This involves changing the shouldExpandAtomicCmpXchgInIR interface, but I have
updated the in-tree backends using this hook (ARM, AArch64, Hexagon) so they
will see no functional change. Previously this hook returned bool, but it now
returns AtomicExpansionKind.
This hook allows targets to select how a given cmpxchg is to be expanded.
D48131 uses this to expand part-word cmpxchg to a target-specific intrinsic.
See my associated RFC for more info on the motivation for this change
<http://lists.llvm.org/pipermail/llvm-dev/2018-June/123993.html>.
Differential Revision: https://reviews.llvm.org/D48130
llvm-svn: 342550
This tries to make use of evaluateAsRelocatable in AArch64AsmParser::classifySymbolRef
to parse more complex expressions as relocatable operands. It is hopefully better than
the existing code which only handles Symbol +- Constant.
This allows us to parse more complex adr/adrp, mov, ldr/str and add operands. It also
loosens the requirements on parsing addends in ld/st and mov's and adds a number of
tests.
Differential Revision: https://reviews.llvm.org/D51792
llvm-svn: 342455
This patch adds codegen support for the saving/restoring
V8-V23 for functions specified with the aarch64_vector_pcs
calling convention attribute, as added in patch D51477.
Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D51479
llvm-svn: 342049
This patch refactors several parts of AArch64FrameLowering
so that it can be easily extended to support saving/restoring
of FPR128 (Q) registers.
Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D51478
llvm-svn: 342038
This patch adds parsing support for the 'aarch64_vector_pcs'
calling convention attribute to calls and function declarations.
More information describing the vector ABI and procedure call standard
can be found here:
https://developer.arm.com/products/software-development-tools/\
hpc/arm-compiler-for-hpc/vector-function-abi
Reviewers: t.p.northover, rnk, rengolin, javed.absar, thegameg, SjoerdMeijer
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D51477
llvm-svn: 342030
The was previously committed as r341749 then reverted as r341750 because
bit_cast needed to do its own thing to check is_trivially_copyable on GCC 4.x.
This is now done and std;:array should now get accepted.
llvm-svn: 341897
Disassemblers cannot depend on main target headers. The same is true for
MCTargetDesc, but there's a lot more cleanup needed for that.
llvm-svn: 341822
Summary: I saw a few places that were punning through a union of FP and integer, and that made me sad. Luckily, C++20 adds bit_cast for exactly that purpose. Implement our own version in ADT (without constexpr, leaving us a bit sad), and use it in the few places my grep-fu found silly union punning.
This was originally committed as r341728 and reverted in r341730.
Reviewers: javed.absar, steven_wu, srhines
Subscribers: dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51693
llvm-svn: 341741
Summary: I saw a few places that were punning through a union of FP and integer, and that made me sad. Luckily, C++20 adds bit_cast for exactly that purpose. Implement our own version in ADT (without constexpr, leaving us a bit sad), and use it in the few places my grep-fu found silly union punning.
Reviewers: javed.absar
Subscribers: dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51693
llvm-svn: 341728
Summary:
Reserving registers x1-7 is used to support CONFIG_ARM64_LSE_ATOMICS in Linux kernel. This change adds support for reserving registers x1 through x7.
Reviewers: javed.absar, phosek, srhines, nickdesaulniers, efriedma
Reviewed By: nickdesaulniers, efriedma
Subscribers: niravd, jfb, manojgupta, nickdesaulniers, jyknight, efriedma, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D48580
llvm-svn: 341706
Summary:
I added a few ARM64 memset codegen tests in r341406 and r341493, and annotated
where the generated code was bad. This patch fixes the majority of the issues by
requesting that a 2xi64 vector be used for memset of 32 bytes and above.
The patch leaves the former request for f128 unchanged, despite f128
materialization being suboptimal: doing otherwise runs into other asserts in
isel and makes this patch too broad.
This patch hides the issue that was present in bzero_40_stack and bzero_72_stack
because the code now generates in a better order which doesn't have the store
offset issue. I'm not aware of that issue appearing elsewhere at the moment.
<rdar://problem/44157755>
Reviewers: t.p.northover, MatzeB, javed.absar
Subscribers: eraman, kristof.beyls, chrib, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51706
llvm-svn: 341558
On Windows, if shouldAssumeDSOLocal returns false, it's either a
dllimport reference, or a reference that we should treat as non-local
and create a stub for.
