduces an alternate entry point for a function or data
structure. E.g.:
safe_foo:
// check preconditions for foo
.alt_entry fast_foo
fast_foo:
// body of foo, can assume preconditions.
The .alt_entry flag is also implicitly set on assembly aliases of the form:
a = b + C
where C is a non-zero constant, since these have the same effect as an
alt_entry symbol: they introduce a label that cannot be moved relative to the
preceding one. Setting the alt_entry flag on aliases of this form fixes
http://llvm.org/PR25381.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263521 91177308-0d34-0410-b5e6-96231b3b80d8
`MCSymbolRefExpr` variant kind for TLSCALL is prefixed with
_ARM_ since this is how it was originally implemented.
The X86_64 version is exactly the same so there's no reason
to create a new variant, we can just rename the existing
one to be machine-independent.
This generalization is the first step to implement support
for GNU2 TLS dialect in MC.
Differential Revision: http://reviews.llvm.org/D18160
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263515 91177308-0d34-0410-b5e6-96231b3b80d8
Until now curly braces could only be used in MS inline assembly to mark block start/end.
All curly braces were removed completely at a very early stage.
This approach caused bugs like:
"m{o}v eax, ebx" turned into "mov eax, ebx" without any error.
In addition, AVX-512 added special operands (e.g., k registers), which are also surrounded by curly braces that mark them as such.
Now, we need to keep the curly braces and identify at a later stage if they are marking block start/end (if so, ignore them), or surrounding special AVX-512 operands (if so, parse them as such).
This patch fixes the bug described above and enables the use of AVX-512 special operands.
This commit is the the llvm part of the patch.
The clang part of the review is: http://reviews.llvm.org/D17766
The llvm part of the review is: http://reviews.llvm.org/D17767
Differential Revision: http://reviews.llvm.org/D17767
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262843 91177308-0d34-0410-b5e6-96231b3b80d8
We supported creating mergeable constant pool entries for smaller
constants but not for 32-byte AVX constants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261584 91177308-0d34-0410-b5e6-96231b3b80d8
This apparently comes up when the register allocator decides that a
variable will become undef along a certain path.
Also improve the error message we emit when we can't map from LLVM
register number to CV register number.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261016 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fixed an issue for mips with an instruction such as 'sdc1 $f1, 272 +8(a0)' which has a space between '272' and '+'. The parser would then parse '272' and '+8' as two arguments instead of a single expression resulting in one too many arguments in the pseudo instruction.
The reason that the test case has been changed is so that the expected
output matches the output of the GNU assembler.
Reviewers: vkalintiris, dsanders
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13592
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260521 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Refactor common value, scope, and label tracking logic out of DwarfDebug
into a common base class called DebugHandlerBase.
Update an old LLVM IR test case to avoid an assertion in LexicalScopes.
Reviewers: dblaikie, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16931
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260432 91177308-0d34-0410-b5e6-96231b3b80d8
CodeView, like most other debug formats, represents the live range of a
variable so that debuggers might print them out.
They use a variety of records to represent how a particular variable
might be available (in a register, in a frame pointer, etc.) along with
a set of ranges where this debug information is relevant.
However, the format only allows us to use ranges which are limited to a
maximum of 0xF000 in size. This means that we need to split our debug
information into chunks of 0xF000.
Because the layout of code is not known until *very* late, we must use a
new fragment to record the information we need until we can know
*exactly* what the range is.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259868 91177308-0d34-0410-b5e6-96231b3b80d8
CodeView requires us to accurately describe the extent of the inlined
code. We did this by grabbing the next debug location in source order
and using *that* to denote where we stopped inlining. However, this is
not sufficient or correct in instances where there is no next debug
location or the next debug location belongs to the start of another
function.
To get this correct, use the end symbol of the function to denote the
last possible place the inlining could have stopped at.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259548 91177308-0d34-0410-b5e6-96231b3b80d8
This directive emits the binary annotations that describe line and code
deltas in inlined call sites. Single-stepping through inlined frames in
windbg now works.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259535 91177308-0d34-0410-b5e6-96231b3b80d8
