The hardware div feature refers only to Thumb, but because of its name
it is tempting to use it to check for hardware division in general,
which may cause problems in ARM mode. See https://reviews.llvm.org/D32005.
This patch adds "Thumb" to its name, to make its scope clear. One
notable place where I haven't made the change is in the feature flag
(used with -mattr), which is still hwdiv. Changing it would also require
changes in a lot of tests, including clang tests, and it doesn't seem
like it's worth the effort.
Differential Revision: https://reviews.llvm.org/D32160
llvm-svn: 300827
In the assembler, we should emit build attributes based on the target
selected with command-line options. This matches the GNU assembler's
behaviour. We only do this for build attributes which describe the
hardware that is expected to be available, not the ones that describe
ABI compatibility.
This is done by moving some of the attribute emission code to
ARMTargetStreamer, so that it can be shared between the assembly and
code-generation code paths. Since the assembler only creates a
MCSubtargetInfo, not an ARMSubtarget, the code had to be changed to
check raw features, and not use the convenience functions in
ARMSubtarget.
If different attributes are later specified using the .eabi_attribute
directive, then they will take precedence, as happens when the same
.eabi_attribute is specified twice.
This must be enabled by an option, because we don't want to do this when
parsing inline assembly. The attributes would match the ones emitted at
the start of the file, so wouldn't actually change the emitted object
file, but the extra directives would be added to every inline assembly
block when emitting assembly, which we'd like to avoid.
The majority of the changes in the build-attributes.ll test are just
re-ordering the directives, because the hardware attributes are now
emitted before the ABI ones. However, I did fix one bug which I spotted:
Tag_CPU_arch_profile was not being emitted for v6M.
Differential revision: https://reviews.llvm.org/D31812
llvm-svn: 300547
- we are now using immediate AsmOperands so that the range check functions are
tablegen'ed.
- Big bonus is that error messages become much more accurate, i.e. instead of a
useless "invalid operand" error message it will not say that the immediate
operand must in range [x,y], which is why regression tests needed updating.
More tablegen operand descriptions could probably benefit from using
immediateAsmOperand, but this is a first good step to get rid of most of the
nearly identical range check functions. I will address the remaining immediate
operands in next clean ups.
Differential Revision: https://reviews.llvm.org/D31333
llvm-svn: 299358
Summary:
To support negative immediates for certain arithmetic instructions, the
instruction is converted to the inverse instruction with a negated (or inverted)
immediate. For example, "ADD r0, r1, #FFFFFFFF" cannot be encoded as an ADD
instruction. However, "SUB r0, r1, #1" is equivalent.
These conversions are different from instruction aliases. An alias maps
several assembler instructions onto one encoding. A conversion, however, maps
an *invalid* instruction--e.g. with an immediate that cannot be represented in
the encoding--to a different (but equivalent) instruction.
Several instructions with negative immediates were being converted already, but
this was not systematically tested, nor did it cover all instructions.
This patch implements all possible substitutions for ARM, Thumb1 and
Thumb2 assembler and adds tests. It also adds a feature flag
(-mattr=+no-neg-immediates) to turn these substitutions off. This is
helpful for users who want their code to assemble to exactly what they
wrote.
Reviewers: t.p.northover, rovka, samparker, javed.absar, peter.smith, rengolin
Reviewed By: javed.absar
Subscribers: aadg, aemerson, llvm-commits
Differential Revision: https://reviews.llvm.org/D30571
llvm-svn: 298380
This instruction was missing from the list of opcodes that we check, so we were
hitting an llvm_unreachable in ARMMCCodeEmitter.cpp for the ARM MOVT
instruction, rather than the diagnostic that is emitted for the other MOVW/MOVT
instructions.
Differential revision: https://reviews.llvm.org/D30936
llvm-svn: 297739
The check for LSL #0 in an IT block was checking if operand 4 was zero, but
operand 4 is the condition code operand so it was actually checking for LSLEQ.
Fix this by checking operand 3, which really is the immediate operand, and add
some tests.
Differential Revision: https://reviews.llvm.org/D30692
llvm-svn: 297142
This parsing code was incorrectly checking for invalid characters, so an
invalid instruction like:
msr spsr_w, r0
would be emitted as:
msr spsr_cxsf, r0
Differential revision: https://reviews.llvm.org/D30462
llvm-svn: 296607
In Thumb2, instructions which write to the PC are UNPREDICTABLE if they are in
an IT block but not the last instruction in the block.
