Commit Graph

453 Commits

Author SHA1 Message Date
Nikita Popov e638a290f7 [ConstantFold] Delay fetching pointer element type
Don't do this while stipping pointer casts, instead fetch it at
the end. This improves compatibility with opaque pointers for the
case where the base object is not opaque.
2021-06-22 15:51:00 +02:00
Nikita Popov 04395fd6cb [ConstantFolding] Separate conditions in GEP evaluation (NFC)
Handle to gep p, 0-v case separately, and not as part of the loop
that ensures all indices are constant integers. Those two things
are not really related.
2021-06-22 11:14:47 +02:00
Serge Pavlov 8ff36aab69 [ConstantFolding] Enable folding of min/max/copysign for all floats
Previously such folding was enabled for half, float and double values
only. With this change it is allowed for other floating point values
also.

Differential Revision: https://reviews.llvm.org/D103956
2021-06-10 11:57:51 +07:00
Arthur Eubanks 8961293851 [OpaquePtr] Create API to make a copy of a PointerType with some address space
Some existing places use getPointerElementType() to create a copy of a
pointer type with some new address space.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D103429
2021-06-01 16:52:32 -07:00
Yang Fan f2264ebb08
[ConstantFolding] Fix -Wunused-variable warning (NFC)
GCC warning:
```
/llvm-project/llvm/lib/Analysis/ConstantFolding.cpp: In function ‘llvm::Constant* llvm::ConstantFoldLoadFromConstPtr(llvm::Constant*, llvm::Type*, const llvm::DataLayout&)’:
/llvm-project/llvm/lib/Analysis/ConstantFolding.cpp:713:19: warning: unused variable ‘SimplifiedGEP’ [-Wunused-variable]
  713 |         if (auto *SimplifiedGEP = dyn_cast<GEPOperator>(Simplified)) {
      |                   ^~~~~~~~~~~~~
```
2021-05-28 16:17:12 +08:00
Arthur Eubanks 8086f9d87e [ConstFold] Simplify a load's GEP operand through local aliases
MSVC-style RTTI produces loads through a GEP of a local alias which
itself is a GEP. Currently we aren't able to devirtualize any virtual
calls when MSVC RTTI is enabled.

This patch attempts to simplify a load's GEP operand by calling
SymbolicallyEvaluateGEP() with an option to look through local aliases.

Differential Revision: https://reviews.llvm.org/D101100
2021-05-27 16:04:19 -07:00
Sanjay Patel a0e71f1832 [ConstProp] propagate poison from vector reduction element(s) to result
This follows from the underlying logic for binops and min/max.
Although it does not appear that we handle this for min/max
intrinsics currently.
https://alive2.llvm.org/ce/z/Kq9Xnh
2021-05-24 10:34:40 -04:00
Serge Pavlov c9c05a91c4 [ConstantFolding] Use APFloat for constant folding. NFC
Replace use of host floating types with operations on APFloat when it is
possible. Use of APFloat makes analysis more convenient and facilitates
constant folding in the case of non-default FP environment.

Differential Revision: https://reviews.llvm.org/D102672
2021-05-22 13:00:20 +07:00
Serge Pavlov c162f086ba [APFloat] convertToDouble/Float can work on shorter types
Previously APFloat::convertToDouble may be called only for APFloats that
were built using double semantics. Other semantics like single precision
were not allowed although corresponding numbers could be converted to
double without loss of precision. The similar restriction applied to
APFloat::convertToFloat.

With this change any APFloat that can be precisely represented by double
can be handled with convertToDouble. Behavior of convertToFloat was
updated similarly. It make the conversion operations more convenient and
adds support for formats like half and bfloat.

Differential Revision: https://reviews.llvm.org/D102671
2021-05-21 11:02:51 +07:00
Nick Desaulniers 8c72749bd9 [LowerConstantIntrinsics] reuse isManifestLogic from ConstantFolding
GlobalVariables are Constants, yet should not unconditionally be
considered true for __builtin_constant_p.

