Summary:
The motivation for this is D49493, where we'd like to test details of
debug_str_offsets behavior which is difficult to trigger from a
traditional test.
This adds the plubming necessary for dwarfgen to generate this section.
The more interesting changes are:
- I've moved emitStringOffsetsTableHeader function from DwarfFile to
DwarfStringPool, so I can generate the section header more easily from
the unit test.
- added a new addAttribute overload taking an MCExpr*. This is used to
generate the DW_AT_str_offsets_base, which links a compile unit to the
offset table.
I've also added a basic test for reading and writing DW_form_strx forms.
Reviewers: dblaikie, JDevlieghere, probinson
Subscribers: llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D49670
llvm-svn: 337910
NFC changes to make scheduler TableGen files more readable, by using loops
instead of a lot of similar defs with just e.g. a latency value that changes.
https://reviews.llvm.org/D49598
Review: Ulrich Weigand, Javed Abshar
llvm-svn: 337909
r337828 resolves a PredicateInfo issue with unnamed types.
Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
llvm-svn: 337904
Add support for inline assembly with output operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR as in the PR).
llvm-svn: 337903
Helpers are available to make this option file format independant. This
patch adds the feature for Wasm file format. It doesn't change the
behavior of the other file format handling.
Differential Revision: https://reviews.llvm.org/D49545
llvm-svn: 337896
code.
This consolidates all our hardening calls, and simplifies the code
a bit. It seems much more clear to handle all of these together.
No functionality changed here.
llvm-svn: 337895
This function actually does two things: it traces the predicate state
through each of the basic blocks in the function (as that isn't directly
handled by the SSA updater) *and* it hardens everything necessary in the
block as it goes. These need to be done together so that we have the
currently active predicate state to use at each point of the hardening.
However, this also made obvious that the flag to disable actual
hardening of loads was flawed -- it also disabled tracing the predicate
state across function calls within the body of each block. So this patch
sinks this debugging flag test to correctly guard just the hardening of
loads.
Unless load hardening was disabled, no functionality should change with
tis patch.
llvm-svn: 337894
The target independent AsmParser doesn't recognise .hword, .word, .dword
which are required for Mips. Currently MipsAsmParser recognises these
through dispatch to MipsAsmParser::parseDataDirective. This contains
equivalent logic to AsmParser::parseDirectiveValue. This patch allows
reuse of AsmParser::parseDirectiveValue by making use of
addAliasForDirective to support .hword, .word and .dword.
Original patch provided by Alex Bradbury at D47001 was modified to fix
handling of microMIPS symbols. The `AsmParser::parseDirectiveValue`
calls either `EmitIntValue` or `EmitValue`. In this patch we override
`EmitIntValue` in the `MipsELFStreamer` to clear a pending set of
microMIPS symbols.
Differential revision: https://reviews.llvm.org/D49539
llvm-svn: 337893
Summary:
Previously, passes use
```
DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy);
DTU.deleteBB(DelBB);
```
to delete a BasicBlock.
But passes which don't have the ability to update DomTree (e.g. tailcallelim, simplifyCFG) cannot recognize a DelBB awaiting deletion and will continue to process this DelBB.
This is a simple approach to notify devs of passes which may use DTU in the future to deal with deleted BasicBlocks under Lazy Strategy correctly.
Reviewers: kuhar, brzycki, dmgreen
Reviewed By: kuhar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49731
llvm-svn: 337891
Summary:
This is a follow-up to r303043. In computeMapping(), we need to disqualify an
InstrMapping if it would be impossible to repair one of the registers in the
instruction to match the mapping.
This change is needed in order to be able to define an instruction
mapping for G_SELECT for the AMDGPU target and will be tested
by test/CodeGen/AMDGPU/GlobalISel/regbankselect-select.mir
Reviewers: ab, qcolombet, t.p.northover, dsanders
Reviewed By: qcolombet
Subscribers: tpr, llvm-commits
Differential Revision: https://reviews.llvm.org/D49735
llvm-svn: 337882
This ports the profiling runtime on Fuchsia and enables the
instrumentation. Unlike on other platforms, Fuchsia doesn't use
files to dump the instrumentation data since on Fuchsia, filesystem
may not be accessible to the instrumented process. We instead use
the data sink to pass the profiling data to the system the same
sanitizer runtimes do.
