Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: llvmorg-21-init, llvmorg-19.1.7, llvmorg-19.1.6, llvmorg-19.1.5, llvmorg-19.1.4
# 38fffa63 06-Nov-2024 Paul Walker <paul.walker@arm.com>

[LLVM][IR] Use splat syntax when printing Constant[Data]Vector. (#112548)


Revision tags: llvmorg-19.1.3, llvmorg-19.1.2, llvmorg-19.1.1, llvmorg-19.1.0, llvmorg-19.1.0-rc4, llvmorg-19.1.0-rc3, llvmorg-19.1.0-rc2, llvmorg-19.1.0-rc1, llvmorg-20-init, llvmorg-18.1.8, llvmorg-18.1.7, llvmorg-18.1.6, llvmorg-18.1.5
# d9a5aa8e 17-Apr-2024 Nikita Popov <npopov@redhat.com>

[PatternMatch] Do not accept undef elements in m_AllOnes() and friends (#88217)

Change all the cstval_pred_ty based PatternMatch helpers (things like
m_AllOnes and m_Zero) to only allow poison elem

[PatternMatch] Do not accept undef elements in m_AllOnes() and friends (#88217)

Change all the cstval_pred_ty based PatternMatch helpers (things like
m_AllOnes and m_Zero) to only allow poison elements inside vector
splats, not undef elements.

Historically, we used to represent non-demanded elements in vectors
using undef. Nowadays, we use poison instead. As such, I believe that
support for undef in vector splats is no longer useful.

At the same time, while poison splat elements are pretty much always
safe to ignore, this is not generally the case for undef elements. We
have existing miscompiles in our tests due to this (see the
masked-merge-*.ll tests changed here) and it's easy to miss such cases
in the future, now that we write tests using poison instead of undef
elements.

I think overall, keeping support for undef elements no longer makes
sense, and we should drop it. Once this is done consistently, I think we
may also consider allowing poison in m_APInt by default, as doing that
change is much less risky than doing the same with undef.

This change involves a substantial amount of test changes. For most
tests, I've just replaced undef with poison, as I don't think there is
value in retaining both. For some tests (where the distinction between
undef and poison is important), I've duplicated tests.

show more ...


Revision tags: llvmorg-18.1.4, llvmorg-18.1.3, llvmorg-18.1.2, llvmorg-18.1.1, llvmorg-18.1.0, llvmorg-18.1.0-rc4, llvmorg-18.1.0-rc3
# 79ce9331 13-Feb-2024 Noah Goldstein <goldstein.w.n@gmail.com>

[InstCombine] Extend `(lshr/shl (shl/lshr -1, x), x)` -> `(lshr/shl -1, x)` for multi-use

We previously did this iff the inner `(shl/lshr -1, x)` was
one-use. No instructions are added even if the i

[InstCombine] Extend `(lshr/shl (shl/lshr -1, x), x)` -> `(lshr/shl -1, x)` for multi-use

We previously did this iff the inner `(shl/lshr -1, x)` was
one-use. No instructions are added even if the inner `(shl/lshr -1,
x)` is multi-use and this canonicalization both makes the resulting
instruction easier to analyze and shrinks its dependency chain.

Closes #81576

show more ...


Revision tags: llvmorg-18.1.0-rc2, llvmorg-18.1.0-rc1, llvmorg-19-init, llvmorg-17.0.6
# 6da4ecdf 18-Nov-2023 Yingwei Zheng <dtcxzyw2333@gmail.com>

[InstCombine] Infer shift flags with unknown shamt (#72535)

Alive2: https://alive2.llvm.org/ce/z/82Wr3q

Related patch:
https://github.com/llvm/llvm-project/commit/2dd52b4527667837cc525aa48435ab5

[InstCombine] Infer shift flags with unknown shamt (#72535)

Alive2: https://alive2.llvm.org/ce/z/82Wr3q

Related patch:
https://github.com/llvm/llvm-project/commit/2dd52b4527667837cc525aa48435ab5cbfa30a0b

show more ...


# e8fe15cc 16-Nov-2023 Yingwei Zheng <dtcxzyw2333@gmail.com>

[InstCombine] Add exact flags for ext idiom `shr (shl X, Y), Y` (#72483)

This patch adds exact flags for sext/zext idiom `shr (shl X, Y), Y`.
Alive2: https://alive2.llvm.org/ce/z/xYFpfB

We can g

[InstCombine] Add exact flags for ext idiom `shr (shl X, Y), Y` (#72483)

This patch adds exact flags for sext/zext idiom `shr (shl X, Y), Y`.
Alive2: https://alive2.llvm.org/ce/z/xYFpfB

We can generalize it to handle pattern `shr (shl X, Y), Z` with `Y u>=
Z` (e.g., non-splat vectors). But I don't think it's worth the effort.

