The SCEV method getBackedgeTakenCount() returns a SCEVCouldNotCompute
object if the backedge-taken count is unpredictable. This fix ensures
there is no longer an attempt to use such an object to find the trip
count.
Patch by: Rosie Sumpter.
Differential Revision: https://reviews.llvm.org/D106970
This is a second attempt to fix the EXPENSIVE_CHECKS issue that was mentioned In D91661#2875179 by @jroelofs.
(The first attempt was in D105983)
D91661 more or less completely reverted D49126 and by doing so also removed the cleanup logic of the created declarations and calls.
This patch is a replacement for D91661 (which must itself be reverted first). It replaces the custom declaration creation with the
generic version and shows the test impact. It also tracks the number of NamedValues to detect if a new prototype was added instead
of looking at the available users of a prototype.
Reviewed By: jroelofs
Differential Revision: https://reviews.llvm.org/D106147
This reverts commit 77080a1eb6.
This change introduced issues detected with EXPENSIVE_CHECKS. Reverting to restore the
needed function cleanup. A next patch will then just improve on the name mangling.
[[noreturn]] can be used since Oct 2016 when the minimum compiler requirement was bumped to GCC 4.8/MSVC 2015.
Note: the definition of LLVM_ATTRIBUTE_NORETURN is kept for now.
The sign_extend we insert here can get turned into a zero_extend if
the sign bit is known zero. This can enable a setcc combine that
shrinks compares with zero_extend. This reduces the use count of
the zero_extend allowing other combines to turn it back into an
any_extend.
This restricts the combine to only cases where the result is used
by a CopyToReg. This works for my original motivating case. I
hope the CopyToReg use will prevent any converted extends from
turning back into an any_extend.
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D106754
Reapply commit 796b84d26f that was
reverted due to reports of crashes. A minor change now guards against
getVariableLocationOperand() returning a nullptr.
Differential Revision: https://reviews.llvm.org/D106659
This transform was added with e38b7e8948
and as shown in:
https://llvm.org/PR51241
...it could crash without an extra check of the blocks.
There might be a more compact way to write this constraint,
but we can't just count the successors/predecessors without
affecting a test that includes a switch instruction.
When we have a terminator sequence (i.e. a tailcall or return),
MIIsInTerminatorSequence is used to work out where the preceding ABI-setup
instructions end, i.e. the parts that were glued to the terminator
instruction. This allows LLVM to split blocks safely without having to
worry about ABI stuff.
The function only ignores DBG_VALUE instructions, meaning that the two
debug instructions I recently added can end terminator sequences early,
causing various MachineVerifier errors. This patch promotes the test for
debug instructions from "isDebugValue" to "isDebugInstr", thus avoiding any
debug-info interfering with this function.
Differential Revision: https://reviews.llvm.org/D106660
In this episode, we are trying to avoid an x86 micro-arch quirk where complex
(3 operand) LEA potentially costs significantly more than simple LEA. So we
simultaneously push and pull the math around the CMOV to balance the operations.
I looked at the debug spew during instruction selection and decided against
trying a later DAGToDAG transform -- it seems very difficult to match if the
trailing memops are already selected and managing the creation of extra
instructions at that level is always tricky.
Differential Revision: https://reviews.llvm.org/D106918
Reworked reordering algorithm. Originally, the compiler just tried to
detect the most common order in the reordarable nodes (loads, stores,
extractelements,extractvalues) and then fully rebuilding the graph in
the best order. This was not effecient, since it required an extra
memory and time for building/rebuilding tree, double the use of the
scheduling budget, which could lead to missing vectorization due to
exausted scheduling resources.
Patch provide 2-way approach for graph reodering problem. At first, all
reordering is done in-place, it doe not required tree
deleting/rebuilding, it just rotates the scalars/orders/reuses masks in
the graph node.
The first step (top-to bottom) rotates the whole graph, similarly to the previous
implementation. Compiler counts the number of the most used orders of
the graph nodes with the same vectorization factor and then rotates the
subgraph with the given vectorization factor to the most used order, if
it is not empty. Then repeats the same procedure for the subgraphs with
the smaller vectorization factor. We can do this because we still need
to reshuffle smaller subgraph when buildiong operands for the graph
nodes with lasrger vectorization factor, we can rotate just subgraph,
not the whole graph.
The second step (bottom-to-top) scans through the leaves and tries to
detect the users of the leaves which can be reordered. If the leaves can
be reorder in the best fashion, they are reordered and their user too.