Differential Revision: https://reviews.llvm.org/D47208
llvm-svn: 337881
against v1.2 BCBS attacks directly.
Attacks using spectre v1.2 (a subset of BCBS) are described in the paper
here:
https://people.csail.mit.edu/vlk/spectre11.pdf
The core idea is to speculatively store over the address in a vtable,
jumptable, or other target of indirect control flow that will be
subsequently loaded. Speculative execution after such a store can
forward the stored value to subsequent loads, and if called or jumped
to, the speculative execution will be steered to this potentially
attacker controlled address.
Up until now, this could be mitigated by enableing retpolines. However,
that is a relatively expensive technique to mitigate this particular
flavor. Especially because in most cases SLH will have already mitigated
this. To fully mitigate this with SLH, we need to do two core things:
1) Unfold loads from calls and jumps, allowing the loads to be post-load
hardened.
2) Force hardening of incoming registers even if we didn't end up
needing to harden the load itself.
The reason we need to do these two things is because hardening calls and
jumps from this particular variant is importantly different from
hardening against leak of secret data. Because the "bad" data here isn't
a secret, but in fact speculatively stored by the attacker, it may be
loaded from any address, regardless of whether it is read-only memory,
mapped memory, or a "hardened" address. The only 100% effective way to
harden these instructions is to harden the their operand itself. But to
the extent possible, we'd like to take advantage of all the other
hardening going on, we just need a fallback in case none of that
happened to cover the particular input to the control transfer
instruction.
For users of SLH, currently they are paing 2% to 6% performance overhead
for retpolines, but this mechanism is expected to be substantially
cheaper. However, it is worth reminding folks that this does not
mitigate all of the things retpolines do -- most notably, variant #2 is
not in *any way* mitigated by this technique. So users of SLH may still
want to enable retpolines, and the implementation is carefuly designed to
gracefully leverage retpolines to avoid the need for further hardening
here when they are enabled.
Differential Revision: https://reviews.llvm.org/D49663
llvm-svn: 337878
Summary: truncateToMinimalBitWidths() doesn't handle all Instructions and the worst case is compiler crash via llvm_unreachable(). Fix is to add a case to handle PHINode and changed the worst case to NO-OP (from compiler crash).
Reviewers: sbaranga, mssimpso, hsaito
Reviewed By: hsaito
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49461
llvm-svn: 337861
if the top level addition in (D + (C-D + x + ...)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x + ...), ensuring homogeneous behaviour of the
transformation and better canonicalization of such expressions.
This enables better canonicalization of expressions like
1 + zext(5 + 20 * %x + 24 * %y) and
zext(6 + 20 * %x + 24 * %y)
which get both transformed to
2 + zext(4 + 20 * %x + 24 * %y)
This pattern is common in address arithmetics and the transformation
makes it easier for passes like LoadStoreVectorizer to prove that 2 or
more memory accesses are consecutive and optimize (vectorize) them.
Reviewed By: mzolotukhin
Differential Revision: https://reviews.llvm.org/D48853
llvm-svn: 337859
We generated a subtract for the power of 2 minus one then negated the result. The negate can be optimized away by swapping the subtract operands, but DAG combine doesn't know how to do that and we don't add any of the new nodes to the worklist anyway.
This patch makes use explicitly emit the swapped subtract.
llvm-svn: 337858
Use a left shift and 2 subtracts like we do for 30. Move this out from behind the slow lea check since it doesn't even use an LEA.
Use this for multiply by 14 as well.
llvm-svn: 337856
Summary:
Currently all wasm atomic memory access instructions are sequentially
consistent, so even if LLVM IR specifies weaker orderings than that, we
should upgrade them to sequential ordering and treat them in the same
way.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D49194
llvm-svn: 337854
Just some gardening here.
Similar to how we moved call information into Candidates, this moves outlined
frame information into OutlinedFunction. This allows us to remove
TargetCostInfo entirely.
