I missed the side-effects of ParseBFI in my previous attempt (r252748).
Thanks dblaikie for the suggestion of adding a void use of the unused
variable instead.
llvm-svn: 252751
If we have a chain of BFIs, we may be able to combine several together into one merged BFI. We can do this if the "from" bits from one BFI OR'd with the "from" bits from the other BFI form a contiguous range, and the same with the "to" bits.
llvm-svn: 252740
If possible and profitable, replace lea %reg, 1(%reg) and lea %reg, -1(%reg) with inc %reg and dec %reg respectively.
Patch by: anton.nadolsky@intel.com
Differential Revision: http://reviews.llvm.org/D14059
llvm-svn: 252722
This patch adds a pass for doing PowerPC peephole optimizations at the
MI level while the code is still in SSA form. This allows for easy
modifications to the instructions while depending on a subsequent pass
of DCE. Both passes are very fast due to the characteristics of SSA.
At this time, the only peepholes added are for cleaning up various
redundancies involving the XXPERMDI instruction. However, I would
expect this will be a useful place to add more peepholes for
inefficiencies generated during instruction selection. The pass is
placed after VSX swap optimization, as it is best to let that pass
remove unnecessary swaps before performing any remaining clean-ups.
The utility of these clean-ups are demonstrated by changes to four
existing test cases, all of which now have tighter expected code
generation. I've also added Eric Schweiz's bugpoint-reduced test from
PR25157, for which we now generate tight code. One other test started
failing for me, and I've fixed it
(test/Transforms/PlaceSafepoints/finite-loops.ll) as well; this is not
related to my changes, and I'm not sure why it works before and not
after. The problem is that the CHECK-NOT: of "statepoint" from test1
fails because of the "statepoint" in test2, and so forth. Adding a
CHECK-LABEL in between keeps the different occurrences of that string
properly scoped.
llvm-svn: 252651
ARM V6T2 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any ARM V6T2
implementation.
The net result of allowing this speculation for the regression tests in this patch is
that we get this code:
ctlz:
clz r0, r0
bx lr
cttz:
rbit r0, r0
clz r0, r0
bx lr
Instead of:
ctlz:
cmp r0, #0
moveq r0, #32
clzne r0, r0
bx lr
cttz:
cmp r0, #0
moveq r0, #32
rbitne r0, r0
clzne r0, r0
bx lr
This will help solve a general speculation/despeculation problem noted in PR24818:
https://llvm.org/bugs/show_bug.cgi?id=24818
Differential Revision: http://reviews.llvm.org/D14469
llvm-svn: 252639
AArch64 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any AArch64
implementation.
The net result of allowing this speculation for the regression tests in this
patch is that we get this code:
ctlz:
clz w0, w0
ret
cttz:
rbit w8, w0
clz w0, w8
ret
Instead of:
ctlz:
cbz w0, .LBB0_2
clz w0, w0
ret
.LBB0_2:
orr w0, wzr, #0x20
ret
cttz:
cbz w0, .LBB1_2
rbit w8, w0
clz w0, w8
ret
.LBB1_2:
orr w0, wzr, #0x20
ret
See D14469 for the larger motivation.
Differential Revision: http://reviews.llvm.org/D14505
llvm-svn: 252625
Added fixes for stage2 failures: CMOV is not commutable; commuting the operands results in the condition being flipped! d'oh!
Original commit message:
If we have a CMOV, OR and AND combination such as:
if (x & CN)
y |= CM;
And:
* CN is a single bit;
* All bits covered by CM are known zero in y;
Then we can convert this to a sequence of BFI instructions. This will always be a win if CM is a single bit, will always be no worse than the TST & OR sequence if CM is two bits, and for thumb will be no worse if CM is three bits (due to the extra IT instruction).
llvm-svn: 252606
For big-endian targets, when we merge two halfword loads into a word load, the
order of the halfwords in the loaded value is reversed compared to
little-endian, so the load-store optimiser needs to swap the destination
registers.
This does not affect merging of two word loads, as we use ldp, which treats the
memory as two separate 32-bit words.
llvm-svn: 252597
For CoreCLR on Windows, stack probes must be emitted as inline sequences that probe successive stack pages
between the current stack limit and the desired new stack pointer location. This implements support for
the inline expansion on x64.
For in-body alloca probes, expansion is done during instruction lowering. For prolog probes, a stub call
is initially emitted during prolog creation, and expanded after epilog generation, to avoid complications
that arise when introducing new machine basic blocks during prolog and epilog creation.
Added a new test case, modified an existing one to exclude non-x64 coreclr (for now).
