It would waste time to specialize a function which would inline finally.
This patch did two things:
- Don't specialize functions which are always-inline.
- Don't spescialize functions whose lines of code are less than threshold
(100 by default).
For spec2017int, this patch could reduce the number of specialized
functions by 33%. Then the compile time didn't increase for every
benchmark.
Reviewed By: SjoerdMeijer, xbolva00, snehasish
Differential Revision: https://reviews.llvm.org/D107897
4ad41902e8 changed this code to
propagate Changed if scalar GEP PRE is performed. However, as
implemented this would skip the load PRE entirely if GEP indices
were PREd. Make sure load PRE runs even if Changed is already
true.
This likely has no functional effect as load PRE would then
occur on a later GVN iteration.
This special cases an unconditional latch and a conditional branch latch exit to improve codegen and test readability. I am hoping to reuse this function in the runtime unroll code, but without this change, the test diffs are far too complex to assess.
The motivation was to get min/max intrinsics to parity
with cmp+select idioms, but this unlocks a few more
folds because isFreeToInvert recognizes add/sub with
constants too.
In the min/max example, we have too many extra uses
for smaller folds to improve things, but this fold
is able to eliminate uses even though we can't reduce
the number of instructions.
Adjusting the reduction recipes still relies on references to the
original IR, which can become outdated by the first-order recurrence
handling. Until reduction recipe construction does not require IR
references, move it before first-order recurrence handling, to prevent a
crash as exposed by D106653.
This may overlap partially with the reassociate pass,
but it seems simple enough that we should try it here
in InstCombine to enable other folds.
This shows up as an opportunity and potential regression
if we improve a subtract fold with 'not' ops to be more
general.
Letting it take SCEV allows further modification on the function to optimize
if the StoreSize / Stride is runtime determined.
The plan is to let memcpy / memmove deal with runtime-determined sizes, just
like what D107353 did to memset.
Reviewed By: bmahjour
Differential Revision: https://reviews.llvm.org/D108289
Currently it's possible to silently use a loop pass that does not
preserve MemorySSA in a loop-mssa pass manager, as we don't
statically know which loop passes preserve MemorySSA (as was the
case with the legacy pass manager).
However, we can at least add a check after the fact that if
MemorySSA is used, then it should also have been preserved.
Hopefully this will reduce confusion as seen in
https://bugs.llvm.org/show_bug.cgi?id=51020.
Differential Revision: https://reviews.llvm.org/D108399
This reverts commit f4122398e7 to
investigate a crash exposed by it.
The patch breaks building the code below with `clang -O2 --target=aarch64-linux`
int a;
double b, c;
void d() {
for (; a; a++) {
b += c;
c = a;
}
}
When the stack is not reset it keeps previously visited Basic Block
which results in bugs where an instruction is hoisted to a
predecessor where the instruction was not fully anticipable.
Differential Revision: https://reviews.llvm.org/D108425
The purpose of __attribute__((disable_sanitizer_instrumentation)) is to
prevent all kinds of sanitizer instrumentation applied to a certain
function, Objective-C method, or global variable.
The no_sanitize(...) attribute drops instrumentation checks, but may
still insert code preventing false positive reports. In some cases
though (e.g. when building Linux kernel with -fsanitize=kernel-memory
or -fsanitize=thread) the users may want to avoid any kind of
instrumentation.
Differential Revision: https://reviews.llvm.org/D108029
The only thing that function should do as per it's semantic,
is to ensure that the switch's default is a block consisting only of
an `unreachable` terminator.
So let's just create such a block and update switch's default
to point to it. There should be no need for all this weird dance
around predecessors/successors.
The COFF specific `DataReferencedByCode` complexity (D103372 D103717) is due to
a link.exe limitation: an external symbol in IMAGE_COMDAT_SELECT_ASSOCIATIVE is
not really dropped, so it can cause duplicate definition error.
This patch extends the runtime unrolling infrastructure to support unrolling a loop with multiple exiting blocks branching to the same exit block used by the latch. It intentionally does not include a cost model change to enable this functionality unless appropriate force flags are used.
This is the prolog companion to D107381. Since this was LGTMed, a problem with DT updating was reported against that patch. I roled in the analogous fix here as it seemed obvious, and not worth re-review.
As an aside, our prolog form leaves a lot of potential value on the floor when there is an invariant load or invariant condition in the loop being runtime unrolled. We should probably consider a "required prolog" heuristic. (Alternatively, maybe we should be peeling these cases more aggressively?)
Differential Revision: https://reviews.llvm.org/D108262
As reported on https://bugs.llvm.org/show_bug.cgi?id=51020, the
guard widening pass doesn't preserve MemorySSA, so it can no
longer be scheduled in the same loop pass manager as LICM. However,
the loop-schedule.ll test indicates that this is supposed to work.
Fix this by preserving MemorySSA if available, as this seems to be
trivial in this case (we only need to drop the memory access for
the removed guards).
Differential Revision: https://reviews.llvm.org/D108386
In 94d0914, I added support for unrolling of multiple exit loops which have multiple exits reaching the latch. Per reports on the review post commit, I'd missed updating the domtree for one case. This fix addresses that ommission.
There's no new test as this is covered by existing tests with expensive verification turned on.
Folding a GEP from outside to inside a loop will materialize an add where there wasn't an equivalent operation before. Check the containing loops before making this fold.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D107935
This reverts commit 9934a5b2ed.
This patch may cause miscompiles because it missed a constraint
as shown in the examples from:
https://llvm.org/PR51531
This makes the intrinsic logic match the cmp+select idiom folds
just below. It's not clearly a win either way unless we think
that a 'not' op costs more than min/max.
The cmp+select folds on these patterns are more extensive than
the intrinsics currently and may have some complicated interactions,
so I'm trying to make those line up and bring the optimizations
for intrinsics up to parity.
There is an assertion failure in computeOverflowForUnsignedMul
(used in checkOverflow) due to the inner and outer trip counts
having different types. This occurs when the IV has been widened,
but the loop components are not successfully rediscovered.
This is fixed by some refactoring of the code in findLoopComponents
which identifies the trip count of the loop.
Differential Revision: https://reviews.llvm.org/D108107
Refactored implementation of AddressSanitizerPass and
HWAddressSanitizerPass to use pass options similar to passes like
MemorySanitizerPass. This makes sure that there is a single mapping
from class name to pass name (needed by D108298), and options like
-debug-only and -print-after makes a bit more sense when (despite
that it is the unparameterized pass name that should be used in those
options).
A result of the above is that some pass names are removed in favor
of the parameterized versions:
- "khwasan" is now "hwasan<kernel;recover>"
- "kasan" is now "asan<kernel>"
- "kmsan" is now "msan<kernel>"
Differential Revision: https://reviews.llvm.org/D105007
I have added a new TTI interface called enableOrderedReductions() that
controls whether or not ordered reductions should be enabled for a
given target. By default this returns false, whereas for AArch64 it
returns true and we rely upon the cost model to make sensible
vectorisation choices. It is still possible to override the new TTI
interface by setting the command line flag:
-force-ordered-reductions=true|false
I have added a new RUN line to show that we use ordered reductions by
default for SVE and Neon:
Transforms/LoopVectorize/AArch64/strict-fadd.ll
Transforms/LoopVectorize/AArch64/scalable-strict-fadd.ll
Differential Revision: https://reviews.llvm.org/D106653
This change enables llvm-profgen to use accurate context-sensitive post-optimization function byte size as a cost proxy to drive global preinline decisions.
To do this, BinarySizeContextTracker is introduced to track function byte size under different inline context during disassembling. In preinliner, we can not query context byte size under switch `context-cost-for-preinliner`. The tracker uses a reverse trie to keep size of functions under different context (callee as parent, caller as child), and it can give best/longest possible matching context size for given input context.
The new size cost is off by default. There're a few TODOs that needs to addressed: 1) avoid dangling string from `Offset2LocStackMap`, which will be addressed in split context work; 2) using inlinee's entry probe to make sure we have correct zero size for inlinee that's completely optimized away after inlining. Some tuning is also needed.
Differential Revision: https://reviews.llvm.org/D108180
This patch implements Flow Sensitive Sample FDO (FSAFDO) profile
loader. We have two profile loaders for FS profile,
one before RegAlloc and one before BlockPlacement.
To enable it, when -fprofile-sample-use=<profile> is specified,
add "-enable-fs-discriminator=true \
-disable-ra-fsprofile-loader=false \
-disable-layout-fsprofile-loader=false"
to turn on the FS profile loaders.
Differential Revision: https://reviews.llvm.org/D107878
MSSA-based LICM has been enabled by default for a few years now.
This drops the old AST-based implementation. Using loop(licm) will
result in a fatal error, the use of loop-mssa(licm) is required
(or just licm, which defaults to loop-mssa).