Via the LangRef
https://llvm.org/docs/LangRef.html#llvm-is-constant-intrinsic:

    This intrinsic generates no code. If its argument is known to be a
    manifest compile-time constant value, then the intrinsic will be
    converted to a constant true value. Otherwise, it will be converted
    to a constant false value.

    In particular, note that if the argument is a constant expression
    which refers to a global (the address of which _is_ a constant, but
    not manifest during the compile), then the intrinsic evaluates to
    false.

Move isManifestConstant from ConstantFolding to be a method of
Constant so that we can reuse the same logic in
LowerConstantIntrinsics.

pr/41459

Reviewed By: rsmith, george.burgess.iv

Differential Revision: https://reviews.llvm.org/D102367
2021-05-14 15:35:21 -07:00
Stanislav Mekhanoshin 22d295f695 [AMDGPU] Constant fold Intrinsic::amdgcn_perm
Differential Revision: https://reviews.llvm.org/D102203
2021-05-10 16:23:11 -07:00
Sanjay Patel 1089158c5a [ConstantFolding] propagate poison through vector reduction intrinsics 2021-04-29 12:54:20 -04:00
Sanjay Patel 71597d40e8 [ConstantFolding] refactor helper for vector reductions; NFC
We should handle other cases (undef/poison), so reduce
the duplication of repeated switches.
2021-04-29 12:09:22 -04:00
Arthur Eubanks cbce28f07e [ConstFold] Use const-folded operands in more places
Previously we were const folding operands but not passing them.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D101394
2021-04-27 14:30:19 -07:00
Joe Ellis effacc1599 [AArch64] Constant fold sve_convert_from_svbool(zero) to zero
Co-authored-by: Paul Walker <paul.walker@arm.com>

Differential Revision: https://reviews.llvm.org/D100463
2021-04-20 10:02:49 +00:00
Arthur Eubanks 5e71b9fa93 Explicitly pass type to cast load constant folding result
Previously we would use the type of the pointee to determine what to
cast the result of constant folding a load. To aid with opaque pointer
types, we should explicitly pass the type of the load rather than
looking at pointee types.

ConstantFoldLoadThroughBitcast() converts the const prop'd value to the
proper load type (e.g. [1 x i32] -> i32). Instead of calling this in
every intermediate step like bitcasts, we only call this when we
actually see the global initializer value.

In some existing uses of this API, we don't know the exact type we're
loading from immediately (e.g. first we visit a bitcast, then we visit
the load using the bitcast). In those cases we have to manually call
ConstantFoldLoadThroughBitcast() when simplifying the load to make sure
that we cast to the proper type.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D100718
2021-04-20 00:53:21 -07:00
Thomas Lively 5c729750a6 [WebAssembly] Remove saturating fp-to-int target intrinsics
Use the target-independent @llvm.fptosi and @llvm.fptoui intrinsics instead.
This includes removing the instrinsics for i32x4.trunc_sat_zero_f64x2_{s,u},
which are now represented in IR as a saturating truncation to a v2i32 followed by
a concatenation with a zero vector.

Differential Revision: https://reviews.llvm.org/D100596
2021-04-16 12:11:20 -07:00
George Mitenkov 807b019ca2 [ConstantFolding] Fixing addo/subo with undef
When folding addo/subo with undef, the current
convention is to use { -1, false } for addo and
{ 0, false } for subo. This was fixed for InstSimplify in
https://reviews.llvm.org/rGf094d65beaa492e845b03561eddd75b5be653a01,
but not in ConstantFolding.

Reviewed By: nikic, lebedev.ri

Differential Revision: https://reviews.llvm.org/D99564
2021-03-31 21:47:29 +03:00
Nikita Popov 9f864d2025 Reapply [ConstantFold] Handle vectors in ConstantFoldLoadThroughBitcast()
There seems to be an impedance mismatch between what the type
system considers an aggregate (structs and arrays) and what
constants consider an aggregate (structs, arrays and vectors).

