An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size.
After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts.
In doing so we can significantly reduce the number of operations required.
Differential Revision: https://reviews.llvm.org/D21578
llvm-svn: 276432
when constraint "w" is used on a 32-bit operand.
This enables compiling the following code, which used to error out in
the backend:
void foo1(int a) {
asm volatile ("sqxtn h0, %s0\n" : : "w"(a):);
}
Fixes PR28633.
llvm-svn: 276344
Summary:
This change also changes findMatchingInsn and
findMatchingUpdateInsnForward to take DBG_VALUE opcodes into account
when tracking register defs and uses, which could potentially inhibit
these optimizations in the presence of debug information.
Reviewers: mcrosier
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D22582
llvm-svn: 276293
At -O0, cmpxchg survives AtomicExpand: it's mostly straightforward
to select it in fast-isel, and let the pseudo be expanded later.
extractvalues on the result are the tricky part: the generic logic
only works for legal types (and it would be painful to make it
support illegal types), so we can only support i32/i64 cmpxchg.
llvm-svn: 276183
This should be all the low-level instruction selection needs to determine how
to implement an operation, with the remaining context taken from the opcode
(e.g. G_ADD vs G_FADD) or other flags not based on type (e.g. fast-math).
llvm-svn: 276158
Inference of the 'returned' attribute was fixed in r276008, lets try
turning the backend support back on.
This reverts commit r275677.
llvm-svn: 276081
As discussed on PR27654, this patch fixes the triples of a lot of aarch64 tests and enables lit tests on windows
This will hopefully help stop cases where windows developers break the aarch64 target
Differential Revision: https://reviews.llvm.org/D22191
llvm-svn: 275973
r275042 reverted function-attribute inference for the 'returned' attribute
because the feature triggered self-hosting failures on ARM and AArch64. James
Molloy determined that the this-return argument forwarding feature, which
directly ties the returned input argument to the returned value, was the cause.
It seems likely that this forwarding code contains, or triggers, a subtle bug.
Disabling for now until we can track that down.
llvm-svn: 275677
Currently the MIR framework prints all its outputs (errors and actual
representation) on stderr.
This patch fixes that by printing the regular output in the output
specified with -o.
Differential Revision: http://reviews.llvm.org/D22251
llvm-svn: 275314
We can freeze the registers after the MachineFrameInfo has been configured (by
telling it about calls, inline asm, ...). This doesn't happen at all yet, but
will be part of IR translation.
Fixes -verify-machineinstrs assertion.
llvm-svn: 275221
If a subtarget has both ZCZeroing and CustomCheapAsMoveHandling features (now
only Kryo has both), set FMOVS0 and FMOVD0 isAsCheapAsAMove.
Differential Revision: http://reviews.llvm.org/D22256
llvm-svn: 275178
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
llvm-svn: 274952
The commit reinstates r273279, which was informally approved.
Original Review: http://reviews.llvm.org/D21414
This reverts commit ca632c91aaa7cafc50942f890c49f727a046ace1.
llvm-svn: 274790
On CPUs with the zero cycle zeroing feature enabled "movi v.2d" should
be used to zero a vector register. This was previously done at
instruction selection time, however the register coalescer sometimes
widened multiple vregs to the Q width because of that leading to extra
spills. This patch leaves the decision on how to zero a register to the
AsmPrinter phase where it doesn't affect register allocation anymore.
This patch also sets isAsCheapAsAMove=1 on FMOVS0, FMOVD0.
This fixes http://llvm.org/PR27454, rdar://25866262
Differential Revision: http://reviews.llvm.org/D21826
llvm-svn: 274686
The way the named arguments for various system instructions are handled at the
moment has a few problems:
- Large-scale duplication between AArch64BaseInfo.h and AArch64BaseInfo.cpp
- That weird Mapping class that I have no idea what I was on when I thought
it was a good idea.
- Searches are performed linearly through the entire list.
- We print absolutely all registers in upper-case, even though some are
canonically mixed case (SPSel for example).
- The ARM ARM specifies sysregs in terms of 5 fields, but those are relegated
to comments in our implementation, with a slightly opaque hex value
indicating the canonical encoding LLVM will use.
