On Windows, if shouldAssumeDSOLocal returns false, it's either a
dllimport reference, or a reference that we should treat as non-local
and create a stub for.
Clean up AArch64Subtarget::ClassifyGlobalReference a little while
touching the flag handling relating to dllimport.
Differential Revision: https://reviews.llvm.org/D51590
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341402 91177308-0d34-0410-b5e6-96231b3b80d8
The runtime pseudo relocations can't handle the AArch64 format PC
relative addressing in adrp+add/ldr pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.
Differential Revision: https://reviews.llvm.org/D51452
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341401 91177308-0d34-0410-b5e6-96231b3b80d8
Use MachineOperand::ChangeToImmediate rather than reassigning
MachineOperands to new values created from MachineOperand::CreateImm,
so that their parent pointers are preserved.
This fixes "Instruction has operand with wrong parent set" errors
reported by the MachineVerifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341389 91177308-0d34-0410-b5e6-96231b3b80d8
Load Hardening.
Wires up the existing pass to work with a proper IR attribute rather
than just a hidden/internal flag. The internal flag continues to work
for now, but I'll likely remove it soon.
Most of the churn here is adding the IR attribute. I talked about this
Kristof Beyls and he seemed at least initially OK with this direction.
The idea of using a full attribute here is that we *do* expect at least
some forms of this for other architectures. There isn't anything
*inherently* x86-specific about this technique, just that we only have
an implementation for x86 at the moment.
While we could potentially expose this as a Clang-level attribute as
well, that seems like a good question to defer for the moment as it
isn't 100% clear whether that or some other programmer interface (or
both?) would be best. We'll defer the programmer interface side of this
for now, but at least get to the point where the feature can be enabled
without relying on implementation details.
This also allows us to do something that was really hard before: we can
enable *just* the indirect call retpolines when using SLH. For x86, we
don't have any other way to mitigate indirect calls. Other architectures
may take a different approach of course, and none of this is surfaced to
user-level flags.
Differential Revision: https://reviews.llvm.org/D51157
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341363 91177308-0d34-0410-b5e6-96231b3b80d8
implementing the proposed mitigation technique described in the original
design document.
The idea is to check after calls that the return address used to arrive
at that location is in fact the correct address. In the event of
a mis-predicted return which reaches a *valid* return but not the
*correct* return, this will detect the mismatch much like it would
a mispredicted conditional branch.
This is the last published attack vector that I am aware of in the
Spectre v1 space which is not mitigated by SLH+retpolines. However,
don't read *too* much into that: this is an area of ongoing research
where we expect more issues to be discovered in the future, and it also
makes no attempt to mitigate Spectre v4. Still, this is an important
completeness bar for SLH.
The change here is of course delightfully simple. It was predicated on
cutting support for post-instruction symbols into LLVM which was not at
all simple. Many thanks to Hal Finkel, Reid Kleckner, and Justin Bogner
who helped me figure out how to do a bunch of the complex changes
involved there.
Differential Revision: https://reviews.llvm.org/D50837
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341358 91177308-0d34-0410-b5e6-96231b3b80d8
retpolines.
This implements the core design of tracing the intended target into the
target, checking it, and using that to update the predicate state. It
takes advantage of a few interesting aspects of SLH to make it a bit
easier to implement:
- We already split critical edges with conditional branches, so we can
assume those are gone.
- We already unfolded any memory access in the indirect branch
instruction itself.
I've left hard errors in place to catch if any of these somewhat subtle
invariants get violated.
There is some code that I can factor out and share with D50837 when it
lands, but I didn't want to couple landing the two patches, so I'll do
that in a follow-up cleanup commit if alright.
Factoring out the code to handle different scenarios of materializing an
address remains frustratingly hard. In a bunch of cases you want to fold
one of the cases into an immediate operand of some other instruction,
and you also have both symbols and basic blocks being used which require
different methods on the MI builder (and different operand kinds).
Still, I'll take a stab at sharing at least some of this code in
a follow-up if I can figure out how.
Differential Revision: https://reviews.llvm.org/D51083
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341356 91177308-0d34-0410-b5e6-96231b3b80d8
This patch modifies hasStandardEncoding() / inMicroMipsMode() /
inMips16Mode() methods of the MipsSubtarget class so only one can be
true at any one time. That prevents the selection of microMIPS and MIPS
instructions and patterns that are defined in TableGen files at the same
time. A few new patterns and instruction definitions hae been added to
keep test cases passed.
Differential revision: https://reviews.llvm.org/D51483
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341338 91177308-0d34-0410-b5e6-96231b3b80d8
A ReadAdvance was incorrectly added to the SchedReadWrite list associated with
the following SSE instructions:
sqrtss
sqrtsd
rsqrtss
rcpss
As a consequence, a wrong operand latency was computed for the register operand
used as the base address of the folded load operand.
This patch removes the wrong ReadAdvance, and updates the llvm-mca test cases.