Note that the core canSinkOrHoistInst() logic has to retain AST
support for now, because it is shared with LoopSink.
Differential Revision: https://reviews.llvm.org/D108244
Decoupling the unrolling logic into three different functions. The shouldPragmaUnroll() covers the 1st and 2nd priorities of the previous code, the shouldFullUnroll() covers the 3rd, and the shouldPartialUnroll() covers the 5th. The output of each function, Optional<unsigned>, could be a value for UP.Count, which means unrolling factor has been set, or None, which means decision hasn't been made yet and should try the next priority.
Reviewed By: mtrofin, jdoerfert
Differential Revision: https://reviews.llvm.org/D106001
When dealing with memmove, we also add the load instruction to the ignored
instructions list passed to `mayLoopAccessLocation`. Renaming "Stores" to
"IgnoredInsts" to be more precise.
Differential Revision: https://reviews.llvm.org/D108275
This very occasionally causes to an assertion failure in the compiler.
Turning off until we can get to the bottom of this.
Reviewed By: hctim
Differential Revision: https://reviews.llvm.org/D108282
Currently, AAKernelInfo will fail on an assertion if we attempt to run
it on a kernel without the init / deinit runtime calls. However, this
occurs for global constructors on the device. This will cause OpenMPOpt
to crash whenever global constructors are present. This patch removes
this assertion and just gives up instead.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D108258
This patch extends the runtime unrolling infrastructure to support unrolling a loop with multiple exiting blocks branching to the same exit block used by the latch. It intentionally does not include a cost model change to enable this functionality unless appropriate force flags are used.
I decided to restrict this to the epilogue case. Given the changes ended up being pretty generic, we may be able to unblock the prolog case too, but I want to do that in a separate change to reduce the amount of code we all have to understand at one time.
Differential Revision: https://reviews.llvm.org/D107381
In the provided test case, we were trying to set the global's
initializer to `i32* null` when the global's value type was `@0`.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D108232
Unfortunatley the IR Verifier doesn't reject debug intrinsics that
have nullptr as arguments, so coro::salvageDebugInfo for now also
needs to deal with them.
rdar://81979541
This was a diagnostic option used to demonstrate a weakness in
the AST-based LICM implementation. This problem does not exist
in the MSSA-based LICM implementation, which has been enabled
for a long time now. As such, this option is no longer relevant.
This patch adds an extra option to print the module after running one of
the OpenMPOpt passes if debugging is enabled. This makes it much easier
to inspect the effects of this pass when doing debugging.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D108146
his is a fix for PR43678, and is an alternate patch to D105723.
The basic issue we're running into is that LSR + SCEVExpander are moving the very instruction whose operand we're in the process of expanding. This breaks the subtle and ill-documented invariant which let LSR work. (Full story can be found here: https://reviews.llvm.org/D105723#2878473)
Rather than attempting a fix, this change just removes the optimization entirely. The code is entirely untested, and removing it appears to have no impact I can find. This code was added back in 2014 by 1e12f8563d with a single test which does not seem to actually test the hoisting logic.
From a philosophical standpoint, it also seems very strange to have the expander implementing optimizations which should live in a dedicated transform pass.
Differential Revision: https://reviews.llvm.org/D106178
Removed AArch64 usage of the getMaxVScale interface, replacing it with
the vscale_range(min, max) IR Attribute.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D106277
If both operands are negated, we can invert the min/max and do
the negation after:
smax (neg nsw X), (neg nsw Y) --> neg nsw (smin X, Y)
smin (neg nsw X), (neg nsw Y) --> neg nsw (smax X, Y)
This is visible as a remaining regression in D98152. I don't see
a way to generalize this for 'unsigned' or adapt Negator to
handle it. This only appears to be safe with 'nsw':
https://alive2.llvm.org/ce/z/GUy1zJ
Differential Revision: https://reviews.llvm.org/D108165
This option has been enabled by default for quite a while now.
The practical impact of removing the option is that MSSA use
cannot be disabled in default pipelines (both LPM and NPM) and
in manual LPM invocations. NPM can still choose to enable/disable
MSSA using loop vs loop-mssa.
The next step will be to require MSSA for LICM and drop the
AST-based implementation entirely.
Differential Revision: https://reviews.llvm.org/D108075
LoopLoadElimination, LoopVersioning and LoopVectorize currently
fetch MemorySSA when construction LoopAccessAnalysis. However,
LoopAccessAnalysis does not actually use MemorySSA and we can pass
nullptr instead.
This saves one MemorySSA calculation in the default pipeline, and
thus improves compile-time.
Differential Revision: https://reviews.llvm.org/D108074
This adds a call to matchSAddSubSat from smin/smax instrinsics, allowing
the same patterns to match if the canonical form of a min/max is an
intrinsics, not a icmp/select.
Differential Revision: https://reviews.llvm.org/D108077
Currently/previously, while SCEV guaranteed that it produces the same value,
the way it was produced may be illegal IR, so we have an ugly check that
the replacement is valid.
But now that the SCEV strictness wrt the pointer/integer types has been improved,
i believe this invariant is already upheld by the SCEV itself, natively.
I think we should add an assertion, wait for a week, and then, if all is good,
rip out all this checking.
Or we could just do the latter directly i guess.
This reverts commit rL127839.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D108043
After recent changes, exit counts and BE taken counts are always
integers, so convert these to assertions.
While here, also convert the loop invariance checks to asserts.
Exit counts are always loop invariant.
Previously we emitted a "does not support scalable vectors"
remark for all targets whenever vectorisation is attempted. This
pollutes the output for architectures that don't support scalable
vectors and is likely confusing to the user.
Instead this patch introduces a debug message that reports when
scalable vectorisation is allowed by the target and only issues
the previous remark when scalable vectorisation is specifically
requested, for example:
#pragma clang loop vectorize_width(2, scalable)
Differential Revision: https://reviews.llvm.org/D108028
The current LIR does not deal with runtime-determined memset-size. This patch
utilizes SCEV and check if the PointerStrideSCEV and the MemsetSizeSCEV are equal.
Before comparison the pass would try to fold the expression that is already
protected by the loop guard.
Testcase file `memset-runtime.ll`, `memset-runtime-debug.ll` added.
This patch deals with proper loop-idiom. Proceeding patch wants to deal with SCEV-s
that are inequal after folding with the loop guards.
Reviewed By: lebedev.ri, Whitney
Differential Revision: https://reviews.llvm.org/D107353
Another simple cleanups set in DSE. CheckCache is removed since 1f1145006b and in consequence KnownNoReads is useless.
Also update description of MemorySSAScanLimit which default value is 150 instead 100.
Differential Revision: https://reviews.llvm.org/D107812
Previously we would allow promotion even if the byval/inalloca
attributes on the call and the callee didn't match.
It's ok if the byval/inalloca types aren't the same. For example, LTO
importing may rename types.
Fixes PR51397.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D107998
AttributeList::hasAttribute() is confusing. In an attempt to change the
name to something that suggests using other methods, fix up some
existing uses.
AttributeList::hasAttribute() is confusing, use clearer methods like
hasParamAttr()/hasRetAttr().
Add hasRetAttr() since it was missing from AttributeList.
It might changed the condition of a branch into a constant,
so we should restart and constant-fold terminator,
instead of continuing with the tautological "conditional" branch.
This fixes the issue reported at https://reviews.llvm.org/rGf30a7dff8a5b32919951dcbf92e4a9d56c4679ff
There is an assertion failure in computeOverflowForUnsignedMul
(used in checkOverflow) due to the inner and outer trip counts
having different types. This occurs when the IV has been widened,
but the loop components are not successfully rediscovered.
This is fixed by some refactoring of the code in findLoopComponents
which identifies the trip count of the loop.
Besides SPMDization, other analysis and optimization for original, frontend-generated SPMD regions uses information from the AAKernelInfoFunction attribute. This fix makes sure disabling SPMDization through the corresponding option applies only to generic mode regions, which should not be SPMDized, while it leaves unaffected the attribute state of original SPMD regions.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D108001
This is a re-try of 6de1dbbd09 which was reverted because
it missed a null check. Extra test for that failure added.
Original commit message:
This is an adaptation of D41603 and another step on the way
to canonicalizing to the intrinsic forms of min/max.
See D98152 for status.
This reverts the revert 28c04794df.
The failing MLIR test that caused the revert should be fixed in this
version.
Also includes a PPC test fix previously in 1f87c7c478.
We really shouldn't deal with a conditional branch that can be trivially
constant-folded into an unconditional branch.
Indeed, barring failure to trigger BB reprocessing, that should be true,
so let's assert as much, and hope the assertion never fires.
If it does, we have a bug to fix.
