The list of subtarget features for the 7em triple contains 't2xtpk',
which actually disables that subtarget feature. Correct that to
'+t2xtpk' and test that the instructions enabled by that feature do
actually work.
Differential Revision: http://reviews.llvm.org/D9936
llvm-svn: 238022
This starts merging MCSection and MCSectionData.
There are a few issues with the current split between MCSection and
MCSectionData.
* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.
* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.
* It makes it harder to remember where each item is.
The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.
Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.
llvm-svn: 237936
Ideally this is going to be and LLVM IR pass (shared, among others
with AArch64), but for the time being just enable it if consumers
ask us for optimization and not unconditionally.
Discussed with Tim Northover on IRC.
llvm-svn: 237837
This was previously returning int. However there are no negative opcode
numbers and more importantly this was needlessly different from
MCInstrDesc::getOpcode() (which even is the value returned here) and
SDValue::getOpcode()/SDNode::getOpcode().
llvm-svn: 237611
Previously, they were forced to immediately follow the actual branch
instruction. This was usually OK (the LEAs actually accessing them got emitted
nearby, and weren't usually separated much afterwards). Unfortunately, a
sufficiently nasty phi elimination dumps many instructions right before the
basic block terminator, and this can increase the range too much.
This patch frees them up to be placed as usual by the constant islands pass,
and consequently has to slightly modify the form of TBB/TBH tables to refer to
a PC-relative label at the final jump. The other jump table formats were
already position-independent.
rdar://20813304
llvm-svn: 237590
This patch implements LLVM support for the ACLE special register intrinsics in
section 10.1, __arm_{w,r}sr{,p,64}.
This patch is intended to lower the read/write_register instrinsics, used to
implement the special register intrinsics in the clang patch for special
register intrinsics (see http://reviews.llvm.org/D9697), to ARM specific
instructions MRC,MCR,MSR etc. to allow reading an writing of coprocessor
registers in AArch32 and AArch64. This is done by inspecting the register
string passed to the intrinsic and then lowering to the appropriate
instruction.
Patch by Luke Cheeseman.
Differential Revision: http://reviews.llvm.org/D9699
llvm-svn: 237579
There's no need to manually pass modifier strings around to tell an operand how
to print now, that information is encoded in the operand itself since the MC
layer came along.
llvm-svn: 237295
We were creating and propagating two separate indices for each jump table (from
back in the mists of time). However, the generic index used by other backends
is sufficient to emit a unique symbol so this was unneeded.
llvm-svn: 237294
The previous logic mixed 2 separate questions:
+ Can we form a TBB/TBH instruction?
+ Can we remove the jump-table calculation before it?
It then performed a bunch of random tests on the instructions earlier in the
basic block, which were probably sufficient to answer 2 but only because of the
very limited ways in which a t2BR_JT can actually be created.
For example there's no reason to expect the LeaInst to define the same base
register as the following indexing calulation. In practice this means we might
have missed opportunities to form TBB/TBH, in theory you could end up
misidentifying a sequence and removing the wrong LEA:
%R1 = t2LEApcrelJT ...
%R2 = t2LEApcrelJT ...
<... using and killing %R2 ...>
%R2 = t2ADDr %R1, $Ridx
Before we would have looked for an LEA defining %R2 and found the wrong one. We
just got lucky that jump table setup was (almost?) always confined to a single
basic block and there was only one jump table per block.
llvm-svn: 237293
Previously, subtarget features were a bitfield with the underlying type being uint64_t.
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.
The first two times this was committed (r229831, r233055), it caused several buildbot failures.
At least some of the ARM and MIPS ones were due to gcc/binutils issues, and should now be fixed.
llvm-svn: 237234
They do more harm than good when used in the MachineScheduler as they
tend to take preference to register pressure minimsation which is more
important for swift.
Differential Revision: http://reviews.llvm.org/D9718
llvm-svn: 237179
AEABI defines aligned variants of memcpy etc. that can be faster than
the default version due to not having to do alignment checks. When
emitting target code for these functions make use of these aligned
variants if possible. Also convert memset to memclr if possible.
Differential Revision: http://reviews.llvm.org/D8060
llvm-svn: 237127
sys/time.h on Solaris (and possibly other systems) defines "SEC" as "1"
using a cpp macro. The result is that this fails to compile.
Fixes https://llvm.org/PR23482
llvm-svn: 237112
to use the information in the module rather than TargetOptions.
We've had and clang has used the use-soft-float attribute for some
time now so have the backends set a subtarget feature based on
a particular function now that subtargets are created based on
functions and function attributes.
For the one middle end soft float check go ahead and create
an overloadable TargetLowering::useSoftFloat function that
just checks the TargetSubtargetInfo in all cases.