Add test case
Fix tests
llvm-svn: 252578
AArch64 has the ability to use the top 8-bits of an "address" for extra
information, with the memory subsystem automatically masking them off for loads
and stores. When that's happening, we can sometimes skip masks on memory
operations in the compiler.
However, this requires the host OS and support stack to preserve those bits so
it can't be enabled everywhere. In principle iOS 8.0 and above do take the
required precautions and but we'll put it under a flag for now.
llvm-svn: 252573
Lower LLVM's 'unreachable' terminator to ISD::TRAP, and lower ISD::TRAP to
wasm's 'unreachable' expression.
WebAssembly type-checks expressions, but a noreturn function with a
return type that doesn't match the context will cause a check
failure. So we lower LLVM 'unreachable' to ISD::TRAP and then lower that
to WebAssembly's 'unreachable' expression, which typechecks in any
context and causes a trap if executed.
Differential Revision: http://reviews.llvm.org/D14515
llvm-svn: 252566
This fixes a bug in ARMAsmPrinter::EmitUnwindingInstruction where
llvm_unreachable was reached because t2ADDri wasn't handled.
Test case provided by Tim Northover.
rdar://problem/23270609
http://reviews.llvm.org/D14518
llvm-svn: 252557
The motivation for this patch starts with the epic fail example in PR18007:
https://llvm.org/bugs/show_bug.cgi?id=18007
...unfortunately, this patch makes no difference for that case, but it solves some
simpler cases. We'll get there some day. :)
The current 'or' matching code was using computeKnownBits() via
isBaseWithConstantOffset() -> MaskedValueIsZero(), but that's an unnecessarily limited use.
We can do more by copying the logic in ValueTracking's haveNoCommonBitsSet(), so we can
treat the 'or' as if it was an 'add'.
There's a TODO comment here because we should lift the bit-checking logic into a helper
function, so it's not duplicated in DAGCombiner.
An example of the better LEA matching:
leal (%rdi,%rdi), %eax
andl $1, %esi
orl %esi, %eax
Becomes:
andl $1, %esi
leal (%rsi,%rdi,2), %eax
Differential Revision: http://reviews.llvm.org/D13956
llvm-svn: 252515
For some reason we'd never run MachineVerifier on WinEH code, and you
explicitly have to ask for it with llc. I added it to a few test cases
to get some coverage.
Fixes PR25461.
llvm-svn: 252512
Summary:
This matches the sum-of-absdiff patterns emitted by the vectoriser using log2 shuffles.
Relies on D14207 to be able to match the `extract_subvector(..., 0)`
Reviewers: t.p.northover, jmolloy
Subscribers: aemerson, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D14208
llvm-svn: 252465
Summary:
Lowering this pattern early to an `EXTRACT_SUBREG` was making it impossible to match larger patterns in tblgen that use `extract_subvector(..., 0)` as part of the their input pattern.
It seems like there will exist somewhere a better way of specifying this pattern over all relevant register value types, but I didn't manage to find it.
Reviewers: t.p.northover, jmolloy
Subscribers: aemerson, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D14207
llvm-svn: 252464
"GCC requires the freestanding environment provide memcpy, memmove, memset
and memcmp": https://gcc.gnu.org/onlinedocs/gcc-5.2.0/gcc/Standards.html
Hence in GNUEABI targets LLVM should not convert 'memops' to their equivalent
'__aeabi_memops'. This convertion violates GCC contract.
The -meabi flag controls whether or not LLVM will modify 'memops' in GNUEABI
targets.
Without -meabi: use the triple default EABI.
With -meabi=default: use the triple default EABI.
With -meabi=gnu: use 'memops'.
With -meabi=4 or -meabi=5: use '__aeabi_memops'.
With -meabi set to an unknown value: same as -meabi=default.
Patch by Vinicius Tinti.
llvm-svn: 252462
Under most circumstances, if SCEV can simplify X-Y to a constant, then it can
also simplify Y-X to a constant. However, there is no guarantee that this is
always true, and concensus is not to consider that a correctness bug in SCEV
(although it is undesirable).
PPCLoopPreIncPrep gathers pointers used to access memory (via loads, stores and
prefetches) into buckets, where in each bucket the relative pointer offsets are
constant. We used to keep each bucket as a multimap, where SCEV's subtraction
operation was used to define the ordering predicate. Instead, use a fixed SCEV
base expression for each bucket, record the constant offsets from that base
expression, and adjust it later, if desirable, once all pointers have been
collected.
Doing it this way should be more compile-time efficient than the previous
scheme (in addition to making the implementation less sensitive to SCEV
simplification quirks).
Fixes PR25170.
llvm-svn: 252417
The TailDuplication machine pass ran across a malformed CFG: a PHI node
referred it's predecessor's predecessor instead of it's predecessor.
