AtomicExpandLoadLinked is currently rather ARM-specific. This patch is the first of
a group that aim at making it more target-independent. See
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075873.html
for details
The command line option is "atomic-expand"
llvm-svn: 216231
There are two add-immediate instructions in Thumb1: tADDi8 and tADDi3. Only
the latter supports using different source and destination registers, so
whenever we materialize a new base register (at a certain offset) we'd do
so by moving the base register value to the new register and then adding in
place. This patch changes the code to use a single tADDi3 if the offset is
small enough to fit in 3 bits.
Differential Revision: http://reviews.llvm.org/D5006
llvm-svn: 216193
The FPv4-SP floating-point unit is generally referred to as
single-precision only, but it does have double-precision registers and
load, store and GPR<->DPR move instructions which operate on them.
This patch enables the use of these registers, the main advantage of
which is that we now comply with the AAPCS-VFP calling convention.
This partially reverts r209650, which added some AAPCS-VFP support,
but did not handle return values or alignment of double arguments in
registers.
This patch also adds tests for Thumb2 code generation for
floating-point instructions and intrinsics, which previously only
existed for ARM.
llvm-svn: 216172
On pre-v6 hardware, 'MOV lo, lo' gives undefined results, so such copies need to
be avoided. This patch trades simplicity for implementation time at the expense
of performance... As they say: correctness first, then performance.
See http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075998.html for a few
ideas on how to make this better.
llvm-svn: 216138
target hook.
This patch teaches the compiler that:
rX, rY = VMOVRRD dZ
is the same as:
rX = EXTRACT_SUBREG dZ, ssub_0
rY = EXTRACT_SUBREG dZ, ssub_1
<rdar://problem/12702965>
llvm-svn: 216132
LLVM generates illegal `rbit r0, #352` instruction for rbit intrinsic.
According to ARM ARM, rbit only takes register as argument, not immediate.
The correct instruction should be rbit <Rd>, <Rm>.
The bug was originally introduced in r211057.
Differential Revision: http://reviews.llvm.org/D4980
llvm-svn: 216064
Summary:
Make use of isAtLeastRelease/Acquire in the ARM/AArch64 backends
These helper functions are introduced in D4844.
Depends D4844
Test Plan: make check-all passes
Reviewers: jfb
Subscribers: aemerson, llvm-commits, mcrosier, reames
Differential Revision: http://reviews.llvm.org/D4937
llvm-svn: 215902
Externally-defined functions with weak linkage should not be
tail-called on ARM or AArch64, as the AAELF spec requires normal calls
to undefined weak functions to be replaced with a NOP or jump to the
next instruction. The behaviour of branch instructions in this
situation (as used for tail calls) is implementation-defined, so we
cannot rely on the linker replacing the tail call with a return.
llvm-svn: 215890
ARM in particular is getting dangerously close to exceeding 32 bits worth of
possible subtarget features. When this happens, various parts of MC start to
fail inexplicably as masks get truncated to "unsigned".
Mostly just refactoring at present, and there's probably no way to test.
llvm-svn: 215887
Simply indicate the functions that are part of the runtime library that we do
not setup libcalls for. This is merely for ease of identification. NFC.
llvm-svn: 215863
The set of functions defined in the RTABI was separated for no real reason.
This brings us closer to proper utilisation of the functions defined by the
RTABI. It also sets the ground for correctly emitting function calls to AEABI
functions on all AEABI conforming platforms.
The previously existing lie on the behaviour of __ldivmod and __uldivmod is
propagated as it is beyond the scope of the change.
The changes to the test are due to the fact that we now use the divmod functions
which return both the quotient and remainder and thus we no longer need to
invoke two functions on Linux (making it closer to EABI's behaviour).
llvm-svn: 215862
This was a thinko. The intent was to flip the explicit bits that need toggling
rather than all bits. This would result in incorrect behaviour (which now is
tested).
Thanks to Nico Weber for pointing this out!
llvm-svn: 215846
In a previous iteration of the pass, we would try to compensate for
writeback by updating later instructions and/or inserting a SUBS to
reset the base register if necessary.
Since such a SUBS sets the condition flags it's not generally safe to do
this. For now, only merge LDR/STRs if there is no writeback to the base
register (LDM that loads into the base register) or the base register is
killed by one of the merged instructions. These cases are clear wins
both in terms of instruction count and performance.
