1296 Commits

Author SHA1 Message Date
Joshua Cao
cb9f1aadda [ValueTracking] Implied conditions for lshr
`V1 >> V2 u<= V1` for any V1, V2

This works for lshr and any div's that are changed to lshr's

This fixes issues in clang and rustc:
https://github.com/llvm/llvm-project/issues/62441
https://github.com/rust-lang/rust/issues/110971

Reviewed By: goldstein.w.n

Differential Revision: https://reviews.llvm.org/D151541
2023-06-06 21:06:22 -07:00
Joshua Cao
f23b4faaff [InstSimplify] Add tests for shl implied conditions 2023-06-06 21:06:22 -07:00
luxufan
1ac99bc452 [InstSimplify] Simplify select i1 ConstExpr, i1 true, i1 false to ConstExpr
`select i1 non-const, i1 true, i1 false` has been optimized to
`non-const`. There is no reason that we can not optimize `select i1
ConstExpr, i1 true, i1 false` to `ConstExpr`.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D151631
2023-06-03 15:09:00 +08:00
Noah Goldstein
2622b2f409 [ValueTracking] Use select condition to help determine if select is non-zero
In `select c, x, y` the condition `c` dominates the resulting `x` or
`y` chosen by the `select`. This adds logic to `isKnownNonZero` to try
and use the `icmp` for the `c` condition to see if it implies the
select `x` or `y` are known non-zero.

For example in:
    ```
    %c = icmp ugt i8 %x, %C
    %r = select i1 %c, i8 %x, i8 %y
    ```
    The true arm of select `%x` is non-zero (when "returned" by the
    `select`) because `%c` being true implies `%x` is non-zero.

Alive2 Links (with `x {pred} C`):
    - EQ  iff `C != 0`:
        - https://alive2.llvm.org/ce/z/umLabn
    - NE  iff `C == 0`:
        - https://alive2.llvm.org/ce/z/DQvy8Y
    - UGT [always]:
        - https://alive2.llvm.org/ce/z/HBkjgQ
    - UGE iff `C != 0`:
        - https://alive2.llvm.org/ce/z/LDNifB
    - SGT iff `C s>= 0`:
        - https://alive2.llvm.org/ce/z/QzWDj3
    - SGE iff `C s> 0`:
        - https://alive2.llvm.org/ce/z/rR4g3D
    - SLT iff `C s<= 0`:
        - https://alive2.llvm.org/ce/z/uysayx
    - SLE iff `C s< 0`:
        - https://alive2.llvm.org/ce/z/2jYc7e

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D147900
2023-05-23 13:52:40 -05:00
Matt Arsenault
4023ca1292 Reapply "InstSimplify: Pass AssumptionCache to isKnownNeverInfinity"
This reverts commit 481191b0a8318e55ce467e983d78d2141e827db1.
2023-05-23 08:48:25 +01:00
Matt Arsenault
c21f1feed3 ValueTracking: Drop rounding mode check for constrained_sqrt in CannotBeNegativeZero
The only value that can produce -0 is exactly -0, no rounding is involved. If the
denormal mode has flushed denormal inputs, a negative value could produce -0.
The constrained intrinsics do not track the denormal mode, and this is just
generally broken in the current set of FP predicates. The move to computeKnownFPClass
will address some of these issues.
2023-05-22 10:49:10 +01:00
Matt Arsenault
15bcb9a697 ValueTracking: Add some regression tests for fabs handling in computeKnownFPClass 2023-05-22 10:33:10 +01:00
Matt Arsenault
6f0344f76a ValueTracking: Add baseline tests for some assume handling 2023-05-19 22:44:12 +01:00
Alina Sbirlea
481191b0a8 Revert "InstSimplify: Pass AssumptionCache to isKnownNeverInfinity"
This reverts commit 0012b94a4e8e0c757ef0adcd68fb61bb0318b26c.
Reverting due to test failures introduced by 73925ef8b0eacc6792f0e3ea21a3e6d51f5ee8b0
Updated floating-point-compare.ll to keep the assume declaration.
2023-05-18 23:31:50 -07:00
Matt Arsenault
c9bbc64eeb InstSimplify: Pass AssumptionCache through fcmp ord/uno simplification 2023-05-19 00:48:04 +01:00
Matt Arsenault
84e64d9bee InstSimplify: Pass AssumptionCache to isKnownNeverNaN queries 2023-05-19 00:48:03 +01:00
Matt Arsenault
b42ee1d6c3 InstSimplify: Pass AssumptionCache through more isKnownNeverNaN queries 2023-05-19 00:48:03 +01:00
Matt Arsenault
0012b94a4e InstSimplify: Pass AssumptionCache to isKnownNeverInfinity
Makes these cases work with assumes.
2023-05-19 00:48:03 +01:00
Matt Arsenault
07365f4a40 InstSimplify: Combine computeKnownFPClass calls and pass AssumptionCache 2023-05-18 23:29:47 +01:00
Tobias Hieta
f84bac329b
[NFC][Py Reformat] Reformat lit.local.cfg python files in llvm
This is a follow-up to b71edfaa4ec3c998aadb35255ce2f60bba2940b0
since I forgot the lit.local.cfg files in that one.