Mainly, i want to add an assertion that `SimplifyCFGOpt::simplifyCondBranch()`
doesn't get asked to deal with non-unconditional branches,
and if i do that, then said assertion fires on existing tests,
and this is what prevents it from firing.
This is a direct translation of the select folds added with
D53033 / D53036 and another step towards canonicalization
using the intrinsics (see D98152).
Currently, LNICM pass does not support sinking instructions out of loop nest.
This patch enables LNICM to sink down as many instructions to the exit block of outermost loop as possible.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D107219
This patch adjusts the intrinsics definition of
llvm.matrix.column.major.load and llvm.matrix.column.major.store to
allow overloading the type of the stride. The bitwidth of the stride is
used to perform the offset computation.
This fixes a crash when using __builtin_matrix_column_major_load or
__builtin_matrix_column_major_store on 32 bit platforms. The stride argument
of the builtins are defined as `size_t`, which is 32 bits wide on 32 bit
platforms.
Note that we still perform offset computations with 64 bit width on 32
bit platforms for accesses that do not take a user-specified stride.
This can be fixed separately.
Fixes PR51304.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D107349
Originally committed as ffc3fb665d
Reverted in fcf2d5f402 due to an
assertion failure.
Original commit message:
Allow the folding even if there is an
intervening bitcast.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D106667
release call
findSafeStoreForStoreStrongContraction checks whether it's safe to move
the release call to the store by inspecting all instructions between the
two, but was ignoring retain instructions. This was causing objects to
be released and deallocated before they were retained.
rdar://81668577
This is a quick fix for a motivating case that looks like this:
https://godbolt.org/z/GeMqzMc38
As noted, we might be able to restore the min/max patterns
with select folds, or we just wait for this to become easier
with canonicalization to min/max intrinsics.
When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX)
due to source changes (e.g. `#if` code runs for profile generation but not for profile use)
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.
Add "lto-pgo-warn-mismatch" option to lld COFF/ELF to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.
Differential Revision: https://reviews.llvm.org/D104431
When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX).
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.
Add this "lto-pgo-warn-mismatch" option to lld to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D104431
When none of the translation units in the binary have been instrumented
we shouldn't need to link the profile runtime. However, because we pass
-u__llvm_profile_runtime on Linux and Fuchsia, the runtime would still
be pulled in and incur some overhead. On Fuchsia which uses runtime
counter relocation, it also means that we cannot reference the bias
variable unconditionally.
This change modifies the InstrProfiling pass to pull in the profile
runtime only when needed by declaring the __llvm_profile_runtime symbol
in the translation unit only when needed. For now we restrict this only
for Fuchsia, but this can be later expanded to other platforms. This
approach was already used prior to 9a041a7522, but we changed it
to always generate the __llvm_profile_runtime due to a TAPI limitation,
but that limitation may no longer apply, and it certainly doesn't apply
on platforms like Fuchsia.
Differential Revision: https://reviews.llvm.org/D98061
PHI nodes are not pass through but change their value, we have to
account for that to avoid missing stores.
Follow up for D107798 to fix PR51249 for good.
Differential Revision: https://reviews.llvm.org/D107808
AAPointerInfoFloating needs to visit all uses and some multiple times if
we go through PHI nodes. Attributor::checkForAllUses keeps a visited set
so we don't recurs endlessly. We now allow recursion for non-phi uses so
we track all pointer offsets via PHI nodes properly without endless
recursion.
This replaces the first attempt D107579.
Differential Revision: https://reviews.llvm.org/D107798
To avoid simplification with wrong constants we need to make sure we
know that we won't perform specific optimizations based on the users
request. The non-SPMDzation and non-CustomStateMachine flags did only
prevent the final transformation but allowed to value simplification
to go ahead.
Differential Revision: https://reviews.llvm.org/D107862
Some files still contained the old University of Illinois Open Source
Licence header. This patch replaces that with the Apache 2 with LLVM
Exception licence.
Differential Revision: https://reviews.llvm.org/D107528
This patch removes the hand-rolled implementation of salvageDebugInfo
for cast and GEPs and replaces it with a call into
llvm::salvageDebugInfoImpl().
A side-effect of this is that additional redundant convert operations
are introduced, but those don't have any negative effect on the
resulting DWARF expression.
rdar://80227769
Differential Revision: https://reviews.llvm.org/D107384
This patch refactors / simplifies salvageDebugInfoImpl(). The goal
here is to simplify the implementation of coro::salvageDebugInfo() in
a followup patch.
1. Change the return value to I.getOperand(0). Currently users of
salvageDebugInfoImpl() assume that the first operand is
I.getOperand(0). This patch makes this information explicit. A
nice side-effect of this change is that it allows us to salvage
expressions such as add i8 1, %a in the future.
2. Factor out the creation of a DIExpression and return an array of
DIExpression operations instead. This change allows users that
call salvageDebugInfoImpl() in a loop to avoid the costly
creation of temporary DIExpressions and to defer the creation of
a DIExpression until the end.
This patch does not change any functionality.
rdar://80227769
Differential Revision: https://reviews.llvm.org/D107383
When converting a store into a memset, we currently insert the new
MemoryDef after the store MemoryDef, which requires all uses to be
renamed to the new def using a whole block scan. Instead, we can
insert the new MemoryDef before the store and not rename uses,
because we know that the location is immediately overwritten, so
all uses should still refer to the old MemoryDef. Those uses will
get renamed when the old MemoryDef is actually dropped, which is
efficient.
I expect something similar can be done for some of the other MSSA
updates in MemCpyOpt. This is an alternative to D107513, at least
for this particular case.
Differential Revision: https://reviews.llvm.org/D107702
The intrinsics have an extra chunk of known bits logic
compared to the normal cmp+select idiom. That allows
folding the icmp in each case to something better, but
that then opposes the canonical form of min/max that
we try to form for a select.
I'm carving out a narrow exception to preserve all
existing regression tests while avoiding the inf-loop.
It seems unlikely that this is the only bug like this
left, but this should fix:
https://llvm.org/PR51419
Avoid stack overflow errors on systems with small stack sizes
by removing recursion in FoldCondBranchOnPHI.
This is a simple change as the recursion was only iteratively
calling the function again on the same arguments.
Ideally this would be compiled to a tail call, but there is
no guarantee.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D107803
I have updated cheapToScalarize to also consider the case when
extracting lanes from a stepvector intrinsic. This required removing
the existing 'bool IsConstantExtractIndex' and passing in the actual
index as a Value instead. We do this because we need to know if the
index is <= known minimum number of elements returned by the stepvector
intrinsic. Effectively, when extracting lane X from a stepvector we
know the value returned is also X.
New tests added here:
Transforms/InstCombine/vscale_extractelement.ll
Differential Revision: https://reviews.llvm.org/D106358
We use the CurrentBlock to determine whether we have already processed a
block. Don't reuse this variable for setting where we should insert the
rematerialization. The rematerialization block is different to the
current block when we rematerialize for coro suspend block users.
Differential Revision: https://reviews.llvm.org/D107573
Teach LV to use masked-store to support interleave-store-group with
gaps (instead of scatters/scalarization).
The symmetric case of using masked-load to support
interleaved-load-group with gaps was introduced a while ago, by
https://reviews.llvm.org/D53668; This patch completes the store-scenario
leftover from D53668, and solves PR50566.
Reviewed by: Ayal Zaks
Differential Revision: https://reviews.llvm.org/D104750
The MemorySSA-based implementation has been enabled for a few months
(since D94376). This patch drops the old MDA-based implementation
entirely.
I've kept this to only the basic cleanup of dropping various
conditions -- the code could be further cleaned up now that there
is only one implementation.
Differential Revision: https://reviews.llvm.org/D102113
In this patch, the "nnan" requirement is removed for the canonicalization of select with fcmp to fabs.
(i) FSub logic: Remove check for nnan flag presence in fsub. Example: https://alive2.llvm.org/ce/z/751svg (fsub).
(ii) FNeg logic: Remove check for the presence of nnan and nsz flag in fneg. Example: https://alive2.llvm.org/ce/z/a_fsdp (fneg).
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D106872
Both patterns are equivalent (https://alive2.llvm.org/ce/z/jfCViF),
so we should have a preference. It seems like mask+negation is better
than two shifts.
After refactoring the phi recipes, we can now iterate over all header
phis in a VPlan to detect reductions when it comes to fixing them up
when tail folding.
This reduces the coupling with the cost model & legal by using the
information directly available in VPlan. It also removes a call to
getOrAddVPValue, which references the original IR value which may
become outdated after VPlan transformations.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D100102
There may be some generalizations (see test comments) of these patterns,
but this should handle the cases motivated by:
https://llvm.org/PR51315https://llvm.org/PR51259
The backend may want to transform differently, but at least for
the x86 examples that I looked at, there does not appear to be
any significant perf diff either way.