Anywhere where we returned a TargetCostInfo struct, we now return an
OutlinedFunction. This establishes OutlinedFunctions as more of a general
repeated sequence, and Candidates as occurrences of those repeated sequences.
llvm-svn: 337848
When building with LTO, builtin functions that are defined but whose calls have not been inserted yet, get internalized. The Global Dead Code Elimination phase in the new LTO implementation then removes these function definitions. Later optimizations add calls to those functions, and the linker then dies complaining that there are no definitions. This CL fixes the new LTO implementation to check if a function is builtin, and if so, to not internalize (and later DCE) the function. As part of this fix I needed to move the RuntimeLibcalls.{def,h} files from the CodeGen subidrectory to the IR subdirectory. I have updated all the files that accessed those two files to access their new location.
Fixes PR34169
Patch by Caroline Tice!
Differential Revision: https://reviews.llvm.org/D49434
llvm-svn: 337847
Summary:
Enabling this fully exposes a latent bug in the instruction folding: we
never update the register constraints for the register operands when
fusing a load into another operation. The fused form could, in theory,
have different register constraints on its operands. And in fact,
TCRETURNm* needs its memory operands to use tailcall compatible
registers.
I've updated the folding code to re-constrain all the registers after
they are mapped onto their new instruction.
However, we still can't enable folding in the general case from
TCRETURNr* to TCRETURNm* because doing so may require more registers to
be available during the tail call. If the call itself uses all but one
register, and the folded load would require both a base and index
register, there will not be enough registers to allocate the tail call.
It would be better, IMO, to teach the register allocator to *unfold*
TCRETURNm* when it runs out of registers (or specifically check the
number of registers available during the TCRETURNr*) but I'm not going
to try and solve that for now. Instead, I've just blocked the forward
folding from r -> m, leaving LLVM free to unfold from m -> r as that
doesn't introduce new register pressure constraints.
The down side is that I don't have anything that will directly exercise
this. Instead, I will be immediately using this it my SLH patch. =/
Still worse, without allowing the TCRETURNr* -> TCRETURNm* fold, I don't
have any tests that demonstrate the failure to update the memory operand
register constraints. This patch still seems correct, but I'm nervous
about the degree of testing due to this.
Suggestions?
Reviewers: craig.topper
Subscribers: sanjoy, mcrosier, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D49717
llvm-svn: 337845
When we inline a function with a min-legal-vector-width attribute we need to make sure the caller also ends up with at least that vector width.
This patch is necessary to make always_inline functions like intrinsics propagate their min-legal-vector-width. Though nothing uses min-legal-vector-width yet.
A future patch will add heuristics to preventing inlining with different vector width mismatches. But that code would need to be in inline cost analysis which is separate from the code added here.
Differential Revision: https://reviews.llvm.org/D49162
llvm-svn: 337844
Mul by constant can expand to a sequence that ends with a negate. If the next instruction is an add or sub we might be able to fold the negate away.
We currently fail to do this because we explicitly don't add anything to the DAG combine worklist when we expand multiplies. This is primarily to keep the multipy from being reformed, but we should consider adding the users to worklist.
llvm-svn: 337843
Before this, TCI contained all the call information for each Candidate.
This moves that information onto the Candidates. As a result, each Candidate
can now supply how it ought to be called. Thus, Candidates will be able to,
say, call the same function in cheaper ways when possible. This also removes
that information from TCI, since it's no longer used there.
A follow-up patch for the AArch64 outliner will demonstrate this.
llvm-svn: 337840
Having the missed remark code in the middle of `findCandidates` made the
function hard to follow. This yanks that out into a new function,
`emitNotOutliningCheaperRemark`.
llvm-svn: 337839
Just some simple gardening to improve clarity.
Before, we had something along the lines of
1) Create a std::vector of Candidates
2) Create an OutlinedFunction
3) Create a std::vector of pointers to Candidates
4) Copy those over to the OutlinedFunction and the Candidate list
Now, OutlinedFunctions create the Candidate pointers. They're still copied
over to the main list of Candidates, but it makes it a bit clearer what's
going on.
llvm-svn: 337838
This patch uses SCEV to avoid inserting some bounds checks when they are not needed. This slightly improves the performance of code compiled with the bounds check sanitizer.