It allows to remove double shuffles to the same ordering of the operands in
many cases and just reorder the user operations instead. Plus, it moves
the final shuffles closer to the top of the graph and in many cases
allows to remove extra shuffle because the same procedure is repeated
again and we can again merge some reordering masks and reorder user nodes
instead of the operands.
Also, patch improves cost model for gathering of loads, which improves
x264 benchmark in some cases.
Gives about +2% on AVX512 + LTO (more expected for AVX/AVX2) for {625,525}x264,
+3% for 508.namd, improves most of other benchmarks.
The compile and link time are almost the same, though in some cases it
should be better (we're not doing an extra instruction scheduling
anymore) + we may vectorize more code for the large basic blocks again
because of saving scheduling budget.
Differential Revision: https://reviews.llvm.org/D105020
On AIX, the linker needs to check whether a given lto_module_t contains
any constructor/destructor functions, in order to implement the behavior
of the -bcdtors:all flag. See
https://www.ibm.com/docs/en/aix/7.2?topic=l-ld-command for the flag's
documentation.
In llvm IR, constructor (destructor) functions are added to a special
global array @llvm.global_ctors (@llvm.global_dtors).
However, because these two symbols are artificial, they are not visited
during the symbol traversal (using the
lto_module_get_[num_symbols|symbol_name|symbol_attribute] API).
This patch adds a new function to the libLTO interface that checks the
presence of one or both of these two symbols.
Reviewed By: steven_wu
Differential Revision: https://reviews.llvm.org/D106887
As suggested in D105008, move the code that fixes up the backedge value
for first order recurrences to VPlan::execute.
Now all that remains in fixFirstOrderRecurrences is the code responsible
for creating the exit values in the middle block.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D106244
This makes a couple of changes to the costing of MLA reduction patterns,
to more accurately cost various patterns that can come up from
vectorization.
- The Arm implementation of getExtendedAddReductionCost is altered to
only provide costs for legal or smaller types. Larger than legal types
need to be split, which currently does not work very well, especially
for predicated reductions where the predicate may be legal but needs to
be split. Currently we limit it to legal or smaller input types.
- The getReductionPatternCost has learnt that reduce(ext(mul(ext, ext))
is a pattern that can come up, and can be treated the same as
reduce(mul(ext, ext)) providing the extension types match.
- And it has been adjusted to not count the ext in reduce(mul(ext, ext))
as part of a reduce(mul) pattern.
Together these changes help to more accurately cost the mla reductions
in cases such as where the extend types don't match or the extend
opcodes are different, picking better vector factors that don't result
in expanded reductions.
Differential Revision: https://reviews.llvm.org/D106166
The device runtime contains several calls to `__kmpc_get_hardware_num_threads_in_block`
and `__kmpc_get_hardware_num_blocks`. If the thread_limit and the num_teams are constant,
these calls can be folded to the constant value.
In this patch we use the already introduced `AAFoldRuntimeCall` and the `NumTeams` and
`NumThreads` kernel attributes (to be introduced in a different patch) to fold these functions.
The code checks all the kernels, and if their attributes match, the functions are folded.
In the future we will explore specializing for multiple values of NumThreads and NumTeams.
Depends on D106390
Reviewed By: jdoerfert, JonChesterfield
Differential Revision: https://reviews.llvm.org/D106033
This patch adds a peephole optimization `SETCC(FREEZE(x),const)` => `FREEZE(SETCC(x,const))`
if the SETCC is only used by BRCOND.
Combined with `BRCOND(FREEZE(X)) => BRCOND(X)`, this leads to a nice improvement in the generated assembly when x is a masked loaded value.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D105344
This reapplies commit cbb709e251 and
includes the use of the lookup method instead of operator[] to avoid
accidentally setting (empty) simplification callbacks.
This reverts commit aa27430a62.
AAValueSimplify, AAValueConstantRange, and AAPotentialValues all look at
the IR by default. If queried for a IR position which has a
simplification callback we should either look at the callback return, or
give up. We do the latter for now.
We already have an indication (error) if the desired inline advisor
cannot be enabled, but we don't have a positive indication. Added
LLVM_DEBUG messages for the latter.
The dst/dstt/dstst/dststt instructions are nop's on all PowerPC
cores that AIX supports. The AIX assembler also does not accept
these mnemonics. Turn them into nop's on AIX (similar to dstall).
`StackAlignment` has only one use: `StackAlignment = std::max(StackAlignment, AI.getAlignment());` So it is redundant.