Previously, we only diagnosed this for LDM instructions, this patch extends the
diagnostic to cover all of the relevant instructions.
Differential Revision: https://reviews.llvm.org/D30398
llvm-svn: 296459
Currently we handle this correctly in arm, but in thumb we don't which leads to
an unpredictable instruction being emitted for LSL #0 in an IT block and SP not
being permitted in some cases when it should be.
For the thumb2 LSL we can handle this by making LSL #0 an alias of MOV in the
.td file, but for thumb1 we need to handle it in checkTargetMatchPredicate to
get the IT handling right. We also need to adjust the handling of
MOV rd, rn, LSL #0 to avoid generating the 16-bit encoding in an IT block. We
should also adjust it to allow SP in the same way that it is allowed in
MOV rd, rn, but I haven't done that here because it looks like it would take
quite a lot of work to get right.
Additionally correct the selection of the 16-bit shift instructions in
processInstruction, where it was checking if the two registers were equal when
it should have been checking if they were low. It appears that previously this
code was never executed and the 16-bit encoding was selected by default, but
the other changes I've done here have somehow made it start being used.
Differential Revision: https://reviews.llvm.org/D30294
llvm-svn: 296342
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.
Differential Revision: https://reviews.llvm.org/D26722
llvm-svn: 295803
PC isn't allowed in the source operand of t2MOVr, so change the register class
to one without PC. SP handling is slightly trickier and changes depending on if
we're in ARMv8, so do that in checkTargetMatchPredicate.
Differential Revision: https://reviews.llvm.org/D30199
llvm-svn: 295732
This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The following changes are involved:
* Add the CodeGen option "-arm-execute-only" to the ARM code generator.
* Add the clang flag "-mexecute-only" as well as the GCC-compatible
alias "-mpure-code" to enable this option.
* When enabled, literal pools are replaced with MOVW/MOVT instructions,
with VMOV used in addition for floating-point literals. As the MOVT
instruction is required, execute-only support is only available in
Thumb mode for targets supporting ARMv8-M baseline or Thumb2.
* Jump tables are placed in data sections when in execute-only mode.
* The execute-only text section is assigned section ID 0, and is
marked as unreadable with the SHF_ARM_PURECODE flag with symbol 'y'.
This also overrides selection of ELF sections for globals.
llvm-svn: 289784
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.
Differential Revision: https://reviews.llvm.org/D26671
llvm-svn: 289647
When we see a non flag-setting instruction for which only the flag-setting
version is available in Thumb1, we should give a better error message than
"invalid instruction".
Differential Revision: https://reviews.llvm.org/D27414
llvm-svn: 288805
As it stands, the OperandMatchResultTy is only included in the generated
header if there is custom operand parsing. However, almost all backends
make use of MatchOperand_Success and friends from OperandMatchResultTy for
e.g. parseRegister. This is a pain when starting an AsmParser for a new
backend that doesn't yet have custom operand parsing. Move the enum to
MCTargetAsmParser.h.
This patch is a prerequisite for D23563
Differential Revision: https://reviews.llvm.org/D23496
llvm-svn: 285705
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:
va_start(ValueArgs, Desc);
with Desc being a StringRef.
Differential Revision: https://reviews.llvm.org/D25342
llvm-svn: 283671
Recommitting after fixing AsmParser initialization and X86 inline asm
error cleanup.
Allow errors to be deferred and emitted as part of clean up to simplify
and shorten Assembly parser code. This will allow error messages to be
emitted in helper functions and be modified by the caller which has
better context.
As part of this many minor cleanups to the Parser:
* Unify parser cleanup on error
* Add Workaround for incorrect return values in ParseDirective instances
* Tighten checks on error-signifying return values for parser functions
and fix in-tree TargetParsers to be more consistent with the changes.
* Fix AArch64 test cases checking for spurious error messages that are
now fixed.
These changes should be backwards compatible with current Target Parsers
so long as the error status are correctly returned in appropriate
functions.
Reviewers: rnk, majnemer
Subscribers: aemerson, jyknight, llvm-commits
Differential Revision: https://reviews.llvm.org/D24047
llvm-svn: 281762
Recommitting after fixing AsmParser Initialization.