Also remove the command line option that hard codes whether or
not soft-float is set by using the attribute for all of the
target specific test cases - for the generic just go ahead and
add the attribute in the one case that showed up.
llvm-svn: 237079
The code that builds the dependence graph assumes that two PseudoSourceValues
don't alias. In a tail calling function two FixedStackObjects might refer to the
same location. Worse 'immutable' fixed stack objects like function arguments are
not immutable and will be clobbered.
Change this so that a load from a FixedStackObject is not invariant in a tail
calling function and don't return a PseudoSourceValue for an instruction in tail
calling functions when building the dependence graph so that we handle function
arguments conservatively.
Fix for PR23459.
rdar://20740035
llvm-svn: 236916
This new class in a global context contain arch-specific knowledge in order
to provide LLVM libraries, tools and projects with the ability to understand
the architectures. For now, only FPU, ARCH and ARCH extensions on ARM are
supported.
Current behaviour it to parse from free-text to enum values and back, so that
all users can share the same parser and codes. This simplifies a lot both the
ASM/Obj streamers in the back-end (where this came from), and the front-end
parsers for command line arguments (where this is going to be used next).
The previous implementation, using .def/.h includes is deprecated due to its
inflexibility to be built without the backend support and for being too
cumbersome. As more architectures join this scheme, and as more features of
such architectures are added (such as hardware features, type sizes, etc) into
a full blown TargetDescription class, having a set of classes is the most
sane implementation.
The ultimate goal of this refactor both LLVM's and Clang's target description
classes into one unique interface, so that we can de-duplicate and standardise
the descriptions, as well as make it available for other front-ends, tools,
etc.
The FPU parsing for command line options in Clang has been converted to use
this new library and a number of aliases were added for compatibility:
* A bogus neon-vfpv3 alias (neon defaults to vfp3)
* armv5/v6
* {fp4/fp5}-{sp/dp}-d16
Next steps:
* Port Clang's ARCH/EXT parsing to use this library.
* Create a TableGen back-end to generate this information.
* Run this TableGen process regardless of which back-ends are built.
* Expose more information and rename it to TargetDescription.
* Continue re-factoring Clang to use as much of it as possible.
llvm-svn: 236900
The patch disabled unrolling in loop vectorization pass when VF==1 on x86 architecture,
by setting MaxInterleaveFactor to 1. Unrolling in loop vectorization pass may introduce
the cost of overflow check, memory boundary check and extra prologue/epilogue code when
regular unroller will unroll the loop another time. Disable it when VF==1 remove the
unnecessary cost on x86. The same can be done for other platforms after verifying
interleaving/memory bound checking to be not perf critical on those platforms.
Differential Revision: http://reviews.llvm.org/D9515
llvm-svn: 236613
With neon enabled, we reach SelectBinaryFPOp and are able to get registers for a <2 x double> add.
However, we shouldn't actually attempt arithmetic on it as ARMIselLowering says "v2f64 is legal so that QR subregs can be extracted as f64 elements, but neither Neon nor VFP support any arithmetic operations on it."
This commit disables SelectBinaryFPOp for any vector types. There's already a FIXME to try handle neon. Doing so would require fixing this conditional which isn't safe for vectors 'VT == MVT::f64 || VT == MVT::i64'
llvm-svn: 236609
Since r234249, i1 are sext instead of zext; because of that, doing
"CMP rN, #0; IT EQ/NE" isn't correct anymore.
"TST #1" is the conservatively correct alternative - the tradeoff being
that it doesn't have a 16-bit encoding -, so use that instead.
llvm-svn: 236569
The register set for LDMIA begins at offset 3, not 4. We were previously
missing the short encoding of this instruction in the case where the base
register was the first register in the register set.
Also clean up some dead code:
- The isARMLowRegister check is redundant with what VerifyLowRegs does;
replace with an assert.
- Remove handling of LDMDB instruction, which has no short encoding (and
does not appear in ReduceTable).
Differential Revision: http://reviews.llvm.org/D9485
llvm-svn: 236535
This patch introduces a new pass that computes the safe point to insert the
prologue and epilogue of the function.
The interest is to find safe points that are cheaper than the entry and exits
blocks.
As an example and to avoid regressions to be introduce, this patch also
implements the required bits to enable the shrink-wrapping pass for AArch64.
** Context **
Currently we insert the prologue and epilogue of the method/function in the
entry and exits blocks. Although this is correct, we can do a better job when
those are not immediately required and insert them at less frequently executed
places.
The job of the shrink-wrapping pass is to identify such places.