Clean up AArch64Subtarget::ClassifyGlobalReference a little while
touching the flag handling relating to dllimport.
Differential Revision: https://reviews.llvm.org/D51590
llvm-svn: 341402
The runtime pseudo relocations can't handle the AArch64 format PC
relative addressing in adrp+add/ldr pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.
Differential Revision: https://reviews.llvm.org/D51452
llvm-svn: 341401
When initial support for dllimport was added for aarch64 in
SVN r316555, ClassifyGlobalReference didn't set the MO_DLLIMPORT
flag - that was only completed in SVN r323810. Reuse the return
value from ClassifyGlobalReference for this purpose as well.
llvm-svn: 341310
Summary:
This is a continuation of https://reviews.llvm.org/D49727
Below the original text, current changes in the comments:
Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.
For example:
extern int bar(int[]);
int foo(int i) {
int a[i]; // VLA
asm volatile(
"mov r7, #1"
:
:
: "r7"
);
return 1 + bar(a);
}
Compiled for thumb, this gives:
$ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
...
foo:
.fnstart
@ %bb.0: @ %entry
.save {r4, r5, r6, r7, lr}
push {r4, r5, r6, r7, lr}
.setfp r7, sp, #12
add r7, sp, #12
.pad #4
sub sp, #4
movs r1, #7
add.w r0, r1, r0, lsl #2
bic r0, r0, #7
sub.w r0, sp, r0
mov sp, r0
@APP
mov.w r7, #1
@NO_APP
bl bar
adds r0, #1
sub.w r4, r7, #12
mov sp, r4
pop {r4, r5, r6, r7, pc}
...
r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.
This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.
The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.
If we find a reserved register, we print a warning:
repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
"mov r7, #1"
^
Reviewers: efriedma, olista01, javed.absar
Reviewed By: efriedma
Subscribers: eraman, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D51165
llvm-svn: 341062
Providing that the load is known to be 4 byte aligned, we can optimise a
ldr(adr address) to just ldr address.
Differential Revision: https://reviews.llvm.org/D51030
llvm-svn: 341058
This adds a new method to ELFObjectFileBase that returns the symbols and addresses of PLT entries.
This design was suggested by pcc and eugenis in https://reviews.llvm.org/D49383.
Differential Revision: https://reviews.llvm.org/D50203
llvm-svn: 340610
This adds the plumbing for the Tiny code model for the AArch64 backend. This,
instead of loading addresses through the normal ADRP;ADD pair used in the Small
model, uses a single ADR. The 21 bit range of an ADR means that the code and
its statically defined symbols need to be within 1MB of each other.
This makes it mostly interesting for embedded applications where we want to fit
as much as we can in as small a space as possible.
Differential Revision: https://reviews.llvm.org/D49673
llvm-svn: 340397
Summary: When run under llvm-mc-disassemble-fuzzer, there is no symbol lookup callback so tryAddingSymbolicOperand() must fail gracefully instead of crashing
Reviewers: aemerson, javed.absar
Reviewed By: aemerson
Subscribers: lhames, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D51005
llvm-svn: 340287
This patch adds system registers for controlling aspects of SVE:
- ZCR_EL1 (r/w) visible at EL1 and EL0.
- ZCR_EL2 (r/w) visible at EL2 and Non-secure EL1 and EL0.
- ZCR_EL3 (r/w) visible at all exception levels.
and a system register identifying SVE:
- ID_AA64ZFR0_EL1 (r) SVE Feature identifier.
Reviewers: SjoerdMeijer, samparker, pbarrio, fhahn, javed.absar
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D50885
llvm-svn: 340158
- Generate pointer authentication instructions
- The functions instrumented depend on function attribtues:
all (all functions instrumentent)
non-leaf (only those that spill LR)
none
- Function epilogues sign the LR before spilling to the stack and authenticate
the LR once restored
- If the target is v8.3a or greater than can use the combined authenticate and
return instruction
Differential revision: https://reviews.llvm.org/D49793
llvm-svn: 340018
Add +fp16fml feature for new FP16 instructions, which are a
mandatory part of FP16 from v8.4-A and an optional part of FP16
from v8.2-A. It doesn't seem to be possible to model this in
LLVM, but the relationship between the options is handled by
the related clang patch.
In keeping with what I think is the usual practice, the fp16fml
extension is accepted regardless of base architecture version.