This missed optimization is discovered with the help of
https://github.com/AliveToolkit/alive2/pull/962.

show more ...


Revision tags: llvmorg-17.0.5, llvmorg-17.0.4, llvmorg-17.0.3, llvmorg-17.0.2, llvmorg-17.0.1, llvmorg-17.0.0, llvmorg-17.0.0-rc4, llvmorg-17.0.0-rc3, llvmorg-17.0.0-rc2, llvmorg-17.0.0-rc1, llvmorg-18-init, llvmorg-16.0.6, llvmorg-16.0.5, llvmorg-16.0.4, llvmorg-16.0.3, llvmorg-16.0.2, llvmorg-16.0.1, llvmorg-16.0.0, llvmorg-16.0.0-rc4, llvmorg-16.0.0-rc3, llvmorg-16.0.0-rc2, llvmorg-16.0.0-rc1, llvmorg-17-init, llvmorg-15.0.7, llvmorg-15.0.6, llvmorg-15.0.5, llvmorg-15.0.4, llvmorg-15.0.3, working, llvmorg-15.0.2, llvmorg-15.0.1, llvmorg-15.0.0, llvmorg-15.0.0-rc3, llvmorg-15.0.0-rc2, llvmorg-15.0.0-rc1, llvmorg-16-init, llvmorg-14.0.6, llvmorg-14.0.5, llvmorg-14.0.4, llvmorg-14.0.3, llvmorg-14.0.2, llvmorg-14.0.1, llvmorg-14.0.0, llvmorg-14.0.0-rc4, llvmorg-14.0.0-rc3, llvmorg-14.0.0-rc2, llvmorg-14.0.0-rc1
# acdc419c 04-Feb-2022 Bjorn Pettersson <bjorn.a.pettersson@ericsson.com>

[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://r

[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://reviews.llvm.org/D119081

show more ...


Revision tags: llvmorg-15-init, llvmorg-13.0.1, llvmorg-13.0.1-rc3, llvmorg-13.0.1-rc2, llvmorg-13.0.1-rc1, llvmorg-13.0.0, llvmorg-13.0.0-rc4, llvmorg-13.0.0-rc3, llvmorg-13.0.0-rc2, llvmorg-13.0.0-rc1, llvmorg-14-init, llvmorg-12.0.1, llvmorg-12.0.1-rc4, llvmorg-12.0.1-rc3, llvmorg-12.0.1-rc2, llvmorg-12.0.1-rc1, llvmorg-12.0.0, llvmorg-12.0.0-rc5, llvmorg-12.0.0-rc4, llvmorg-12.0.0-rc3, llvmorg-12.0.0-rc2, llvmorg-11.1.0, llvmorg-11.1.0-rc3, llvmorg-12.0.0-rc1, llvmorg-13-init, llvmorg-11.1.0-rc2, llvmorg-11.1.0-rc1, llvmorg-11.0.1, llvmorg-11.0.1-rc2
# 395607af 28-Nov-2020 Juneyoung Lee <aqjune@gmail.com>

Reapply [ConstantFold] Fold more operations to poison

This was reverted to mitigate mitigate miscompiles caused by
the logical and/or to bitwise and/or fold. Reapply it now that
the underlying issue

Reapply [ConstantFold] Fold more operations to poison

This was reverted to mitigate mitigate miscompiles caused by
the logical and/or to bitwise and/or fold. Reapply it now that
the underlying issue has been fixed by D101191.

-----

This patch folds more operations to poison.

Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fold to poison when raising UB)

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D92270

show more ...


# 06829034 03-Feb-2021 Juneyoung Lee <aqjune@gmail.com>

Revert "[ConstantFold] Fold more operations to poison"

This reverts commit 53040a968dc2ff20931661e55f05da2ef8b964a0 due to its
bad interaction with select i1 -> and/or i1 transformation.

This fixes

Revert "[ConstantFold] Fold more operations to poison"

This reverts commit 53040a968dc2ff20931661e55f05da2ef8b964a0 due to its
bad interaction with select i1 -> and/or i1 transformation.

This fixes:
https://bugs.llvm.org/show_bug.cgi?id=49005
https://bugs.llvm.org/show_bug.cgi?id=48435

show more ...


# 53040a96 28-Nov-2020 Juneyoung Lee <aqjune@gmail.com>

[ConstantFold] Fold more operations to poison

This patch folds more operations to poison.

Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fol

[ConstantFold] Fold more operations to poison

This patch folds more operations to poison.

Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fold to poison when raising UB)

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D92270

show more ...


