Shift-left immediate with sign-/zero-extensions also works for boolean values.
Update the assert and the test cases to reflect that fact.
This should fix a bug found by Chad.
llvm-svn: 218275
When looking through sign/zero-extensions the code would always assume there is
such an extension instruction and use the wrong operand for the address.
There was also a minor issue in the handling of 'AND' instructions. I
accidentially used a 'cast' instead of a 'dyn_cast'.
llvm-svn: 218161
When folding the intrinsic flag into the branch or select we also have to
consider the fact if the intrinsic got simplified, because it changes the
flag we have to check for.
llvm-svn: 218034
Small optimization in 'simplifyAddress'. When the offset cannot be encoded in
the load/store instruction, then we need to materialize the address manually.
The add instruction can encode a wider range of immediates than the load/store
instructions. This change tries to fold the offset into the add instruction
first before materializing the offset in a register.
llvm-svn: 218031
The 'AND' instruction could be used to mask out the lower 32 bits of a register.
If this is done inside an address computation we might be able to fold the
instruction into the memory instruction itself.
and x1, x1, #0xffffffff ---> ldrb x0, [x0, w1, uxtw]
ldrb x0, [x0, x1]
llvm-svn: 218030
This takes advanatage of the CBZ and CBNZ instruction to further optimize the
common null check pattern into a single instruction.
This is related to rdar://problem/18358882.
llvm-svn: 217972
This adds the last two missing floating-point condition codes (FCMP_UEQ and
FCMP_ONE) also to the branch selection. In these two cases an additonal branch
instruction is required.
This also adds unit tests to checks all the different condition codes.
This is related o rdar://problem/18358882.
llvm-svn: 217966
This required a new hook called hasLoadLinkedStoreConditional to know whether
to expand atomics to LL/SC (ARM, AArch64, in a future patch Power) or to
CmpXchg (X86).
Apart from that, the new code in AtomicExpandPass is mostly moved from
X86AtomicExpandPass. The main result of this patch is to get rid of that
pass, which had lots of code duplicated with AtomicExpandPass.
llvm-svn: 217928
Allow handling of vectors during return lowering at least for little endian machines.
This was restricted in r208200 to fix it for big endian machines (according to
the comment), but it also disabled it for little endian too.
llvm-svn: 217846
This lowers frem to a runtime libcall inside fast-isel.
The test case also checks the CallLoweringInfo bug that was exposed by this
change.
This fixes rdar://problem/18342783.
llvm-svn: 217833
... Just make sure we check uses first so we see the kill first. It
turns out ignoring defs gives some pretty nasty runtime failures.
I'm certain this is the fix but I'm still reducing a testcase.
llvm-svn: 217735
Vector MUL/MLAs have tied operands, which gives us extra constraints
that we currently can't handle. Instead of silently doing the wrong
thing, remove support to be readded later properly.
llvm-svn: 217690
Defs are seen before uses, so a def without the kill flag doesn't necessarily
mean that the register is not killed on that instruction. It may be killed
in a later use operand.
llvm-svn: 217689
The increase of the interleave factor to 4 has side-effects
like performance losses eg. due to reminder loops being executed
more frequently and may increase code size. It requires more
analysis and careful heuristic tuning. Expect double digit gains
in small benchmarks like lowercase.c and losses in puzzle.c.
llvm-svn: 217540
"Unroll" is not the appropriate name for this variable. Clang already uses
the term "interleave" in pragmas and metadata for this.
Differential Revision: http://reviews.llvm.org/D5066
llvm-svn: 217528
This adds target specific support for using the PBQP register allocator on the
AArch64, for the A57 cpu.
By default, the PBQP allocator is not used, unless explicitely required
on the command line with "-aarch64-pbqp".
llvm-svn: 217504
using static relocation model and small code model.
Summary: currently we generate GOT based relocations for weak symbol
references regardless of the underlying relocation model. This should
be change so that in static relocation model we use a constant pool
load instead.
Patch from: Keith Walker
Reviewers: Renato Golin, Tim Northover
llvm-svn: 217503
Patched by Sergey Dmitrouk.
