Certain ARM instructions accept 32-bit immediate operands encoded as a 8-bit
integer value (0-255) and a 4-bit rotation (0-30, even). Current ARM assembly
syntax support in LLVM allows the decoded (32-bit) immediate to be specified
as a single immediate operand for such instructions:
mov r0, #4278190080
The ARMARM defines an extended assembly syntax allowing the encoding to be made
more explicit, as in:
mov r0, #255, #8 ; (same 32-bit value as above)
The behaviour of the two instructions can be different w.r.t flags, which is
documented under "Modified immediate constants" in ARMARM. This patch enables
support for this extended syntax at the MC layer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223113 91177308-0d34-0410-b5e6-96231b3b80d8
This corrects the emission of IMAGE_REL_ARM_MOV32T relocations. Previously, we
were avoiding the high portion of the relocation too early. If there was a
section-relative relocation with an offset greater than 16-bits (65535), you
would end up truncating the high order bits of the offset. Allow the current
relocation representation to flow through out the MC layer to the object writer.
Use the new ability to restrict recorded relocations to avoid emitting the
relocation into the final object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209337 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce support for WoA PE/COFF object file emission from LLVM. Add the new
target specific PE/COFF Streamer (ARMWinCOFFStreamer) that handles the ARM
specific behaviour of PE/COFF object emission. ARM exception information is not
yet emitted and is a TODO item.
The ARM specific object writer (ARMWinCOFFObjectWriter) handles the ARM specific
relocation handling in conjunction with the WinCOFFObjectWriter in the MC layer.
The MC layer needs to be updated to deal with the relocation adjustments.
Branch relocations are adjusted by 4 bytes (unlikely their ELF counterparts).
Minor tweaks to switch multiple conditional checks into equivalent switch
statements. The ObjectFileInfo is updated to relax the object file setup for
Windows COFF. Move the architecture checks into an assertion. Windows COFF is
currently only supported on x86, x86_64, and ARM (thumb). Rather than
defaulting to ELF, we will refuse to generate an object file. This is better
though as you do not get an (arbitrary) object file which is different from the
request.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207345 91177308-0d34-0410-b5e6-96231b3b80d8
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
Issue subject: Crash using integrated assembler with immediate arithmetic
Fix description:
Expressions like 'cmp r0, #(l1 - l2) >> 3' could not be evaluated on asm parsing stage,
since it is impossible to resolve labels on this stage. In the end of stage we still have
expression (MCExpr).
Then, when we want to encode it, we expect it to be an immediate, but it still an expression.
Patch introduces a Fixup (MCFixup instance), that is processed after main encoding stage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205094 91177308-0d34-0410-b5e6-96231b3b80d8
I started trying to fix a small issue, but this code has seen a small fix too
many.
The old code was fairly convoluted. Some of the issues it had:
* It failed to check if a symbol difference was in the some section when
converting a relocation to pcrel.
* It failed to check if the relocation was already pcrel.
* The pcrel value computation was wrong in some cases (relocation-pc.s)
* It was missing quiet a few cases where it should not convert symbol
relocations to section relocations, leaving the backends to patch it up.
* It would not propagate the fact that it had changed a relocation to pcrel,
requiring a quiet nasty work around in ARM.
* It was missing comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205076 91177308-0d34-0410-b5e6-96231b3b80d8
Fix description:
Expressions like 'cmp r0, #(l1 - l2) >> 3' could not be evaluated on asm parsing stage,
since it is impossible to resolve labels on this stage. In the end of stage we still have
expression (MCExpr).
Then, when we want to encode it, we expect it to be an immediate, but it still an expression.
Patch introduces a Fixup (MCFixup instance), that is processed after main encoding stage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204899 91177308-0d34-0410-b5e6-96231b3b80d8
The commit r203762 introduced silent failure for complext SO expression, and it's even worse than compiler crash.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204427 91177308-0d34-0410-b5e6-96231b3b80d8
Support to the IAS was added to actually parse and handle the complex SO
expressions. However, the object file lowering was not updated to compensate
for the fact that the shift operand may be an absolute expression.
When trying to assemble to an object file, the lowering would fail while
succeeding when emitting purely assembly. Add an appropriate test.
The test case is inspired by the test case provided by Jiangning Liu who also
brought the issue to light.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203762 91177308-0d34-0410-b5e6-96231b3b80d8
The subtarget info is explicitly passed to the EncodeInstruction
method and we should use that subtarget info to influence any
encoding decisions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200350 91177308-0d34-0410-b5e6-96231b3b80d8
A 32-bit immediate value can be formed from a constant expression and loaded
into a register. Add support to emit this into an object file. Because this
value is a constant, a relocation must *not* be produced for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199023 91177308-0d34-0410-b5e6-96231b3b80d8
The ARM backend has been using most of the MachO related subtarget
checks almost interchangeably, and since the only target it's had to
run on has been IOS (which is all three of MachO, Darwin and IOS) it's
worked out OK so far.