Attempt to enable MemCpyOpt unconditionally in D104801 uncovered the fact that
there are users that do not expect LLVM to materialize `memset` intrinsic.
While other passes can do that, too, MemCpyOpt triggers it more frequently and
breaks sanitizers and some downstream users.
For now introduce a flag to force-enable the flag and opt-in only CUDA
compilation with NVPTX back-end.
Differential Revision: https://reviews.llvm.org/D106401
- Loads from the constant memory (either explicit one or as the source
of memory transfer intrinsics) won't alias any stores.
Reviewed By: asbirlea, efriedma
Differential Revision: https://reviews.llvm.org/D107605
This patch adds more instructions to the Uniforms list, for example certain
intrinsics that are uniform by definition or whose operands are loop invariant.
This list includes:
1. The intrinsics 'experimental.noalias.scope.decl' and 'sideeffect', which
are always uniform by definition.
2. If intrinsics 'lifetime.start', 'lifetime.end' and 'assume' have
loop invariant input operands then these are also uniform too.
Also, in VPRecipeBuilder::handleReplication we check if an instruction is
uniform based purely on whether or not the instruction lives in the Uniforms
list. However, there are certain cases where calls to some intrinsics can
be effectively treated as uniform too. Therefore, we now also treat the
following cases as uniform for scalable vectors:
1. If the 'assume' intrinsic's operand is not loop invariant, then we
are free to treat this as uniform anyway since it's only a performance
hint. We will get the benefit for the first lane.
2. When the input pointers for 'lifetime.start' and 'lifetime.end' are loop
variant then for scalable vectors we assume these still ultimately come
from the broadcast of an alloca. We do not support scalable vectorisation
of loops containing alloca instructions, hence the alloca itself would
be invariant. If the pointer does not come from an alloca then the
intrinsic itself has no effect.
I have updated the assume test for fixed width, since we now treat it
as uniform:
Transforms/LoopVectorize/assume.ll
I've also added new scalable vectorisation tests for other intriniscs:
Transforms/LoopVectorize/scalable-assume.ll
Transforms/LoopVectorize/scalable-lifetime.ll
Transforms/LoopVectorize/scalable-noalias-scope-decl.ll
Differential Revision: https://reviews.llvm.org/D107284
The may get changed before specialization by RunSCCPSolver. In other
words, the pass may change the function without specialization happens.
Add test and comment to reveal this.
And it may return No Changed if the function get changed by
RunSCCPSolver before the specialization. It looks like a potential bug.
Test Plan: check-all
Reviewed By: https://reviews.llvm.org/D107622
Differential Revision: https://reviews.llvm.org/D107622
Noticed that the computation for function specialization cost of a
function wouldn't change during the traversal of the arguments for the
function. We could hoist the computation out of the traversal. I
observed about ~1% improvement on compile time for spec2017. But I guess
it may not be precise. This should be NFC and fine.
Reviewed By: Sjoerd Meijer
Differential Revision: https://reviews.llvm.org/D107621
This is recommit of the patch 16ff91ebcc,
reverted in 0c28a7c990 because it had
an error in call of getFastMathFlags (base type should be FPMathOperator
but not Instruction). The original commit message is duplicated below:
Clang has builtin function '__builtin_isnan', which implements C
library function 'isnan'. This function now is implemented entirely in
clang codegen, which expands the function into set of IR operations.
There are three mechanisms by which the expansion can be made.
* The most common mechanism is using an unordered comparison made by
instruction 'fcmp uno'. This simple solution is target-independent
and works well in most cases. It however is not suitable if floating
point exceptions are tracked. Corresponding IEEE 754 operation and C
function must never raise FP exception, even if the argument is a
signaling NaN. Compare instructions usually does not have such
property, they raise 'invalid' exception in such case. So this
mechanism is unsuitable when exception behavior is strict. In
particular it could result in unexpected trapping if argument is SNaN.
* Another solution was implemented in https://reviews.llvm.org/D95948.
It is used in the cases when raising FP exceptions by 'isnan' is not
allowed. This solution implements 'isnan' using integer operations.
It solves the problem of exceptions, but offers one solution for all
targets, however some can do the check in more efficient way.
* Solution implemented by https://reviews.llvm.org/D96568 introduced a
hook 'clang::TargetCodeGenInfo::testFPKind', which injects target
specific code into IR. Now only SystemZ implements this hook and it
generates a call to target specific intrinsic function.
Although these mechanisms allow to implement 'isnan' with enough
efficiency, expanding 'isnan' in clang has drawbacks:
* The operation 'isnan' is hidden behind generic integer operations or
target-specific intrinsics. It complicates analysis and can prevent
some optimizations.
* IR can be created by tools other than clang, in this case treatment
of 'isnan' has to be duplicated in that tool.
Another issue with the current implementation of 'isnan' comes from the
use of options '-ffast-math' or '-fno-honor-nans'. If such option is
specified, 'fcmp uno' may be optimized to 'false'. It is valid
optimization in general, but it results in 'isnan' always returning
'false'. For example, in some libc++ implementations the following code
returns 'false':
std::isnan(std::numeric_limits<float>::quiet_NaN())
The options '-ffast-math' and '-fno-honor-nans' imply that FP operation
operands are never NaNs. This assumption however should not be applied
to the functions that check FP number properties, including 'isnan'. If
such function returns expected result instead of actually making
checks, it becomes useless in many cases. The option '-ffast-math' is
often used for performance critical code, as it can speed up execution
by the expense of manual treatment of corner cases. If 'isnan' returns
assumed result, a user cannot use it in the manual treatment of NaNs
and has to invent replacements, like making the check using integer
operations. There is a discussion in https://reviews.llvm.org/D18513#387418,
which also expresses the opinion, that limitations imposed by
'-ffast-math' should be applied only to 'math' functions but not to
'tests'.
To overcome these drawbacks, this change introduces a new IR intrinsic
function 'llvm.isnan', which realizes the check as specified by IEEE-754
and C standards in target-agnostic way. During IR transformations it
does not undergo undesirable optimizations. It reaches instruction
selection, where is lowered in target-dependent way. The lowering can
vary depending on options like '-ffast-math' or '-ffp-model' so the
resulting code satisfies requested semantics.
Differential Revision: https://reviews.llvm.org/D104854
All information to fix-up the reduction phi nodes in the vectorized loop
is available in VPlan now. This patch moves the code to do so, to make
this clearer. Fixing up the loop exit value still relies on other
information and remains outside of VPlan for now.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D100113
Now the recursive functions may get specialized many times when
`func-specialization-max-iters` increases. See discussion in
https://reviews.llvm.org/D106426 for details.
For a very large module, __llvm_gcov_reset can become very large.
__llvm_gcov_reset previously emitted stores to a bunch of globals in one
huge basic block. MemCpyOpt would turn many of these stores into
memsets, and updating MemorySSA would be extremely slow.
Verified that this makes the compile time of certain files go down
drastically (20min -> 5min).
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D107538
The SCEV-based salvaging method caches dbg.value information pre-LSR so
that salvaging may be attempted post-LSR. If the dbg.value are already
undef pre-LSR then a salvage attempt would be fruitless, so avoid
caching them.
Reviewed By: StephenTozer
Differential Revision: https://reviews.llvm.org/D107448
If the vectorized insertelements instructions form indentity subvector
(the subvector at the beginning of the long vector), it is just enough
to extend the vector itself, no need to generate inserting subvector
shuffle.
Differential Revision: https://reviews.llvm.org/D107494
Since all operands to ExtractValue must be loop-invariant when we deem
the loop vectorizable, we can consider ExtractValue to be uniform.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D107286
In SimplifyCFG we may simplify the CFG by speculatively executing
certain stores, when they are preceded by a store to the same
location. This patch allows such speculation also when the stores are
similarly preceded by a load.
In order for this transformation to be correct we need to ensure that
the memory location is writable and the store in the new location does
not introduce a data race.
Local objects (created by an `alloca` instruction) are always
writable, so once we are past a read from a location it is valid to
also write to that same location.
Seeing just a load does not guarantee absence of a data race (unlike
if we see a store) - the load may still be part of a race, just not
causing undefined behaviour
(cf. https://llvm.org/docs/Atomics.html#optimization-outside-atomic).
In the original program, a data race might have been prevented by the
condition, but once we move the store outside the condition, we must
be sure a data race wasn't possible anyway, no matter what the
condition evaluates to.
One way to be sure that a local object is never concurrently
read/written is check that its address never escapes the function.
Hence this transformation is restricted to local, non-escaping
objects.
Reviewed By: nikic, lebedev.ri
Differential Revision: https://reviews.llvm.org/D107281
We can only trust the range of the index if it is guaranteed
non-poison.