This pass tries to make consecutive compares of values use same operands to
allow CSE pass to remove duplicated instructions. For this it analyzes
branches and adjusts comparisons with immediate values by converting:
GE -> GT
GT -> GE
LT -> LE
LE -> LT
and adjusting immediate values appropriately. It basically corrects two
immediate values towards each other to make them equal.
llvm-svn: 217220
Follow up to r217138, extending the logic to other NEON-immediate instructions.
As before, the instruction already performs the correct operation and we're
just using a different type for convenience, so we want a true nop-cast.
Patch by Asiri Rathnayake.
llvm-svn: 217159
We were materialising big-endian constants using DAG nodes with types different
from what was requested, followed by a bitcast. This is fine on little-endian
machines where bitcasting is a nop, but we need a slightly different
representation for big-endian. This adds a new set of NVCAST (natural-vector
cast) operations which are always nops.
Patch by Asiri Rathnayake.
llvm-svn: 217138
Summary:
Split shouldExpandAtomicInIR() into different versions for Stores/Loads/RMWs/CmpXchgs.
Makes runOnFunction cleaner (no more redundant checking/casting), and will help moving
the X86 backend to this pass.
This requires a way of easily detecting which instructions are atomic.
I followed the pattern of mayReadFromMemory, mayWriteOrReadMemory, etc.. in making
isAtomic() a method of Instruction implemented by a switch on the opcodes.
Test Plan: make check
Reviewers: jfb
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D5035
llvm-svn: 217080
This is the final round of renaming. This changes tblgen to emit lower-case
function names for FastEmitInst_* and FastEmit_*, and updates all its uses
in the source code.
Reviewed by Eric
llvm-svn: 217075
Things got a little bit messy over the years and it is time for a little bit
spring cleaning.
This first commit is focused on the FastISel base class itself. It doxyfies all
comments, C++11fies the code where it makes sense, renames internal methods to
adhere to the coding standard, and clang-formats the files.
Reviewed by Eric
llvm-svn: 217060
This reapplies r216805 with a fix to a copy-past error, which resulted in an
incorrect register class.
Original commit message:
Select the correct register class for the various instructions that are
generated when combining instructions and constrain the registers to the
appropriate register class.
This fixes rdar://problem/18183707.
llvm-svn: 217019
There is already target-dependent instruction selection support for Adds/Subs to
support compares and the intrinsics with overflow check. This takes advantage of
the existing infrastructure to also support Add/Sub, which allows the folding of
immediates, sign-/zero-extends, and shifts.
This fixes rdar://problem/18207316.
llvm-svn: 217007
This uses the target-dependent selection code for shifts first, which allows us
to create better code for shifts with immediates and sign-/zero-extend folding.
Vector type are not handled yet and the code falls back to target-independent
instruction selection for these cases.
This fixes rdar://problem/17907920.
llvm-svn: 216985
FastISel for AArch64 supports more value types than are actually legal. Use a
dedicated helper function to reflect this.
It is very similar to the isLoadStoreTypeLegal function, with the exception
that vector types are not supported yet.
llvm-svn: 216984
This change moves FastISel for AArch64 to target-dependent instruction selection
only. This change replicates the existing target-independent behavior, therefore
there are no changes to the unit tests or new tests.
Future changes will take advantage of this change and update functionality
and unit tests.
llvm-svn: 216955
This removes static initializers from the backends which generate this data, and also makes this struct match the other Tablegen generated structs in behaviour
Reviewed by Andy Trick and Chandler C
llvm-svn: 216919
Summary:
Left shift of negative integer is an undefined behavior, and
is reported by UBSan. It's ok for imm values to be negative, so we can
just replace left shifts with multiplications.
Test Plan: check-llvm test suite
Reviewers: t.p.northover
Reviewed By: t.p.northover
Subscribers: aemerson, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D5132
llvm-svn: 216910
Select the correct register class for the various instructions that are
generated when combining instructions and constrain the registers to the
appropriate register class.
