Reapply after fixing SimplifyWithOpReplaced() to never return
the original value, which would lead to an infinite loop in this
transform.
-----
For selects of the type X == Y ? A : B, check if we can simplify A
by using the X == Y equality and replace the operand if that's
possible. We already try to do this in InstSimplify, but will only
fold if the result of the simplification is the same as B, in which
case the select can be dropped entirely. Here the select will be
retained, just one operand simplified.
As we are performing an actual replacement here, we don't have
problems with refinement / poison values.
Differential Revision: https://reviews.llvm.org/D87480
Fix lowering and instruction selection for v3x16 types
and enable InstCombine to emit them.
This patch only implements it for the selection dag.
GlobalISel tests in GlobalISel/llvm.amdgcn.image.load.1d.d16.ll and
GlobalISel/llvm.amdgcn.image.store.2d.d16.ll still don't work.
Differential Revision: https://reviews.llvm.org/D84420
https://bugs.llvm.org/show_bug.cgi?id=45932
assert(OutlinedFunctionCost >= Cloner.OutlinedRegionCost && "Outlined function cost should be no less than the outlined region") getting triggered in computeBBInlineCost.
Intrinsics like "assume" are considered regular function calls while computing costs.
This patch enables computeBBInlineCost to queries TTI for intrinsic call cost.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D87132
Although LLVM supports vectorization of loops containing log10/sqrt, it did not support using SVML implementation of it. Added support so that when clang is invoked with -fveclib=SVML now an appropriate SVML library log2 implementation will be invoked.
Follow up on: https://reviews.llvm.org/D77114
Tests:
Added unit tests to svml-calls.ll, svml-calls-finite.ll. Can be run with llvm-lint.
Created a simple c++ file that tests log10/sqrt, and used clang+ to build it, and output final assembly.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D87169
D65060 was reverted because it introduced non-determinism by using BFI counts from already freed blocks. The parent of this revision fixes that by using a VH callback on blocks to prevent this from happening and makes sure BFI data is passed correctly in LoopStandardAnalysisResults.
This re-introduces the previous optimization of using BFI data to prevent LICM from hoisting/sinking if the instruction will end up moving to a colder block.
Internally at Facebook this change results in a ~7% win in a CPU related metric in one of our big services by preventing hoisting cold code into a hot pre-header like the added test case demonstrates.
Testing:
ninja check
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D87551
For scalable type, the aggregated size is unknown at compile-time.
Skip instructions with scalable type to ensure the list of instructions
for vectorizeSimpleInstructions does not contains any scalable-vector instructions.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D87550
Invalid IR in unreachable code is technically valid IR. In this case,
the address space of the value was never inferred, and we tried to
rewrite it with an invalid address space value which would assert.
This patch is a first draft of a new pass that adds a more flexible way
to eliminate compares based on more complex constraints collected from
dominating conditions.
In particular, it aims at simplifying conditions of the forms below
using a forward propagation approach, rather than instcomine-style
ad-hoc backwards walking of def-use chains.
if (x < y)
if (y < z)
if (x < z) <- simplify
or
if (x + 2 < y)
if (x + 1 < y) <- simplify assuming no wraps
The general approach is to collect conditions and blocks, sort them by
dominance and then iterate over the sorted list. Conditions are turned
into a linear inequality and add it to a system containing the linear
inequalities that hold on entry to the block. For blocks, we check each
compare against the system and see if it is implied by the constraints
in the system.
We also keep a stack of processed conditions and remove conditions from
the stack and the constraint system once they go out-of-scope (= do not
dominate the current block any longer).
Currently there still are the least the following areas for improvements
* Currently large unsigned constants cannot be added to the system
(coefficients must be represented as integers)
* The way constraints are managed currently is not very optimized.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D84547
Similar to the tsan suppression in
`Utils/VNCoercion.cpp:getLoadLoadClobberFullWidthSize` (rL175034; load widening used by GVN),
the D81766 optimization should be suppressed under tsan due to potential
spurious data race reports:
struct A {
int i;
const short s; // the load cannot be vectorized because
int modify; // it overlaps with bytes being concurrently modified
long pad1, pad2;
};
// __tsan_read16 does not know that some bytes are undef and accessing is safe
Similarly, under asan, users can mark memory regions with
`__asan_poison_memory_region`. A widened load can lead to a spurious
use-after-poison error. hwasan/memtag should be similarly suppressed.
`mustSuppressSpeculation` suppresses asan/hwasan/tsan but not memtag, so
we need to exclude memtag in `vectorizeLoadInsert`.
Note, memtag suppression can be relaxed if the load is aligned to the
its granule (usually 16), but that is out of scope of this patch.
Reviewed By: spatel, vitalybuka
Differential Revision: https://reviews.llvm.org/D87538
If the constant operand is the opposite of the min/max value,
then the result must be the other value.
This is based on the similar codegen transform proposed in:
D87571
The "takeName" logic in ScalarizerVisitor::gather did not consider
that the value vector could refer to non-instructions, such as
global variables. This patch make sure that we avoid changing the
name of a value if it isn't an instruction.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D87685
I've amended the isLoadInvariantInLoop function to bail out for
scalable vectors for now since the invariant.start intrinsic is only
ever generated by the clang frontend for thread locals or struct
and class constructors, neither of which support sizeless types.