Revision tags: llvmorg-11.0.1-rc1, llvmorg-11.0.0, llvmorg-11.0.0-rc6, llvmorg-11.0.0-rc5
# ee34d9b2 29-Sep-2020 Sanjay Patel <spatel@rotateright.com>

[InstCombine] use redirect of input file in regression tests; NFC

This is a repeat of 1880092722 from 2009. We should have less risk
of hitting bugs at this point because we auto-generate positive C

[InstCombine] use redirect of input file in regression tests; NFC

This is a repeat of 1880092722 from 2009. We should have less risk
of hitting bugs at this point because we auto-generate positive CHECK
lines only, but this makes things consistent.

Copying the original commit msg:
"Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename."

show more ...


Revision tags: llvmorg-11.0.0-rc4, llvmorg-11.0.0-rc3, llvmorg-11.0.0-rc2, llvmorg-11.0.0-rc1, llvmorg-12-init, llvmorg-10.0.1, llvmorg-10.0.1-rc4, llvmorg-10.0.1-rc3, llvmorg-10.0.1-rc2, llvmorg-10.0.1-rc1, llvmorg-10.0.0, llvmorg-10.0.0-rc6, llvmorg-10.0.0-rc5, llvmorg-10.0.0-rc4, llvmorg-10.0.0-rc3, llvmorg-10.0.0-rc2, llvmorg-10.0.0-rc1, llvmorg-11-init, llvmorg-9.0.1, llvmorg-9.0.1-rc3, llvmorg-9.0.1-rc2, llvmorg-9.0.1-rc1
# c3b394ff 07-Oct-2019 Roman Lebedev <lebedev.ri@gmail.com>

[InstCombine] dropRedundantMaskingOfLeftShiftInput(): propagate undef shift amounts

Summary:
When we do `ConstantExpr::getZExt()`, that "extends" `undef` to `0`,
which means that for patterns a/b we

[InstCombine] dropRedundantMaskingOfLeftShiftInput(): propagate undef shift amounts

Summary:
When we do `ConstantExpr::getZExt()`, that "extends" `undef` to `0`,
which means that for patterns a/b we'd assume that we must not produce
any bits for that channel, while in reality we simply didn't care
about that channel - i.e. we don't need to mask it.

Reviewers: spatel

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68239

llvm-svn: 373960

show more ...


# 0205be8f 30-Sep-2019 Roman Lebedev <lebedev.ri@gmail.com>

[NFC][InstCombine] Redundant-left-shift-input-masking: add some more undef tests

llvm-svn: 373248


# 0a51e1f6 23-Sep-2019 Roman Lebedev <lebedev.ri@gmail.com>

[InstCombine] dropRedundantMaskingOfLeftShiftInput(): pat. c/d/e with mask (PR42563)

Summary:
If we have a pattern `(x & (-1 >> maskNbits)) << shiftNbits`,
we already know (have a fold) that will dr

[InstCombine] dropRedundantMaskingOfLeftShiftInput(): pat. c/d/e with mask (PR42563)

Summary:
If we have a pattern `(x & (-1 >> maskNbits)) << shiftNbits`,
we already know (have a fold) that will drop the `& (-1 >> maskNbits)`
mask iff `(shiftNbits-maskNbits) s>= 0` (i.e. `shiftNbits u>= maskNbits`).

So even if `(shiftNbits-maskNbits) s< 0`, we can still
fold, we will just need to apply a **constant** mask afterwards:
```
Name: c, normal+mask
%t0 = lshr i32 -1, C1
%t1 = and i32 %t0, %x
%r = shl i32 %t1, C2
=>
%n0 = shl i32 %x, C2
%n1 = i32 ((-(C2-C1))+32)
%n2 = zext i32 %n1 to i64
%n3 = lshr i64 -1, %n2
%n4 = trunc i64 %n3 to i32
%r = and i32 %n0, %n4
```
https://rise4fun.com/Alive/gslRa

Naturally, old `%masked` will have to be one-use.
This is not valid for pattern f - where "masking" is done via `ashr`.

https://bugs.llvm.org/show_bug.cgi?id=42563

Reviewers: spatel, nikic, xbolva00

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67725

llvm-svn: 372630

show more ...


# 8b719a3b 18-Sep-2019 Roman Lebedev <lebedev.ri@gmail.com>

[NFC][InstCombine] More tests for PR42563 "Dropping pointless masking before left shift"

For patterns c/d/e we too can deal with the pattern even if we can't
just drop the mask, we can just apply it

[NFC][InstCombine] More tests for PR42563 "Dropping pointless masking before left shift"

For patterns c/d/e we too can deal with the pattern even if we can't
just drop the mask, we can just apply it afterwars:
https://rise4fun.com/Alive/gslRa

llvm-svn: 372244

show more ...