This patch cleans up and fixes issues in the M-Class system register handling:
1. It defines the system registers and the encoding (SYSm values) in one place:
a new ARMSystemRegister.td using SearchableTable, thereby removing the
hand-coded values which existed in multiple places.
2. Some system registers e.g. BASEPRI_MAX_NS which do not exist were being allowed!
Ref: ARMv6/7/8M architecture reference manual.
Reviewed by: @t.p.northover, @olist01, @john.brawn
Differential Revision: https://reviews.llvm.org/D35209
llvm-svn: 308456
The issue is not if the value is pcrel. It is whether we have a
relocation or not.
If we have a relocation, the static linker will select the upper
bits. If we don't have a relocation, we have to do it.
llvm-svn: 307730
For ELF, a movw+movt pair is handled as two separate relocations.
If an offset should be applied to the symbol address, this offset is
stored as an immediate in the instruction (as opposed to stored as an
offset in the relocation itself).
Even though the actual value stored in the movt immediate after linking
is the top half of the value, we need to store the unshifted offset
prior to linking. When the relocation is made during linking, the offset
gets added to the target symbol value, and the upper half of the value
is stored in the instruction.
This makes sure that movw+movt with offset symbols get properly
handled, in case the offset addition in the lower half should be
carried over to the upper half.
This makes the output from the additions to the test case match
the output from GNU binutils.
For COFF and MachO, the movw/movt relocations are handled as a pair,
and the overflow from the lower half gets carried over to the movt,
so they should keep the shifted offset just as before.
Differential Revision: https://reviews.llvm.org/D35242
llvm-svn: 307713
This change allows the pc to be used as a destination register for the
pseudo instruction LDR pc,=expression . The pseudo instruction must not be
transformed into a MOV, but it can use the Thumb2 LDR (literal) instruction
to a constant pool entry. See (A7.7.43 from ARMv7M ARM ARM).
Differential Revision: https://reviews.llvm.org/D34751
llvm-svn: 307640
This implements suggesting other mnemonics when an invalid one is specified,
for example:
$ echo "adXd r1,r2,#3" | llvm-mc -triple arm
<stdin>:1:1: error: invalid instruction, did you mean: add, qadd?
adXd r1,r2,#3
^
The implementation is target agnostic, but as a first step I have added it only
to the ARM backend; so the ARM backend is a good example if someone wants to
enable this too for another target.
Differential Revision: https://reviews.llvm.org/D33128
llvm-svn: 307148
processFixupValue is called on every relaxation iteration. applyFixup
is only called once at the very end. applyFixup is then the correct
place to do last minute changes and value checks.
While here, do proper range checks again for fixup_arm_thumb_bl. We
used to do it, but dropped because of thumb2. We now do it again, but
use the thumb2 range.
llvm-svn: 306177
Summary:
The ARM ELF ABI requires the linker to do interworking for wide
conditional branches from Thumb code to ARM code.
That was pointed out by @peter.smith in the comments for D33436.
Reviewers: rafael, peter.smith, echristo
Reviewed By: peter.smith
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits, peter.smith
Differential Revision: https://reviews.llvm.org/D34447
llvm-svn: 306009
Summary:
Relocations are required for unconditional branches to function symbols with
different execution mode. Without this patch, incorrect branches are
generated for tail calls between functions with different execution
mode.
Reviewers: peter.smith, rafael, echristo, kristof.beyls
Reviewed By: peter.smith
Subscribers: aemerson, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33898
llvm-svn: 304882
This change adds a new fixup fixup_t2_so_imm for the t2_so_imm_asmoperand
"T2SOImm". The fixup permits code such as:
.L1:
sub r3, r3, #.L2 - .L1
.L2:
to assemble in Thumb2 as well as in ARM state.
The operand predicate isT2SOImm() explicitly doesn't match expressions
containing :upper16: and :lower16: as expressions with these operators
must match the movt and movw instructions.
