The idea behind this canonicalization is that it allows us to handle less
patterns, because we know that some will be canonicalized away. This is
indeed very useful to e.g. know that constants are always on the right.
However, this is only useful if the canonicalization is actually
reliable. This is the case for constants, but not for arguments: Moving
these to the right makes it look like the "more complex" expression is
guaranteed to be on the left, but this is not actually the case in
practice. It fails as soon as you replace the argument with another
instruction.
The end result is that it looks like things correctly work in tests,
while they actually don't. We use the "thwart complexity-based
canonicalization" trick to handle this in tests, but it's often a
challenge for new contributors to get this right, and based on the
regressions this PR originally exposed, we clearly don't get this right
in many cases.
For this reason, I think that it's better to remove this complexity
canonicalization. It will make it much easier to write tests for
commuted cases and make sure that they are handled.
Since all optimizations that use range metadata now also handle range attribute, this patch replaces writes of
range metadata for call instructions to range attributes.
When constructing vectors from elements, use poison instead of
undef as the base value. These literals always initialize all
elements (padding the remainder with zero), so that the choice
of base value does not affect semantics.
Use KnownBits to infer the nneg flag on zext instructions.
Currently we only set nneg when converting sext -> zext, but don't set
it when we have a zext in the first place. If we want to use it in
optimizations, we should make sure the flag inference is consistent.
This is the consolidation of D151644 and D151943 moved from
InstCombine to FunctionAttrs. This is based on discussion in the above
patches as well as D152081 (Attributor). This patch was written in a
way so it can have an immediate impact in currently active passes
(FunctionAttrs), but should be easy to port elsewhere (Attributor or
Inliner) if that makes more sense later on.
Some function attributes imply the attribute for all/some instructions
in the function. These attributes can be safely propagated to
callsites within the function that are missing the attribute. This can
be useful when 1) analyzing individual instructions in a function
and 2) if the original caller is later inlined, as if the attributes are
not propagated, they will be lost.
This patch implements propagation in a new class/file
`InferCallsiteAttrs` which can hypothetically be included elsewhere.
At the moment this patch infers the following:
Function Attributes:
- mustprogress
- nofree
- willreturn
- All memory attributes (readnone, readonly, writeonly, argmem,
etc...)
- The memory attributes are only propagated IFF the set of
pointers available to the callsite is the same as the set
available outside the caller (i.e no local memory arguments
from alloca or local malloc like functions).
Argument Attributes:
- noundef
- nonnull
- nofree
- readnone
- readonly
- writeonly
- nocapture
- nocapture is only propagated IFF the set of pointers
available to the callsite is the same as the set available
outside the caller and its guranteed that between the
callsite and function return, the state of any capture
pointers will not change (so the nocaptured gurantee of the
caller has been met by the instruction preceding the
callsite and will not changed).
Argument are only propagated to callsite arguments that are also function
arguments, but not derived values.
Return Attributes:
- noundef
- nonnull
Return attributes are only propagated if the callsite's return value
is used as the caller's return and execution is guranteed to pass from
callsite to return.
The compile time hit of this for -O3 and -O3+thinLTO is ~[.02, .37]%
regression. Proper LTO, however, has more significant regressions (up
to 3.92%):
https://llvm-compile-time-tracker.com/compare.php?from=94407e1bba9807193afde61c56b6125c0fc0b1d1&to=79feb6e78b818e33ec69abdc58c5f713d691554f&stat=instructions:u
Differential Revision: https://reviews.llvm.org/D152226
According to github.com/WebAssembly/simd/blob/main/proposals/simd/SIMD.md,
the shift count of bit shift instructions is taken modulo lane width.
This patch adds such operation.
Fixes PR#60655
Differential Revision: https://reviews.llvm.org/D144169
This reverts commit e71b81cab09bf33e3b08ed600418b72cc4117461.
As discussed in the planned follow-on to this patch (D138874),
this and the subsequent patches in this set can cause trouble for
the backend, and there's probably no quick fix. We may even
want to canonicalize in the opposite direction (towards insertelt).
