Add an extra know to UnrollingPreferences to let backends control the
maximum budget for SCEV expansions.
This gives backends more fine-grained control on the cost of the runtime
checks for runtime unrolling.
PR: https://github.com/llvm/llvm-project/pull/118316
Preserve !alias.scope, !noalias and !mem.parallel_loop_access metadata
on the replacement instruction, if it does not move. In that case, the
program would be UB, if the aliasing property encoded in the metadata
does not hold. This makes use of the clarification re aliasing metadata
implying UB if the property does not hold: #116220
Same as #115868, but for !alias.scope, !noalias and
!mem.parallel_loop_access.
PR: https://github.com/llvm/llvm-project/pull/117716
This should act like range.
Previously ConstantRangeList assumed a 64-bit range. Now query from the
actual entries. This also means that the empty range has no bitwidth, so
move asserts to avoid checking the bitwidth of empty ranges.
This is a follow up of #96878 to support hoisting load/store from BBs
have the same predecessor, if load/store are the only instructions and
the branch is unpredictable, e.g.:
```
void test (int a, int *c, int *d) {
if (a)
*c = a;
else
*d = a;
}
```
Summary:
Consolidate the logic in a single function. We do an extra pass over
Instructions but this is necessary to untangle things and extract
metadata cloning in a future diff.
Test Plan:
```
$ ninja check-llvm-unit check-llvm
[211/213] Running the LLVM regression tests
Testing Time: 106.06s
Total Discovered Tests: 62601
Skipped : 17 (0.03%)
Unsupported : 2518 (4.02%)
Passed : 59911 (95.70%)
Expectedly Failed: 155 (0.25%)
[212/213] Running lit suite
Testing Time: 12.47s
Total Discovered Tests: 8474
Skipped: 17 (0.20%)
Passed : 8457 (99.80%)
```
Extracted from #109032 (commit 3) (there are more refactors and cleanups
in subsequent commits)
Preserve llvm.access.group metadata on the replacement instruction, if
it does not move. In that case, the program would be UB, if the parallel
property encoded in the metadata does not hold.
This matches the LangRef recently updated in #116220
PR https://github.com/llvm/llvm-project/pull/115868
Currently when we merge invokes as part of SimplifyCFG we apply a merge
of the invoke DILocations to the merged invoke. We also insert an
unconditional branch to the merged invoke at the positions previously
occupied by the original invokes; as this branch is part of the
substitution for the invoke it has replaced, we should propagate the
original invoke DebugLoc to it.
Relands 7ff3a9acd84654c9ec2939f45ba27f162ae7fbc3 after regenerating the
test case.
Supersedes the draft PR #94992, taking a different approach following
feedback:
* Lower in PreISelIntrinsicLowering
* Don't require that the number of bytes to set is a compile-time
constant
* Define llvm.memset_pattern rather than llvm.memset_pattern.inline
As discussed in the [RFC
thread](https://discourse.llvm.org/t/rfc-introducing-an-llvm-memset-pattern-inline-intrinsic/79496),
the intent is that the intrinsic will be lowered to loops, a sequence of
stores, or libcalls depending on the expected cost and availability of
libcalls on the target. Right now, there's just a single lowering path
that aims to handle all cases. My intent would be to follow up with
additional PRs that add additional optimisations when possible (e.g.
when libcalls are available, when arguments are known to be constant
etc).
This reverts commit 7ff3a9acd84654c9ec2939f45ba27f162ae7fbc3.
Recent scheduling changes means tests need to be re-generated. Reverting
to green while I do that.