Allow errors to be deferred and emitted as part of clean up to simplify
and shorten Assembly parser code. This will allow error messages to be
emitted in helper functions and be modified by the caller which has
better context.
As part of this many minor cleanups to the Parser:
* Unify parser cleanup on error
* Add Workaround for incorrect return values in ParseDirective instances
* Tighten checks on error-signifying return values for parser functions
and fix in-tree TargetParsers to be more consistent with the changes.
* Fix AArch64 test cases checking for spurious error messages that are
now fixed.
These changes should be backwards compatible with current Target Parsers
so long as the error status are correctly returned in appropriate
functions.
Reviewers: rnk, majnemer
Subscribers: aemerson, jyknight, llvm-commits
Differential Revision: https://reviews.llvm.org/D24047
llvm-svn: 281336
The changes made in r269352, r269353 and r269354 to support the
transformation of the ldr rd,=immediate to mov introduced a regression
from 3.8 (ldr.w rd, =immediate) not supported.
This change puts support back in for ldr.w by means of a t2InstAlias for
the .w form. The .w is ignored in ARM state and propagated to the ldr in
Thumb2.
llvm-svn: 281319
Allow errors to be deferred and emitted as part of clean up to simplify
and shorten Assembly parser code. This will allow error messages to be
emitted in helper functions and be modified by the caller which has
better context.
As part of this many minor cleanups to the Parser:
* Unify parser cleanup on error
* Add Workaround for incorrect return values in ParseDirective instances
* Tighten checks on error-signifying return values for parser functions
and fix in-tree TargetParsers to be more consistent with the changes.
* Fix AArch64 test cases checking for spurious error messages that are
now fixed.
These changes should be backwards compatible with current Target Parsers
so long as the error status are correctly returned in appropriate
functions.
Reviewers: rnk, majnemer
Subscribers: aemerson, jyknight, llvm-commits
Differential Revision: https://reviews.llvm.org/D24047
llvm-svn: 281249
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
Summary:
The assembler currently does not check the branch target for CBZ/CBNZ
instructions, which only permit branching forwards with a positive offset. This
adds validation for the branch target to ensure negative PC-relative offsets are
not encoded into the instruction, whether specified as a literal or as an
assembler symbol.
Reviewers: rengolin, t.p.northover
Subscribers: llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D23312
llvm-svn: 278788
This currently breaks the greendragon clang-stage1-configure-RA/ and
brotli. It is probably just uncovering a pre-existing problem. Reverting
temporarily to get the buildbots green again. A reduced testcase will
follow shortly.
This reverts commit r278659.
llvm-svn: 278711
Summary:
The assembler currently does not check the branch target for CBZ/CBNZ
instructions, which only permit branching forwards with a positive offset. This
adds validation for the branch target to ensure negative PC-relative offsets are
not encoded into the instruction, whether specified as a literal or as an
assembler symbol.
Reviewers: rengolin, t.p.northover
Subscribers: llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D23312
llvm-svn: 278659
- More informative message when extension name is not an identifier token.
- Stop parsing directive if extension is unknown (avoid duplicate error
messages).
- Report unsupported extensions with a source location, rather than
report_fatal_error.
Differential Revision: https://reviews.llvm.org/D22806
llvm-svn: 276748
This option, compatible with gas's -mimplicit-it, controls the
generation/checking of implicit IT blocks in ARM/Thumb assembly.
This option allows two behaviours that were not possible before:
- When in ARM mode, emit a warning when assembling a conditional
instruction that is not in an IT block. This is enabled with
-mimplicit-it=never and -mimplicit-it=thumb.
- When in Thumb mode, automatically generate IT instructions when an
instruction with a condition code appears outside of an IT block. This
is enabled with -mimplicit-it=thumb and -mimplicit-it=always.
The default option is -mimplicit-it=arm, which matches the existing
behaviour (allow conditional ARM instructions outside IT blocks without
warning, and error if a conditional Thumb instruction is outside an IT
block).