The first attempt was reverted because a clang test changed
unexpectedly - the file is already marked with a FIXME, so
I just updated it this time to pass.
Original commit message:
This is the main patch for converting a truncated scalar that is
inserted into a vector to bitcast+shuffle. We could go either way
on patterns like this, but this direction will allow collapsing a
pair of these sequences on the motivating example from issue
The patch is split into 3 parts to make it easier to see the
progression of tests diffs. We allow inserting/shuffling into a
different size vector for flexibility, so there are several test
variations. The length-changing is handled by shortening/padding
the shuffle mask with undef elements.
In part 1, handle the basic pattern:
inselt undef, (trunc T), IndexC --> shuffle (bitcast T), IdentityMask
Proof for the endian-dependency behaving as expected:
https://alive2.llvm.org/ce/z/BsA7yC
The TODO items for handling shifts and insert into an arbitrary base
vector value are implemented as follow-ups.
Differential Revision: https://reviews.llvm.org/D138872
When F calls G calls H, G is nounwind, and G is inlined into F, then the
inlined call-site to H should be effectively nounwind so as not to lose
information during inlining.
If H itself is nounwind (which often happens when H is an intrinsic), we
no longer mark the callsite explicitly as nounwind. Previously, there
were cases where the inlined call-site of H differs from a pre-existing
call-site of H in F *only* in the explicitly added nounwind attribute,
thus preventing common subexpression elimination.
v2:
- just check CI->doesNotThrow
v3 (resubmit after revert at 344378808778c61d5599f4e0ac783ef7e6f8ed05):
- update Clang tests
Differential Revision: https://reviews.llvm.org/D129860
Now that integer min/max intrinsics have good support in both
InstCombine and other passes, start canonicalizing SPF min/max
to intrinsic min/max.
Once this sticks, we can stop matching SPF min/max in various
places, and can remove hacks we have for preventing infinite loops
and breaking of SPF canonicalization.
Differential Revision: https://reviews.llvm.org/D98152
The basic idea to this is that a) having a single canonical type makes CSE easier, and b) many of our transforms are inconsistent about which types we end up with based on visit order.
I'm restricting this to constants as for non-constants, we'd have to decide whether the simplicity was worth extra instructions. For constants, there are no extra instructions.
We chose the canonical type as i64 arbitrarily. We might consider changing this to something else in the future if we have cause.
Differential Revision: https://reviews.llvm.org/D115387
This patch is for fixing potential shufflevector-related bugs like D93818.
As D93818, this patch change shufflevector's default placeholder to poison.
To reduce risk, it was divided into several patches, and this patch is for InstCombineCasts.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D110226
Partially reverts 85157c007903, which had removed these builtins and intrinsics
in favor of normal codegen patterns. It turns out that it is possible for the
patterns to be split over multiple basic blocks, however, which means that DAG
ISel is not able to select them to the pmin/pmax instructions. To make sure the
SIMD intrinsics generate the correct instructions in these cases, reintroduce
the clang builtins and corresponding LLVM intrinsics, but also keep the normal
pattern matching as well.
Differential Revision: https://reviews.llvm.org/D108387
On some platforms, negative shift values mean to shift in the opposite
direction, but this is not true with WebAssembly. To avoid confusion, make the
shift values in the shift intrinsics unsigned.
Differential Revision: https://reviews.llvm.org/D108415
For each SIMD intrinsic function that takes or returns a scalar signed integer
value, ensure there is a corresponding intrinsic that returns or an
unsigned value. This is a convenience for users who use -Wsign-conversion so
they don't have to insert explicit casts, especially when the intrinsic
arguments are integer literals that fit into the unsigned integer type but not
the signed type.
Differential Revision: https://reviews.llvm.org/D108412
Since they are bitmasks, it will be more common for them to be used and
potentially extended to 64-bit integers as unsigned values rather than signed
values.
Differential Revision: https://reviews.llvm.org/D108401
Replace the clang builtins and LLVM intrinsics for the SIMD extmul instructions
with normal codegen patterns.