This fixes rdar://problem/18183707.
llvm-svn: 216805
This patch checks for DAG patterns that are an add or a sub followed by a
compare on 16 and 8 bit inputs. Since AArch64 does not support those types
natively they are legalized into 32 bit values, which means that mask operations
are inserted into the DAG to emulate overflow behaviour. In many cases those
masks do not change the result of the processing and just introduce a dependent
operation, often in the middle of a hot loop.
This patch detects the relevent DAG patterns and then tests to see if the
transforms are equivalent with and without the mask, removing the mask if
possible. The exact mechanism of this patch was discusses in
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074444.html
There is a reasonably good chance there are missed oppurtunities due to similiar
(but not identical) DAG patterns that could be funneled into this test, adding
them should be simple if we see test cases.
Tests included.
rdar://13754426
llvm-svn: 216776
When we select a trunc instruction we don't emit any code if the type is already
i32 or smaller. This is because the instruction that uses the truncated value
will deal with it.
This behavior can incorrectly transfer a kill flag, which was meant for the
result of the truncate, onto the source register.
%2 = trunc i32 %1 to i16
... = ... %2 -> ... = ... vreg1 <kill>
... = ... %1 ... = ... vreg1
This commit fixes this by emitting a COPY instruction, so that the result and
source register are distinct virtual registers.
This fixes rdar://problem/18178188.
llvm-svn: 216750
In an llvm-stress generated test, we were trying to create a v0iN type and
asserting when that failed. This case could probably be handled by the
function, but not without added complexity and the situation it arises in is
sufficiently odd that there's probably no benefit anyway.
Should fix PR20775.
llvm-svn: 216725
and forget about the previously used accumulator.
Coming up with a simple testcase is not easy, as this highly depends on
what the register allocator is doing: this issue showed up while working
with the PBQP allocator, which produced a different allocation scheme.
A testcase would need to come up with chain starting in D[0-7], then
moving to D[8-15], followed by a call to a function whose regmask
clobbers the starting accumulator in D[0-7], then another use of the chain.
Fixed some formatting, added some invariant checks while there.
llvm-svn: 216721
This fix checks first if the instruction to be folded (e.g. sign-/zero-extend,
or shift) is in the same machine basic block as the instruction we are folding
into.
Not doing so can result in incorrect code, because the value might not be
live-out of the basic block, where the value is defined.
This fixes rdar://problem/18169495.
llvm-svn: 216700
The AArch64 target lowering for [zs]ext of vectors is set up to handle
input simple types and expects the generic SDag path to do something reasonable
with anything that's not a simple type. The code, however, was only
checking that the result type was a simple type and assuming that
implied that the source type would also be a simple type. That's not a
valid assumption, as operations like "zext <1 x i1> %0 to <1 x i32>"
demonstrate. The fix is to simply explicitly validate the source type
as well as the result type.
PR20791
llvm-svn: 216689
Currently instructions are folded very aggressively into the memory operation,
which can lead to the use of killed operands:
%vreg1<def> = ADDXri %vreg0<kill>, 2
%vreg2<def> = LDRBBui %vreg0, 2
... = ... %vreg1 ...
This usually happens when the result is also used by another non-memory
instruction in the same basic block, or any instruction in another basic block.
If the computed address is used by only memory operations in the same basic
block, then it is safe to fold them. This is because all memory operations will
fold the address computation and the original computation will never be emitted.
This fixes rdar://problem/18142857.
llvm-svn: 216629
When the address comes directly from a shift instruction then the address
computation cannot be folded into the memory instruction, because the zero
register is not available as a base register. Simplify addess needs to emit the
shift instruction and use the result as base register.
llvm-svn: 216621
Use the zero register directly when possible to avoid an unnecessary register
copy and a wasted register at -O0. This also uses integer stores to store a
positive floating-point zero. This saves us from materializing the positive zero
in a register and then storing it.
llvm-svn: 216617
This teaches the AArch64 backend to deal with the operations required
to deal with the operations on v4f16 and v8f16 which are exposed by
NEON intrinsics, plus the add, sub, mul and div operations.
llvm-svn: 216555
When a shift with extension or an add with shift and extension cannot be folded
into the memory operation, then the address calculation has to be materialized
separately. While doing so the code forgot to consider a possible sign-/zero-
extension. This fix folds now also the sign-/zero-extension into the add or
shift instruction which is used to materialize the address.