The test mov r0, foo2 in thumb2-diagnostics is moved to a new file as the
fixup delays the error message till after the assembler has quit due to
the other errors.
As the mov instruction shares the t2_so_imm_asmoperand mov instructions
with a non constant expression now match t2MOVi rather than t2MOVi16 so the
error message is slightly different.
Fixes PR28647
Differential Revision: https://reviews.llvm.org/D33492
llvm-svn: 304702
Summary:
Without using a fixup in this case, BL will be used instead of BLX to
call internal ARM functions from Thumb functions.
Reviewers: rafael, t.p.northover, peter.smith, kristof.beyls
Reviewed By: peter.smith
Subscribers: srhines, echristo, aemerson, rengolin, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33436
llvm-svn: 304413
Re-applying now that PR32825 which was raised on the commit this fixed up is now known to have also been fixed by this commit.
Original commit message:
Multiple ldr pseudoinstructions with the same constant value will
reuse the same constant pool entry. However, if the constant pool
is explicitly flushed with a .ltorg directive, we should not try
to reference constants in the previous pool any longer, since they
may be out of range.
This fixes assembling hand-written assembler source which repeatedly
loads the same constant value, across a binary size larger than the
pc-relative fixup range for ldr instructions (4096 bytes). Such
assembler source already uses explicit .ltorg instructions to emit
constant pools with regular intervals. However if we try to reuse
constants emitted in earlier pools, they end up out of range.
This makes the output of the testcase match what binutils gas does
(prior to this patch, it would fail to assemble).
Differential Revision: https://reviews.llvm.org/D32847
llvm-svn: 303540
Re-applying now that the open bug on this commit, PR32825, is known to be fixed.
Original commit message:
Summary: This patch returns the same label if the CP entry with the same value has been created.
Reviewers: eli.friedman, rengolin, jmolloy
Subscribers: majnemer, jmolloy, llvm-commits
Differential Revision: https://reviews.llvm.org/D25804
llvm-svn: 303539
This reverts commit r302416. This was a fixup for r286006, which has now been reverted so this doesn't apply (either in concept or in code).
This commit itself has no problems, but the underlying issue it was fixing has now disappeared from the codebase.
llvm-svn: 303536
Multiple ldr pseudoinstructions with the same constant value will
reuse the same constant pool entry. However, if the constant pool
is explicitly flushed with a .ltorg directive, we should not try
to reference constants in the previous pool any longer, since they
may be out of range.
This fixes assembling hand-written assembler source which repeatedly
loads the same constant value, across a binary size larger than the
pc-relative fixup range for ldr instructions (4096 bytes). Such
assembler source already uses explicit .ltorg instructions to emit
constant pools with regular intervals. However if we try to reuse
constants emitted in earlier pools, they end up out of range.
This makes the output of the testcase match what binutils gas does
(prior to this patch, it would fail to assemble).
Differential Revision: https://reviews.llvm.org/D32847
llvm-svn: 302416
Recently support was added for substituting one intruction for another by
negating or inverting the immediate, but ORR and ORN were missed so this patch
adds them.
This one is slightly different to the others in that ORN only exists in thumb,
so we only do the substitution in thumb.
Differential Revision: https://reviews.llvm.org/D32534
llvm-svn: 302224
ChangeSection incorrectly registers LastEMSInfo as belonging to the previous
section, not the current section. This happens to work when changing sections
using .section, as the previous section is set to the current section before
the call to ChangeSection, but not when using .popsection.
Differential Revision: https://reviews.llvm.org/D32225
llvm-svn: 300831
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
A number of backends (AArch64, MIPS, ARM) have been using
MCContext::reportError to report issues such as out-of-range fixup values in
their TgtAsmBackend. This is great, but because MCContext couldn't easily be
threaded through to the adjustFixupValue helper function from its usual
callsite (applyFixup), these backends ended up adding an MCContext* argument
and adding another call to applyFixup to processFixupValue. Adding an
MCContext parameter to applyFixup makes this unnecessary, and even better -
applyFixup can take a reference to MCContext rather than a potentially null
pointer.