Fixes PR50949.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D107364
This patch adds more instructions to the Uniforms list, for example certain
intrinsics that are uniform by definition or whose operands are loop invariant.
This list includes:
1. The intrinsics 'experimental.noalias.scope.decl' and 'sideeffect', which
are always uniform by definition.
2. If intrinsics 'lifetime.start', 'lifetime.end' and 'assume' have
loop invariant input operands then these are also uniform too.
Also, in VPRecipeBuilder::handleReplication we check if an instruction is
uniform based purely on whether or not the instruction lives in the Uniforms
list. However, there are certain cases where calls to some intrinsics can
be effectively treated as uniform too. Therefore, we now also treat the
following cases as uniform for scalable vectors:
1. If the 'assume' intrinsic's operand is not loop invariant, then we
are free to treat this as uniform anyway since it's only a performance
hint. We will get the benefit for the first lane.
2. When the input pointers for 'lifetime.start' and 'lifetime.end' are loop
variant then for scalable vectors we assume these still ultimately come
from the broadcast of an alloca. We do not support scalable vectorisation
of loops containing alloca instructions, hence the alloca itself would
be invariant. If the pointer does not come from an alloca then the
intrinsic itself has no effect.
I have updated the assume test for fixed width, since we now treat it
as uniform:
Transforms/LoopVectorize/assume.ll
I've also added new scalable vectorisation tests for other intriniscs:
Transforms/LoopVectorize/scalable-assume.ll
Transforms/LoopVectorize/scalable-lifetime.ll
Transforms/LoopVectorize/scalable-noalias-scope-decl.ll
Differential Revision: https://reviews.llvm.org/D107284
This change wasn't strictly necessary for D106164 and could be removed.
This patch addresses the post-commit comments from @fhahn on D106164, and
also changes sve-widen-gep.ll to use the same IR test as shown in
pointer-induction.ll.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D106878
Letting it take SCEV allows further modification on the function to optimize
if the StoreSize / Stride is runtime determined.
This is a preceeding of D107353.
The big picture is to let LoopIdiom deal with runtime-determined sizes.
Reviewed By: Whitney, lebedev.ri
Differential Revision: https://reviews.llvm.org/D104595
Rather than blocking the whole MemCpyOpt pass if the libcalls are
not available, only disable creation of new memset/memcpy intrinsics
where only load/stores were used previously. This only affects the
store merging and load-store conversion optimization. Other
optimizations are derived from existing intrinsics, which are
well-defined in the absence of libcalls -- not having the libcalls
just means that call simplification won't convert them to intrinsics.
This is a weaker variation of D104801, which dropped these checks
entirely. Ideally we would not couple emission of intrinsics to
libcall availability at all, but as the intrinsics may be legalized
to libcalls we need to be a bit careful right now.
Differential Revision: https://reviews.llvm.org/D106769
This patch expands SPMDization (converting generic execution mode to SPMD for target regions) by guarding code regions that should be executed only by the main thread. Specifically, it generates guarded regions, which only the main thread executes, and the synchronization with worker threads using simple barriers. For correctness, the patch aborts SPMDization for target regions if the same code executes in a parallel region, thus must be not be guarded. This check is implemented using the ParallelLevels AA.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D106892
Rather than emitting the bias variable lazily as needed, emit it
eagerly. This allows profile runtime to refer to this variable
unconditionally without having to use the weak reference. The bias
variable is in a COMDAT so there'll never be more than one instance,
and if it's not needed, linker should be able to GC it, so the overhead
should be minimal.
Differential Revision: https://reviews.llvm.org/D107377
SCEV-based salvaging in LSR translates SCEVs to DIExpressions. SCEVs may
contain very large integers but the translation does not support
integers greater than 64 bits. This patch adds checks to ensure
conversions of these large integers is not attempted. A regression test
is added to ensure no such translation is attempted.
Reviewed by: StephenTozer
PR: https://bugs.llvm.org/show_bug.cgi?id=51329
Differential Revision: https://reviews.llvm.org/D107438
Clang has builtin function '__builtin_isnan', which implements C
library function 'isnan'. This function now is implemented entirely in
clang codegen, which expands the function into set of IR operations.
There are three mechanisms by which the expansion can be made.
* The most common mechanism is using an unordered comparison made by
instruction 'fcmp uno'. This simple solution is target-independent
and works well in most cases. It however is not suitable if floating
point exceptions are tracked. Corresponding IEEE 754 operation and C
function must never raise FP exception, even if the argument is a
signaling NaN. Compare instructions usually does not have such
property, they raise 'invalid' exception in such case. So this
mechanism is unsuitable when exception behavior is strict. In
particular it could result in unexpected trapping if argument is SNaN.
* Another solution was implemented in https://reviews.llvm.org/D95948.
It is used in the cases when raising FP exceptions by 'isnan' is not
allowed. This solution implements 'isnan' using integer operations.
It solves the problem of exceptions, but offers one solution for all
targets, however some can do the check in more efficient way.
* Solution implemented by https://reviews.llvm.org/D96568 introduced a
hook 'clang::TargetCodeGenInfo::testFPKind', which injects target
specific code into IR. Now only SystemZ implements this hook and it
generates a call to target specific intrinsic function.
Although these mechanisms allow to implement 'isnan' with enough
efficiency, expanding 'isnan' in clang has drawbacks:
* The operation 'isnan' is hidden behind generic integer operations or
target-specific intrinsics. It complicates analysis and can prevent
some optimizations.
* IR can be created by tools other than clang, in this case treatment
of 'isnan' has to be duplicated in that tool.
Another issue with the current implementation of 'isnan' comes from the
use of options '-ffast-math' or '-fno-honor-nans'. If such option is
specified, 'fcmp uno' may be optimized to 'false'. It is valid
optimization in general, but it results in 'isnan' always returning
'false'. For example, in some libc++ implementations the following code
returns 'false':
std::isnan(std::numeric_limits<float>::quiet_NaN())
The options '-ffast-math' and '-fno-honor-nans' imply that FP operation
operands are never NaNs. This assumption however should not be applied
to the functions that check FP number properties, including 'isnan'. If
such function returns expected result instead of actually making
checks, it becomes useless in many cases. The option '-ffast-math' is
often used for performance critical code, as it can speed up execution
by the expense of manual treatment of corner cases. If 'isnan' returns
assumed result, a user cannot use it in the manual treatment of NaNs
and has to invent replacements, like making the check using integer
operations. There is a discussion in https://reviews.llvm.org/D18513#387418,
which also expresses the opinion, that limitations imposed by
'-ffast-math' should be applied only to 'math' functions but not to
'tests'.
To overcome these drawbacks, this change introduces a new IR intrinsic
function 'llvm.isnan', which realizes the check as specified by IEEE-754
and C standards in target-agnostic way. During IR transformations it
does not undergo undesirable optimizations. It reaches instruction
selection, where is lowered in target-dependent way. The lowering can
vary depending on options like '-ffast-math' or '-ffp-model' so the
resulting code satisfies requested semantics.
Differential Revision: https://reviews.llvm.org/D104854
This adds support for specialising recursive functions. For example:
int Global = 1;
void recursiveFunc(int *arg) {
if (*arg < 4) {
print(*arg);
recursiveFunc(*arg + 1);
}
}
void main() {
recursiveFunc(&Global);
}
After 3 iterations of function specialisation, followed by inlining of the
specialised versions of recursiveFunc, the main function looks like this:
void main() {
print(1);
print(2);
print(3);
}
To support this, the following has been added:
- Update the solver and state of the new specialised functions,
- An optimisation to propagate constant stack values after each iteration of
function specialisation, which is necessary for the next iteration to
recognise the constant values and trigger.
Specialising recursive functions is (at the moment) controlled by option
-func-specialization-max-iters and is opt-in for compile-time reasons. I.e.,
the default is -func-specialization-max-iters=1, but for the example above we
would need to use -func-specialization-max-iters=3. Future work is to see if we
can increase the default, or improve the cost-model/heuristics to control
compile-times.
Differential Revision: https://reviews.llvm.org/D106426
Currently, in OptimizeGlobalAddressOfMalloc, the transformation for global loads assumes that they have the same Type. With the support of ConstantExpr (https://reviews.llvm.org/D106589), this may not be true any more (as seen in the test case), and we miss the code to handle this, This is to fix that.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D107397
This transform has been restricted to legal types since
https://reviews.llvm.org/rG65df808f6254617b9eee931d00e95d900610b660
in 2012.
This is particularly restrictive on RISCV64 which only has i64
as a legal integer type. i32 is a very common type in code
generated from C, but we won't form a lookup table with it.
This also effects other common types like i8/i16 types on ARM,
AArch64, RISCV, etc.
This patch proposes to allow power of 2 types larger than 8 bit, if
they will fit in the largest legal integer type in DataLayout.