Adjust the type check to consider vectors as well. The previous
version of the patch dropped the type check entirely, but it
turns out that getAggregateElement() does require the constant
to be an aggregate in some edge cases: For Poison/Undef the
getNumElements() API is called, without checking in advance that
we're dealing with an aggregate. Possibly the implementation should
avoid doing that, but for now I'm adding an assert so the next
person doesn't fall into this trap.
2021-03-21 17:48:21 +01:00
Zequan Wu cbd7eabea8 Revert "[ConstantFold] Handle vectors in ConstantFoldLoadThroughBitcast()"
That commit caused chromium build to crash: https://bugs.chromium.org/p/chromium/issues/detail?id=1188885

This reverts commit edf7004851.
2021-03-16 14:36:21 -07:00
Bjorn Pettersson 3638bdfbda [ConstantFold] Handle undef/poison when constant folding smul_fix/smul_fix_sat
Do constant folding according to
  posion * C -> poison
  C * poison -> poison
  undef * C -> 0
  C * undef -> 0
for smul_fix and smul_fix_sat intrinsics (for any scale).

Reviewed By: nikic, aqjune, nagisa

Differential Revision: https://reviews.llvm.org/D98410
2021-03-12 09:09:58 +01:00
Nikita Popov edf7004851 [ConstantFold] Handle vectors in ConstantFoldLoadThroughBitcast()
There seems to be an impedance mismatch between what the type
system considers an aggregate (structs and arrays) and what
constants consider an aggregate (structs, arrays and vectors).

Rather than adjusting the type check, simply drop it entirely,
as getAggregateElement() is well-defined for non-aggregates: It
simply returns null in that case.
2021-03-06 12:17:56 +01:00
Nikita Popov 1ecae1e62a [ConstantFold] Fold fptoi.sat intrinsics
The APFloat::convertToInteger() API already implements the desired
saturation semantics.
2021-01-10 17:37:27 +01:00
David Green e185b1dd7b [ConstProp] Constant propagation for get.active.lane.mask instrinsics
Similar to the Arm VCTP intrinsics, if the operands of an
active.lane.mask are both known, the constant lane mask can be
calculated. This can come up after unrolling the loops.

Differential Revision: https://reviews.llvm.org/D94103
2021-01-08 16:10:01 +00:00
Luo, Yuanke 981a0bd858 [X86] Add x86_amx type for intel AMX.
The x86_amx is used for AMX intrisics. <256 x i32> is bitcast to x86_amx when
it is used by AMX intrinsics, and x86_amx is bitcast to <256 x i32> when it
is used by load/store instruction. So amx intrinsics only operate on type x86_amx.
It can help to separate amx intrinsics from llvm IR instructions (+-*/).
Thank Craig for the idea. This patch depend on https://reviews.llvm.org/D87981.

Differential Revision: https://reviews.llvm.org/D91927
2020-12-30 13:52:13 +08:00
Leonard Chan a97f62837f [llvm][IR] Add dso_local_equivalent Constant
The `dso_local_equivalent` constant is a wrapper for functions that represents a
value which is functionally equivalent to the global passed to this. That is, if
this accepts a function, calling this constant should have the same effects as
calling the function directly. This could be a direct reference to the function,
the `@plt` modifier on X86/AArch64, a thunk, or anything that's equivalent to the
resolved function as a call target.

When lowered, the returned address must have a constant offset at link time from
some other symbol defined within the same binary. The address of this value is
also insignificant. The name is leveraged from `dso_local` where use of a function
or variable is resolved to a symbol in the same linkage unit.

In this patch:
- Addition of `dso_local_equivalent` and handling it
- Update Constant::needsRelocation() to strip constant inbound GEPs and take
  advantage of `dso_local_equivalent` for relative references

This is useful for the [Relative VTables C++ ABI](https://reviews.llvm.org/D72959)
which makes vtables readonly. This works by replacing the dynamic relocations for
function pointers in them with static relocations that represent the offset between
the vtable and virtual functions. If a function is externally defined,
`dso_local_equivalent` can be used as a generic wrapper for the function to still
allow for this static offset calculation to be done.

See [RFC](http://lists.llvm.org/pipermail/llvm-dev/2020-August/144469.html) for more details.