Builds on/replaces Sjoerd Meijer's patch to add these instructions at
https://reviews.llvm.org/D49839.
Differential Revision: https://reviews.llvm.org/D50228
llvm-svn: 340013
a generically extensible collection of extra info attached to
a `MachineInstr`.
The primary change here is cleaning up the APIs used for setting and
manipulating the `MachineMemOperand` pointer arrays so chat we can
change how they are allocated.
Then we introduce an extra info object that using the trailing object
pattern to attach some number of MMOs but also other extra info. The
design of this is specifically so that this extra info has a fixed
necessary cost (the header tracking what extra info is included) and
everything else can be tail allocated. This pattern works especially
well with a `BumpPtrAllocator` which we use here.
I've also added the basic scaffolding for putting interesting pointers
into this, namely pre- and post-instruction symbols. These aren't used
anywhere yet, they're just there to ensure I've actually gotten the data
structure types correct. I'll flesh out support for these in
a subsequent patch (MIR dumping, parsing, the works).
Finally, I've included an optimization where we store any single pointer
inline in the `MachineInstr` to avoid the allocation overhead. This is
expected to be the overwhelmingly most common case and so should avoid
any memory usage growth due to slightly less clever / dense allocation
when dealing with >1 MMO. This did require several ergonomic
improvements to the `PointerSumType` to reasonably support the various
usage models.
This also has a side effect of freeing up 8 bits within the
`MachineInstr` which could be repurposed for something else.
The suggested direction here came largely from Hal Finkel. I hope it was
worth it. ;] It does hopefully clear a path for subsequent extensions
w/o nearly as much leg work. Lots of thanks to Reid and Justin for
careful reviews and ideas about how to do all of this.
Differential Revision: https://reviews.llvm.org/D50701
llvm-svn: 339940
`MachineMemOperand` pointers attached to `MachineSDNodes` and instead
have the `SelectionDAG` fully manage the memory for this array.
Prior to this change, the memory management was deeply confusing here --
The way the MI was built relied on the `SelectionDAG` allocating memory
for these arrays of pointers using the `MachineFunction`'s allocator so
that the raw pointer to the array could be blindly copied into an
eventual `MachineInstr`. This creates a hard coupling between how
`MachineInstr`s allocate their array of `MachineMemOperand` pointers and
how the `MachineSDNode` does.
This change is motivated in large part by a change I am making to how
`MachineFunction` allocates these pointers, but it seems like a layering
improvement as well.
This would run the risk of increasing allocations overall, but I've
implemented an optimization that should avoid that by storing a single
`MachineMemOperand` pointer directly instead of allocating anything.
This is expected to be a net win because the vast majority of uses of
these only need a single pointer.
As a side-effect, this makes the API for updating a `MachineSDNode` and
a `MachineInstr` reasonably different which seems nice to avoid
unexpected coupling of these two layers. We can map between them, but we
shouldn't be *surprised* at where that occurs. =]
Differential Revision: https://reviews.llvm.org/D50680
llvm-svn: 339740
Intentionally excluding nodes from the DAGCombine worklist is likely to
lead to weird optimizations and infinite loops, so it's generally a bad
idea.
To avoid the infinite loops, fix DAGCombine to use the
isDesirableToCommuteWithShift target hook before performing the
transforms in question, and implement the target hook in the ARM backend
disable the transforms in question.
Fixes https://bugs.llvm.org/show_bug.cgi?id=38530 . (I don't have a
reduced testcase for that bug. But we should have sufficient test
coverage for PerformSHLSimplify given that we're not playing weird
tricks with the worklist. I can try to bugpoint it if necessary,
though.)
Differential Revision: https://reviews.llvm.org/D50667
llvm-svn: 339734
Summary:
Ensure that NormalizedBuildVector returns a BUILD_VECTOR with operands of the
same type. This fixes an assertion failure in VerifySDNode.
Reviewers: SjoerdMeijer, t.p.northover, javed.absar
Reviewed By: SjoerdMeijer
Subscribers: kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D50202
llvm-svn: 339013
As a part of adding the tiny codemodel, we need to support ldr's with :got:
relocations on them. This seems to be mostly already done, just needs the
relocation type support.
