Summary:
Select folding in JumpThreading can create a conditional branch on a
code patch that did not have one in the original program. This is not a
valid transformation in sanitize_memory functions.
Note that JumpThreading does select folding in 3 different places. Two
of them seem safe - they apply to a select instruction in a BB that ends
with an unconditional branch to another BB, which (in turn) ends with a
conditional branch or a switch with the same condition.
Fixes PR45220.
Reviewers: glider, dvyukov, efriedma
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76332
Summary:
When we encounter an XCOFF file, reflect that in the triple information.
In addition to knowing the object file format, we know that the
associated OS is AIX.
This means that we can expect that there is no output difference in the
processing of an XCOFF32 input file between cases where the triple is
left unspecified by the user and cases where the user specifies
`--triple powerpc-ibm-aix` explicitly.
Reviewers: jhenderson, sfertile, jasonliu, daltenty
Reviewed By: jasonliu
Subscribers: wuzish, nemanjai, hiraditya, MaskRay, rupprecht, steven.zhang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77025
The UnwindHelp object is used during exception handling by runtime
code. It must be findable from a fixed offset from FP.
This change allocates the UnwindHelp object as a fixed object (as is
done for x86_64) to ensure that both the generated code and runtime
agree on the location of the object.
Fixes https://bugs.llvm.org/show_bug.cgi?id=45346
Differential Revision: https://reviews.llvm.org/D77016
The generated code for a funclet can have an add to sp in the epilogue
for which there is no corresponding sub in the prologue.
This patch removes the early return from emitPrologue that was
preventing the sub to sp, and instead conditionalizes the appropriate
parts of the rest of the function.
Fixes https://bugs.llvm.org/show_bug.cgi?id=45345
Differential Revision: https://reviews.llvm.org/D77015
This reverts commit 28518d9ae39ff5c6044e230d58b6ae28b0252cae.
There is a failure in MsgPackReader.cpp when built with clang. It
complains about "signext and zeroext" are incompatible. Investigating
offline if it is infact a UB in the MsgPackReader code.
Instead, represent the mask as out-of-line data in the instruction. This
should be more efficient in the places that currently use
getShuffleVector(), and paves the way for further changes to add new
shuffles for scalable vectors.
This doesn't change the syntax in textual IR. And I don't currently plan
to change the bitcode encoding in this patch, although we'll probably
need to do something once we extend shufflevector for scalable types.
I expect that once this is finished, we can then replace the raw "mask"
with something more appropriate for scalable vectors. Not sure exactly
what this looks like at the moment, but there are a few different ways
we could handle it. Maybe we could try to describe specific shuffles.
Or maybe we could define it in terms of a function to convert a fixed-length
array into an appropriate scalable vector, using a "step", or something
like that.
Differential Revision: https://reviews.llvm.org/D72467
The attached test case is simplified from tcmalloc. Both function calls should be optimized as tailcall. But llvm can only optimize the first call. The second call can't be optimized because function dupRetToEnableTailCallOpts failed to duplicate ret into block case2.
There 2 problems blocked the duplication:
1 Intrinsic call llvm.assume is not handled by dupRetToEnableTailCallOpts.
2 The control flow is more complex than expected, dupRetToEnableTailCallOpts can only duplicate ret into its predecessor, but here we have an intermediate block between call and ret.
The solutions:
1 Since CodeGenPrepare is already at the end of LLVM IR phase, we can simply delete the intrinsic call to llvm.assume.
2 A general solution to the complex control flow is hard, but for this case, after exit2 is duplicated into case1, exit2 is the only successor of exit1 and exit1 is the only predecessor of exit2, so they can be combined through eliminateFallThrough. But this function is called too late, there is no more dupRetToEnableTailCallOpts after it. We can add an earlier call to eliminateFallThrough to solve it.
Differential Revision: https://reviews.llvm.org/D76539
We have loads preserving low and high 16 bits of their
destinations. However, we always use a whole 32 bit register
for these. The same happens with 16 bit stores, we have to
use full 32 bit register so if high bits are clobbered the
register needs to be copied. One example of such code is
added to the load-hi16.ll.
The proper solution to the problem is to define 16 bit subregs
and use them in the operations which do not read another half
of a VGPR or preserve it if the VGPR is written.
This patch simply defines subregisters and register classes.
At the moment there should be no difference in code generation.
A lot more work is needed to actually use these new register
classes. Therefore, there are no new tests at this time.
Register weight calculation has changed with new subregs so
appropriate changes were made to keep all calculations just
as they are now, especially calculations of register pressure.
Differential Revision: https://reviews.llvm.org/D74873
Consider a callee function that has a call (C) within it which feeds
into the return. When we inline that callee into a callsite that has
return attributes, we can backward propagate those attributes to the
call (C) within that inlined callee body.
This is safe to do so only if we can guarantee transfer of execution to
successor in the window of instructions between return value (i.e. the
call C) and the return instruction.
See added test cases.