Also add three new test cases, and update the existing ones accordingly.
llvm-svn: 215729
This adds some code back that was deleted in r92053. The location of the
last merged memory operation needs to be kept up-to-date since MemOps
may be in a different order to the original instruction stream to
allow merging (since registers need to be in ascending order). Also
simplify the logic to determine BaseKill using findRegisterUseOperandIdx
to use an equivalent function call instead.
llvm-svn: 215728
We actually need to return the register into which we materialized the constant
and not just "true" for success. This code is currently partially dead, that is
why it didn't trigger any failures yet. Once I change the order of the constant
materialization this code will be fully exercised.
llvm-svn: 215727
These are system-only instructions for CPUs with virtualization
extensions, allowing a hypervisor easy access to all of the various
different AArch32 registers.
rdar://problem/17861345
llvm-svn: 215700
FastEmit_i won't always succeed to materialize an i32 constant and just fail.
This would trigger a fall-back to SelectionDAG, which is really not necessary.
This fix will first fall-back to a constant pool load to materialize the constant
before giving up for good.
This fixes <rdar://problem/18022633>.
llvm-svn: 215682
This change is also in preparation for a future change to make sure that
the constant materialization uses MOVT/MOVW when available and not a load
from the constant pool.
llvm-svn: 215584
getRegClassFor returns the incorrect register class when in Thumb2 mode.
This fix simply manually selects the register class as in the code just a few
lines above.
There is no test case for this code, because the code is currently
unreachable. This will be changed in a future commit and existing test
cases will exercise this code.
llvm-svn: 215583
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
Type::dump() doesn't print a newline, which makes for a poor
experience in a debugger. This looks like it was an ommission
considering Value::dump() two lines above, so I've changed Type to add
a newline as well.
Of the two in-tree callers, one added a newline anyway, and I've
updated the other one to use Type::print instead.
llvm-svn: 215421
For many Thumb-1 register register instructions, setting the CPSR is not
permitted inside an IT block. We would not correctly flag those instructions.
The previous change to identify this scenario was insufficient as it did not
actually catch all the instances. The current list is formed by manual
inspection of the ARMv6M ARM.
The change to the Thumb2 IT block test is due to the fact that the new more
stringent checking of the MIs results in the If Conversion pass being prevented
from executing (since not all the instructions in the BB are predicable). This
results in code gen changes.
Thanks to Tim Northover for pointing out that the previous patch was
insufficient and hinting that the use of the v6M ARM would be much easier to use
than the v7 or v8!
llvm-svn: 215382
By default, LLVM uses the "C" calling convention for all runtime
library functions. The half-precision FP conversion functions use the
soft-float calling convention, and are needed for some targets which
use the hard-float convention by default, so must have their calling
convention explicitly set.
llvm-svn: 215348
The ARM ARM states that CPSR may not be updated by a MUL in thumb mode. Due to
an ordering of Thumb 2 Size Reduction and If Conversion, we would end up
generating a THUMB MULS inside an IT block.
The If Conversion pass uses the TTI isPredicable method to ensure that it can
transform a Basic Block. However, because we only check for IT handling on
Thumb2 functions, we may miss some cases. Even then, it only validates that the
CPSR is not *live* rather than it is not accessed. This corrects the handling
for that particular case since the same restriction does not hold on the vast
majority of the instructions.
This does prevent the IfConversion optimization from kicking in in certain
cases, but generating correct code is more valuable. Addresses PR20555.
llvm-svn: 215328
be deleted. This will be reapplied as soon as possible and before
the 3.6 branch date at any rate.
Approved by Jim Grosbach, Lang Hames, Rafael Espindola.
This reverts commits r215111, 215115, 215116, 215117, 215136.
llvm-svn: 215154
I am sure we will be finding bits and pieces of dead code for years to
come, but this is a good start.