This occurred because we split the edge in X86ISelLowering when we
processed the CATCHRET but forgot to do something about the PHI nodes.
This fixes PR25444.
llvm-svn: 252413
Summary:
The CLR's personality routine passes these in rdx/edx, not rax/eax.
Make getExceptionPointerRegister a virtual method parameterized by
personality function to allow making this distinction.
Similarly make getExceptionSelectorRegister a virtual method parameterized
by personality function, for symmetry.
Reviewers: pgavlin, majnemer, rnk
Subscribers: jyknight, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D14344
llvm-svn: 252383
Some implicit ilist iterator conversions have crept back into Analysis,
Transforms, Hexagon, and llvm-stress. This removes them.
I'll commit a patch immediately after this to disallow them (in a
separate patch so that it's easy to revert if necessary).
llvm-svn: 252371
We used to try to constant-fold them to i32 immediates.
Given that fast-isel doesn't otherwise support vNi1, when selecting
the result users, we'd fallback to SDAG anyway.
However, if the users were in another block, we'd insert broken
cross-class copies (GPR32 to FPR64).
Give up, let SDAG agree with itself on a vNi1 legalization strategy.
llvm-svn: 252364
When matching non-LSB-extracting truncating broadcasts, we now insert
the necessary SRL. If the scalar resulted from a load, the SRL will be
folded into it, creating a narrower, offset, load.
However, i16 loads aren't Desirable, so we get i16->i32 zextloads.
We already catch i16 aextloads; catch these as well.
llvm-svn: 252363
Now that we recognize this, we can support it instead of bailing out.
That is, we can fold:
(v8i16 (shufflevector
(v8i16 (bitcast (v4i32 (build_vector X, Y, ...)))),
<1,1,...,1>))
into:
(v8i16 (vbroadcast (i16 (trunc (srl Y, 16)))))
llvm-svn: 252362
We used to incorrectly assume that the offset we're extracting from
was a multiple of the element size. So, we'd fold:
(v8i16 (shufflevector
(v8i16 (bitcast (v4i32 (build_vector X, Y, ...)))),
<1,1,...,1>))
into:
(v8i16 (vbroadcast (i16 (trunc Y))))
whereas we should have extracted the higher bits from X.
Instead, bail out if the assumption doesn't hold.
llvm-svn: 252361
Summary:
Pass the VOPProfile object all the through to *_m multiclasses. This will
allow us to do more simplifications in the future.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D13437
llvm-svn: 252339
All 3 operands of FMA3 instructions are commutable now.
Patch by Slava Klochkov
Reviewers: Quentin Colombet(qcolombet), Ahmed Bougacha(ab).
Differential Revision: http://reviews.llvm.org/D13269
llvm-svn: 252335
Modelling of the expression stack is evolving. This patch takes another
step by making pushes explicit.
Differential Revision: http://reviews.llvm.org/D14338
llvm-svn: 252334
Mark kernels that use certain features that require user
SGPRs to support with kernel attributes. We need to know
before instruction selection begins because it impacts
the kernel calling convention lowering.
For now this only detects the workitem intrinsics.
llvm-svn: 252323
For some reason VS_32 ends up factoring into the pressure heuristics
even though we should never see a virtual register with this class.
When SGPRs are reserved for register spilling, this for some reason
triggers reg-crit scheduling.
Setting isAllocatable = 0 may help with this since that seems to remove
it from the default implementation's generated table.
llvm-svn: 252321
Summary:
In this implementation, LiveIntervalAnalysis invents a few register
masks on basic block boundaries that preserve no registers. The nice
thing about this is that it prevents the prologue inserter from thinking
it needs to spill all XMM CSRs, because it doesn't see any explicit
physreg defs in the MI.
Reviewers: MatzeB, qcolombet, JosephTremoulet, majnemer
Subscribers: MatzeB, llvm-commits
Differential Revision: http://reviews.llvm.org/D14407
llvm-svn: 252318
The benefit from converting narrow loads into a wider load (r251438) could be
micro-architecturally dependent, as it assumes that a single load with two bitfield
extracts is cheaper than two narrow loads. Currently, this conversion is
enabled only in cortex-a57 on which performance benefits were verified.
llvm-svn: 252316
Summary:
The bug was that the sldi instructions have immediate widths dependant on
their element size. So sldi.d has a 1-bit immediate and sldi.b has a 4-bit
immediate. All of these were using 4-bit immediates previously.
Reviewers: vkalintiris
Subscribers: llvm-commits, atanasyan, dsanders
Differential Revision: http://reviews.llvm.org/D14018
llvm-svn: 252297
Summary:
The bug was that the MIPS32R6/MIPS64R6/microMIPS32R6 versions of LSA and DLSA
(unlike the MSA version) failed to account for the off-by-one encoding of the
immediate. The range is actually 1..4 rather than 0..3.