I noticed that the two C functions emitted different IR:
```
int switch_duplicate_arms(int switch_val, int v, int w) {
switch (switch_val) {
default:
break;
case 0:
w = v;
break;
case 1:
w = v;
break;
}
return w;
}
int if_duplicate_arms(int switch_val, int v, int w) {
if (switch_val == 0)
w = v;
else if (switch_val == 1)
w = v;
return v0;
}
```
We generate IR that looks like this:
```
define i32 @switch_duplicate_arms(i32 %0, i32 %1, i32 %2, i32 %3) {
switch i32 %1, label %7 [
i32 0, label %5
i32 1, label %6
]
5:
br label %7
6:
br label %7
7:
%8 = phi i32 [ %3, %4 ], [ %2, %6 ], [ %2, %5 ]
ret i32 %8
}
define i32 @if_duplicate_arms(i32 %0, i32 %1, i32 %2, i32 %3) {
%5 = icmp ult i32 %1, 2
%6 = select i1 %5, i32 %2, i32 %3
ret i32 %6
}
```
For `switch_duplicate_arms`, taking case 0 and 1 are the same since %5
and %6
branch to the same location and the incoming values for %8 are the same
from
those blocks. We could remove one on the duplicate switch targets and
update
the switch with the single target.
On RISC-V, prior to this patch, we generate the following code:
```
switch_duplicate_arms:
li a4, 1
beq a1, a4, .LBB0_2
mv a0, a3
bnez a1, .LBB0_3
.LBB0_2:
mv a0, a2
.LBB0_3:
ret
if_duplicate_arms:
li a4, 2
mv a0, a2
bltu a1, a4, .LBB1_2
mv a0, a3
.LBB1_2:
ret
```
After this patch, the O3 code is optimized to the icmp + select pair,
which
gives us the same code gen as `if_duplicate_arms`, as desired. This
results
is one less branch instruction in the final assembly.
This may help with both code size and further switch simplification. I
found
that this patch causes no significant impact to spec2006/int/ref and
spec2017/intrate/ref.
---------
Co-authored-by: Min Hsu <min@myhsu.dev>
Supersedes the draft PR #94992, taking a different approach following
feedback:
* Lower in PreISelIntrinsicLowering
* Don't require that the number of bytes to set is a compile-time
constant
* Define llvm.memset_pattern rather than llvm.memset_pattern.inline
As discussed in the [RFC
thread](https://discourse.llvm.org/t/rfc-introducing-an-llvm-memset-pattern-inline-intrinsic/79496),
the intent is that the intrinsic will be lowered to loops, a sequence of
stores, or libcalls depending on the expected cost and availability of
libcalls on the target. Right now, there's just a single lowering path
that aims to handle all cases. My intent would be to follow up with
additional PRs that add additional optimisations when possible (e.g.
when libcalls are available, when arguments are known to be constant
etc).
`IRNormalizer` will reorder instructions. Thus, we need to invalidate
analyses. Done in cd500d28cba3177c213f2f2faf50f14ea56e230b. This should
resolve the [BuildBot
failure](https://github.com/llvm/llvm-project/pull/68176#issuecomment-2428243474).
---
Original PR: #68176
Original commit: 1295d2e6da2fe90f3b770ab1d35bf5caecd38bed
Reverted with: 8a12e0131f3d84b470fac63af042aa96a1b19f56
---
Add the llvm-canon tool. Description from the [original
PR](https://reviews.llvm.org/D66029#change-wZv3yOpDdxIu):
> Added a new llvm-canon tool which aims to transform LLVM Modules into
a canonical form by reordering and renaming instructions while
preserving the same semantics. This tool makes it easier to spot
semantic differences while diffing two modules which have undergone
different transformation passes.
The current version of this tool can:
- Reorder instructions within a function.
- Rename instructions based on the operands.
- Sort commutative operands.
This code was originally written by @michalpaszkowski and [submitted to
mainline
LLVM](14d358537f).
However, it was quickly
[reverted](335de55fa3)
to do BuildBot errors.
Michal presented his version of the tool in [LLVM-Canon: Shooting for
Clear Diffs](https://www.youtube.com/watch?v=c9WMijSOEUg).
@AidanGoldfarb and I ported the code to the new pass manager, added more
tests, and fixed some bugs related to PHI nodes that may have been the
root cause of the BuildBot errors that caused the patch to be reverted.
Additionally, we rewrote the implementation of instruction reordering to
fix cases where the original algorithm would break use-def chains.
Note that this is @AidanGoldfarb and I's first time submitting to LLVM.
Please liberally critique the PR!
CC @plotfi for initial review.