Thanks to Lang Hames for making MCJIT a good replacement!
llvm-svn: 215111
The commit after this changes { } and 0bxx literals to be of type bits<n> and not int. This means we need to write exactly the right number of bits, and not rely on the values being silently zero extended for us.
llvm-svn: 215082
to get the subtarget and that's accessible from the MachineFunction
now. This helps clear the way for smaller changes where we getting
a subtarget will require passing in a MachineFunction/Function as
well.
llvm-svn: 214988
Particularly on MachO, we were generating "blx _dest" instructions on M-class
CPUs, which don't actually exist. They happen to get fixed up by the linker
into valid "bl _dest" instructions (which is why such a massive issue has
remained largely undetected), but we shouldn't rely on that.
llvm-svn: 214959
This reverts r214893, re-applying r214881 with the test case relaxed a bit to
satiate the build bots.
POP on armv4t cannot be used to change thumb state (unilke later non-m-class
architectures), therefore we need a different return sequence that uses 'bx'
instead:
POP {r3}
ADD sp, #offset
BX r3
This patch also fixes an issue where the return value in r3 would get clobbered
for functions that return 128 bits of data. In that case, we generate this
sequence instead:
MOV ip, r3
POP {r3}
ADD sp, #offset
MOV lr, r3
MOV r3, ip
BX lr
http://reviews.llvm.org/D4748
llvm-svn: 214928
POP on armv4t cannot be used to change thumb state (unilke later non-m-class
architectures), therefore we need a different return sequence that uses 'bx'
instead:
POP {r3}
ADD sp, #offset
BX r3
This patch also fixes an issue where the return value in r3 would get clobbered
for functions that return 128 bits of data. In that case, we generate this
sequence instead:
MOV ip, r3
POP {r3}
ADD sp, #offset
MOV lr, r3
MOV r3, ip
BX lr
http://reviews.llvm.org/D4748
llvm-svn: 214881
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.
Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.
llvm-svn: 214838
Those registers are VFP/NEON and vector instructions should be used instead,
but old cores rely on those co-processors to enable VFP unwinding. This change
was prompted by the libc++abi's unwinding routine and is also present in many
legacy low-level bare-metal code that we ought to compile/assemble.
Fixing bug PR20025 and allowing PR20529 to proceed with a fix in libc++abi.
llvm-svn: 214802
expanding pseudo LOAD_STATCK_GUARD using instructions that are normally used
in pic mode. This patch fixes the bug.
<rdar://problem/17886592>
llvm-svn: 214614
so that we can use it to get the old-style JIT out of the subtarget.
This code should be removed when the old-style JIT is removed
(imminently).
llvm-svn: 214560
This is a followup patch for r214366, which added the same behavior to the
AArch64 and X86 FastISel code. This fix reproduces the already existing
behavior of SelectionDAG in FastISel.
llvm-svn: 214531
Note: The current code in DecodeMSRMask() rejects the unpredictable A/R MSR mask '0000' with Fail. The code in the patch follows this style and rejects unpredictable M-class MSR masks also with Fail (instead of SoftFail). If SoftFail is preferred in this case then additional changes to ARMInstPrinter (to print non-symbolic masks) and ARMAsmParser (to parse non-symbolic masks) will be needed.
Patch by Petr Pavlu!
llvm-svn: 214505
The ARM ARM prohibits LDRB/LDRSB instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
llvm-svn: 214500
The ARM ARM prohibits LDRH/LDRSH instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
llvm-svn: 214499
The ARM ARM prohibits LDR instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDR instructions with unpredictable behavior.
llvm-svn: 214498
Currently when DAGCombine converts loads feeding a switch into a switch of
addresses feeding a load the new load inherits the isInvariant flag of the left
side. This is incorrect since invariant loads can be reordered in cases where it
is illegal to reoarder normal loads.
This patch adds an isInvariant parameter to getExtLoad() and updates all call
sites to pass in the data if they have it or false if they don't. It also
changes the DAGCombine to use that data to make the right decision when
creating the new load.
llvm-svn: 214449
The subtarget information is the ultimate source of truth for the feature set
that is enabled at this point. We would previously not propagate the feature
information to the subtarget. While this worked for the most part (features
would be enabled/disabled as requested), if another operation that changed the
feature bits was encountered (such as a mode switch via a .arm or .thumb
directive), we would end up resetting the behaviour of the architectural
extensions.
Handling this properly requires a slightly more complicated handling. We need
to check if the feature is now being toggled. If so, only then do we toggle the
features. In return, we no longer have to calculate the feature bits ourselves.
The test changes are mostly to the diagnosis, which is now more uniform (a nice
side effect!). Add an additional test to ensure that we handle this case
properly.