These types are common in C code so generally well handled in
the backends.
We could probably do this for other types like i24 and rely on
alignment and padding to allow the backend to use a single wider
load. This isn't my main concern right now and it will need more
tests.
We could also allow larger types up to some limit and let the
backend split into multiple loads, but we need to define that
limit. It's also not my main concern right now.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D107233
If the vectorized insertelements instructions form indentity subvector
(the subvector at the beginning of the long vector), it is just enough
to extend the vector itself, no need to generate inserting subvector
shuffle.
Differential Revision: https://reviews.llvm.org/D107344
Fixed type assertion failure caused by trying to fold a masked load with a
select where the select condition is a scalar value
Reviewed By: sdesmalen, lebedev.ri
Differential Revision: https://reviews.llvm.org/D107372
The inttoptr/ptrtoint roundtrip optimization is not always correct.
We are working towards removing this optimization and adding support to specific cases where this optimization works.
In this patch, we focus on phi-node operands with inttoptr casts.
We know that ptrtoint( inttoptr( ptrtoint x) ) is same as ptrtoint (x).
So, we want to remove this roundtrip cast which goes through phi-node.
Reviewed By: aqjune
Differential Revision: https://reviews.llvm.org/D106289
I'm renaming the flag because a future patch will add a new
enableOrderedReductions() TTI interface and so the meaning of this
flag will change to be one of forcing the target to enable/disable
them. Also, since other places in LoopVectorize.cpp use the word
'Ordered' instead of 'strict' I changed the flag to match.
Differential Revision: https://reviews.llvm.org/D107264
I'm not sure this is the best way to approach this,
but the situation is rather not very detectable unless we explicitly call it out when refusing to advise to unroll.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D107271
This aligns the multiple exit costing with all the other cost decisions. Note that UnrollAndJam, which is the only other caller of the original home of this code, unconditionally bails out of multiple exit loops.
The option to not preserve LCSSA is in fact not tested at all in upstream. I was tempted to just remove the code entirely, but realized I didn't need to for my actual goal.
This patch updates VPInterleaveRecipe::print to print the actual defined
VPValues for load groups and the store VPValue operands for store
groups.
The IR references may become outdated while transforming the VPlan and
the defined and stored VPValues always are up-to-date.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D107223
When the limit of the inner loop is a known integer, the InstCombine
pass now causes the transformation e.g. imcp ult i32 %inc, tripcount ->
icmp ult %j, tripcount-step (where %j is the inner loop induction
variable and %inc is add %j, step), which is now accounted for when
identifying the trip count of the loop. This is also an acceptable use
of %j (provided the step is 1) so is ignored as long as the compare
that it's used in is also the condition of the inner branch.
Differential Revision: https://reviews.llvm.org/D105802
I'm working on extending the OptimizeGlobalAddressOfMalloc to handle some more general cases. This is to add support of the ConstantExpr use of the global variables. The function allUsesOfLoadedValueWillTrapIfNull is now iterative with the added CE use of GV. Also, the recursive function valueIsOnlyUsedLocallyOrStoredToOneGlobal is changed to iterative using a worklist with the GEP case added.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D106589
I don't know much about this pass, but we need a stronger
check on the memset length arg to avoid an assert. The
current code was added with D59000.
The test is reduced from:
https://llvm.org/PR50910
Differential Revision: https://reviews.llvm.org/D106462
Additional asserts were added to ScalarEvolution to enforce
pointer/int type rules. An assert is triggered when the LSR pass
attempts to extend a pointer SCEV in GenerateTruncates.
This patch changes GenerateTruncates to exit early if the Formaula
contains a ScaledReg or BaseReg with a pointer type.
Differential Revision: https://reviews.llvm.org/D107185
Change `CountersPtr` in `__profd_` to a label difference, which is a link-time
constant. On ELF, when linking a shared object, this requires that `__profc_` is
either private or linkonce/linkonce_odr hidden. On COFF, we need D104564 so that
`.quad a-b` (64-bit label difference) can lower to a 32-bit PC-relative relocation.
```
# ELF: R_X86_64_PC64 (PC-relative)
.quad .L__profc_foo-.L__profd_foo
# Mach-O: a pair of 8-byte X86_64_RELOC_UNSIGNED and X86_64_RELOC_SUBTRACTOR
.quad l___profc_foo-l___profd_foo
# COFF: we actually use IMAGE_REL_AMD64_REL32/IMAGE_REL_ARM64_REL32 so
# the high 32-bit value is zero even if .L__profc_foo < .L__profd_foo
# As compensation, we truncate CountersDelta in the header so that
# __llvm_profile_merge_from_buffer and llvm-profdata reader keep working.
.quad .L__profc_foo-.L__profd_foo
```
(Note: link.exe sorts `.lprfc` before `.lprfd` even if the object writer
has `.lprfd` before `.lprfc`, so we cannot work around by reordering
`.lprfc` and `.lprfd`.)
With this change, a stage 2 (`-DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_BUILD_INSTRUMENTED=IR`)
`ld -pie` linked clang is 1.74% smaller due to fewer R_X86_64_RELATIVE relocations.
```
% readelf -r pie | awk '$3~/R.*/{s[$3]++} END {for (k in s) print k, s[k]}'
R_X86_64_JUMP_SLO 331
R_X86_64_TPOFF64 2
R_X86_64_RELATIVE 476059 # was: 607712
R_X86_64_64 2616
R_X86_64_GLOB_DAT 31
```
The absolute function address (used by llvm-profdata to collect indirect call
targets) can be converted to relative as well, but is not done in this patch.
Differential Revision: https://reviews.llvm.org/D104556
Replace insertelement instructions for splats with just single
insertelement + broadcast shuffle. Also, try to merge these instructions
if they come from the same/shuffled gather node.
Differential Revision: https://reviews.llvm.org/D107104
For the nodes with reused scalars the user may be not only of the size
of the final shuffle but also of the size of the scalars themselves,
need to check for this. It is safe to just modify the check here, since
the order of the scalars themselves is preserved, only indeces of the
reused scalars are changed. So, the users with the same size as the
number of scalars in the node, will not be affected, they still will get
the operands in the required order.
Reported by @mstorsjo in D105020.
Differential Revision: https://reviews.llvm.org/D107080
If the instruction was previously deleted, it should not be treated as
an external user. This fixes cost estimation and removes dead
extractelement instructions.
Differential Revision: https://reviews.llvm.org/D107106
Need to check that the minimum acceptable vector factor is at least 2,
not 0, to avoid compiler crash during gathered loads analysis.
Differential Revision: https://reviews.llvm.org/D107058
This work provides four flags to disable four different sets of OpenMP optimizations. These flags take effect in llvm/lib/Transforms/IPO/OpenMPOpt.cpp and include the following:
- openmp-opt-disable-deglobalization: Defaults to false, adding this flag sets the variable DisableOpenMPOptDeglobalization to true. This prevents AA registration for HeapToStack and HeapToShared.
- openmp-opt-disable-spmdization: Defaults to false, adding this flag sets the variable DisableOpenMPOptSPMDization to true. This indicates a pessimistic fixpoint in changeToSPMDMode.
- openmp-opt-disable-folding: Defaults to false, adding this flag sets the variable DisableOpenMPOptFolding to true. This indicates a pessimistic fixpoint in the attributor init for AAFoldRuntimeCall.
- openmp-opt-disable-state-machine-rewrite: Defaults to false, adding this flag sets the variable DisableOpenMPOptStateMachineRewrite to true. This first prevents changes to the state machine in rewriteDeviceCodeStateMachine by returning before changes are made, and if a custom state machine is built in buildCustomStateMachine, stops by returning a pessimistic fixpoint.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D106802
Patch by Mohammad Fawaz
This issues started happening after
b373b5990d
Basically, if the memcpy is volatile, the collectUsers() function should
return false, just like we do for volatile loads.
Differential Revision: https://reviews.llvm.org/D106950
SCEVToIterCountExpr only expects to be fed affine expressions, but
DbgRewriteSalvageableDVIs is feeding it non-affine induction variables.
Following this up with an obvious fix, will add test coverage too if
this avoids D105207 being reverted.
When the trip count of the inner loop is a constant, the InstCombine
pass now causes the transformation e.g. imcp ult i32 %inc, tripcount ->
icmp ult %j, tripcount-step (where %j is the inner loop induction
variable and %inc is add %j, step), which is now accounted for when
identifying the trip count of the loop. This is also an acceptable use
of %j (provided the step is 1) so is ignored as long as the compare
that it's used in is also the condition of the inner branch.
