expressions for mov instructions instead of silently truncating by default.
For the ARM assembler, we want to avoid misleadingly allowing something
like "mov r0, <symbol>" especially when we turn it into a movw and the
expression <symbol> does not have a :lower16: or :upper16" as part of the
expression. We don't want the behavior of silently truncating, which can be
unexpected and lead to bugs that are difficult to find since this is an easy
mistake to make.
This does change the previous behavior of llvm but actually matches an
older gnu assembler that would not allow this but print less useful errors
of like “invalid constant (0x927c0) after fixup” and “unsupported relocation on
symbol foo”. The error for llvm is "immediate expression for mov requires
:lower16: or :upper16" with correct location information on the operand
as shown in the added test cases.
rdar://12342160
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206669 91177308-0d34-0410-b5e6-96231b3b80d8
Both ZLIB and the debug info compressed section header ("ZLIB" + the
size of the uncompressed data) take some constant overhead so in some
cases the compressed data is actually larger than the uncompressed data.
In these cases, just don't compress or rename the section at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206659 91177308-0d34-0410-b5e6-96231b3b80d8
While unnamed relocations are already cached in side tables in
ELFObjectWriter::RecordRelocation, symbols still need their fragments
updated to refer to the newly compressed fragment (even if that fragment
isn't big enough to fit the offset). Even though we only create
temporary symbols in debug info sections this comes up in 32 bit builds
where even temporary symbols in mergeable sections (such as debug_str)
have to be emitted as named symbols.
I tried a few other ways to do this but they all didn't work for various
reasons:
1) Canonicalize the MCSymbolData in RecordRelocation, nulling out the
Fragment (so it didn't have to be updated by CompressDebugSection). This
doesn't work because some code relies on symbols having fragments to
indicate that they're defined, I think.
2) Canonicalize the MCSymbolData in RecordRelocation to be "first
fragment + absolute offset" so it would be cheaper to just test and
update the fragment in CompressDebugSections. This doesn't work because
the offset computed in RecordRelocation isn't that of the symbol's
fragment, it's the passed in fragment (I haven't figured out what that
fragment is - perhaps it's the location where the relocation is to be
written). And if the fragment offset has to be computed only for this
use we might as well just do it when we need to, in
CompressDebugSection.
I also added an assert to help catch this a bit more clearly, even
though it is UB. The test case improvements would either assert fail
and/or valgrind vail without the fix, even if they wouldn't necessarily
fail the FileCheck output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206653 91177308-0d34-0410-b5e6-96231b3b80d8
This commit was attributed to a different person from the person who
posted the patch to the list, and the person who posted it the list
claimed when they did that they were not the author, but that the author
was yet a third person. I don't know what is going on here, but
reverting until the attribution is clear and the author has explicitly
contributed the patch.
Also, the review hasn't really involved any of the MC maintainers and
that seems questionable too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206576 91177308-0d34-0410-b5e6-96231b3b80d8
Update the SXT[BHW]/UXTW instruction aliases and the shifted reg addressing
mode handling.
PR19455 and rdar://16650642
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This enables TableGen to generate an additional two operand
matcher for our shift_rotate_imm and shift_rotate_reg class of instructions.
The tests were also updated so that they include now encoding information
for all affected instructions.
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This is so that EF_MIPS_NAN2008 is set if we are using IEEE 754-2008
NaN encoding (-mnan=2008). This patch also adds support for parsing
'.nan legacy' and '.nan 2008' assembly directives. The handling of
these directives should match GAS' behaviour i.e., the last directive
in use sets the ELF header bit (EF_MIPS_NAN2008).
Differential Revision: http://reviews.llvm.org/D3346
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Adjust the tests to validate the number of auxiliary entries used to store the
filename.
Thanks to majnemer's sharp eye for catching the missing - 1 in the round up
calculation.
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Add support for emitting .file records. This is mostly a quality of
implementation change (more complete support for COFF file emission) that was
noticed while working on COFF file emission for Windows on ARM.