In addition, the intrinsic itself does not currently support the
concept of a scaled size, which makes it impossible to compare
the sizes of different scalable objects, e.g. <vscale x 32 x i8>
and <vscale x 16 x i8>.
Added new tests here:
Transforms/LICM/AArch64/sve-load-hoist.ll
Transforms/LICM/hoisting.ll
Differential Revision: https://reviews.llvm.org/D87227
As to not conflict with the legacy PM example passes under
llvm/lib/Transforms/Hello, this is under HelloNew. This makes the
CMakeLists.txt and general directory structure less confusing for people
following the example.
Much of the doc structure was taken from WritinAnLLVMPass.rst.
This adds a HelloWorld pass which simply prints out each function name.
More will follow after this, e.g. passes over different units of IR, analyses.
https://llvm.org/docs/WritingAnLLVMPass.html contains a lot more.
Relanded with missing "Support" dependency in LLVMBuild.txt.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D86979
As to not conflict with the legacy PM example passes under
llvm/lib/Transforms/Hello, this is under HelloNew. This makes the
CMakeLists.txt and general directory structure less confusing for people
following the example.
Much of the doc structure was taken from WritinAnLLVMPass.rst.
This adds a HelloWorld pass which simply prints out each function name.
More will follow after this, e.g. passes over different units of IR, analyses.
https://llvm.org/docs/WritingAnLLVMPass.html contains a lot more.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D86979
For selects of the type X == Y ? A : B, check if we can simplify A
by using the X == Y equality and replace the operand if that's
possible. We already try to do this in InstSimplify, but will only
fold if the result of the simplification is the same as B, in which
case the select can be dropped entirely. Here the select will be
retained, just one operand simplified.
As we are performing an actual replacement here, we don't have
problems with refinement / poison values.
Differential Revision: https://reviews.llvm.org/D87480
As discussed in the sibling codegen functionality patch D87571,
this transform was created with D52766, but it is not correct.
The incorrect test diffs were missed during review, but the
'TODO' comment about this functionality was still in the code -
we need 'nnan' to enable this fold.
AliasAnalysis/MemoryLocation does not account for loops. Two
MemoryLocation can be must-overwrite, even if the first one writes
multiple locations in a loop.
This patch prevents removing such stores, by only considering candidates
that are known to be loop invariant, or executed in the same BB.
Currently the invariant check is quite conservative and only considers
Alloca and Alloca-like instructions and arguments as invariant base pointers.
It also considers GEPs with all constant indices and invariant bases as
invariant.
This can be improved in the future, but the current implementation has
only minor impact on the total number of stores eliminated (25903 vs
26047 for the baseline). There are some 2-10% swings for some individual
benchmarks. In roughly half of the cases, the number of stores removed
increases actually, because we skip candidates that are unlikely to be
valid candidates early.
The function LoopIdiomRecognize::isLegalStore looks for stores in loops
that could be transformed into memset or memcpy. However, the algorithm
currently requires that we know how big the store is at runtime, i.e.
that the store size will not overflow an unsigned integer. For scalable
vectors we cannot guarantee this so I have changed the code to bail out
for now. In addition, even if we add a way to query the maximum value of
vscale in future we will still need to update the algorithm to cope with
non-constant strides. The additional cost associated with calculating
the memset and memcpy arguments will need to be taken into account as
well.
This patch also fixes up an implicit TypeSize -> uint64_t cast,
thereby removing a warning. I've added tests here showing a fixed
width vector loop being transformed into memcpy, and a scalable
vector loop remaining unchanged:
Transforms/LoopIdiom/memcpy-vectors.ll
Differential Revision: https://reviews.llvm.org/D87439
This fixes PR47297.
When ProcessBlock() was able to constant fold the terminator's
condition, but not do any more transformations, the function would
return false, which would lead to the JumpThreading pass returning an
incorrect modified status. This patch makes so that ProcessBlock()
returns true in such cases. This will trigger an unnecessary invocation
of ProcessBlock() in such cases, but this should be rare to occur.
This was caught using the check introduced by D80916.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87392
This patch fixes a problem of the commit 52cc97a0.
A test case is created to demonstrate the crash caused by
the instruction iterator invalidated by the recursive
removal of dead operands of assume. The solution restarts
from the blocks's first instruction in case CurInstIterator
is invalidated by RecursivelyDeleteTriviallyDeadInstructions().
Reviewed By: bkramer
Differential Revision: https://reviews.llvm.org/D87434
Demonstrates that redundant masked stores may be removed, as long as we're able to replace the AVX/AVX2 masked store with a generic masked store (constant mask or sign-extended bool vector mask).
gcov is an "Edge Profiling with Edge Counters" application according to
Optimally Profiling and Tracing Programs (1994).
The minimum number of counters necessary is |E|-(|V|-1). The unmeasured edges
form a spanning tree. Both GCC --coverage and clang -fprofile-generate leverage
this optimization. This patch implements the optimization for clang --coverage.
The produced .gcda files are much smaller now.
When deleting stores at the end of a function, we have to do PHI
translation, otherwise we might miss reads in different iterations of a
loop. See multiblock-loop-carried-dependence.ll for details.
This fixes a mis-compile and surprisingly also increases the number of
eliminated stores from 26047 to 26572 for MultiSource/SPEC2000/SPEC2006
on X86 with -O3 -flto. This is most likely because we save budget by not
exploring through MemoryPhis, which are less likely to result in valid
candidates for elimination.
The issue was reported post-commit for fb109c42d91c.
