This version of the patch includes a fix for the cfi failures.
(undoes the revert commit 7db390cc7738a9ba0ed7d4ca59ab6ea2e69c47e9)
It also undoes reverts of follow-up patches that also needed reverting
originally:
* [LTO] Add option enable NewPM with LTOCodeGenerator.
(undoes revert commit 0a17664b47c153aa26a0d31b4835f26375440ec6)
* [LTOCodeGenerator] Use lto::Config for options (NFC)."
(undoes revert commit b0a8e41cfff717ff067bf63412d6edb0280608cd)
In the future Windows will enable Control-flow Enforcement Technology (CET aka shadow stacks). To protect the path where the context is updated during exception handling, the binary is required to enumerate valid unwind entrypoints in a dedicated section which is validated when the context is being set during exception handling.
This change allows llvm to generate the section that contains the appropriate symbol references in the form expected by the msvc linker.
This feature is enabled through a new module flag, ehcontguard, which was modelled on the cfguard flag.
The change includes a test that when the module flag is enabled the section is correctly generated.
The set of exception continuation information includes returns from exceptional control flow (catchret in llvm).
In order to collect catchret we:
1) Includes an additional flag on machine basic blocks to indicate that the given block is the target of a catchret operation,
2) Introduces a new machine function pass to insert and collect symbols at the start of each block, and
3) Combines these targets with the other EHCont targets that were already being collected.
Change originally authored by Daniel Frampton <dframpto@microsoft.com>
For more details, see MSVC documentation for `/guard:ehcont`
https://docs.microsoft.com/en-us/cpp/build/reference/guard-enable-eh-continuation-metadata
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D94835
Add intrinsic which demotes all active lanes to helper lanes.
This is used to implement demote to helper Vulkan extension.
In practice demoting a lane to helper simply means removing it
from the mask of live lanes used for WQM/WWM/Exact mode.
Where the shader does not use WQM, demotes just become kills.
Additionally add llvm.amdgcn.live.mask intrinsic to complement
demote operations. In theory llvm.amdgcn.ps.live can be used
to detect helper lanes; however, ps.live can be moved by LICM.
The movement of ps.live cannot be remedied without changing
its type signature and such a change would require ps.live
users to update as well.
Reviewed By: piotr
Differential Revision: https://reviews.llvm.org/D94747
The implementation for vectors is broken and doesn't seem to be used by
anything. Explicitly remove support for them, they can be added again
later when they're properly implemented.
Reviewed By: aemerson
Differential Revision: https://reviews.llvm.org/D95699
Adds an *unaudited* SHA-256 implementation to `llvm/Support`. The ongoing lld-macho effort needs this to emit an adhoc code signature for macho files on macOS Big Sur.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D96540
At this point, we can treat the case of GEP/GEP aliasing and
GEP/non-GEP aliasing in essentially the same way. The only
differences are that we need to do an additional negative GEP base
check, and that we perform a bailout on unknown sizes for the
GEP/non-GEP case (the latter exists only to limit compile-time).
This change is not quite NFC due to the peculiar effect that
the DecomposedGEP for V2 can actually be non-trivial even if V2
is not a GEP. The reason for this is that getUnderlyingObject()
can look through LCSSA phi nodes, while stripPointerCasts() doesn't.
This can lead to slightly better results if single-entry phi nodes
occur inside a loop, where looking through the phi node via aliasPhi()
would subject it to phi cycle equivalence restrictions. It would
probably make sense to adjust pointer cast stripping (for AA) to
handle this case, and ensure consistent results.
For two GEPs with identical offsets, we currently first perform
a base address query without size information, and then if it is
MayAlias, perform another with size information. This is pointless,
as the latter query should produce strictly better results.
This was not quite true historically due to the way that NoAlias
assumptions were handled, but that issue has since been resolved.
We currently detect GEPs that have exactly the same indexes by
comparing the Offsets and VarIndices. However, the latter implicitly
performs equality comparisons between two values, which is not
generally legal inside BasicAA, due to the possibility of comparisons
across phi cycles.
I believe that in this particular instance this actually ends up being
unproblematic, at least I wasn't able to come up with any cases that
could result in an incorrect root query result.
In the interest of being defensive, compute GetIndexDifference earlier
(which knows how to handle phi cycles properly) and use the result of
that to determine whether the offsets are identical.