Reformatting is done with `black`.

If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.

If you run into any problems, post to discourse about it and
we will try to help.

RFC Thread below:

https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style

Reviewed By: barannikov88, kwk

Differential Revision: https://reviews.llvm.org/D150762
2023-05-17 17:03:15 +02:00
Zhongyunde
cd87fe0c8b [Instsimplfy] X == Y ? 0 : X ^ Y --> X ^ Y
Alive2: https://alive2.llvm.org/ce/z/cykffE
Fixes: https://github.com/llvm/llvm-project/issues/62753

Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D150750
2023-05-17 18:36:39 +08:00
Nikita Popov
9b7616856c [ValueTracking] Fix i1 abs range (PR62760)
For i1 operations, we may end up returning an empty range instead
of a full one. Make sure to use the getNonEmpty constructor.

Fixes https://github.com/llvm/llvm-project/issues/62760.
2023-05-17 12:31:13 +02:00
Nikita Popov
7d9f03f4d8 [InstSimplify] Add tests for PR62760 (NFC) 2023-05-17 12:31:13 +02:00
khei4
0d67d9aeda [ConstantFolding] fold integer bitwidth is greater than 63, and not multiple of 8 variables
Differential Revision: https://reviews.llvm.org/D150422
2023-05-17 11:09:18 +09:00
Jun Zhang
a47b56f4ef
[Instsimplfy] X == Y ? 0 : X - Y --> X - Y
Alive2: https://alive2.llvm.org/ce/z/rPN1GB
Fixes: https://github.com/llvm/llvm-project/issues/62238

Depends on D150377

Signed-off-by: Jun Zhang <jun@junz.org>

Differential Revision: https://reviews.llvm.org/D150378
2023-05-16 19:15:47 +08:00
Jun Zhang
ba3dbcc779
Add baseline tests for PR62238
Differential Revision: https://reviews.llvm.org/D150377

Signed-off-by: Jun Zhang <jun@junz.org>
2023-05-16 19:15:30 +08:00
Siyuan Zhu
edcdc81e2b [ValueTracking] add UGT/UGE and SGT/SGE in isImpliedCondOperands
Partially `fix` https://github.com/llvm/llvm-project/issues/62441.

Extend isImpliedCondOperands() to handle ugt/uge and sgt/sge predicates.

alive2 proof: https://alive2.llvm.org/ce/z/jLFDAv and
https://alive2.llvm.org/ce/z/Z8idUd

Differential Revision: https://reviews.llvm.org/D149510
2023-05-04 16:59:07 +02:00
Siyuan Zhu
2444fb93e6 [InstSimplify] Test case for icmp imply (NFC)
ugt/uge/sgt/sge test for the extension to isImpliedCondOperands
case from issue 62441 and 61393:
(X >> Z) <=(u) Y ==> X <=(to u) Y and (X > Y +_{nuw} 1) ==> X != Y

Differential Revision: https://reviews.llvm.org/D149512
2023-05-04 16:57:38 +02:00
ManuelJBrito
853d212e32 [InstSimplify] Update to handle new shufflevector semantics
Simplifying poison mask elements yields poison values.

Differential Revision: https://reviews.llvm.org/D149544
2023-05-03 21:31:19 +01:00
Matt Arsenault
bc37be1855 LangRef: Add "dynamic" option to "denormal-fp-math"
This is stricter than the default "ieee", and should probably be the
default. This patch leaves the default alone. I can change this in a
future patch.

There are non-reversible transforms I would like to perform which are
legal under IEEE denormal handling, but illegal with flushing zero
behavior. Namely, conversions between llvm.is.fpclass and fcmp with
zeroes.

Under "ieee" handling, it is legal to translate between
llvm.is.fpclass(x, fcZero) and fcmp x, 0.

Under "preserve-sign" handling, it is legal to translate between
llvm.is.fpclass(x, fcSubnormal|fcZero) and fcmp x, 0.

I would like to compile and distribute some math library functions in
a mode where it's callable from code with and without denormals
enabled, which requires not changing the compares with denormals or
zeroes.

