Summary:
In order to get the whole fold as specified in [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]],
let's first handle the simple straight-forward things.
Let's start with the `and` -> `or` simplification.
The one obvious thing missing here: the constant mask is not handled.
I have an idea how to handle it, but it will require some thinking,
and is not strictly required here, so i've left that for later.
https://rise4fun.com/Alive/Pkmg
Reviewers: spatel, craig.topper, eli.friedman, jingyue
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45631
llvm-svn: 330101
These simplifications were previously enabled only with isFast(), but that
is more restrictive than required. Since r317488, FMF has 'reassoc' to
control these cases at a finer level.
llvm-svn: 330089
It debateable whether instcombine should be in the business of
reassociation, but it is currently.
These tests and PR37098 demonstrate a missing ability to do a
simple reassociation that allows eliminating shifts.
If we decide that functionality belongs somewhere else, then we
should still have some tests to show that we've intentionally
limited instcombine to *not* include this ability.
llvm-svn: 330086
(and plain 'or', for completeness sake.)
After submitting D45631, i have realized that it will *already*
affect 'and' pattern, and it was obvious that there were no
good test patterns to show that.
Since the masked-merge.ll is getting kinda big,
unify naming schemes a bit, and split into 'xor'/'and'/'or'
testfiles, with the only difference being the last operation.
llvm-svn: 330072
The function getMinimumVF(ElemWidth) will return the minimum VF for
a vector with elements of size ElemWidth bits. This value will only
apply to targets for which TTI::shouldMaximizeVectorBandwidth returns
true. The value of 0 indicates that there is no minimum VF.
Differential Revision: https://reviews.llvm.org/D45271
llvm-svn: 330062
This was intended since initially, but i did not really think
about it, and did not know how to force that. Now that the
xor->or fold is working (patch upcoming), this came up
to improve the test coverage.
A followup for rL330003, rL330007
https://bugs.llvm.org/show_bug.cgi?id=6773
llvm-svn: 330039
Summary:
The fold added in D45108 did not account for the fact that
the and instruction is commutative, and if the mask is a variable,
the mask variable and the fold variable may be swapped.
I have noticed this by accident when looking into [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]]
This extends/generalizes that fold, so it is handled too.
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45539
llvm-svn: 330001
This completes the work started in r329604 and r329605 when we changed clang to no longer use the intrinsics.
We lost some InstCombine SimplifyDemandedBit optimizations through this change as we aren't able to fold 'and', bitcast, shuffle very well.
llvm-svn: 329990
This lifts a restriction on DILocation::getMergedLocation(), allowing it
to create merged locations for instructions other than calls.
Instruction::applyMergedLocation() now defaults to creating merged
locations for all instructions.
The default behavior of getMergedLocation() is unchanged: callers which
invoke it directly are unaffected.
This change will enable a follow-up Mem2Reg fix which improves crash
reporting.
Differential Revision: https://reviews.llvm.org/D45396
llvm-svn: 329955
Created a helper function to query for non negative SCEVs. Uses the
SGE predicate to catch constants that could be interpreted as
negative.
Differential Revision: https://reviews.llvm.org/D45481
llvm-svn: 329907
Summary:
The fold added in D45108 did not account for the fact that
the and instruction is commutative, and if the mask is a variable,
the mask variable and the fold variable may be swapped.
I have noticed this by accident when looking into [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]]
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45538
llvm-svn: 329901
We're already removing allocsize attributes from Functions that we
remove args from, since removing arguments from a function may make the
allocsize attribute incorrect. It appears we forgot to also remove them
from callsites.
Without this, I get verifier errors on `@Test2`.
It probably wouldn't be too hard to make DAE properly update allocsize
attributes instead of dropping them, but I can't think of a scenario
where that'd be useful in practice.
llvm-svn: 329868
Summary:
These tests show that DSE currently does nothing with the atomic memory
intrinsics. Future work will teach DSE how to simplify these.
llvm-svn: 329845
Summary:
In preparation for a future commit, this regenerates the test checks for
test/Transforms/DeadStoreElimination/OverwriteStoreBegin.ll
test/Transforms/DeadStoreElimination/OverwriteStoreEnd.ll
llvm-svn: 329839
Summary:
In preparation for a future commit, this regenerates the test checks for
test/Transforms/DeadStoreElimination/simple.ll
test/Transforms/DeadStoreElimination/memintrinsics.ll
llvm-svn: 329824
Author: Samuel Pitoiset
ds_read_b128 and ds_write_b128 have been recently enabled
under the amdgpu-ds128 option because the performance benefit
is unclear.