This is a follow-up of D95238's LangRef update.
This patch updates `programUndefinedIfUndefOrPoison(V)` to return true if
`V` is used by any memory-accessing instruction.
Interestingly, this affected many tests in Attributors, mainly about adding noundefs.
The tests are updated using llvm/utils/update_test_checks.py. I checked that the diffs
are about updating noundefs.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D96642
This is unusual in the general (non-reciprocal) case because we need
an extra instruction, but that should be better for general FP
reassociation and codegen. We conservatively check for "arcp" FMF
here as we do with existing fdiv folds, but it is not strictly
necessary to have that.
This is part of solving:
https://llvm.org/PR49147
(The powi variant potentially has a different constraint.)
Differential Revision: https://reviews.llvm.org/D96648
This patch fixes pr48832 by correctly generating the mask when a poison value is involved.
Consider this CFG (which is a part of the input):
```
for.body: ; preds = %for.cond
br i1 true, label %cond.false, label %land.rhs
land.rhs: ; preds = %for.body
br i1 poison, label %cond.end, label %cond.false
cond.false: ; preds = %for.body, %land.rhs
br label %cond.end
cond.end: ; preds = %land.rhs, %cond.false
%cond = phi i32 [ 0, %cond.false ], [ 1, %land.rhs ]
```
The path for.body -> land.rhs -> cond.end should be taken when 'select i1 false, i1 poison, i1 false' holds (which means it's never taken); but VPRecipeBuilder::createEdgeMask was emitting 'and i1 false, poison' instead.
The former one successfully blocks poison propagation whereas the latter one doesn't, making the condition poison and thus causing the miscompilation.
SimplifyCFG has a similar bug (which didn't expose a real-world bug yet), and a patch for this is also ongoing (see https://reviews.llvm.org/D95026).
Reviewed By: bjope
Differential Revision: https://reviews.llvm.org/D95217
The new tests added by 1487747e990ce9f8851f3d92c3006a74134d7518 for lld
and gold plugin were largely equivalent, but the gold one was missing
one of the cases added to lld. Add that test to the gold plugin version.
As we don't sort local symbols, don't sort non-local symbols. This makes
non-local symbols appear in their register order, which matches GNU as. The
register order is nice in that you can write tests with interleaved CHECK
prefixes, e.g.
```
// CHECK: something about foo
.globl foo
foo:
// CHECK: something about bar
.globl bar
bar:
```
With the lexicographical order, the user needs to place lexicographical smallest
symbol first or keep CHECK prefixes in one place.
This removes IRBuilder methods accepting unsigned alignments
in favor of their Align/MaybeAlign variants. These methods have
been deprecated for more than a year at this point, so they
should be safe to remove.
As discussed on D96413, as long as the promoted bits of the args are zero we can use the basic ISD::USUBSAT pattern directly, without the shifting like we do for other ops.
I think something similar should be possible for ISD::UADDSAT as well, which I'll look at later.
Also, create a ISD::USUBSAT node directly - this will be expanded back by the legalizer later on if necessary.
Differential Revision: https://reviews.llvm.org/D96622
Instcombine will convert the nonnull and alignment assumption that use the boolean condtion
to an assumption that uses the operand bundles when knowledge retention is enabled.
Differential Revision: https://reviews.llvm.org/D82703
We lost this in D56387/rG69bc0990a9181e6eb86228276d2f59435a7fae67 - where I got the src/dst bitwidths mixed up and assumed getValidShiftAmountConstant would catch it.
Patch by @craig.topper - confirmed by @Carrot that it fixes PR49162
Previously we assumed `rethrow`'s argument was always 0, but it turned
out `rethrow` follows the same rule with `br` or `delegate`:
https://github.com/WebAssembly/exception-handling/pull/137https://github.com/WebAssembly/exception-handling/issues/146#issuecomment-777349038
Currently `rethrow`s generated by our backend always rethrow the
exception caught by the innermost enclosing catch, so this adds a
function to compute that and replaces `rethrow`'s argument with its
computed result.
This also renames `EHPadStack` in `InstPrinter` to `TryStack`, because
in CFGStackify we use `EHPadStack` to mean the range between
`catch`~`end`, while in `InstPrinter` we used it to mean the range
between `try`~`catch`, so choosing different names would look clearer.
Doesn't contain any functional changes in `InstPrinter`.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D96595