The general strategy for generating IT blocks in Thumb mode is to keep a
small list of instructions which should be in the IT block, and only
emit them when we encounter something in the input which means we cannot
continue the block. This could be caused by:
- A non-predicable instruction
- An instruction with a condition not compatible with the IT block
- The IT block already contains 4 instructions
- A branch-like instruction (including ALU instructions with the PC as
the destination), which cannot appear in the middle of an IT block
- A label (branching into an IT block is not legal)
- A change of section, architecture, ISA, etc
- The end of the assembly file.
Some of these, such as change of section and end of file, are parsed
outside of the ARM asm parser, so I've added a new virtual function to
AsmParser to ensure any previously-parsed instructions have been
emitted. The ARM implementation of this flushes the currently pending IT
block.
We now have to try instruction matching up to 3 times, because we cannot
know if the current IT block is valid before matching, and instruction
matching changes depending on the IT block state (due to the 16-bit ALU
instructions, which set the flags iff not in an IT block). In the common
case of not having an open implicit IT block and the instruction being
matched not needing one, we still only have to run the matcher once.
I've removed the ITState.FirstCond variable, because it does not store
any information that isn't already represented by CurPosition. I've also
updated the comment on CurPosition to accurately describe it's meaning
(which this patch doesn't change).
Differential Revision: https://reviews.llvm.org/D22760
llvm-svn: 276747
Immediate branch targets aren't commonly used, but if they are we should make
sure they can actually be encoded. This means they must be divisible by 2 when
targeting Thumb mode, and by 4 when targeting ARM mode.
Also do a little naming cleanup while I was changing everything around anyway.
llvm-svn: 275116
Recommiting after fixing non-atomic insert to front of SmallVector in
MCAsmLexer.h
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 273007
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 272953
These instructions end in "S" but are not flag-setting, so they need including
in the list of special cases in the assembly parser.
Differential Revision: http://reviews.llvm.org/D21077
llvm-svn: 272015
new instruction to ARM and AArch64 targets and several system registers.
Patch by: Roger Ferrer Ibanez and Oliver Stannard
Differential Revision: http://reviews.llvm.org/D20282
llvm-svn: 271670
This change implements the transformation in processInstruction() for the
LDR rt, =expression to MOV rt, expression when the expression can be evaluated
and can fit into the immediate field of the MOV or a MVN.
Across the ARM and Thumb instruction sets there are several cases to consider,
each with a different range of representatble constants.
In ARM we have:
* Modified immediate (All ARM architectures)
* MOVW (v6t2 and above)
In Thumb we have:
* Modified immediate (v6t2, v7m and v8m.mainline)
* MOVW (v6t2, v7m, v8.mainline and v8m.baseline)
* Narrow Thumb MOV that can be used in an IT block (non flag-setting)
If the immediate fits any of the available alternatives then we make the transformation.
Fixes 25722.
Patch by Peter Smith.
llvm-svn: 269354
This change adds a new constant pool kind to ARMOperand. When parsing the
operand for =immediate we create an instance of this operand rather than
creating a constant pool entry and rewriting the operand.
As the new operand kind is only created for ldr rt,= we can make ldr rt,=
an explicit pseudo instruction in ARM, Thumb and Thumb2
The pseudo instruction is expanded in processInstruction(). This creates the
constant pool and transforms the pseudo instruction into a pc-relative ldr to
the constant pool.
There are no functional changes and no modifications needed to existing tests.
Required by the patch that fixes PR25722.
Patch by Peter Smith.
llvm-svn: 269352
Fix "Logic error" warnings of the type "Called C++ object pointer is
null" reported by Clang Static Analyzer.
Patch by Apelete Seketeli.
llvm-svn: 269285
When we see a .arch or .cpu directive, we should try to avoid switching
ARM/Thumb mode if possible.
If we do have to switch modes, we also need to emit the correct mapping
symbol for the new ISA. We did not do this previously, so could emit
ARM code with Thumb mapping symbols (or vice-versa).
The GAS behaviour is to always stay in the same mode, and to emit an
error on any instructions seen when the current mode is not available on
the current target. We can't represent that situation easily (we assume
that Thumb mode is available if ModeThumb is set), so we differ from the
GAS behaviour when switching to a target that can't support the old
mode. I've added a warning for when this implicit mode-switch occurs.
Differential Revision: http://reviews.llvm.org/D18955
llvm-svn: 265936
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi
Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark
Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D16471
llvm-svn: 258861
Diana Picus