If an IEEE function transforms an llvm.is.fpclass call into an fcmp 0,
it is no longer possible to call the function from code with denormals
enabled, or write an optimization to move the function into a denormal
flushing mode. For the original function, if x was a denormal, the
class would evaluate to false. If the function compiled with denormal
handling was converted to or called from a preserve-sign function, the
fcmp now evaluates to true.

This could also be of use for strictfp handling, where code may be
changing the denormal mode.

Alternative name could be "unknown".

Replaces the old AMDGPU custom inlining logic with more conservative
logic which tries to permit inlining for callees with dynamic handling
and avoids inlining other mismatched modes.
2023-04-29 08:44:59 -04:00
ManuelJBrito
8b56da5e9f [IR] Change shufflevector undef mask to poison
With this patch an undefined mask in a shufflevector will be printed as poison.
This change is done to support the new shufflevector semantics
for undefined mask elements.

Differential Revision: https://reviews.llvm.org/D149210
2023-04-27 14:41:10 +01:00
Serguei Katkov
faf8407aec [InstSimplify] Extend handlng of fp min/max.
Add support the cases like
  m(m(X,Y),m'(X,Y)) => m(X,Y)
where m is one of maxnum, minnum, maximum, minimum and
m' is m or inverse of m.

alive2 correctness check:
maxnum(maxnum,maxnum) https://alive2.llvm.org/ce/z/kSyAzo
maxnum(maxnum,minnum) https://alive2.llvm.org/ce/z/Vra8j2
minnum(minnum,minnum) https://alive2.llvm.org/ce/z/B6h-hW
minnum(minnum,maxnum) https://alive2.llvm.org/ce/z/rG2u_b
maximum(maximum,maximum) https://alive2.llvm.org/ce/z/N2nevY
maximum(maximum,minimum) https://alive2.llvm.org/ce/z/23RFcP
minimum(minimum,minimum) https://alive2.llvm.org/ce/z/spHZ-U
minimum(minimum,maximum) https://alive2.llvm.org/ce/z/Aa-VE8

Reviewed By: dantrushin, RKSimon
Differential Revision: https://reviews.llvm.org/D147137
2023-04-27 10:45:27 +07:00
Zhongyunde
f9478f729e [InstSimplify] with logical ops: (X & Y) == -1 ? X : -1 --> -1
Use simplifySelectWithICmpEq to handle the implied equalities from the icmp-and,
then both of ICMP_NE and ICMP_EQ will be addressed including vector type.
    (X & Y) == -1 ?  X : -1 --> -1 (commuted 2 ways)
    (X & Y) != -1 ? -1 :  X --> -1 (commuted 2 ways)
This is a supplement to the icmp-or scenario on D148986.

Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D149229
2023-04-26 15:53:02 +08:00
Zhongyunde
0f28cecf1b [tests] precommit tests for D149229
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D149230
2023-04-26 15:50:30 +08:00
Zhongyunde
b80f31c48d [InstSimplify] with logical ops: (X | Y) ? 0 : X --> 0
Use simplifySelectWithICmpEq to handle the implied equalities from the icmp-or,
then both of ICMP_NE and ICMP_EQ will be addressed
  (X | Y) == 0 ?  X : 0 --> 0 (commuted 2 ways)
  (X | Y) != 0 ?  0 : X --> 0 (commuted 2 ways)
Fixes https://github.com/llvm/llvm-project/issues/62263

Reviewed By: nikic, RKSimon
Differential Revision: https://reviews.llvm.org/D148986
2023-04-25 21:51:41 +08:00
Nikita Popov
9d92f479c3 Reapply [InstSimplify] Support all instructions in simplifyWithOpReplaced()
Relative to the previous attempt, this includes a bailout for phi
nodes, whose arguments might refer to a previous cycle iteration.

We did not hit this before by a fortunate deficiency of the
ConstantFoldInstOperands() API, which doesn't handle phi nodes,
unlike ConstantFoldInstruction().

-----

Instead of hardcoding a few instruction kinds, use the generic
interface now that we have it.

The primary effect of this is that intrinsics are now supported.

It's worth noting that this is still limited in that it does not
support vectors, so we can't remove e.g. existing fshl special
cases.
2023-04-25 15:45:32 +02:00
Zhongyunde
e50b4ea8be [tests] precommit tests for D148986
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D149115
2023-04-25 21:43:22 +08:00
Nikita Popov
beb16abf31 [InstSimplify] Add test for select op replacement in phi (NFC) 2023-04-25 15:41:07 +02:00
Nikita Popov
4d05d846ec Revert "[InstSimplify] Support all instructions in simplifyWithOpReplaced()"
This reverts commit 3e3e41b263f4aa76a5a36f02727827bebccdbf07.