Differential Revision: https://reviews.llvm.org/D105802
The current implementation of function internalization creats a copy of each
function and replaces every use. This has the downside that the external
versions of the functions will call into the internalized versions of the
functions. This prevents them from being fully independent of eachother. This
patch replaces the current internalization scheme with a method that creates
all the copies of the functions intended to be internalized first and then
replaces the uses as long as their caller is not already internalized.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106931
Reapply commit d675b594f4 that was
reverted due to buildbot failures. A simple fix has been applied to
remove an assertion.
Differential Revision: https://reviews.llvm.org/D105207
The SCEV method getBackedgeTakenCount() returns a SCEVCouldNotCompute
object if the backedge-taken count is unpredictable. This fix ensures
there is no longer an attempt to use such an object to find the trip
count.
Patch by: Rosie Sumpter.
Differential Revision: https://reviews.llvm.org/D106970
This is a second attempt to fix the EXPENSIVE_CHECKS issue that was mentioned In D91661#2875179 by @jroelofs.
(The first attempt was in D105983)
D91661 more or less completely reverted D49126 and by doing so also removed the cleanup logic of the created declarations and calls.
This patch is a replacement for D91661 (which must itself be reverted first). It replaces the custom declaration creation with the
generic version and shows the test impact. It also tracks the number of NamedValues to detect if a new prototype was added instead
of looking at the available users of a prototype.
Reviewed By: jroelofs
Differential Revision: https://reviews.llvm.org/D106147
This reverts commit 77080a1eb6.
This change introduced issues detected with EXPENSIVE_CHECKS. Reverting to restore the
needed function cleanup. A next patch will then just improve on the name mangling.
[[noreturn]] can be used since Oct 2016 when the minimum compiler requirement was bumped to GCC 4.8/MSVC 2015.
Note: the definition of LLVM_ATTRIBUTE_NORETURN is kept for now.
Reapply commit 796b84d26f that was
reverted due to reports of crashes. A minor change now guards against
getVariableLocationOperand() returning a nullptr.
Differential Revision: https://reviews.llvm.org/D106659
This transform was added with e38b7e8948
and as shown in:
https://llvm.org/PR51241
...it could crash without an extra check of the blocks.
There might be a more compact way to write this constraint,
but we can't just count the successors/predecessors without
affecting a test that includes a switch instruction.
Reworked reordering algorithm. Originally, the compiler just tried to
detect the most common order in the reordarable nodes (loads, stores,
extractelements,extractvalues) and then fully rebuilding the graph in
the best order. This was not effecient, since it required an extra
memory and time for building/rebuilding tree, double the use of the
scheduling budget, which could lead to missing vectorization due to
exausted scheduling resources.
Patch provide 2-way approach for graph reodering problem. At first, all
reordering is done in-place, it doe not required tree
deleting/rebuilding, it just rotates the scalars/orders/reuses masks in
the graph node.
The first step (top-to bottom) rotates the whole graph, similarly to the previous
implementation. Compiler counts the number of the most used orders of
the graph nodes with the same vectorization factor and then rotates the
subgraph with the given vectorization factor to the most used order, if
it is not empty. Then repeats the same procedure for the subgraphs with
the smaller vectorization factor. We can do this because we still need
to reshuffle smaller subgraph when buildiong operands for the graph
nodes with lasrger vectorization factor, we can rotate just subgraph,
not the whole graph.
The second step (bottom-to-top) scans through the leaves and tries to
detect the users of the leaves which can be reordered. If the leaves can
be reorder in the best fashion, they are reordered and their user too.
It allows to remove double shuffles to the same ordering of the operands in
many cases and just reorder the user operations instead. Plus, it moves
the final shuffles closer to the top of the graph and in many cases
allows to remove extra shuffle because the same procedure is repeated
again and we can again merge some reordering masks and reorder user nodes
instead of the operands.
Also, patch improves cost model for gathering of loads, which improves
x264 benchmark in some cases.
Gives about +2% on AVX512 + LTO (more expected for AVX/AVX2) for {625,525}x264,
+3% for 508.namd, improves most of other benchmarks.
The compile and link time are almost the same, though in some cases it
should be better (we're not doing an extra instruction scheduling
anymore) + we may vectorize more code for the large basic blocks again
because of saving scheduling budget.
Differential Revision: https://reviews.llvm.org/D105020
As suggested in D105008, move the code that fixes up the backedge value
for first order recurrences to VPlan::execute.
Now all that remains in fixFirstOrderRecurrences is the code responsible
for creating the exit values in the middle block.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D106244
This makes a couple of changes to the costing of MLA reduction patterns,
to more accurately cost various patterns that can come up from
vectorization.
- The Arm implementation of getExtendedAddReductionCost is altered to
only provide costs for legal or smaller types. Larger than legal types
need to be split, which currently does not work very well, especially
for predicated reductions where the predicate may be legal but needs to
be split. Currently we limit it to legal or smaller input types.
- The getReductionPatternCost has learnt that reduce(ext(mul(ext, ext))
is a pattern that can come up, and can be treated the same as
reduce(mul(ext, ext)) providing the extension types match.
- And it has been adjusted to not count the ext in reduce(mul(ext, ext))
as part of a reduce(mul) pattern.
Together these changes help to more accurately cost the mla reductions
in cases such as where the extend types don't match or the extend
opcodes are different, picking better vector factors that don't result
in expanded reductions.
Differential Revision: https://reviews.llvm.org/D106166
The device runtime contains several calls to `__kmpc_get_hardware_num_threads_in_block`
and `__kmpc_get_hardware_num_blocks`. If the thread_limit and the num_teams are constant,
these calls can be folded to the constant value.
In this patch we use the already introduced `AAFoldRuntimeCall` and the `NumTeams` and
`NumThreads` kernel attributes (to be introduced in a different patch) to fold these functions.
The code checks all the kernels, and if their attributes match, the functions are folded.
In the future we will explore specializing for multiple values of NumThreads and NumTeams.
Depends on D106390
Reviewed By: jdoerfert, JonChesterfield
Differential Revision: https://reviews.llvm.org/D106033
This reapplies commit cbb709e251 and
includes the use of the lookup method instead of operator[] to avoid
accidentally setting (empty) simplification callbacks.
This reverts commit aa27430a62.
AAValueSimplify, AAValueConstantRange, and AAPotentialValues all look at
the IR by default. If queried for a IR position which has a
simplification callback we should either look at the callback return, or
give up. We do the latter for now.
`StackAlignment` has only one use: `StackAlignment = std::max(StackAlignment, AI.getAlignment());` So it is redundant.
Reviewed By: vitalybuka, MTC
Differential Revision: https://reviews.llvm.org/D106741
As an instruction is replaced in optimizeTransposes RAUW will replace it in
the ShapeMap (ShapeMap is ValueMap so that uses are updated). In
finalizeLowering however we skip updating uses if they are in the ShapeMap
since they will be lowered separately at which point we pick up the lowered
operands.
In the testcase what happened was that since we replaced the doubled-transpose
with the shuffle, it ended up in the ShapeMap. As we lowered the
columnwise-load the use in the shuffle was not updated. Then as we removed
the original columnwise-load we changed that to an undef. I.e. we ended up
with:
```
%shuf = shufflevector <8 x double> undef, <8 x double> poison, <6 x i32>
^^^^^
<i32 0, i32 1, i32 2, i32 4, i32 5, i32 6>
```
Besides the fix itself, I have fortified this last bit. As we change uses to
undef when removing instruction we track the undefed instruction to make sure
we eventually remove those too. This would have caught the issue at compile
time.
Differential Revision: https://reviews.llvm.org/D106714
The current JumpThreading pass does not jump thread loops since it can
result in irreducible control flow that harms other optimizations. This
prevents switch statements inside a loop from being optimized to use
unconditional branches.
This code pattern occurs in the core_state_transition function of
Coremark. The state machine can be implemented manually with goto
statements resulting in a large runtime improvement, and this transform
makes the switch implementation match the goto version in performance.
This patch specifically targets switch statements inside a loop that
have the opportunity to be threaded. Once it identifies an opportunity,
it creates new paths that branch directly to the correct code block.
For example, the left CFG could be transformed to the right CFG:
```
sw.bb sw.bb
/ | \ / | \
case1 case2 case3 case1 case2 case3
\ | / / | \
latch.bb latch.2 latch.3 latch.1
br sw.bb / | \
sw.bb.2 sw.bb.3 sw.bb.1
br case2 br case3 br case1
```
Co-author: Justin Kreiner @jkreiner
Co-author: Ehsan Amiri @amehsan
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D99205
Patch by Mohammad Fawaz
This patch allows lifetime calls to be ignored (and later erased) if we
know that the copy-constant-to-alloca optimization is going to happen.
The case that is missed is when the global variable is in a different address
space than the alloca (as shown in the example added to the lit test.)