Differential Revision: https://reviews.llvm.org/D49602
llvm-svn: 337830
This is a workaround and it would be better to fix this generally, but
doing it generally is quite tricky. See D48541 and PR38117.
Doing it in PredicateInfo directly allows us to use the type address to
differentiate different unnamed types, because neither the created
declarations nor the ssa_copy calls should be visible after
PredicateInfo got destroyed.
Reviewers: efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D49126
llvm-svn: 337828
For the final DTPREL addition, rather than a lui/daddiu/daddu triple,
LLVM was erronously emitting a daddiu/daddiu pair, treating the %dtprel_hi
as if it were a %dtprel_lo, since Mips::Hi expands unshifted for Sym64.
Instead, use a new TlsHi node and, although unnecessary due to the exact
structure of the nodes emitted, use TlsHi for local exec too to prevent
future bugs. Also garbage-collect the unused TprelLo and TlsGd nodes,
and TprelHi since its functionality is provided by the new common TlsHi node.
Patch by James Clarke.
Differential revision: https://reviews.llvm.org/D49259
llvm-svn: 337827
helper and restructure the post-load hardening to use this.
This isn't as trivial as I would have liked because the post-load
hardening used a trick that only works for it where it swapped in
a temporary register to the load rather than replacing anything.
However, there is a simple way to do this without that trick that allows
this to easily reuse a friendly API for hardening a value in a register.
That API will in turn be usable in subsequent patcehs.
This also techincally changes the position at which we insert the subreg
extraction for the predicate state, but that never resulted in an actual
instruction and so tests don't change at all.
llvm-svn: 337825
ARM Stage 2 builders have been suspiciously broken since the pass was
committed. Disabling to hopefully fix the bots and give me time to
debug.
llvm-svn: 337821
SmallVectorTemplateCommon wants to know the address of the first element
so it can detect whether it's in "small size" mode.
The old implementation split the small array, creating the storage for
the first element in SmallVectorTemplateCommon, and pulling the rest
into SmallVectorStorage where we know the size of the array. This
bloats SmallVector size 0 by the larger of sizeof(void*) and sizeof(T),
and we're not even using the storage.
The new implementation leaves the full small storage to
SmallVectorStorage. To calculate the offset of the first element in
SmallVectorTemplateCommon, we just need to know how far to jump, which
we can calculate out-of-band. One subtlety is that we need
SmallVectorStorage to be properly aligned even when the size is 0, to be
sure that (for large alignments) we actually have the padding and it's
well defined to do the pointer math.
llvm-svn: 337820
This test was already checking microscopic behavior of tail call under
specific conditions. This just makes the CHECK lines much more
consistent, clear, and easily updated when intentional changes are made.
I've also switched the test to consistently name the entry block and to
order the helper declarations and comments for specific tests in the
more usual locations.
llvm-svn: 337806
There are two forms for label debug information in DWARF format.
1. Labels in a non-inlined function:
DW_TAG_label
DW_AT_name
DW_AT_decl_file
DW_AT_decl_line
DW_AT_low_pc
2. Labels in an inlined function:
DW_TAG_label
DW_AT_abstract_origin
DW_AT_low_pc
We will collect label information from DBG_LABEL. Before every DBG_LABEL,
we will generate a temporary symbol to denote the location of the label.
The symbol could be used to get DW_AT_low_pc afterwards. So, we create a
mapping between 'inlined label' and DBG_LABEL MachineInstr in DebugHandlerBase.
The DBG_LABEL in the mapping is used to query the symbol before it.
The AbstractLabels in DwarfCompileUnit is used to process labels in inlined
functions.
We also keep a mapping between scope and labels in DwarfFile to help to
generate correct tree structure of DIEs.
Differential Revision: https://reviews.llvm.org/D45556
Patch by Hsiangkai Wang.
llvm-svn: 337799