Differential Revision: https://reviews.llvm.org/D77248
2020-11-19 10:26:17 -08:00
Jay Foad 1417abe54c [AMDGPU] Add new llvm.amdgcn.fma.legacy intrinsic
Differential Revision: https://reviews.llvm.org/D89558
2020-10-16 17:10:21 +01:00
Amara Emerson 322d0afd87 [llvm][mlir] Promote the experimental reduction intrinsics to be first class intrinsics.
This change renames the intrinsics to not have "experimental" in the name.

The autoupgrader will handle legacy intrinsics.

Relevant ML thread: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140729.html

Differential Revision: https://reviews.llvm.org/D88787
2020-10-07 10:36:44 -07:00
Sanjay Patel f74a334fe3 [ConstantFolding] add undef handling for fmin/fmax intrinsics
The output here may not be optimal (yet), but it should be
consistent for commuted operands (it was not before) and
correct. We can do better by checking FMF and NaN if needed.

Code in InstSimplify generally assumes that we have already
folded code like this, so it was not handling 2 constant
inputs by commuting consistently.
2020-09-19 10:31:01 -04:00
Thomas Lively 514445e035 [WebAssembly][ConstantFolding] Fold fp-to-int truncation intrinsics
Constant fold both the trapping and saturating versions of the
WebAssembly truncation intrinsics. The tests are adapted from the
WebAssembly spec tests for the corresponding instructions.

Requested in PR46982.

Differential Revision: https://reviews.llvm.org/D85392
2020-08-10 12:40:05 -07:00
Sanjay Patel e591713bff [ConstantFolding] fold abs intrinsic
The handling for minimum value is similar to cttz/ctlz with 0 just above this case.

Differential Revision: https://reviews.llvm.org/D84942
2020-07-31 14:08:44 -04:00
Vitaly Buka b0eb40ca39 [NFC] Remove unused GetUnderlyingObject paramenter
Depends on D84617.

Differential Revision: https://reviews.llvm.org/D84621
2020-07-31 02:10:03 -07:00
Vitaly Buka 89051ebace [NFC] GetUnderlyingObject -> getUnderlyingObject
I am going to touch them in the next patch anyway
2020-07-30 21:08:24 -07:00
Sanjay Patel 9ee7d7122c [ConstantFolding] fold integer min/max intrinsics
If both operands are undef, return undef.
If one operand is undef, clamp to limit constant.
2020-07-29 11:01:13 -04:00
Juneyoung Lee 32088f4f7f [ConstantFolding] Fold freeze if it is never undef or poison
This is a simple patch that adds constant folding for freeze
instruction.

IIUC, it isn't needed to update ConstantFold.cpp because there is no freeze
constexpr.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D84597
2020-07-26 21:54:44 +09:00
Christopher Tetreault 23c5e59d9f [SVE] Remove calls to VectorType::getNumElements from Analysis
Reviewers: efriedma, fpetrogalli, c-rhodes, asbirlea, RKSimon

Reviewed By: RKSimon

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81504
2020-07-22 15:19:05 -07:00
David Green becaa6803a [ARM] Constant fold VCTP intrinsics
We can sometimes get into the situation where the operand to a vctp
intrinsic becomes constant, such as after a loop is fully unrolled. This
adds the constant folding needed for them, allowing them to simplify
away and hopefully simplifying remaining instructions.

Differential Revision: https://reviews.llvm.org/D84110
2020-07-21 11:39:31 +01:00
Jameson Nash 8b354cc8db [ConstantFolding] check applicability of AllOnes constant creation first
The getAllOnesValue can only handle things that are bitcast from a
ConstantInt, while here we bitcast through a pointer, so we may see more
complex objects (like Array or Struct).

Differential Revision: https://reviews.llvm.org/D83870
2020-07-19 13:13:57 -04:00
Jameson Nash 2c7a07b59d [GVN] teach ConstantFolding correct handling of non-integral addrspace casts
Here we teach the ConstantFolding analysis pass that it is not legal to
replace a load of a bitcast constant (having a non-integral addrspace)
with a bitcast of the value of that constant (with a different
non-integral addrspace).