Differential Revision: https://reviews.llvm.org/D30264
llvm-svn: 299529
Dont emit Mapping symbols for sections that contain only data.
Summary:
Dont emit mapping symbols for sections that contain only data.
Reviewers: rengolin, weimingz, kparzysz, t.p.northover, peter.smith
Reviewed By: t.p.northover
Patched by Shankar Easwaran <shankare@codeaurora.org>
Subscribers: alekseyshl, t.p.northover, llvm-commits
Differential Revision: https://reviews.llvm.org/D30724
llvm-svn: 299392
- 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
Fixing triple format in the tests added for the branch label fix for Thumb
Targets. Also recommitting previously approved patch, see
https://reviews.llvm.org/D30943.
Reviewed by: samparker
Differential Revision: https://reviews.llvm.org/D30987
llvm-svn: 298056
Different MCInstrAnalysis classes for arm and thumb mode, each with
their own evaluateBranch implementation. I added a test case and
fixed the coff-relocations test to use '<label>:' rather than
'<label>' in the CHECK-LABEL entries, since the ones without the
colon would match branch targets. Might be worth noticing that
llvm-objdump does not lookup the relocation and thus assigns it a
target depending on the encoded immediate which #0, so it thinks it
branches to the next instruction.
Committed on behalf of Andre Vieira (avieira).
Differential Revision: https://reviews.llvm.org/D30943
llvm-svn: 297821
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
Summary:
This is a continuation of D28861. Add an SMLoc to MCUnaryExpr such that
a better diagnostic can be given in case of an error in later stages of
assembling.
Reviewers: rengolin, grosbach, javed.absar, olista01
Reviewed By: olista01
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30581
llvm-svn: 297454
I previously removed the T2XtPk feature from the ARM backend, but it
looks like I missed some of the tests that were using the feature.
Differential Revision: https://reviews.llvm.org/D30778
llvm-svn: 297386
Minor cleanup in ARMInstrVFP.td: removed some FIXMEs and added a MC test for
vcmp that was actually missing.
Differential Revision: https://reviews.llvm.org/D30745
llvm-svn: 297376
On Windows stderr and stdout happen to get interleaved in a way that causes the
test to fail, so split it up into a test that checks for errors and a test that
doesn't.
llvm-svn: 297273
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
This is for running the assembler with -g (to emit DWARF describing
the assembler source).
Differential Revision: http://reviews.llvm.org/D30475
llvm-svn: 296541
Summary:
clang adds !srcloc metadata to inline assembly in LLVM bitcode generated
for inline assembly in C. The value of this !srcloc is passed to the
diagnostics handler if the inline assembly generates a diagnostic.
clang is able to turn this cookie back to a location in the C source
file.
To test this functionality without a dependency, make llc print the
!srcloc metadata if it is present. The added test uses this mechanism
to test that the correct !srclocs are passed to the diag handler.
Reviewers: rengolin, rnk, echristo, grosbach, mehdi_amini
Reviewed By: mehdi_amini
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30167
llvm-svn: 296465
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
The Requires class overrides the target requirements of an instruction,
rather than adding to them, so all ARM instructions need to include the
IsARM predicate when they have overwitten requirements.
This caused the swp and swpb instructions to be allowed in thumb mode
assembly, and the ARM encoding of CDP to be selected in codegen (which
is different for conditional instructions).
Differential Revision: https://reviews.llvm.org/D29283
llvm-svn: 293634
Add a SMLoc to MCExpr. Most code does not generate or consume the SMLoc (yet).
Patch by Sanne Wouda <sanne.wouda@arm.com>!
Differential Revision: https://reviews.llvm.org/D28861
llvm-svn: 292515
Javed Absar