This fixes rdar://problem/18141718.
llvm-svn: 216511
It seems on Darwin the illegal round-trip ::iterator -> MachineInstr* -> ::iterator breaks execution horribly when the iterator is not a real MachineInstr, like ::end().
llvm-svn: 216455
This patch adds support to recognize division by uniform power of 2 and modifies the cost table to vectorize division by uniform power of 2 whenever possible.
Updates Cost model for Loop and SLP Vectorizer.The cost table is currently only updated for X86 backend.
Thanks to Hal, Andrea, Sanjay for the review. (http://reviews.llvm.org/D4971)
llvm-svn: 216371
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
This is mostly achieved by providing the correct register class manually,
because getRegClassFor always returns the GPR*AllRegClass for MVT::i32 and
MVT::i64.
Also cleanup the code to use the FastEmitInst_* method whenever possible. This
makes sure that the operands' register class is properly constrained. For all
the remaining cases this adds the missing constrainOperandRegClass calls for
each operand.
llvm-svn: 216225
The AdvSIMD pass may produce copies that are not coalescer-friendly. The
peephole optimizer knows how to fix that as demonstrated in the test case.
<rdar://problem/12702965>
llvm-svn: 216200
This fixes a bug I introduced in a previous commit (r216033). Sign-/Zero-
extension from i1 cannot be folded into the ADDS/SUBS instructions. Instead both
operands have to be sign-/zero-extended with separate instructions.
Related to <rdar://problem/17913111>.
llvm-svn: 216073
Use FMOVWSr/FMOVXDr instead of FMOVSr/FMOVDr, which have the proper register
class to be used with the zero register. This makes the MachineInstruction
verifier happy again.
This is related to <rdar://problem/18027157>.
llvm-svn: 216040
Factor out the ADDS/SUBS instruction emission code into helper functions and
make the helper functions more clever to support most of the different ADDS/SUBS
instructions the architecture support. This includes better immedediate support,
shift folding, and sign-/zero-extend folding.
This fixes <rdar://problem/17913111>.
llvm-svn: 216033
Note: This was originally reverted to track down a buildbot error. Reapply
without any modifications.
Original commit message:
FastISel didn't take much advantage of the different addressing modes available
to it on AArch64. This commit allows the ComputeAddress method to recognize more
addressing modes that allows shifts and sign-/zero-extensions to be folded into
the memory operation itself.
For Example:
lsl x1, x1, #3 --> ldr x0, [x0, x1, lsl #3]
ldr x0, [x0, x1]
sxtw x1, w1
lsl x1, x1, #3 --> ldr x0, [x0, x1, sxtw #3]
ldr x0, [x0, x1]
llvm-svn: 216013
Note: This was originally reverted to track down a buildbot error. Reapply
without any modifications.
Original commit message:
This change materializes now the value "0" from the zero register.
The zero register can be folded by several instruction, so no
materialization is need at all.
Fixes <rdar://problem/17924413>.
llvm-svn: 216009
This fixes a few BuildMI callsites where the result register was added by
using addReg, which is per default a use and therefore an operand register.
Also use the zero register as result register when emitting a compare
instruction (SUBS with unused result register).
llvm-svn: 215997
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
The floating-point value positive zero (+0.0) is a valid immedate value
according to isFPImmLegal. As a result AArch64 FastISel went ahead and
used the immediate version of fmov to materialize the constant.
The problem is that the immediate version of fmov cannot encode an imediate for
postive zero. Instead a fmov from the zero register was supposed to be used in
this case.
This fix adds handling for this special case and uses fmov from the zero
register to materialize a positive zero (negative zeroes go to the constant
pool).