Differential Revision: https://reviews.llvm.org/D106724
Replace the clang builtins and LLVM intrinsics for {f32x4,f64x2}.{pmin,pmax}
with standard codegen patterns. Since wasm_simd128.h uses an integer vector as
the standard single vector type, the IR for the pmin and pmax intrinsic
functions contains bitcasts that would not be there otherwise. Add extra codegen
patterns that can still select the pmin and pmax instructions in the presence of
these bitcasts.
Differential Revision: https://reviews.llvm.org/D106612
Commit db7efcab7dd9 changed the implementations of the wasm_*_extract_lane and
wasm_*_replace_lane intrinsics from using builtin functions to using the
standard vector extensions. This did not change the resulting IR, but it changes
how update_cc_test_checks.py labels values in the IR. This commit simply updates
those labels.
Differential Revision: https://reviews.llvm.org/D106611
Replace the experimental clang builtins and LLVM intrinsics for these
instructions with normal codegen patterns. Resolves PR50435.
Differential Revision: https://reviews.llvm.org/D106019
Replace the experimental clang builtin and LLVM intrinsics for these
instructions with normal codegen patterns. Resolves PR50433.
Differential Revision: https://reviews.llvm.org/D105950
Replace the clang builtin function and LLVM intrinsic for
f32x4.demote_zero_f64x2 with combines from normal SDNodes. Also add missing
combines for i32x4.trunc_sat_zero_f64x2_{s,u}, which share the same pattern.
Differential Revision: https://reviews.llvm.org/D105755
Replace the clang builtin function and LLVM intrinsic previously used to select
the f64x2.promote_low_f32x4 instruction with custom combines from standard
SelectionDAG nodes. Implement the new combines to share code with the similar
combines for f64x2.convert_low_i32x4_{s,u}. Resolves PR50232.
Differential Revision: https://reviews.llvm.org/D105675
To improve hygiene, consistency, and usability, it would be good to replace all
the macro intrinsics in wasm_simd128.h with functions. The reason for using
macros in the first place was to enforce the use of constants for some arguments
using `_Static_assert` with `__builtin_constant_p`. This commit switches to
using functions and uses the `__diagnose_if__` attribute rather than
`_Static_assert` to enforce constantness.
The remaining macro intrinsics cannot be made into functions until the builtin
functions they are implemented with can be replaced with normal code patterns
because the builtin functions themselves require that their arguments are
constants.
This commit also fixes a bug with the const_splat intrinsics in which the f32x4
and f64x2 variants were incorrectly producing integer vectors.
Differential Revision: https://reviews.llvm.org/D102018
The builtins were updated to take signed parameters in 627a52695537, but the
intrinsics that use those builtins were not updated as well. The intrinsic test
did not catch this sign mismatch because it is only reported as an error under
-fno-lax-vector-conversions.
This commit fixes the type mismatch and adds -fno-lax-vector-conversions to the
test to catch similar problems in the future.
Differential Revision: https://reviews.llvm.org/D101979
These intrinsics do not correspond to their own underlying instruction, but are
a convenience for the common case of materializing a constant vector that has
the same value in each lane.
Differential Revision: https://reviews.llvm.org/D101885
Update the SIMD builtin load functions to take pointers to const data and update
the intrinsics themselves to not cast away constness.
Differential Revision: https://reviews.llvm.org/D101884
We previously did not have tests demonstrating that the intrinsics in
wasm_simd128.h lower to reasonable LLVM IR. This commit adds such a test.
Differential Revision: https://reviews.llvm.org/D101805
Adds new intrinsics for instructions that are in the final SIMD spec but did not
previously have intrinsics. Also updates the names of existing intrinsics to
reflect the final names of the underlying instructions in the spec. Keeps the
old names as deprecated functions to ease the transition to the new names.
Differential Revision: https://reviews.llvm.org/D101112
47f7174ffa changed the types used in the Wasm SIMD builtin functions,
but not all of their uses in wasm_simd128.h were updated. This commit
fixes wasm_simd128.h and adds tests to make sure similar problems do
not pass uncaught in the future.
Differential Revision: https://reviews.llvm.org/D85347