---------
Co-authored-by: Aidan <aidan.goldfarb@mail.mcgill.ca>
Reorganize the code into phases:
* Analyze/normalize
* Create extracted function prototype
* Generate the new function's implementation
* Generate call to new function
* Connect call to original function's CFG
The motivation is #114669 to optionally clone the selected code region
into the new function instead of moving it. The current structure made
it difficult to add such functionality since there was no obvious place
to do so, not made easier by some functions doing more than their name
suggests. For instance, constructFunction modifies code outside the
constructed function, but also function properties such as
setPersonalityFn are derived somewhere else. Another example is
emitCallAndSwitchStatement, which despite its name also inserts stores
for output parameters.
Many operations also implicitly depend on the order they are applied
which this patch tries to reduce. For instance, ExtractedFuncRetVals
becomes the list exit blocks which also defines the return value when
leaving via that block. It is computed early such that the new
function's return instructions and the switch can be generated
independently. Also, ExtractedFuncRetVals is combining the lists
ExitBlocks and OldTargets which were not always kept consistent with
each other or NumExitBlocks. The method recomputeExitBlocks() will
update it when necessary.
The coding style partially contradict the current coding standard. For
instance some local variable start with lower case letters. I updated
some, but not all occurrences to make the diff match at least some lines
as unchanged.
The patch [D96854](https://reviews.llvm.org/D96854) introduced some
confusion of function argument indexes this is fixed here as well, hence
the patch is not NFC anymore. Tested in modified CodeExtractorTest.cpp.
Patch [D121061](https://reviews.llvm.org/D121061) introduced
AllocationBlock, but not all allocas were inserted there.
Efectively includes the following fixes:
1. ce73b1672a
2. 4aaa925786
3. Missing allocas, still unfixed
Originally submitted as https://reviews.llvm.org/D115218
The expansion of a SCEVUnknown is trivial (it's just the wrapped value).
If we try to reuse an existing value it might be a more complex
expression that simplifies to the SCEVUnknown.
This is inspired by https://github.com/llvm/llvm-project/issues/114879,
because SCEVExpander replacing a constant with a phi node is just silly.
(I don't consider this a fix for that issue though.)
Note that PointerUnion::{is,get,dyn_cast} have been soft deprecated in
PointerUnion.h:
// FIXME: Replace the uses of is(), get() and dyn_cast() with
// isa<T>, cast<T> and the llvm::dyn_cast<T>
This patch fixes a simple error where as part of loop unrolling we
optimize conditional loop-exiting branches into unconditional branches
when we know that they will or won't exit the loop, but does not
propagate the source location of the original branch to the new one.
Found using https://github.com/llvm/llvm-project/pull/107279.
64-bit flat cmpxchg instructions do not work correctly for scratch
addresses, and need to be expanded as non-atomic.
Allow custom expansion of cmpxchg in AtomicExpand, as is
already the case for atomicrmw.
The code extractor tries to apply the names of source input and output
values to function arguments. Not all input and output values get added
as arguments: some are instead placed inside of a struct passed to the
function. The existing renaming code skipped trying to set these
struct-packed arguments names (as there is no corresponding function
argument to rename), but it still incremented the iterator over the
function arguments. This could result in dereferencing an end iterator
if struct-packed inputs/outputs preceded non-struct-packed
inputs/outputs.
This patch rewrites this loop to avoid the end iterator dereference.
This patch intersects attributes of two calls to avoid introducing UB.
It also skips incompatible call pairs in GVN/NewGVN. However, I cannot
provide negative tests for these changes.
Fixes https://github.com/llvm/llvm-project/issues/113997.
This patch adds basic support for `hypot`. Constant folding support will
be submitted in a subsequent patch.
Related issue: https://github.com/llvm/llvm-project/issues/113711
Note: It's my first time contributing to the LLVM with encouragement
from one of my friends, @fawdlstty. I learned a lot from
https://github.com/llvm/llvm-project/pull/99611, and thanks for that.
Note: I had created the same PR and merged
(https://github.com/llvm/llvm-project/pull/113724), but reverted caused
by the merging issue. (The CI issue happened in 3 A.M. at my timezone.
So, I need to fall asleep again after I replied about why issue
happened.) So, I rebased to the latest main branch and recreate the PR
and hope I won't have the third time to create the same PR.
