a generically extensible collection of extra info attached to
a `MachineInstr`.
The primary change here is cleaning up the APIs used for setting and
manipulating the `MachineMemOperand` pointer arrays so chat we can
change how they are allocated.
Then we introduce an extra info object that using the trailing object
pattern to attach some number of MMOs but also other extra info. The
design of this is specifically so that this extra info has a fixed
necessary cost (the header tracking what extra info is included) and
everything else can be tail allocated. This pattern works especially
well with a `BumpPtrAllocator` which we use here.
I've also added the basic scaffolding for putting interesting pointers
into this, namely pre- and post-instruction symbols. These aren't used
anywhere yet, they're just there to ensure I've actually gotten the data
structure types correct. I'll flesh out support for these in
a subsequent patch (MIR dumping, parsing, the works).
Finally, I've included an optimization where we store any single pointer
inline in the `MachineInstr` to avoid the allocation overhead. This is
expected to be the overwhelmingly most common case and so should avoid
any memory usage growth due to slightly less clever / dense allocation
when dealing with >1 MMO. This did require several ergonomic
improvements to the `PointerSumType` to reasonably support the various
usage models.
This also has a side effect of freeing up 8 bits within the
`MachineInstr` which could be repurposed for something else.
The suggested direction here came largely from Hal Finkel. I hope it was
worth it. ;] It does hopefully clear a path for subsequent extensions
w/o nearly as much leg work. Lots of thanks to Reid and Justin for
careful reviews and ideas about how to do all of this.
Differential Revision: https://reviews.llvm.org/D50701
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339940 91177308-0d34-0410-b5e6-96231b3b80d8
When potential jump instruction and target are in the same segment, use
jump instruction with immediate field.
In cases where offset does not fit immediate value of a bc/j instructions,
offset is stored into register, and then jump register instruction is used.
Differential Revision: https://reviews.llvm.org/D48019
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339126 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for this target hook, covering MIPS, microMIPS and MIPSR6, along
with some tests. Also add missing getOppositeBranchOpc() cases exposed by the
tests.
Reviewers: atanasyan, abeserminji, smaksimovic
Differential Revision: https://reviews.llvm.org/D46794
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332446 91177308-0d34-0410-b5e6-96231b3b80d8
Because we create a new kind of debug instruction, DBG_LABEL, we need to
check all passes which use isDebugValue() to check MachineInstr is debug
instruction or not. When expelling debug instructions, we should expel
both DBG_VALUE and DBG_LABEL. So, I create a new function,
isDebugInstr(), in MachineInstr to check whether the MachineInstr is
debug instruction or not.
This patch has no new test case. I have run regression test and there is
no difference in regression test.
Differential Revision: https://reviews.llvm.org/D45342
Patch by Hsiangkai Wang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331844 91177308-0d34-0410-b5e6-96231b3b80d8
This patch provides mitigation for CVE-2017-5715, Spectre variant two,
which affects the P5600 and P6600. It implements the LLVM part of
-mindirect-jump=hazard. It is _not_ enabled by default for the P5600.
The migitation strategy suggested by MIPS for these processors is to use
hazard barrier instructions. 'jalr.hb' and 'jr.hb' are hazard
barrier variants of the 'jalr' and 'jr' instructions respectively.
These instructions impede the execution of instruction stream until
architecturally defined hazards (changes to the instruction stream,
privileged registers which may affect execution) are cleared. These
instructions in MIPS' designs are not speculated past.
These instructions are used with the attribute +use-indirect-jump-hazard
when branching indirectly and for indirect function calls.
These instructions are defined by the MIPS32R2 ISA, so this mitigation
method is not compatible with processors which implement an earlier
revision of the MIPS ISA.
Performance benchmarking of this option with -fpic and lld using
-z hazardplt shows a difference of overall 10%~ time increase
for the LLVM testsuite. Certain benchmarks such as methcall show a
substantially larger increase in time due to their nature.
Reviewers: atanasyan, zoran.jovanovic
Differential Revision: https://reviews.llvm.org/D43486
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325653 91177308-0d34-0410-b5e6-96231b3b80d8
Fix an off by one error in the bounds checking for 'dinsu' and update
the ranges in the test comments so that they are accurate.
This version has the correct commit message.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41183
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320991 91177308-0d34-0410-b5e6-96231b3b80d8
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318490 91177308-0d34-0410-b5e6-96231b3b80d8
PR35071 exposed the fact that MipsInstrInfo::removeBranch did not walk past
debug instructions when removing branches for the control flow optimizer, which
lead to duplicated conditional branches. If the target of the branch was a
removable block, only the conditional branch in the terminating position would
have it's MBB operands updated, leaving the first branch with a dangling MBB
operand. The MIPS long branch pass would then trigger an assertion when
attempting to examine the instruction with dangling MBB operand.