But we'd like to support embedded targets under the "*-*-none-macho"
triple, which means everything starts falling apart and inconsistent
behaviours emerge.
This patch should pick a reasonably sensible set of behaviours for the
new triple (and any others that come along, with luck). Some choices
were debatable (notably FP == r7 or r11), but we can revisit those
later when deficiencies become apparent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198617 91177308-0d34-0410-b5e6-96231b3b80d8
an MCExpr, in order to avoid writing an encoded zero value in the immediate
field.
When getUnconditionalBranchTargetOpValue is called with an MCExpr target, we
don't know what the final immediate field value should be. We shouldn't
explicitly set the immediate field to an encoded zero value as zero is encoded
with a non-zero bit pattern. This leads to bits being set that pollute the
final immediate value. The nature of the encoding is such that the polluted
bits only affect very large immediate values, explaining why this hasn't
caused problems earlier.
Fixes <rdar://problem/15155975>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193535 91177308-0d34-0410-b5e6-96231b3b80d8
Thumb2 literal loads use an offset encoding which allows for
negative zero. This fixes parsing and encoding so that #-0
is correctly processed. The parser represents #-0 as INT32_MIN.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188549 91177308-0d34-0410-b5e6-96231b3b80d8
The long encoding for Thumb2 unconditional branches is broken.
Additionally, there is no range checking for target operands; as such
for instructions originating in assembly code, only short Thumb encodings
are generated, regardless of the bitsize needed for the offset.
Adding range checking is non trivial due to the representation of Thumb
branch instructions. There is no true difference between conditional and
unconditional branches in terms of operands and syntax - even unconditional
branches have a predicate which is expected to match that of the IT block
they are in. Yet, the encodings and the permitted size of the offset differ.
Due to this, for any mnemonic there are really 4 encodings to choose for.
The problem cannot be handled in the parser alone or by manipulating td files.
Because the parser builds first a set of match candidates and then checks them
one by one, whatever tablegen-only solution might be found will ultimately be
dependent of the parser's evaluation order. What's worse is that due to the fact
that all branches have the same syntax and the same kinds of operands, that
order is governed by the lexicographical ordering of the names of operand
classes...
To circumvent all this, any necessary disambiguation is added to the instruction
validation pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188067 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a new class for non-predicable NEON instructions and a
new DecoderNamespace for v8 NEON instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186504 91177308-0d34-0410-b5e6-96231b3b80d8
When using a positive offset, literal loads where encoded
as if it was negative, because:
- The sign bit was not assigned to an operand
- The addrmode_imm12 operand was not encoding the sign bit correctly
This patch also makes the assembler look at the .w/.n specifier for
loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184182 91177308-0d34-0410-b5e6-96231b3b80d8
Someone may want to do something crazy, like replace these objects if they
change or something.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184175 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes an issue where trying to assemlbe valid ADR instructions would cause
LLVM to hit a failed assertion.
Patch by Keith Walker.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176189 91177308-0d34-0410-b5e6-96231b3b80d8
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes load/store instructions to handle less common cases
like "asr #32", "rrx" properly throughout the MC layer.
Patch by Chris Lidbury.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164455 91177308-0d34-0410-b5e6-96231b3b80d8
the register info for getEncodingValue. This builds on the
small patch of yesterday to set HWEncoding in the register
file.
One (deprecated) use was turned into a hard number to avoid
needing register info in the old JIT.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161628 91177308-0d34-0410-b5e6-96231b3b80d8
Add the MCRegisterInfo to the factories and constructors.
Patch by Tom Stellard <Tom.Stellard@amd.com>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156828 91177308-0d34-0410-b5e6-96231b3b80d8
Expressions for movw/movt don't always have an :upper16: or :lower16:
on them and that's ok. When they don't, it's just a plain [0-65536]
immediate result, effectively the same as a :lower16: variant kind.
rdar://10550147
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155941 91177308-0d34-0410-b5e6-96231b3b80d8
We on the linker to resolve calls to the appropriate BL/BLX instruction
to make interworking function correctly. It uses the symbol in the
relocation to do that, so we need to be careful about being too clever.
To enable this for ARM mode, split the BL/BLX fixup kind off from the
unconditional-branch fixups.
rdar://10927209
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151571 91177308-0d34-0410-b5e6-96231b3b80d8
Adjust an example MachObjectWriter diagnostic to use the information
to issue a better message.
Before:
LLVM ERROR: unknown ARM fixup kind!
After:
x.s:6:5: error: unsupported relocation on symbol
beq bar
^
rdar://9800182
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149093 91177308-0d34-0410-b5e6-96231b3b80d8
