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
Bugpoint has lots of assumptions and hacks around the legacy PM, put off migrating it to NPM until later.
Fixes tests under BugPoint under NPM.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D87655
Was missing MODULE_ALIAS_ANALYSIS, previously only FUNCTION_ALIAS_ANALYSIS was taken into account.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D87664
Pin RUN lines with -analyze to legacy PM, add corresponding NPM RUN line if missing.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D87658
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
Make it possible to run the script command with a different language
than currently selected.
$ ./bin/lldb -l python
(lldb) script -l lua
>>> io.stdout:write("Hello, World!\n")
Hello, World!
When passing the language option and a raw command, you need to separate
the flag from the script code with --.
$ ./bin/lldb -l python
(lldb) script -l lua -- io.stdout:write("Hello, World!\n")
Hello, World!
Differential revision: https://reviews.llvm.org/D86996
PR47534 exposes a case where calling lowerShuffleWithSHUFPS directly from a derived repeated mask (found by is128BitLaneRepeatedShuffleMask) results in us using an non-canonicalized mask.
The missed canonicalization in this case is trivial - just commute the mask so we have more (swapped) LHS than RHS references so lowerShuffleWithSHUFPS can handle it.
Forward declare AAResults instead of the (old) AliasAnalysis type.
Remove includes from SLPVectorizer.cpp that are already included in SLPVectorizer.h.
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
Currently we might derive the dynamic symbol table size from the DT_HASH hash table (using its `nchain` field).
It is possible to crash dumpers with a broken relocation that refers to a symbol with an index
that is too large. To trigger it, the inferred size of the dynamic symbol table should go past the end of the object.
This patch adds a size validation + warning.
Differential revision: https://reviews.llvm.org/D86923
2508ef01 doesn't totally fix the issue since we did not handle the case
when unused temporary negated result is the same with the result, which
is found by address sanitizer.
GetElementPtrInst::Create returns a GetElementPtrInst* so we don't need to cast. Similarly IntegerType inherits from the Type base class.
Also, I've used auto* in a few places to cleanup the code.
Helps fix some clang-tidy warnings which saw the dyn_casts and warned that these can return null.
The FailureReason input parameter maybe null, we check this in all other cases in the method but this one was missed somehow.
Fixes clang-tidy warning.
This patch adds a isConditionImplied function that
takes a constraint and returns true if the constraint
is implied by the current constraints in the system.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D84545
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
This seems to have caused incorrect register allocation in some cases,
breaking tests in the Zig standard library (PR47278).
As discussed on the bug, revert back to green for now.
> Record internal state based on register units. This is often more
> efficient as there are typically fewer register units to update
> compared to iterating over all the aliases of a register.
>
> Original patch by Matthias Braun, but I've been rebasing and fixing it
> for almost 2 years and fixed a few bugs causing intermediate failures
> to make this patch independent of the changes in
> https://reviews.llvm.org/D52010.
This reverts commit 66251f7e1de79a7c1620659b7f58352b8c8e892e, and
follow-ups 931a68f26b9a3de853807ffad7b2cd0a2dd30922
and 0671a4c5087d40450603d9d26cf239f1a8b1367e. It also adjust some
test expectations.
This patch recommits "[ConstraintSystem] Add helpers to deal with linear constraints."
(it reverts the revert commit 8da6ae4ce1b686c5c13698e4c5ee937811fda6f7).
The reason for the revert was using __builtin_multiply_overflow, which
is not available for all compilers. The patch has been updated to use
MulOverflow from MathExtras.h
We're now getting close to having the necessary analysis/combines etc. for the new generic llvm smax/smin/umax/umin intrinsics.
This patch updates the SSE/AVX integer MINMAX intrinsics to emit the generic equivalents instead of the icmp+select code pattern.
Differential Revision: https://reviews.llvm.org/D87603
960cbc53 immediately removes nodes that won't be used to avoid
compilation time explosion. This patch adds the removal to constants to
fix PR47517.
Reviewed By: RKSimon, steven.zhang
Differential Revision: https://reviews.llvm.org/D87614