Thanks to Nico Weber for alerting me to this issue!
llvm-svn: 214057
Rename to allowsMisalignedMemoryAccess.
On R600, 8 and 16 byte accesses are mostly OK with 4-byte alignment,
and don't need to be split into multiple accesses. Vector loads with
an alignment of the element type are not uncommon in OpenCL code.
llvm-svn: 214055
address of the stack guard was being spilled to the stack.
Previously the address of the stack guard would get spilled to the stack if it
was impossible to keep it in a register. This patch introduces a new target
independent node and pseudo instruction which gets expanded post-RA to a
sequence of instructions that load the stack guard value. Register allocator
can now just remat the value when it can't keep it in a register.
<rdar://problem/12475629>
llvm-svn: 213967
assembly instructions.
This is necessary to ensure ARM assembler switches to Thumb mode before it
starts assembling the file level inline assembly instructions at the beginning
of a .s file.
<rdar://problem/17757232>
llvm-svn: 213924
In order to enable the preservation of noalias function parameter information
after inlining, and the representation of block-level __restrict__ pointer
information (etc.), additional kinds of aliasing metadata will be introduced.
This metadata needs to be carried around in AliasAnalysis::Location objects
(and MMOs at the SDAG level), and so we need to generalize the current scheme
(which is hard-coded to just one TBAA MDNode*).
This commit introduces only the necessary refactoring to allow for the
introduction of other aliasing metadata types, but does not actually introduce
any (that will come in a follow-up commit). What it does introduce is a new
AAMDNodes structure to hold all of the aliasing metadata nodes associated with
a particular memory-accessing instruction, and uses that structure instead of
the raw MDNode* in AliasAnalysis::Location, etc.
No functionality change intended.
llvm-svn: 213859
The ARM ARM prohibits STRH instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STRH instructions with unpredictable behavior.
llvm-svn: 213850
We were assuming all SBFX-like operations would have the shl/asr form, but
often when the field being extracted is an i8 or i16, we end up with a
SIGN_EXTEND_INREG acting on a shift instead. Simple enough to check for though.
llvm-svn: 213754
Although the final shifter operand is a rotate, this actually only matters for
the half-word extends when the amount == 24. Otherwise folding a shift in is
just as good.
llvm-svn: 213753
The ARM ARM prohibits STRB instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STRB instructions with unpredictable behavior.
llvm-svn: 213750
The ARM ARM prohibits STR instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STR instructions with unpredictable behavior.
llvm-svn: 213745
The post-indexed instructions were missing the constraint, causing unpredictable STRH instructions to be emitted.
The earlyclobber constraint on the pre-indexed STR instructions is not strictly necessary, as the instruction selection for pre-indexed STR instructions goes through an additional layer of pseudo instructions which have the constraint defined, however it doesn't hurt to specify the constraint directly on the pre-indexed instructions as well, since at some point someone might create instances of them programmatically and then the constraint is definitely needed.
llvm-svn: 213729
As discussed in a previous checking to support the .localentry
directive on PowerPC, we need to inspect the actual target symbol
in needsRelocateWithSymbol to make the appropriate decision based
on that symbol's st_other bits.
Currently, needsRelocateWithSymbol does not get the target symbol.
However, it is directly available to its sole caller. This patch
therefore simply extends the needsRelocateWithSymbol by a new
parameter "const MCSymbolData &SD", passes in the target symbol,
and updates all derived implementations.
In particular, in the PowerPC implementation, this patch removes
the FIXME added by the previous checkin.
llvm-svn: 213487
When performing a dynamic stack adjustment without optimisations, we would mark
SP as def and R4 as kill. This occurred as part of the expansion of a
WIN__CHKSTK SDNode which indicated the proper handling of SP and R4. The result
would be that we would double define SP as part of an operation, which is
obviously incorrect.
Furthermore, the VTList for the chain had an incorrect parameter type of i32
instead of Other.
Correct these to permit proper lowering of __builtin_alloca at -O0.
llvm-svn: 213442
On AArch64 the pseudo instruction ldr <reg>, =... supports both
32-bit and 64-bit constants. Add support for 64 bit constants for
the pools to support the pseudo instruction fully.