But also teach it that certain bit patterns are always known and
convertable (a fact it already uses elsewhere). This required us to also
fix a globalopt test, since, after this change, LLVM is able to realize
that the test actually is a valid transform (NULL is always a known
bit-pattern) and so it doesn't need to emit the failure remarks for it.

Also simplify some of the negative tests for transforms by avoiding a
type change in their bitcast, and add positive versions of the same
tests, to show that they otherwise should work.

Differential Revision: https://reviews.llvm.org/D59730
2020-07-13 21:44:17 -04:00
Jameson Nash 19f01a4847 [GVN] add early exit to ConstantFoldLoadThroughBitcast [NFC]
And adds some additional test coverage to ensure later commits don't
introduce regressions.

Differential Revision: https://reviews.llvm.org/D59730
2020-07-13 21:44:17 -04:00
Simon Pilgrim 03fe47a29c ConstantFoldScalarCall3 - use const APInt& returned by getValue()
Avoids unnecessary APInt copies and silences clang tidy warning.
2020-07-09 11:16:47 +01:00
Christopher Tetreault b265cad93e [NFC] Bail out for scalable vectors before calling getNumElements
Summary:
Move the bail out logic to before constructing the Result and Lane
vectors. This is both potentially faster, and avoids calling
getNumElements on a potentially scalable vector

Reviewers: efriedma, sunfish, chandlerc, c-rhodes, fpetrogalli

Reviewed By: fpetrogalli

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81619
2020-06-16 13:41:29 -07:00
Jay Foad 7c7941fb4b [AMDGPU] Fold llvm.amdgcn.cos and llvm.amdgcn.sin intrinsics (fix)
Try to fix Windows buildbots.
2020-06-03 09:44:33 +01:00
Jay Foad c823cfde21 [AMDGPU] Fold llvm.amdgcn.cos and llvm.amdgcn.sin intrinsics
Differential Revision: https://reviews.llvm.org/D80702
2020-06-03 09:34:22 +01:00
David Green a01c0049b1 [ConstantFolding] Constant folding for integer vector reduce intrinsics
This add constant folding for all the integer vector reduce intrinsics,
providing that the argument is a constant vector. zeroinitializer always
produces 0 for all intrinsics, and other values can be handled with
APInt operators.

Differential Revision: https://reviews.llvm.org/D80516
2020-05-29 17:58:42 +01:00
Christopher Tetreault 434d122e94 [SVE] Eliminate calls to default-false VectorType::get() from Analysis
Reviewers: efriedma, fpetrogalli, kmclaughlin, sunfish

Reviewed By: fpetrogalli

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80324
2020-05-28 14:21:32 -07:00
Serge Pavlov 4d20e31f73 [FPEnv] Intrinsic llvm.roundeven
This intrinsic implements IEEE-754 operation roundToIntegralTiesToEven,
and performs rounding to the nearest integer value, rounding halfway
cases to even. The intrinsic represents the missed case of IEEE-754
rounding operations and now llvm provides full support of the rounding
operations defined by the standard.

Differential Revision: https://reviews.llvm.org/D75670
2020-05-26 19:24:58 +07:00
Matt Arsenault 88c20fa3d2 InstCombine: Add constant folding/simplify for amdgcn.ldexp intrinsic
This really belongs in InstructionSimplify since it doesn't introduce
new instructions. Put it in instcombine to avoid increasing the number
of passes considering target intrinsics.

I also noticed that we seem to now be interpreting strictfp attributes
on call sites, so try to handle that.
2020-05-22 08:21:38 -04:00
Christopher Tetreault 9174e0229f [SVE] Remove calls to VectorType::isScalable from analysis
Reviewers: efriedma, sdesmalen, chandlerc, sunfish

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77692
2020-04-23 12:44:22 -07:00
Christopher Tetreault b96558f5e5 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: sunfish, sdesmalen, efriedma

Reviewed By: efriedma

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77273
2020-04-09 12:41:28 -07:00