Currently, clang ignores the 0 initialisation in finite math
For example:
```
double f_prod = 0;
double arr[1000];
for (size_t i = 0; i < 1000; i++) {
f_prod *= arr[i];
}
```
Clang will ignore that `f_prod` is set to zero and it will generate assembly to iterate over the loop.
Reviewed By: fhahn, spatel
Differential Revision: https://reviews.llvm.org/D131672
We don't have a dominator tree in this pass, so we
can't bail out sooner by checking for unreachable
code, but this is a minimal fix for the example in
issue #56875.
If computeKnownBits encounters a phi node, and we fail to determine any known bits through direct analysis, see if the incoming value is part of a branch condition feeding the phi.
Handle cases where icmp(IncomingValue PRED Constant) is driving a branch instruction feeding that phi node - at the moment this only handles EQ/ULT/ULE predicate cases as they are the most straightforward to handle and most likely for branch-loop 'max upper bound' cases - we can extend this if/when necessary.
I investigated a more general icmp(LHS PRED RHS) KnownBits system, but the hard limits we put on value tracking depth through phi nodes meant that we were mainly catching constants anyhow.
Fixes the pointless vectorization in PR38280 / Issue #37628 (excessive unrolling still needs handling though)
Differential Revision: https://reviews.llvm.org/D131838
Currently, we try to vectorize values, feeding into stores, only if
slp-vectorize-hor-store option is provided. We can safely enable
vectorization of the value operand of a single store in the basic block,
if the operand value is used only in store.
It should enable extra vectorization and should not increase compile
time significantly.
Fixes https://github.com/llvm/llvm-project/issues/51320
Differential Revision: https://reviews.llvm.org/D131894
Previously we would only CSE constrained FP intrinsics in the default
floating point environment. Exception behavior of "strict" is still not
allowed since we are not allowed to remove any traps in that case.
There are no restrictions on CSE across function calls inside a function.
Differential Revision: https://reviews.llvm.org/D112256
This reverts commit 354fa0b480.
Returning as is. The patch was reverted due to a miscompile, but
this patch is not causing it. This patch made it possible to infer
some nuw flags in code guarded by `false` condition, and then someone
else to managed to propagate the flag from dead code outside.
Returning the patch to be able to reproduce the issue.
The basic patterns look like this:
https://alive2.llvm.org/ce/z/MDj9EC
The tests have a use of the overflow value too.
Otherwise, existing folds should reduce already.
This was noted as a missing IR fold in:
926e7312b2
Hopefully, this makes it easier to implement a backend
fix because we should get the same IR regardless of
whether the source used builtins or inline code.
We already support SGE, so the same logic should hold for SLE with
the LHS and RHS swapped.
I didn't see this in the wild. Just happened to walk past this code
and thought it was odd that it was asymmetric in what condition
codes it handled.
Reviewed By: spatel, reames
Differential Revision: https://reviews.llvm.org/D131805
This reverts commit 34ae308c73.
Our internal testing found a miscompile. Not sure if it's caused by
this patch or it revealed something else. Reverting while investigating.
(A | ?) | (A ^ B) --> (A | ?) | B
https://alive2.llvm.org/ce/z/dbNQw4
This extends the existing transform to peek through
another 'or' instruction for the common operand.
This is the underlying missing fold that should allow
issue #56711 and issue #57120 to reduce even more.
The value of the attribute is a size in bytes. It has the effect of
suppressing inlining of functions whose stacksizes exceed the given value.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D129904
Contextual knowledge may be used to prove invariance of some conditions.
For example, in this case:
```
; %len >= 0
guard(%iv = {start,+,1}<nuw> <s %len)
guard(%iv = {start,+,1}<nuw> <u %len)
```
the 2nd check always fails if `start` is negative and always passes otherwise.
It looks like there are more opportunities of this kind that are still to be
implemented in the future.
Differential Revision: https://reviews.llvm.org/D129753
Reviewed By: apilipenko
Closing https://github.com/llvm/llvm-project/issues/56329
The problem happens when we try to simplify the suspend points. We might
break the assumption that the final suspend lives in the last slot of
Shape.CoroSuspends. This patch tries to main the assumption and fixes
the problem.
Coroutine splitting is not possible if the one-to-one mapping between the two is
lost. Every suspend point must have a matching continuation function
pointer.
rdar://98404664
Differential Revision: https://reviews.llvm.org/D131684
We manage to iteratively achieve this result with no extra
uses, and the reassociate pass can also do this, but this
pattern falls through the cracks in the example from
issue #57053.
Another ticket split out of D107285, this extends the optimization
of 0.0 - -X to just X when using constrained intrinsics and the
optimization is allowed.
If the negation of X is done with fsub then the match fails because of
the lack of IR Matcher support for constrained intrinsics.
While I'm here, remove some TODO notices since the work is no longer
planned.
Differential Revision: https://reviews.llvm.org/D131607
Expand TypePromotion pass to try to promote PHI-nodes in loops that are the
operand of a ZExt, using the ZExt's result type to determine the Promote Width.
Differential Revision: https://reviews.llvm.org/D111237
Zain Jaffal