There is no test case for this, because this code is currently dead. It will be
enabled in a future commit and I will add a test case in a separate commit
after that.
This fixes <rdar://problem/18027157>.
llvm-svn: 215753
Note: This reapplies r215582 without any modifications. The refactoring wasn't
responsible for the buildbot failures.
Original commit message:
Cleanup and prepare constant materialization code for future commits.
llvm-svn: 215752
This reverts:
r215595 "[FastISel][X86] Add large code model support for materializing floating-point constants."
r215594 "[FastISel][X86] Use XOR to materialize the "0" value."
r215593 "[FastISel][X86] Emit more efficient instructions for integer constant materialization."
r215591 "[FastISel][AArch64] Make use of the zero register when possible."
r215588 "[FastISel] Let the target decide first if it wants to materialize a constant."
r215582 "[FastISel][AArch64] Cleanup constant materialization code. NFCI."
llvm-svn: 215673
Certain functions such as objc_autoreleaseReturnValue have to be called as
tail-calls even at -O0. Since normal fast-isel doesn't emit calls as tail calls,
we have to fall back to SelectionDAG to select calls that are marked as tail.
<rdar://problem/17991614>
llvm-svn: 215600
FastISel didn't take much advantage of the different addressing modes available
to it on AArch64. This commit allows the ComputeAddress method to recognize more
addressing modes that allows shifts and sign-/zero-extensions to be folded into
the memory operation itself.
For Example:
lsl x1, x1, #3 --> ldr x0, [x0, x1, lsl #3]
ldr x0, [x0, x1]
sxtw x1, w1
lsl x1, x1, #3 --> ldr x0, [x0, x1, sxtw #3]
ldr x0, [x0, x1]
llvm-svn: 215597
This change materializes now the value "0" from the zero register.
The zero register can be folded by several instruction, so no
materialization is need at all.
Fixes <rdar://problem/17924413>.
llvm-svn: 215591
This is a cleaner solution to the problem described in r215431.
When instructions are combined a dangling DBG_VALUE is removed.
This resolves bug 20598.
llvm-svn: 215587
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
The combiner ignored DBG nodes when checking
the uses of a virtual register.
It combined a sequence like
%vreg1 = madd %vreg2, %vreg3,...
DBG_VALUE (%vreg1 ...)
%vreg4 = add %vreg1,...
to
%vreg4 = madd %vreg2, %vreg3
leaving behind a dangling DBG_VALUE with
a definition. This triggered an assertion
in the MachineTraceMetrics.cpp module.
llvm-svn: 215431
std::map invalidates the iterator to any element that gets deleted, which means
we can't increment it correctly afterwards. This was causing Darwin test
failures.
llvm-svn: 215233
For best-case performance on Cortex-A57, we should try to use a balanced mix of odd and even D-registers when performing a critical sequence of independent, non-quadword FP/ASIMD floating-point multiply or multiply-accumulate operations.
This pass attempts to detect situations where the register allocation may adversely affect this load balancing and to change the registers used so as to better utilize the CPU.
Ideally we'd just take each multiply or multiply-accumulate in turn and allocate it alternating even or odd registers. However, multiply-accumulates are most efficiently performed in the same functional unit as their accumulation operand. Therefore this pass tries to find maximal sequences ("Chains") of multiply-accumulates linked via their accumulation operand, and assign them all the same "color" (oddness/evenness).
This optimization affects S-register and D-register floating point multiplies and FMADD/FMAs, as well as vector (floating point only) muls and FMADD/FMA. Q register instructions (and 128-bit vector instructions) are not affected.
llvm-svn: 215199
This short-circuited our error reporting for incorrectly specified
target triples (you'd get AArch64 code instead).
Should fix PR20567.
llvm-svn: 215191
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
Re-commit of r214832,r21469 with a work-around that
avoids the previous problem with gcc build compilers
The work-around is to use SmallVector instead of ArrayRef
of basic blocks in preservesResourceLen()/MachineCombiner.cpp
llvm-svn: 215151
Oliver Stannard