There is still a problem with correctly modeling partial register writes on XMM
registers This other problem is currently tracked here:
https://bugs.llvm.org/show_bug.cgi?id=38813
Differential Revision: https://reviews.llvm.org/D51542
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341326 91177308-0d34-0410-b5e6-96231b3b80d8
Also adjust some of dsymutil's headers to put the header guards at the top,
otherwise the compiler will not recognize them as header guards.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341323 91177308-0d34-0410-b5e6-96231b3b80d8
When initial support for dllimport was added for aarch64 in
SVN r316555, ClassifyGlobalReference didn't set the MO_DLLIMPORT
flag - that was only completed in SVN r323810. Reuse the return
value from ClassifyGlobalReference for this purpose as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341310 91177308-0d34-0410-b5e6-96231b3b80d8
For instructions that spill/fill to and from multiple frame-indices
in a single instruction, hasStoreToStackSlot and hasLoadFromStackSlot
should return an array of accesses, rather than just the first encounter
of such an access.
This better describes FI accesses for AArch64 (paired) LDP/STP
instructions.
Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D51537
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When doing some instruction scheduling work, we noticed some missing itineraries.
Before we switch to machine scheduler, those missing itineraries might not have impact to actually scheduling,
because we can still get same latency due to default values.
With machine scheduler, however, itineraries will have impact to scheduling.
eg: NumMicroOps will default to be 0 if there is NO itineraries for specific instruction class.
And most of the instruction class with itineraries will have NumMicroOps default to 1.
This will has impact on the count of RetiredMOps, affects the Pending/Available Queue,
then causing different scheduling or suboptimal scheduling further.
Patch by jsji (Jinsong Ji)
Differential Revision: https://reviews.llvm.org/D51506
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341293 91177308-0d34-0410-b5e6-96231b3b80d8
The 'rol Rd' instruction is equivalent to 'adc Rd'.
This caused compile warnings from tablegen because of conflicting bits
shared between each instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341275 91177308-0d34-0410-b5e6-96231b3b80d8
These intrinsics use the same implementation as PTEST intrinsics, but use vXi1 vectors.
New clang builtins will be accompanying them shortly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341259 91177308-0d34-0410-b5e6-96231b3b80d8
This patch recognizes shuffles that shift elements and fill with zeros. I've copied and modified the shift matching code we use for normal vector registers to do this. I'm not sure if there's a good way to share more of this code without making the existing function more complex than it already is.
This will be used to enable kshift intrinsics in clang.
Differential Revision: https://reviews.llvm.org/D51401
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341227 91177308-0d34-0410-b5e6-96231b3b80d8
The presence of a ReadAdvance for input operand #0 is problematic
because it changes the input latency of the register used as the base address
for the folded load.
A broadcast cannot start executing if the load address hasn't been computed yet.
In the llvm-mca example, the VBROADCASTSS is dependent on the address generated
by the LEAQ. That means, it cannot start until LEAQ reaches the write-back
stage. If we apply ReadAdvance, then we wrongly assume that the load can start 3
cycles in advance.
Differential Revision: https://reviews.llvm.org/D51534
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341222 91177308-0d34-0410-b5e6-96231b3b80d8
The `mtc1` and `mfc1` definitions in the MipsInstrFPU.td have MMRel,
but do not have StdMMR6Rel tags. When these instructions are emitted
for microMIPS R6 targets, `Mips::MipsR62MicroMipsR6` nor
`Mips::Std2MicroMipsR6` cannot find correct op-codes and as a result the
backend uses mips32 variant of the instructions encoding.
The patch fixes this problem by adding the StdMMR6Rel tag and check
instructions encoding in the test case.
Differential revision: https://reviews.llvm.org/D51482
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341221 91177308-0d34-0410-b5e6-96231b3b80d8
The intention is to enable the extract_vector_elt load combine,
and doing this for other operations interferes with more
useful optimizations on vectors.
Handle any type of load since in principle we should do the
same combine for the various load intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341219 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes the number of micro opcodes, and processor resource cycles for
the following AVX instructions:
vinsertf128rr/rm
vperm2f128rr/rm
vbroadcastf128
Tests have been regenerated using the usual scripts in the llvm/utils directory.
Differential Revision: https://reviews.llvm.org/D51492
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341185 91177308-0d34-0410-b5e6-96231b3b80d8
These stubs should never be emitted for internal symbols, and
nothing in AsmPrinter ever actually use this value when producing
the stubs for COFF anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341177 91177308-0d34-0410-b5e6-96231b3b80d8
The runtime pseudo relocations can't handle the ARM format embedded
addresses in movw/movt pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.
Differential Revision: https://reviews.llvm.org/D51450
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341176 91177308-0d34-0410-b5e6-96231b3b80d8
It has essentially the same benefit it has on 64-bit ARM: it
substantially reduces the number of constants used by large GEP
operations. Seems to be generally helpful across a few different
codebases I've tried.
Differential Revision: https://reviews.llvm.org/D51462
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341136 91177308-0d34-0410-b5e6-96231b3b80d8
Wouter van Oortmerssen