Though, using 128-bit loads/stores for the local address space
appears to introduce regressions in tessellation shaders. Not
sure what is broken, but as ds_read_b128/ds_write_b128 are not
enabled by default, just introduce a global option and enable
128-bit only if requested (until it's fixed/used correctly).
v2: - fix regressions in merge-stores.ll and multiple_tails.ll
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105464
llvm-svn: 329764
This is based on an example that was recently posted on llvm-dev:
void *propagate_null(void* b, int* g) {
if (!b) {
return 0;
}
(*g)++;
return b;
}
https://godbolt.org/g/xYk3qG
The original code or constant propagation in other passes has obscured the fact
that the phi can be removed completely.
Differential Revision: https://reviews.llvm.org/D45448
llvm-svn: 329755
Fix PR36484, as suggested:
<quote>
during moves, mark the direct users of the erased things that were phis as "not to be optimized"
<quote>
llvm-svn: 329621
Summary:
We do not try to move the instructions and split the block till we
know the blocks can be split, i.e. BCE-cmp-insts can be separated from
non-BCE-cmp-insts.
Reviewers: davide, courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44443
llvm-svn: 329564
In IRCE, we have a very old legacy check that works when we collect comparisons that we
treat as range checks. It ensures that the value against which the indvar is compared is
loop invariant and is also positive.
This latter condition remained there since the times when IRCE was only able to handle
signed latch comparison. As the optimization evolved, it now learned how to intersect
signed or unsigned ranges, and this logic has no reliance on the fact that the right border
of each range should be positive.
The old implementation of this non-negativity check was also naive enough and just looked
into ranges (while most of other IRCE logic tries to use power of SCEV implications), so this
check did not allow to deal with the most simple case that looks like follows:
int size; // not known non-negative
int length; //known non-negative;
i = 0;
if (size != 0) {
do {
range_check(i < size);
range_check(i < length);
++i;
} while (i < size)
}
In this case, even if from some dominating conditions IRCE could parse loop
structure, it could only remove the range check against `length` and simply
ignored the check against `size`.
In this patch we remove this obsolete check. It will allow IRCE to pick comparison
against `size` as a potential range check and then let Range Intersection logic
decide whether it is OK to eliminate it or not.
Differential Revision: https://reviews.llvm.org/D45362
Reviewed By: samparker
llvm-svn: 329547
There are a pair of folds that try to merge fneg into fsub
with an intervening cast, but as shown in the FIXME tests,
they can create extra instructions.
llvm-svn: 329501
D45344 is proposing to remove the use restriction that made the calloc
transform safe, but it doesn't currently address the problematic example
given inD16337. Add a test to make sure that doesn't break.
llvm-svn: 329412
Summary:
Fixing an issue where initializations of globals where constructors use
casts were silently translated to 0-initialization.
Reviewers: davidxl, evgeny777
Reviewed By: evgeny777
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45198
llvm-svn: 329409
Inserting instrumentation between a musttail call and ret instruction
would create invalid IR. Instead, treat musttail calls as function
exits.
llvm-svn: 329385
This restores what was lost with rL73243 but without
re-introducing the bug that was present in the old code.
Note that we already have these transforms if the ops are
marked 'fast' (and I assume that's happening somewhere in
the code added with rL170471), but we clearly don't need
all of 'fast' for these transforms.
llvm-svn: 329362
A fold for this pattern was removed at rL73243 to fix PR4374:
https://bugs.llvm.org/show_bug.cgi?id=4374
...and apparently there were no tests that went with that fold.
llvm-svn: 329360
Summary:
More tests for D45108:
* One use tests
* allow shift to be a variable, too
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45329
llvm-svn: 329348
Summary:
This is a fix to PR37005.
Essentially, rL328539 ([InstCombine] reassociate loop invariant GEP chains to enable LICM) contains a bug
whereby it will convert:
%src = getelementptr inbounds i8, i8* %base, <2 x i64> %val
%res = getelementptr inbounds i8, <2 x i8*> %src, i64 %val2
into:
%src = getelementptr inbounds i8, i8* %base, i64 %val2
%res = getelementptr inbounds i8, <2 x i8*> %src, <2 x i64> %val
By swapping the index operands if the GEPs are in a loop, and %val is loop variant while %val2
is loop invariant.
This fix recreates new GEP instructions if the index operand swap would result in the type
of %src changing from vector to scalar, or vice versa.
Reviewers: sebpop, spatel
Reviewed By: sebpop
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45287
llvm-svn: 329331
There used to be a fold that would handle this case more generally,
but it was removed at rL73243 to fix PR4374:
https://bugs.llvm.org/show_bug.cgi?id=4374
llvm-svn: 329322
Using cstfp_pred_ty in the definition allows us to match vectors with undef elements.
This replicates the change for m_Not from D44076 / rL326823 and continues
towards making all pattern matchers allow undef elements in vectors.
llvm-svn: 329303
Roman Lebedev