** Motivating example **
Let us consider the following function that perform a call only in one branch of
a if:
define i32 @f(i32 %a, i32 %b) {
%tmp = alloca i32, align 4
%tmp2 = icmp slt i32 %a, %b
br i1 %tmp2, label %true, label %false
true:
store i32 %a, i32* %tmp, align 4
%tmp4 = call i32 @doSomething(i32 0, i32* %tmp)
br label %false
false:
%tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ]
ret i32 %tmp.0
}
On AArch64 this code generates (removing the cfi directives to ease
readabilities):
_f: ; @f
; BB#0:
stp x29, x30, [sp, #-16]!
mov x29, sp
sub sp, sp, #16 ; =16
cmp w0, w1
b.ge LBB0_2
; BB#1: ; %true
stur w0, [x29, #-4]
sub x1, x29, #4 ; =4
mov w0, wzr
bl _doSomething
LBB0_2: ; %false
mov sp, x29
ldp x29, x30, [sp], #16
ret
With shrink-wrapping we could generate:
_f: ; @f
; BB#0:
cmp w0, w1
b.ge LBB0_2
; BB#1: ; %true
stp x29, x30, [sp, #-16]!
mov x29, sp
sub sp, sp, #16 ; =16
stur w0, [x29, #-4]
sub x1, x29, #4 ; =4
mov w0, wzr
bl _doSomething
add sp, x29, #16 ; =16
ldp x29, x30, [sp], #16
LBB0_2: ; %false
ret
Therefore, we would pay the overhead of setting up/destroying the frame only if
we actually do the call.
** Proposed Solution **
This patch introduces a new machine pass that perform the shrink-wrapping
analysis (See the comments at the beginning of ShrinkWrap.cpp for more details).
It then stores the safe save and restore point into the MachineFrameInfo
attached to the MachineFunction.
This information is then used by the PrologEpilogInserter (PEI) to place the
related code at the right place. This pass runs right before the PEI.
Unlike the original paper of Chow from PLDI’88, this implementation of
shrink-wrapping does not use expensive data-flow analysis and does not need hack
to properly avoid frequently executed point. Instead, it relies on dominance and
loop properties.
The pass is off by default and each target can opt-in by setting the
EnableShrinkWrap boolean to true in their derived class of TargetPassConfig.
This setting can also be overwritten on the command line by using
-enable-shrink-wrap.
Before you try out the pass for your target, make sure you properly fix your
emitProlog/emitEpilog/adjustForXXX method to cope with basic blocks that are not
necessarily the entry block.
** Design Decisions **
1. ShrinkWrap is its own pass right now. It could frankly be merged into PEI but
for debugging and clarity I thought it was best to have its own file.
2. Right now, we only support one save point and one restore point. At some
point we can expand this to several save point and restore point, the impacted
component would then be:
- The pass itself: New algorithm needed.
- MachineFrameInfo: Hold a list or set of Save/Restore point instead of one
pointer.
- PEI: Should loop over the save point and restore point.
Anyhow, at least for this first iteration, I do not believe this is interesting
to support the complex cases. We should revisit that when we motivating
examples.
Differential Revision: http://reviews.llvm.org/D9210
<rdar://problem/3201744>
llvm-svn: 236507
When forming an IT block from the first MOV here:
%R2<def> = t2MOVr %R0, pred:1, pred:%CPSR, opt:%noreg
%R3<def> = tMOVr %R0<kill>, pred:14, pred:%noreg
the move in to R3 is moved out of the IT block so that later instructions on the same predicate can be inside this block, and we can share the IT instruction.
However, when moving the R3 copy out of the IT block, we need to clear its kill flags for anything in use at this point in time, ie, R0 here.
This appeases the machine verifier which thought that R0 wasn't defined when used.
I have a test case, but its extremely register allocator specific. It would be too fragile to commit a test which depends on the register allocator here.
llvm-svn: 236468
Converting from t2LDRs to tLDRr caused the shift argument to drop the internal flag. This would then throw machine verifier errors.
Unfortunately i'm having trouble reducing a test case. I'm going to keep trying, but so far its a scary combination of machine sinking, an 'and i1', loads feeding loads, and a bunch of code which shouldn't change IT block formation, but does. Its not useful to commit a test in that state as we have no way of knowing if it even hits this code reliably in future.
rdar://problem/20752113
llvm-svn: 236333
Functions with jump tables need an alignment of 4 because they use the ADR
instruction, which aligns the PC to 4 bytes before adding an offset.
Differential Revision: http://reviews.llvm.org/D9424
llvm-svn: 236327
If we move an instruction from one block down to a MOVC and predicate it,
then the original instruction could be moved in to a loop. In this case,
its invalid for any kill flags to remain on there.
Fails with -verfy-machineinstrs.
rdar://problem/20752113
llvm-svn: 236290
The expansion for t2ABS was always setting the kill flag on the rsb instruction.
It should instead only be set on rsb if it was set on the original ABS instruction.
rdar://problem/20752113
llvm-svn: 236272