This appears to cause a stage2 miscompile of llvm-profgen.
2023-04-24 16:51:54 +02:00
Nikita Popov
3e3e41b263 [InstSimplify] Support all instructions in simplifyWithOpReplaced()
Instead of hardcoding a few instruction kinds, use the generic
interface now that we have it.

The primary effect of this is that intrinsics are now supported.

It's worth noting that this is still limited in that it does not
support vectors, so we can't remove e.g. existing fshl special
cases.
2023-04-24 15:22:20 +02:00
Nikita Popov
d6ee8f3181 [InstSimplify] Add additional test for select icmp of umin (NFC)
This is a representative test for the simplifyWithOpReplaced()
fold on intrinsics.
2023-04-24 15:09:33 +02:00
Jay Foad
593e25ffae [Vectorize] Fix vectorization, scalarization and folding of llvm.is.fpclass
llvm.is.fpclass is different from other vectorizable intrinsics in that
it is overloaded on an argument type, not on the return type.

Differential Revision: https://reviews.llvm.org/D148905
2023-04-24 13:42:08 +01:00
Siyuan Zhu
946b326803 [InstSimplify] sdiv a (1 srem b) --> a
Extend the existing fold for division by zero or one to use known
bits, so it catches additional patterns like division by
(1 srem b).

Fixes https://github.com/llvm/llvm-project/issues/62163.

Differential Revision: https://reviews.llvm.org/D149001
2023-04-24 14:37:07 +02:00
Siyuan Zhu
2eb72fa917 [InstSimplify] Test case for D149001 (NFC)
Differential Revision: https://reviews.llvm.org/D149012
2023-04-24 14:28:41 +02:00
Jay Foad
2b81ec3265 Revert "[ConstantFolding] Fix crash when folding vector llvm.is.fpclass"
This reverts commit 5fc6425fb6c77052a26cf0cf7b886449fabe1af4.

It is reported to cause other crashes that require a larger fix.
2023-04-21 14:01:06 +01:00
Jay Foad
5fc6425fb6 [ConstantFolding] Fix crash when folding vector llvm.is.fpclass
Differential Revision: https://reviews.llvm.org/D148803
2023-04-20 15:34:50 +01:00
Serguei Katkov
7ae436d891 [InstSimplify] Update tests for max(min,max) to cover more types. 2023-04-19 12:05:29 +07:00
Congcong Cai
ee3a260e78 [InstCombine] support fold select(X|Y,X|Y,X) to X|Y
Fixed: https://github.com/llvm/llvm-project/issues/62113
Add addtional check in `visitSelectInst` to:
1. match `select(X|Y==0, X, X|Y)` and replaced with `X|Y`
2. match `select(X&Y==-1, X, X&Y)` and replaced with `X&Y`

alive proof:
https://alive2.llvm.org/ce/z/4qHmv-
https://alive2.llvm.org/ce/z/c2MBGy

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D148275
2023-04-17 22:07:01 +02:00
Congcong Cai
beefca7239 [InstCombine][NFC] Add tests for simplifying select(X|Y,X|Y,X) to X|Y
Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D148562
2023-04-17 22:06:45 +02:00
Peixin Qiao
b7e000d8c9 [InstSimplify] Precommit a test
This patch precommits a test for:

https://reviews.llvm.org/D148420
2023-04-17 21:55:51 +08:00
chenglin.bi
2a7e1a132d [InstSimplify] Precommit tests for dominate conditions are not single predecessor; NFC 2023-04-15 16:12:31 +08:00
Matt Arsenault
ba19fb3bd7 InstSimplify: Regenerate checks in a test
For some reason this was missing the "Assertions have been autogenerated"
comment so were getting spurious diffs in a future change.
2023-04-13 12:05:05 -04:00
Serguei Katkov
17398b06fd [InstSimplify] Pre-land test for fp min/max optimization. 2023-04-05 12:09:53 +07:00
Noah Goldstein
87c97d052c [InstSimplify] Extend simplifications for (icmp ({z|s}ext X), C) where C is vector
Previous logic only applied for `ConstantInt` which misses all vector
cases. New code works for splat/non-splat vectors as well. No change
to the underlying simplifications.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D147275
2023-04-03 11:04:57 -05:00
Noah Goldstein
0ac84ab1cb [InstSimplify] Add tests for simplifying (icmp ({z|s}ext X), C) where C is vector; NFC
Differential Revision: https://reviews.llvm.org/D147274
2023-04-03 11:04:51 -05:00