This resolves PR35071.
Thanks to Alex Richardson for reporting the issue!
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D39288
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316654 91177308-0d34-0410-b5e6-96231b3b80d8
In the case where there was a conditional branch followed by a unconditional
branch with debug instruction separating them, MipsInstrInfo::analyzeBranch
would not skip past debug instruction when searching for the second branch
which give erroneous results about the control flow of the block.
This could lead to the branch folder to merge the non-fall through case
into it's predecessor, leaving the conditional branch with a dangling
basic block operand.
This resolves PR34975.
Thanks to Alexander Richardson for reporting the issue!
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D39003
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316084 91177308-0d34-0410-b5e6-96231b3b80d8
This patch complements D16810 "[mips] Make isel select the correct DEXT variant
up front.". Now ISel picks the right variant of DINS, so now there is no need
to replace DINS with the appropriate variant during
MipsMCCodeEmitter::encodeInstruction().
This patch also enables target specific instruction verification for ins, dins,
dinsm, dinsu, ext, dext, dextm, dextu. These instructions have constraints that
are checked when generating MipsISD::Ins and MipsISD::Ext nodes, but these
constraints are not checked during instruction selection. Adding machine
verification should catch outstanding cases.
Finally, correct a bug that instruction verification uncovered, where the
position operand of a DINSU generated during lowering was being silently
and accidently corrected to the correct value.
Reviewers: slthakur
Differential Revision: https://reviews.llvm.org/D34809
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313254 91177308-0d34-0410-b5e6-96231b3b80d8
While simplifying branches in the MachineInstr representation, the
routine BuildCondBr must preserve flags on register MachineOperands. In
particular, it must preserve the <undef> flag.
This fixes a bug that is unlikely to occur in any real scenario, but
which bugpoint is likely to introduce.
Patch By Nick Johnson!
Reviewers: ahatanak, sdardis
Differential Revision: https://reviews.llvm.org/D34041
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305290 91177308-0d34-0410-b5e6-96231b3b80d8
Implementation of TargetInstrInfo::findCommutedOpIndices for MIPS target,
restricting commutativity to second and third operand only for
dpaadd_[su].df instructions therein.
Prior to this change, there were cases where the vector that is to be added
to the dot product of the other two could take a position other than the
first one in the instruction, generating false output in the destination
vector.
Such behavior has been noticed in the two functions generating v2i64 output
values so far. Other ones may exhibit such behavior as well, just not for
the vector operands which are present in the test at the moment.
Tests altered so that the function's first operand is a constant splat so
that it can be loaded with a ldi instruction, since that is the case in
which the erroneous instruction operand placement has occurred. We check
that the register which is present in the ldi instruction is placed as the
first operand in the corresponding dpadd instruction.
Patch by Stefan Maksimovic.
Differential Revision: https://reviews.llvm.org/D30827
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299223 91177308-0d34-0410-b5e6-96231b3b80d8
The main change is to return the code size from
InsertBranch/RemoveBranch.
Patch mostly by Tim Northover
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281505 91177308-0d34-0410-b5e6-96231b3b80d8
Now that MachineBasicBlock::reverse_instr_iterator knows when it's at
the end (since r281168 and r281170), implement
MachineBasicBlock::reverse_iterator directly on top of an
ilist::reverse_iterator by adding an IsReverse template parameter to
MachineInstrBundleIterator. This replaces another hard-to-reason-about
use of std::reverse_iterator on list iterators, matching the changes for
ilist::reverse_iterator from r280032 (see the "out of scope" section at
the end of that commit message). MachineBasicBlock::reverse_iterator
now has a handle to the current node and has obvious invalidation
semantics.
r280032 has a more detailed explanation of how list-style reverse
iterators (invalidated when the pointed-at node is deleted) are
different from vector-style reverse iterators like std::reverse_iterator
(invalidated on every operation). A great motivating example is this
commit's changes to lib/CodeGen/DeadMachineInstructionElim.cpp.
Note: If your out-of-tree backend deletes instructions while iterating
on a MachineBasicBlock::reverse_iterator or converts between
MachineBasicBlock::iterator and MachineBasicBlock::reverse_iterator,
you'll need to update your code in similar ways to r280032. The
following table might help:
[Old] ==> [New]
delete &*RI, RE = end() delete &*RI++
RI->erase(), RE = end() RI++->erase()
reverse_iterator(I) std::prev(I).getReverse()
reverse_iterator(I) ++I.getReverse()
--reverse_iterator(I) I.getReverse()
reverse_iterator(std::next(I)) I.getReverse()
RI.base() std::prev(RI).getReverse()
RI.base() ++RI.getReverse()
--RI.base() RI.getReverse()
std::next(RI).base() RI.getReverse()
(For more details, have a look at r280032.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281172 91177308-0d34-0410-b5e6-96231b3b80d8
r277708 enabled tails calls for MIPS but used the 'jr' instruction when the
jump target was held in a register. For MIPSR6, 'jalr $zero, $reg' should
have been used. Additionally, add missing patterns for external and global
symbols for tail calls.