Reviewers: vkalintiris
Subscribers: atanasyan, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D14015
llvm-svn: 252295
Summary:
Without these patterns we would generate a complete LL/SC sequence.
This would be problematic for memory regions marked as WRITE-only or
READ-only, as the instructions LL/SC would read/write to the protected
memory regions correspondingly.
Reviewers: dsanders
Subscribers: llvm-commits, dsanders
Differential Revision: http://reviews.llvm.org/D14397
llvm-svn: 252293
This adds the EH_RESTORE x86 pseudo instr, which is responsible for
restoring the stack pointers: EBP and ESP, and ESI if stack realignment
is involved. We only need this on 32-bit x86, because on x64 the runtime
restores CSRs for us.
Previously we had to keep the CATCHRET instruction around during SEH so
that we could convince X86FrameLowering to restore our frame pointers.
Now we can split these instructions earlier.
This was confusing, because we had a return instruction which wasn't
really a return and was ultimately going to be removed by
X86FrameLowering. This change also simplifies X86FrameLowering, which
really shouldn't be building new MBBs.
No observable functional change currently, but with the new register
mask stuff in D14407, CATCHRET will become a register allocator barrier,
and our existing tests rely on us having reasonable register allocation
around SEH.
llvm-svn: 252266
We already had a test for this for 32-bit SEH catchpads, but those don't
actually create funclets. We had a bug that only appeared in funclet
prologues, where we would establish EBP and ESI as our FP and BP, and
then downstream prologue code would overwrite them.
While I was at it, I fixed Win64+funclets+stackrealign. This issue
doesn't come up as often there due to the ABI requring 16 byte stack
alignment, but now we can rest easy that AVX and WinEH will work well
together =P.
llvm-svn: 252210
Mangling type information into MachineInstr opcode names was a temporary
measure, and it's starting to get hairy. At the same time, the MC instruction
printer wants to use AsmString strings for printing. This patch takes the
first step, starting the process of adding AsmStrings for instructions.
llvm-svn: 252203
Also, remove an enum hack where enum values were used as indexes into an array.
We may want to make this a real class to allow pattern-based queries/customization (D13417).
llvm-svn: 252196
Summary:
This review is related to another review request http://reviews.llvm.org/D11268, does the same and merely fixes a couple of issues with it.
D11268 is quite old and has merge conflicts against the current trunk.
This request
- rebases D11268 onto the new trunk;
- resolves the merge conflicts;
- fixes the prologue_end tests, which do not pass due to the subprogram definitions not marked as distinct.
Reviewers: echristo, rengolin, kubabrecka
Subscribers: aemerson, rengolin, jyknight, dsanders, llvm-commits, asl
Differential Revision: http://reviews.llvm.org/D14338
llvm-svn: 252177
This fixes the issue of wrong CFA calculation in the following case:
0x08048400 <+0>: push %ebx
0x08048401 <+1>: sub $0x8,%esp
0x08048404 <+4>: **call 0x8048409 <test+9>**
0x08048409 <+9>: **pop %eax**
0x0804840a <+10>: add $0x1bf7,%eax
0x08048410 <+16>: mov %eax,%ebx
0x08048412 <+18>: call 0x80483f0 <bar>
0x08048417 <+23>: add $0x8,%esp
0x0804841a <+26>: pop %ebx
0x0804841b <+27>: ret
The highlighted instructions are a product of movpc instruction. The call
instruction changes the stack pointer, and pop instruction restores its
value. However, the rule for computing CFA is not updated and is wrong on
the pop instruction. So, e.g. backtrace in gdb does not work when on the pop
instruction. This adds cfi instructions for both call and pop instructions.
cfi_adjust_cfa_offset** instruction is used with the appropriate offset for
setting the rules to calculate CFA correctly.
Patch by Violeta Vukobrat.
Differential Revision: http://reviews.llvm.org/D14021
llvm-svn: 252176
We can conservatively know that CMOV's known bits are the intersection of known bits for each of its operands. This helps PerformCMOVToBFICombine find more opportunities.
I tried hard to create a testcase for this and failed - we have to sufficiently confuse DAG.computeKnownBits which can see through all the cheap tricks I tried to narrow my larger testcase down :(
This code is actually exercised in CodeGen/ARM/bfi.ll, there's just no functional difference because DAG.computeKnownBits gets the right answer in that case.
llvm-svn: 252168
The operand layout is slightly different for the atomic
opcodes from the usual MUBUF loads and stores.
This should only fix it on SI/CI. VI is still broken
because it still emits the addr64 replacement.
llvm-svn: 252140