A .file record is emitted as a symbol with storage class FILE (103) and the name
".file". A series of auxiliary format 4 records follow which contain the file
name. The filename is stored as an ANSI string and is padded with NULL if the
length is not a multiple of COFF::SymbolSize (18).
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Sometimes we need emit the bits that would actually be a MOVN when producing a
relocated MOVZ instruction (don't ask). But not always, a check which ARM64 got
wrong until now.
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Currently, we bind those directives with the last symbol, so if none
has been defined, this would lead to a crash of the compiler.
<rdar://problem/15939159>
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This allows correct relocations to be generated for a symbolic
address that is being adjusted by a negative constant. Since r204294,
such expressions have triggered undefined behavior when LLVM was built
without assertions.
Credit goes to Rafael for this patch; I'm submitting it on his behalf
as he is on vacation this week.
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This was most likely caused by an uninitialized value and the relevant code was re-written in r205292. Reverting to see if it still fails on any of the buildbots.
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To support compressing the debug_line section that contains multiple
fragments (due, I believe, to variation in choices of line table
encoding depending on the size of instruction ranges in the actual
program code) we needed to support compressing multiple MCFragments in a
single pass.
This patch implements that behavior by mutating the post-relaxed and
relocated section to be the compressed form of its former self,
including renaming the section.
This is a more flexible (and less invasive, to a degree) implementation
that will allow for other features such as "use compression only if it's
smaller than the uncompressed data".
Compressing debug_frame would be a possible further extension to this
work, but I've left it for now. The hurdle there is alignment sections -
which might require going as far as to refactor
MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an
MCObjectWriter (there's already a virtual call there, so it shouldn't
add substantial compile-time cost) which could in turn involve
refactoring MCAsmBackend::writeNopData to use that same abstraction...
which involves touching all the backends. This would remove the limited
handling of fragment writing seen in
ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's
more invasive.
I did discover that I (perhaps obviously) don't need to handle
relocations when I rewrite the fragments - since the relocations have
already been applied and computed (and stored into
ELFObjectWriter::Relocations) by this stage (necessarily, because we
need to have written any immediate values or assembly-time relocations
into the data already before we compress it, which we have). The test
case doesn't necessarily cover that in detail - I can add more test
coverage if that's preferred.
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To support compression for debug_line and debug_frame a different
approach is required. To simplify review, revert the old implementation
and XFAIL the test case. New implementation to follow shortly.
Reverts r205059 and r204958.
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alignments on vld/vst instructions. And report errors for
alignments that are not supported.
While this is a large diff and an big test case, the changes
are very straight forward. But pretty much had to touch
all vld/vst instructions changing the addrmode to one of the
new ones that where added will do the proper checking for
the specific instruction.
FYI, re-committing this with a tweak so MemoryOp's default
constructor is trivial and will work with MSVC 2012. Thanks
to Reid Kleckner and Jim Grosbach for help with the tweak.
rdar://11312406
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Summary:
It is now the smallest superset for these ISA's.
FeatureMips4 now contains FeatureFPIdx since [ls][dw]xc1 were added in MIPS-IV.
Made the FPIdx feature bit lowercase so that it can be used in the -mattr option.
Depends on D3274
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://reviews.llvm.org/D3275
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It doesn't build with MSVC 2012, because MSVC doesn't allow union
members that have non-trivial default constructors. This change added
'SMLoc AlignmentLoc' to MemoryOp, which made MemoryOp's default ctor
non-trivial.
This reverts commit r205930.
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alignments on vld/vst instructions. And report errors for
alignments that are not supported.
While this is a large diff and an big test case, the changes
are very straight forward. But pretty much had to touch
all vld/vst instructions changing the addrmode to one of the
new ones that where added will do the proper checking for
the specific instruction.
rdar://11312406
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205930 91177308-0d34-0410-b5e6-96231b3b80d8