Reviewed-By: reames, jdoerfert
Differential Revision: https://reviews.llvm.org/D76140
Registers used in any address (as well as in a few other contexts)
have special semantics when a "zero" register is used, which is
why the back-end defines extra register classes ADDR32, ADDR64 etc
to be used to prevent the register allocator from using %r0 there.
However, when writing assembler code "by hand", you sometimes need
to trigger that special semantics. However, currently the AsmParser
will reject %r0 in those places. In some cases it may be possible
to write that instruction differently - but in others it is currently
not possible at all.
This check in AsmParser simply seems overly strict, so this patch
just removes the check completely. This brings the behaviour of
AsmParser in line with the GNU assembler as well.
Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=45092
Make InstCombine aware of the aligned_alloc library function.
Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>
Depends on D76970.
Differential Revision: https://reviews.llvm.org/D76971
Summary:
CGProfilePass is run by default in certain new pass manager optimization pipeline. Assemblers other than llvm as (such as gnu as) cannot recognize the .cgprofile entries generated and emitted from this pass, causing build time error.
This patch adds new options in clang CodeGenOpts and PassBuilder options so that we can turn cgprofile off when not using integrated assembler.
Reviewers: Bigcheese, xur, george.burgess.iv, chandlerc, manojgupta
Reviewed By: manojgupta
Subscribers: manojgupta, void, hiraditya, dexonsmith, llvm-commits, tcwang, llozano
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D62627
Summary: this patch preserve information from various places in EarlyCSE into assume bundles.
Reviewers: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76769
--no-threads is a name copied from gold.
gold has --no-thread, --thread-count and several other --thread-count-*.
There are needs to customize the number of threads (running several lld
processes concurrently or customizing the number of LTO threads).
Having a single --threads=N is a straightforward replacement of gold's
--no-threads + --thread-count.
--no-threads is used rarely. So just delete --no-threads instead of
keeping it for compatibility for a while.
If --threads= is specified (ELF,wasm; COFF /threads: is similar),
--thinlto-jobs= defaults to --threads=,
otherwise all available hardware threads are used.
There is currently no way to override a --threads={1,2,...}. It is still
a debate whether we should use --threads=all.
Reviewed By: rnk, aganea
Differential Revision: https://reviews.llvm.org/D76885
This is the Waymarking algorithm implemented as an independent utility.
The utility is operating on a range of sequential elements.
First we "tag" the elements, by calling `fillWaymarks`.
Then we can "follow" the tags from every element inside the tagged
range, and reach the "head" (the first element), by calling
`followWaymarks`.
Differential Revision: https://reviews.llvm.org/D74415
If canLowerByDroppingEvenElements indicates that the shuffle is a N:1 compaction pattern and the inputs are suitably sign/zero extended then we can use a chain of PACKSS/PACKUS to compact.
This helps avoid PSHUFB (and its mask load) for short shuffle chains, shuffle combining will still replace with a PSHUFB if we have enough shuffles as getFauxShuffleMask can recognise PACKSS/PACKUS chains.
The script now includes extra info about command-line options used
when generating its advertisement heading, but we don't want that
here. This is a special-case because we have enhanced the check
lines (as noted in the 2nd comment line).
This is a speculative fix to silence the spurious C4129 warning that
some version of MSVC generate for the raw string literals in the changed
files.
Before disabling the warning (D76428), try a potential fix suggested in
the review.
This patch updates ValueLattice to distinguish between ranges that are
guaranteed to not include undef and ranges that may include undef.
A constant range guaranteed to not contain undef can be used to simplify
instructions to arbitrary values. A constant range that may contain
undef can only be used to simplify to a constant. If the value can be
undef, it might take a value outside the range. For example, consider
the snipped below
define i32 @f(i32 %a, i1 %c) {
br i1 %c, label %true, label %false
true:
%a.255 = and i32 %a, 255
br label %exit
false:
br label %exit
exit:
%p = phi i32 [ %a.255, %true ], [ undef, %false ]
%f.1 = icmp eq i32 %p, 300
call void @use(i1 %f.1)
%res = and i32 %p, 255
ret i32 %res
}
In the exit block, %p would be a constant range [0, 256) including undef as
%p could be undef. We can use the range information to replace %f.1 with
false because we remove the compare, effectively forcing the use of the
constant to be != 300. We cannot replace %res with %p however, because
if %a would be undef %cond may be true but the second use might not be
< 256.
Currently LazyValueInfo uses the new behavior just when simplifying AND
instructions and does not distinguish between constant ranges with and
without undef otherwise. I think we should address the remaining issues
in LVI incrementally.
Reviewers: efriedma, reames, aqjune, jdoerfert, sstefan1
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D76931
For the PHI node
%1 = phi [%A, %entry], [%X, %latch]
it is incorrect to use SCEV of backedge val %X as an exit value
of PHI unless %X is loop invariant.
This is because exit value of %1 is value of %X at one-before-last
iteration of the loop.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D73181
