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
This patch was originally committed as r257884, but was reverted due to windows
failures. The cause of these failures has been fixed under r258677, hence
re-committing the original patch.
llvm-svn: 258682
This patch was originally committed as r257883, but was reverted due to windows
failures. The cause of these failures has been fixed under r258677, hence
re-committing the original patch.
llvm-svn: 258681
This was originally committed as r255762, but reverted as it broke windows
bots. Re-commitiing the exact same patch, as the underlying cause was fixed by
r258677.
ARMv8.2-A adds 16-bit floating point versions of all existing VFP
floating-point instructions. This is an optional extension, so all of
these instructions require the FeatureFullFP16 subtarget feature.
The assembly for these instructions uses S registers (AArch32 does not
have H registers), but the instructions have ".f16" type specifiers
rather than ".f32" or ".f64". The top 16 bits of each source register
are ignored, and the top 16 bits of the destination register are set to
zero.
These instructions are mostly the same as the 32- and 64-bit versions,
but they use coprocessor 9 rather than 10 and 11.
Two new instructions, VMOVX and VINS, have been added to allow packing
and extracting two 16-bit floats stored in the top and bottom halves of
an S register.
New fixup kinds have been added for the PC-relative load and store
instructions, but no ELF relocations have been added as they have a
range of 512 bytes.
Differential Revision: http://reviews.llvm.org/D15038
llvm-svn: 258678
# The first commit's message is:
Revert "[ARM] Add DSP build attribute and extension targeting"
This reverts commit b11cc50c0b4a7c8cdb628abc50b7dc226ff583dc.
# This is the 2nd commit message:
Revert "[ARM] Add new system registers to ARMv8-M Baseline/Mainline"
This reverts commit 837d08454e3e5beb8581951ac26b22fa07df3cd5.
llvm-svn: 257916
ARMv8.2-A adds 16-bit floating point versions of all existing SIMD
floating-point instructions. This is an optional extension, so all of
these instructions require the FeatureFullFP16 subtarget feature.
Note that VFP without SIMD is not a valid combination for any version of
ARMv8-A, but I have ensured that these instructions all depend on both
FeatureNEON and FeatureFullFP16 for consistency.
Differential Revision: http://reviews.llvm.org/D15039
llvm-svn: 255764
ARMv8.2-A adds 16-bit floating point versions of all existing VFP
floating-point instructions. This is an optional extension, so all of
these instructions require the FeatureFullFP16 subtarget feature.
The assembly for these instructions uses S registers (AArch32 does not
have H registers), but the instructions have ".f16" type specifiers
rather than ".f32" or ".f64". The top 16 bits of each source register
are ignored, and the top 16 bits of the destination register are set to
zero.
These instructions are mostly the same as the 32- and 64-bit versions,
but they use coprocessor 9 rather than 10 and 11.
Two new instructions, VMOVX and VINS, have been added to allow packing
and extracting two 16-bit floats stored in the top and bottom halves of
an S register.
New fixup kinds have been added for the PC-relative load and store
instructions, but no ELF relocations have been added as they have a
range of 512 bytes.
Differential Revision: http://reviews.llvm.org/D15038
llvm-svn: 255762
Prakhar Bahuguna