I hope @arsenm can help me review the code again. I’m sorry for that.
Kenji Mouri
This patch is a part of step-by-step refactoring of CloneFunctionInto.
The goal is to extract reusable pieces out of it that will be later used
to optimize function cloning e.g. in coroutine processing.
Extracted from #109032 (commit 2)
The spec for llvm.experimental.convergence.entry says that is must be in
the entry block for a function, and must preceed any other convergent
operation. It does not have to be the first instruction in the entry
block.
Inlining assumes that the call to llvm.experimental.convergence.entry
will be the first instruction after any phi instructions. This commit
modifies inlining to search the entire block for the call.
# What
This PR renames the newly-introduced llvm attribute
`sanitize_realtime_unsafe` to `sanitize_realtime_blocking`. Likewise,
sibling variables such as `SanitizeRealtimeUnsafe` are renamed to
`SanitizeRealtimeBlocking` respectively. There are no other functional
changes.
# Why?
- There are a number of problems that can cause a function to be
real-time "unsafe",
- we wish to communicate what problems rtsan detects and *why* they're
unsafe, and
- a generic "unsafe" attribute is, in our opinion, too broad a net -
which may lead to future implementations that need extra contextual
information passed through them in order to communicate meaningful
reasons to users.
- We want to avoid this situation and make the runtime library boundary
API/ABI as simple as possible, and
- we believe that restricting the scope of attributes to names like
`sanitize_realtime_blocking` is an effective means of doing so.
We also feel that the symmetry between `[[clang::blocking]]` and
`sanitize_realtime_blocking` is easier to follow as a developer.
# Concerns
- I'm aware that the LLVM attribute `sanitize_realtime_unsafe` has been
part of the tree for a few weeks now (introduced here:
https://github.com/llvm/llvm-project/pull/106754). Given that it hasn't
been released in version 20 yet, am I correct in considering this to not
be a breaking change?
The IR lowering of memcpy/memmove intrinsics uses a target-specific type
for its load/store operations. So far, the loaded and stored addresses
are computed with GEPs based on this type. That is wrong if the
allocation size of the type differs from its store size: The width of
the accesses is determined by the store size, while the GEP stride is
determined by the allocation size. If the allocation size is greater
than the store size, some bytes are not copied/moved.
This patch changes the GEPs to use i8 addressing, with offsets based on
the type's store size. The correctness of the lowering therefore no
longer depends on the type's allocation size.
This is in support of PR #112332, which allows adjusting the memcpy loop
lowering type through a command line argument in the AMDGPU backend.
Add the llvm-canon tool. Description from the [original
PR](https://reviews.llvm.org/D66029#change-wZv3yOpDdxIu):
> Added a new llvm-canon tool which aims to transform LLVM Modules into
a canonical form by reordering and renaming instructions while
preserving the same semantics. This tool makes it easier to spot
semantic differences while diffing two modules which have undergone
different transformation passes.
The current version of this tool can:
- Reorder instructions within a function.
- Rename instructions based on the operands.
- Sort commutative operands.
This code was originally written by @michalpaszkowski and [submitted to
mainline
LLVM](14d358537f).
However, it was quickly
[reverted](335de55fa3)
to do BuildBot errors.
Michal presented his version of the tool in [LLVM-Canon: Shooting for
Clear Diffs](https://www.youtube.com/watch?v=c9WMijSOEUg).
@AidanGoldfarb and I ported the code to the new pass manager, added more
tests, and fixed some bugs related to PHI nodes that may have been the
root cause of the BuildBot errors that caused the patch to be reverted.
Additionally, we rewrote the implementation of instruction reordering to
fix cases where the original algorithm would break use-def chains.
Note that this is @AidanGoldfarb and I's first time submitting to LLVM.
Please liberally critique the PR!
CC @plotfi for initial review.
---------
Co-authored-by: Aidan <aidan.goldfarb@mail.mcgill.ca>
This patch adds basic support for `scalbln, scalblnf, scalblnl, scalbn,
scalbnf, scalbnl`. Constant folding support will be submitted in a
subsequent patch.
Related issue: <#112631>