This adds a new TableGen backend to produce efficiently searchable tables, and
switches AArch64 over to using that infrastructure.
llvm-svn: 274576
This reverts commit r259387 because it inserts illegal code after legalization
in some backends where i64 OR type is illegal for example.
llvm-svn: 274573
The other use really does only care about the SDNode (it checks the
opcode against a whitelist), but bitFieldPlacement can be misled if
the node produces multiple results.
Patch by Ismail Badawi.
llvm-svn: 274567
In bidirectional scheduling this gives more stable results than just
comparing the "reason" fields of the top/bottom node because the reason
field may be higher depending on what other nodes are in the queue.
Differential Revision: http://reviews.llvm.org/D19401
llvm-svn: 273755
r273271 changed the RUN line of the regression test to use
-march=cyclone instead of -mtriple=aarch64-none-none.
This caused a change in the output syntax for the ext
instruction, causing the test to fail. Change this test
back to using -mtriple=aarch64-none-none.
llvm-svn: 273286
Summary:
We have switched to using features for all heuristics, but
the tests for these are still using -mcpu, which means we
are not directly testing the features.
This converts at least some of the existing regression tests
to use the new features.
This still leaves the following features untested:
merge-narrow-ld
predictable-select-expensive
alternate-sextload-cvt-f32-pattern
disable-latency-sched-heuristic
Reviewers: mcrosier, t.p.northover, rengolin
Subscribers: MatzeB, aemerson, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D21288
llvm-svn: 273271
The backend has been around for years, it's pretty ridiculous that we can't
even use the preferred form for printing "MOV" aliases. Unfortunately, TableGen
can't handle the complex predicates when printing so it's a bunch of nasty C++.
Oh well.
llvm-svn: 272865
Of course the assembly was right but because the opcode was MOVZWi it was
encoded as "movz w16, #65535, lsl #32" which is an unallocated encoding and
would go horribly wrong on a CPU.
No idea how this bug survived this long. It seems nobody is using that aspect
of patchpoints.
llvm-svn: 272831
This reapplies commit r271930, r271915, r271923. They hit a bug in
Thumb which is fixed in r272258 now.
The original message:
The code layout that TailMerging (inside BranchFolding) works on is not the
final layout optimized based on the branch probability. Generally, after
BlockPlacement, many new merging opportunities emerge.
This patch calls Tail Merging after MBP and calls MBP again if Tail Merging
merges anything.
llvm-svn: 272267
Summary:
Consider the following diamond CFG:
A
/ \
B C
\/
D
Suppose A->B and A->C have probabilities 81% and 19%. In block-placement, A->B is called a hot edge and the final placement should be ABDC. However, the current implementation outputs ABCD. This is because when choosing the next block of B, it checks if Freq(C->D) > Freq(B->D) * 20%, which is true (if Freq(A) = 100, then Freq(B->D) = 81, Freq(C->D) = 19, and 19 > 81*20%=16.2). Actually, we should use 25% instead of 20% as the probability here, so that we have 19 < 81*25%=20.25, and the desired ABDC layout will be generated.
Reviewers: djasper, davidxl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20989
llvm-svn: 272203
Teach AArch64RegisterBankInfo that G_OR can be mapped on either GPR or
FPR for 64-bit or 32-bit values.
Add test cases demonstrating how this information is used to coalesce a
computation on a single register bank.
llvm-svn: 272170
The code layout that TailMerging (inside BranchFolding) works on is not the
final layout optimized based on the branch probability. Generally, after
BlockPlacement, many new merging opportunities emerge.
This patch calls Tail Merging after MBP and calls MBP again if Tail Merging
merges anything.
Differential Revision: http://reviews.llvm.org/D20276
llvm-svn: 271925
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.
This is a port of r213754 from ARM to AArch64.
llvm-svn: 271677
Summary:
If the target requests it, use emptry spaces in the fixed and
callee-save stack area to allocate local stack objects.
AArch64: Change last callee-save reg stack object alignment instead of
size to leave a gap to take advantage of above change.
Reviewers: t.p.northover, qcolombet, MatzeB
Subscribers: rengolin, mcrosier, llvm-commits, aemerson
Differential Revision: http://reviews.llvm.org/D20220
llvm-svn: 271527
Tim Northover