Reviewed By: vitalybuka, MTC
Differential Revision: https://reviews.llvm.org/D106741
As an instruction is replaced in optimizeTransposes RAUW will replace it in
the ShapeMap (ShapeMap is ValueMap so that uses are updated). In
finalizeLowering however we skip updating uses if they are in the ShapeMap
since they will be lowered separately at which point we pick up the lowered
operands.
In the testcase what happened was that since we replaced the doubled-transpose
with the shuffle, it ended up in the ShapeMap. As we lowered the
columnwise-load the use in the shuffle was not updated. Then as we removed
the original columnwise-load we changed that to an undef. I.e. we ended up
with:
```
%shuf = shufflevector <8 x double> undef, <8 x double> poison, <6 x i32>
^^^^^
<i32 0, i32 1, i32 2, i32 4, i32 5, i32 6>
```
Besides the fix itself, I have fortified this last bit. As we change uses to
undef when removing instruction we track the undefed instruction to make sure
we eventually remove those too. This would have caught the issue at compile
time.
Differential Revision: https://reviews.llvm.org/D106714
The current JumpThreading pass does not jump thread loops since it can
result in irreducible control flow that harms other optimizations. This
prevents switch statements inside a loop from being optimized to use
unconditional branches.
This code pattern occurs in the core_state_transition function of
Coremark. The state machine can be implemented manually with goto
statements resulting in a large runtime improvement, and this transform
makes the switch implementation match the goto version in performance.
This patch specifically targets switch statements inside a loop that
have the opportunity to be threaded. Once it identifies an opportunity,
it creates new paths that branch directly to the correct code block.
For example, the left CFG could be transformed to the right CFG:
```
sw.bb sw.bb
/ | \ / | \
case1 case2 case3 case1 case2 case3
\ | / / | \
latch.bb latch.2 latch.3 latch.1
br sw.bb / | \
sw.bb.2 sw.bb.3 sw.bb.1
br case2 br case3 br case1
```
Co-author: Justin Kreiner @jkreiner
Co-author: Ehsan Amiri @amehsan
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D99205
Patch by Mohammad Fawaz
This patch allows lifetime calls to be ignored (and later erased) if we
know that the copy-constant-to-alloca optimization is going to happen.
The case that is missed is when the global variable is in a different address
space than the alloca (as shown in the example added to the lit test.)
This used to work before 6da31fa4a6
Differential Revision: https://reviews.llvm.org/D106573
Consider the following loop:
void foo(float *dst, float *src, int N) {
for (int i = 0; i < N; i++) {
dst[i] = 0.0;
for (int j = 0; j < N; j++) {
dst[i] += src[(i * N) + j];
}
}
}
When we are not building with -Ofast we may attempt to vectorise the
inner loop using ordered reductions instead. In addition we also try
to select an appropriate interleave count for the inner loop. However,
when choosing a VF=1 the inner loop will be scalar and there is existing
code in selectInterleaveCount that limits the interleave count to 2
for reductions due to concerns about increasing the critical path.
For ordered reductions this problem is even worse due to the additional
data dependency, and so I've added code to simply disable interleaving
for scalar ordered reductions for now.
Test added here:
Transforms/LoopVectorize/AArch64/strict-fadd-vf1.ll
Differential Revision: https://reviews.llvm.org/D106646
This is partially a workaround. SILowerI1Copies does not understand
unstructured loops. This would result in inserting instructions to
merge a mask register in the same block where it was defined in an
unstructured loop.
Replace the clang builtins and LLVM intrinsics for the SIMD extmul instructions
with normal codegen patterns.
Differential Revision: https://reviews.llvm.org/D106724
- This patch consists of the bare basic code needed in order to generate some assembly for the z/OS target.
- Only the .text and the .bss sections are added for now.
- The relevant MCSectionGOFF/Symbol interfaces have been added. This enables us to print out the GOFF machine code sections.
- This patch enables us to add simple lit tests wherever possible, and contribute to the testing coverage for the z/OS target
- Further improvements and additions will be made in future patches.
Reviewed By: tmatheson
Differential Revision: https://reviews.llvm.org/D106380
When hoisting/moving calls to locations, we strip unknown metadata. Such calls are usually marked `speculatable`, i.e. they are guaranteed to not cause undefined behaviour when run anywhere. So, we should strip attributes that can cause immediate undefined behaviour if those attributes are not valid in the context where the call is moved to.
This patch introduces such an API and uses it in relevant passes. See
updated tests.
Fix for PR50744.
Reviewed By: nikic, jdoerfert, lebedev.ri
Differential Revision: https://reviews.llvm.org/D104641
Patrick Holland