Differential Revision: https://reviews.llvm.org/D50137
llvm-svn: 338673
AArch64 ELF ABI does not define a static relocation type for TLS offset within
a module, which makes it impossible for compiler to generate a valid
DW_AT_location content for thread local variables. Currently LLVM generates an
invalid R_AARCH64_ABS64 relocation at the DW_AT_location field for a TLS
variable. That causes trouble for linker because thread local variable does
not have an absolute address at link time. AArch64 GCC solves the problem by
not generating DW_AT_location for thread local variables. We should do the
same in LLVM.
Differential Revision: https://reviews.llvm.org/D43860
llvm-svn: 338655
Contrary to ELF, we don't add any markers that distinguish data generated
with .long from normal instructions, so the .inst directive only adds
compatibility with assembly that uses it.
Differential Revision: https://reviews.llvm.org/D49935
llvm-svn: 338355
Also refactors some existing code to materialize addresses for the large code
model so it can be shared between G_GLOBAL_VALUE and G_BLOCK_ADDR.
This implements PR36390.
Differential Revision: https://reviews.llvm.org/D49903
llvm-svn: 338337
The vector contains the SDNodes that these functions create. The number of nodes is always a small number so we should use SmallVector to avoid a heap allocation.
llvm-svn: 338329
This teaches the outliner to save LR to a register rather than the stack when
possible. This allows us to avoid bumping the stack in outlined functions in
some cases. By doing this, in a later patch, we can teach the outliner to do
something like this:
f1:
...
bl OUTLINED_FUNCTION
...
f2:
...
move LR's contents to a register
bl OUTLINED_FUNCTION
move the register's contents back
instead of falling back to saving LR in both cases.
llvm-svn: 338278
This patch enables instructions that are destructive on their
destination- and first source operand, to be prefixed with a
MOVPRFX instruction.
This patch also adds a variety of tests:
- positive tests for all instructions and forms that accept a
movprfx for either or both predicated and unpredicated forms.
- negative tests for all instructions and forms that do not accept
an unpredicated or predicated movprfx.
- negative tests for the diagnostics that get emitted when a MOVPRFX
instruction is used incorrectly.
This is patch [2/2] in a series to add MOVPRFX instructions:
- Patch [1/2]: https://reviews.llvm.org/D49592
- Patch [2/2]: https://reviews.llvm.org/D49593
Reviewers: rengolin, SjoerdMeijer, samparker, fhahn, javed.absar
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D49593
llvm-svn: 338261
This patch adds predicated and unpredicated MOVPRFX instructions, which
can be prepended to SVE instructions that are destructive on their first
source operand, to make them a constructive operation, e.g.
add z1.s, p0/m, z1.s, z2.s <=> z1 = z1 + z2
can be made constructive:
movprfx z0, z1
add z0.s, p0/m, z0.s, z2.s <=> z0 = z1 + z2
The predicated MOVPRFX instruction can additionally be used to zero
inactive elements, e.g.
movprfx z0.s, p0/z, z1.s
add z0.s, p0/m, z0.s, z2.s
Not all instructions can be prefixed with the MOVPRFX instruction
which is why this patch also adds a mechanism to validate prefixed
instructions. The exact rules when a MOVPRFX applies is detailed in
the SVE supplement of the Architectural Reference Manual.
This is patch [1/2] in a series to add MOVPRFX instructions:
- Patch [1/2]: https://reviews.llvm.org/D49592
- Patch [2/2]: https://reviews.llvm.org/D49593
Reviewers: rengolin, SjoerdMeijer, samparker, fhahn, javed.absar
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D49592
llvm-svn: 338258
The WHILE instructions generate a predicate that is true while the
comparison of the first scalar operand (incremented for each predicate
element) with the second scalar operand is true and false thereafter.
WHILELE While incrementing signed scalar less than or equal to scalar
WHILELO While incrementing unsigned scalar lower than scalar
WHILELS While incrementing unsigned scalar lower than or same as scalar
WHILELT While incrementing signed scalar less than scalar
e.g.
whilele p0.s, x0, x1
generates predicate p0 (for 32bit elements) by incrementing
(signed) x0 and comparing that vector to splat(x1).
llvm-svn: 338211
The instructions added in this patch permit active elements within
a vector to be processed sequentially without unpacking the vector.
PFIRST Set the first active element to true.
PNEXT Find next active element in predicate.
CTERMEQ Compare and terminate loop when equal.
CTERMNE Compare and terminate loop when not equal.
llvm-svn: 338210
Alex Bradbury