Reviewers: dsanders, vkalintiris
Differential Review: https://reviews.llvm.org/D23301
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279064 91177308-0d34-0410-b5e6-96231b3b80d8
Enable tail calls by default for (micro)MIPS(64).
microMIPS is slightly more tricky than doing it for MIPS(R6) or microMIPSR6.
microMIPS has two instruction encodings: 16bit and 32bit along with some
restrictions on the size of the instruction that can fill the delay slot.
For safe tail calls for microMIPS, the delay slot filler attempts to find
a correct size instruction for the delay slot of TAILCALL pseudos.
Reviewers: dsanders, vkalintris
Subscribers: jfb, dsanders, sdardis, llvm-commits
Differential Revision: https://reviews.llvm.org/D21138
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277708 91177308-0d34-0410-b5e6-96231b3b80d8
MIPS64R6 compact branch support. As the MIPS LLVM backend uses distinct
MachineInstrs for certain 32 and 64 bit instructions (e.g. BEQ & BEQ64) that
map to the same instruction, extend compact branch support for the
corresponding 64bit branches.
Reviewers: dsanders
Differential Revision: https://reviews.llvm.org/D20164
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276739 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid implicit conversions from MachineInstrBundleIterator to
MachineInstr* in the Mips backend, mainly by preferring MachineInstr&
over MachineInstr* when a pointer isn't nullable and using range-based
for loops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275141 91177308-0d34-0410-b5e6-96231b3b80d8
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272512 91177308-0d34-0410-b5e6-96231b3b80d8
Restrict the creation of compact branches so that they do meet the ISA
requirements. Notably do not permit $zero to be used as a operand for compact
branches and ensure that some other branches fulfil the requirement that
rs != rt.
Fixup cases where $rs > $rt for bnec and beqc.
Recommit of rL269893 with reviewers comments.
Reviewers: dsanders, vkalintiris
Differential Review: http://reviews.llvm.org/D20284
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269899 91177308-0d34-0410-b5e6-96231b3b80d8
Restrict the creation of compact branches so that they meet the ISA encoding
requirements. Notably do not permit $zero to be used as a operand for compact
branches and ensure that some other branches fulfil the requirement that
rs != rt.
Fixup cases where $rs > $rt for bnec and beqc.
Reviewers: dsanders, vkalintiris
Differential Review: http://reviews.llvm.org/D20284
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269893 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This stops it misidentifying unconditional branches as conditional branches
which fixes a -verify-machineinstrs error about exiting a function via fall through.
Reviewers: sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D19864
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268731 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support for compact jumps similiar to the previous compact
branch support for MIPSR6. Unlike compact branches, compact jumps do not
have a forbidden slot.
As MipsInstrInfo::getEquivalentCompactForm can determine the correct
expansion for jumps and branches for both microMIPS and MIPSR6, remove the
unnecessary distinction in the delay slot filler.
Reviewers: vkalintiris
Subscribers: llvm-commits, dsanders
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265390 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
MIPSR6 introduces a class of branches called compact branches. Unlike the
traditional MIPS branches which have a delay slot, compact branches do not
have a delay slot. The instruction following the compact branch is only
executed if the branch is not taken and must not be a branch.
It works by generating compact branches for MIPS32R6 when the delay slot
filler cannot fill a delay slot. Then, inspecting the generated code for
forbidden slot hazards (a compact branch with an adjacent branch or other
CTI) and inserting nops to clear this hazard.
Patch by Simon Dardis.
Reviewers: vkalintiris, dsanders
Subscribers: MatzeB, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D16353
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263444 91177308-0d34-0410-b5e6-96231b3b80d8
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest). All of these
functions require non-null parameters already, so references are more
clear. As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261605 91177308-0d34-0410-b5e6-96231b3b80d8
This commit removes the global manager variable which is responsible for
storing and allocating pseudo source values and instead it introduces a new
manager class named 'PseudoSourceValueManager'. Machine functions now own an
instance of the pseudo source value manager class.
This commit also modifies the 'get...' methods in the 'MachinePointerInfo'
class to construct pseudo source values using the instance of the pseudo
source value manager object from the machine function.
This commit updates calls to the 'get...' methods from the 'MachinePointerInfo'
class in a lot of different files because those calls now need to pass in a
reference to a machine function to those methods.
This change will make it easier to serialize pseudo source values as it will
enable me to transform the mips specific MipsCallEntry PseudoSourceValue
subclass into two target independent subclasses.
Reviewers: Akira Hatanaka
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244693 91177308-0d34-0410-b5e6-96231b3b80d8
