The original commit ( fe1f3cfc2669 ) was reverted because it could
crash / assert when trying to fold a value that was replaced
by a constant. In that case, there might not be an entry for the
constant in the solver yet.
This version adds a check for that possibility along with tests to
exercise that pattern (they used to crash).
Original commit message:
This extends the transform added with D81756 to handle div/rem opcodes.
For example:
https://alive2.llvm.org/ce/z/cX6za6
This replicates part of what CVP already does, but the motivating example
from issue #57472 demonstrates a phase ordering problem - we convert
branches to select before CVP runs and miss the transform.
Differential Revision: https://reviews.llvm.org/D133198
This reverts commit fe1f3cfc2669aca387a45c8ce615b45c1db50fc6.
It looks like this commit breaks building llvm-test-suite.
To reproduce, run `opt -passes=ipsccp` on the IR below.
@g = internal global i32 256, align 4
define void @test() {
entry:
%0 = load i32, ptr @g, align 4
%div = sdiv i32 %0, undef
ret void
}
This extends the transform added with D81756 to handle div/rem opcodes.
For example:
https://alive2.llvm.org/ce/z/cX6za6
This replicates part of what CVP already does, but the motivating example
from issue #57472 demonstrates a phase ordering problem - we convert
branches to select before CVP runs and miss the transform.
Differential Revision: https://reviews.llvm.org/D133198
The legacy PM is deprecated, so update a bunch of lit tests running
opt to use the new PM syntax when specifying the pipeline.
In this patch focus has been put on test cases for ConstantMerge,
ConstraintElimination, CorrelatedValuePropagation, GlobalDCE,
GlobalOpt, SCCP, TailCallElim and PredicateInfo.
Differential Revision: https://reviews.llvm.org/D114516
Currently UREM & SREM on constant ranges produces overly pessimistic
results for single element constant ranges.
Delegate to APInt's implementation if both operands are single element
constant ranges. We already do something similar for other binary
operators, like binary AND.
Fixes PR49731.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D105115
For PHIs with multiple incoming values, we can improve precision by
using constant ranges for integers. We can over-approximate phis
by merging the incoming values.
Reviewers: davide, efriedma, mssimpso
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D71933
If one of the operands of a binary operator is a constant range, we can
use ConstantRange::binaryOp to approximate the result.
We still handle single element constant ranges as we did previously,
with ConstantExpr::get(), because ConstantRange::binaryOp still gives
worse results in a few cases for single element ranges.
Also note that we bail out early if any of the operands is still unknown.
Reviewers: davide, efriedma, mssimpso
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D71936