Changes the AArch64 ldr-pseudo tests to use 32-bit registers and
adds tests with 64-bit registers.
Patch by Janne Grunau!
Differential Revision: http://reviews.llvm.org/D4279
llvm-svn: 213387
The post-indexed instructions were missing the constraint, causing unpredictable STR instructions to be emitted.
The earlyclobber constraint on the pre-indexed STR instructions is not strictly necessary, as the instruction selection for pre-indexed STR instructions goes through an additional layer of pseudo instructions which have the constraint defined, however it doesn't hurt to specify the constraint directly on the pre-indexed instructions as well, since at some point someone might create instances of them programmatically and then the constraint is definitely needed.
This fixes PR20323.
llvm-svn: 213369
This makes the two intrinsics @llvm.convert.from.f16 and
@llvm.convert.to.f16 accept types other than simple "float". This is
only strictly needed for the truncate operation, since otherwise
double rounding occurs and there's no way to represent the strict IEEE
conversion. However, for symmetry we allow larger types in the extend
too.
During legalization, we can expand an "fp16_to_double" operation into
two extends for convenience, but abort when the truncate isn't legal. A new
libcall is probably needed here.
Even after this commit, various target tweaks are needed to actually use the
extended intrinsics. I've put these into separate commits for clarity, so there
are no actual tests of f64 conversion here.
llvm-svn: 213248
Refactoring; no functional changes intended
Removed PostRAScheduler bits from subtargets (X86, ARM).
Added PostRAScheduler bit to MCSchedModel class.
This bit is set by a CPU's scheduling model (if it exists).
Removed enablePostRAScheduler() function from TargetSubtargetInfo and subclasses.
Fixed the existing enablePostMachineScheduler() method to use the MCSchedModel (was just returning false!).
Added methods to TargetSubtargetInfo to allow overrides for AntiDepBreakMode, CriticalPathRCs, and OptLevel for PostRAScheduling.
Added enablePostRAScheduler() function to PostRAScheduler class which queries the subtarget for the above values.
Preserved existing scheduler behavior for ARM, MIPS, PPC, and X86:
a. ARM overrides the CPU's postRA settings by enabling postRA for any non-Thumb or Thumb2 subtarget.
b. MIPS overrides the CPU's postRA settings by enabling postRA for everything.
c. PPC overrides the CPU's postRA settings by enabling postRA for everything.
d. X86 is the only target that actually has postRA specified via sched model info.
Differential Revision: http://reviews.llvm.org/D4217
llvm-svn: 213101
The coalescer is very aggressive at propagating constraints on the register classes, and the register allocator doesn’t know how to split sub-registers later to recover. This patch provides an escape valve for targets that encounter this problem to limit coalescing.
This patch also implements such for ARM to lower register pressure when using lots of large register classes. This works around PR18825.
llvm-svn: 213078
This completes the handling for DLL import storage symbols when lowering
instructions. A DLL import storage symbol must have an additional load
performed prior to use. This is applicable to variables and functions.
This is particularly important for non-function symbols as it is possible to
handle function references by emitting a thunk which performs the translation
from the unprefixed __imp_ symbol to the proper symbol (although, this is a
non-optimal lowering). For a variable symbol, no such thunk can be
accommodated.
llvm-svn: 212431
Add support for tracking DLLImport storage class information on a per symbol
basis in the ARM instruction selection. Use that information to correctly
mangle the symbol (dllimport symbols are referenced via *__imp_<name>).
llvm-svn: 212430
Ensure that all paths that retrieve the symbol name go through GetARMGVSymbol
rather than getSymbol. This is desirable so that any global symbol mangling can
be centralised to this function. The motivation for this is handling of symbols
that are marked as having dll import dll storage. Such a symbol requires an
extra load that is currently handled in the backend and a __imp_ prefix on the
symbol name.
llvm-svn: 212429
The linker relies on relocation type info (e.g. is it a branch?) to perform the
correct actions, so we should keep that even when we end up using a scattered
relocation for whatever reason.
rdar://problem/17553104
llvm-svn: 212333
subtarget. This involved having the movt predicate take the current
function - since we care about size in instruction selection for
whether or not to use movw/movt take the function so we can check
the attributes. This required adding the current MachineFunction to
FastISel and propagating through.
llvm-svn: 212309
Robin Morisset