This used to work before 6da31fa4a6
Differential Revision: https://reviews.llvm.org/D106573
Consider the following loop:
void foo(float *dst, float *src, int N) {
for (int i = 0; i < N; i++) {
dst[i] = 0.0;
for (int j = 0; j < N; j++) {
dst[i] += src[(i * N) + j];
}
}
}
When we are not building with -Ofast we may attempt to vectorise the
inner loop using ordered reductions instead. In addition we also try
to select an appropriate interleave count for the inner loop. However,
when choosing a VF=1 the inner loop will be scalar and there is existing
code in selectInterleaveCount that limits the interleave count to 2
for reductions due to concerns about increasing the critical path.
For ordered reductions this problem is even worse due to the additional
data dependency, and so I've added code to simply disable interleaving
for scalar ordered reductions for now.
Test added here:
Transforms/LoopVectorize/AArch64/strict-fadd-vf1.ll
Differential Revision: https://reviews.llvm.org/D106646
When hoisting/moving calls to locations, we strip unknown metadata. Such calls are usually marked `speculatable`, i.e. they are guaranteed to not cause undefined behaviour when run anywhere. So, we should strip attributes that can cause immediate undefined behaviour if those attributes are not valid in the context where the call is moved to.
This patch introduces such an API and uses it in relevant passes. See
updated tests.
Fix for PR50744.
Reviewed By: nikic, jdoerfert, lebedev.ri
Differential Revision: https://reviews.llvm.org/D104641
This reapplies commit 76f3ffb2b2 that was
reverted due to buildbot failures.
- Update lit tests with REQUIRES condition.
- Abandon salvage attempt if SCEVUnknown::getValue() returns nullptr.
Differential Revision: https://reviews.llvm.org/D105207
This patch extends salvaging of debuginfo in the Loop Strength Reduction
(LSR) pass by translating Scalar Evaluations (SCEV) into DIExpressions.
The method is as follows:
- Cache dbg.value intrinsics that are salvageable.
- Obtain a loop Induction Variable (IV) from ScalarExpressionExpander or
the loop header.
- Translate the IV SCEV into an expression that recovers the current
loop iteration count. Combine this with the dbg.value's location
op SCEV to create a DIExpression that salvages the value.
Review by: jmorse
Differential Revision: https://reviews.llvm.org/D105207
The loop vectorizer may decide to use tail folding when the trip-count
is low. When that happens, scalable VFs are no longer a candidate,
since tail folding/predication is not yet supported for scalable vectors.
This can be re-enabled in a future patch.
Reviewed By: kmclaughlin
Differential Revision: https://reviews.llvm.org/D106657
Replace pattern-matching with existing SCEV and Loop APIs as a more
robust way of identifying the loop increment and trip count. Also
rename 'Limit' as 'TripCount' to be consistent with terminology.
Differential Revision: https://reviews.llvm.org/D106580
Eliminating loads/stores in the device code is worth the extra effort,
especially for the new device runtime.
At the same time we do not compute AAExecutionDomain for non-device code
anymore, there is no point.
Differential Revision: https://reviews.llvm.org/D106845
When we simplify at least one operand in the Attributor simplification
we can use the InstSimplify to work on the simplified operands. This
allows us to avoid duplication of the logic.
Depends on D106189
Differential Revision: https://reviews.llvm.org/D106190
This change slightly relaxed the current ICP threshold in top-down inliner, specifically always allow one ICP for it. It shows some perf improvements on SPEC and our internal benchmarks. Also renamed the previous flag. We can also try to turn off PGO ICP in the future.
Reviewed By: wenlei, hoy, wmi
Differential Revision: https://reviews.llvm.org/D106588
D106185 allows us to determine if a store is needed easily. Using that
knowledge we can start to delete dead stores.
In AAIsDead we now track more state as an instruction can be dead (= the
old optimisitc state) or just "removable". A store instruction can be
removable while being very much alive, e.g., if it stores a constant
into an alloca or internal global. If we would pretend it was dead
instead of only removablewe we would ignore it when we determine what
values a load can see, so that is not what we want.
Differential Revision: https://reviews.llvm.org/D106188
This patch introduces `getPotentialCopiesOfStoredValue` which uses
AAPointerInfo to determine all "aliases" or "potential copies" of a
value that is stored into memory. This operation can fail but if it
succeeds it means we can visit all "uses" of a value even if it is
temporarily stored in memory.
There are two users for the function:
1) `Attributor::checkForAllUses` which will now ignore the value use
in a store if all "potential copies" can be identified and instead
be visited. This allows various AAs, including AAPointerInfo
itself, to look through memory.
2) `AANoCapture` which uses a custom use tracking through the
CaptureTracker interface and therefore needs to be thought
explicitly.
Differential Revision: https://reviews.llvm.org/D106185
Similar to D105787, this patch tries to fold `__kmpc_parallel_level` if possible.
Note that `__kmpc_parallel_level` doesn't take activeness into consideration,
based on current `deviceRTLs`, its return value can be such as 0, 1, 2, instead
of 0, 129, 130, etc. that also indicate activeness.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106154
While rewriteDeviceCodeStateMachine should probably be folded into
buildCustomStateMachine, we at least need the optimization to happen.
This was not reliably the case in the CGSCC pass but in the Module pass
it seems to work reliably.
This also ports a test to the new kernel encoding (target_init/deinit),
and makes sure we cannot run the kernel in SPMD mode.
Differential Revision: https://reviews.llvm.org/D106345
This caused us to rerun AAMemoryBehaviorFloating::updateImpl over and
over again. Unfortunately it turned out to be hard to reproduce the
behavior in a reasonable way.
If we add a new live edge we need to indicate a change or otherwise the
new live block is not shown to users. Similarly, new known dead ends and
a changed `ToBeExploredFrom` set need to cause us to return CHANGED.
Nowadays, simplifycfg pass already tail-merges all the ret blocks together
before doing anything, and it should not increase the count of ret's,
so this is dead code.
Invalid costs can be used to avoid vectorization with a given VF, which is
used for scalable vectors to avoid things that the code-generator cannot
handle. If we override the cost using the -force-target-instruction-cost
option of the LV, we would override this mechanism, rendering the flag useless.
This change ensures the cost is only overriden when the original cost that
was calculated is valid. That allows the flag to be used in combination
with the -scalable-vectorization option.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D106677
Summary:
There was an unnecessary variable assigned to the information cache when we
only need it in the constructor to extract the function declaration.
Proposed alternative to D105338.
This is ugly, but short-term I think it's the best way forward: first,
let's formalize the hacks into a coherent model. Then we can consider
extensions of that model (we could have different flavors of volatile
with different rules).
Differential Revision: https://reviews.llvm.org/D106309
This patch removes RtCheck from RuntimeCheckingPtrGroup to make it
possible to construct RuntimeCheckingPtrGroup objects without a
RuntimePointerChecking object. This should make it easier to
re-use the code to generate runtime checks, e.g. in D102834.
RtCheck was only used to access the pointer info for a given index.
Instead, the start and end expressions can be passed directly.
For code-gen, we also need to know the address space to use. This can
also be explicitly passed at construction.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D105481
Scalarization for scalable vectors is not (yet) supported, so the
LV discards a VF when scalarization is chosen as the widening
decision. It should therefore not assert that the VF is not scalable
when it computes the decision to scalarize.
The code can get here when both the interleave-cost, gather/scatter cost
and scalarization-cost are all illegal. This may e.g. happen for SVE
when the VF=1, to avoid generating `<vscale x 1 x eltty>` types that
the code-generator cannot yet handle.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D106656
Apparently this fails to line up the types -- try to sidestep the
issue entirely by writing the code in a more reasonable way: Walk
over the operands and perform a set lookup, rather than walking
over the set and performing an operand scan.
We could try harder to screen out libcalls by
function signature (and that would be a much larger
change than for sprintf alone), but that might make
the transition to type-less pointers more difficult.
https://llvm.org/PR51200
Separate out the BCECmp part from BCECmpBlock, which just stores
the comparison atoms without the branch instruction. At the same
time switch the code to return Optional<> rather than objects in
invalid state and partially constructed objects.
This fixes an issue that was found in D105199, where a GEP instruction
is used both as the address of a store, as well as the value of a store.
For the former, the value is scalar after vectorization, but the latter
(as value) requires widening.
Other code in that function seems to prevent similar cases from happening,
but it seems this case was missed.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D106164
This reverts the revert commit b1777b04dc.
The patch originally got reverted due to a crash:
https://bugs.chromium.org/p/chromium/issues/detail?id=1232798#c2
The underlying issue was that we were not using the stored values from
the modified memory recipes, but the out-of-date values directly from
the IR (accessed via the VPlan). This should be fixed in d995d6376. A
reduced version of the reproducer has been added in 93664503be.
This adjusts mayHaveSideEffect() to return true for !willReturn()
instructions. Just like other side-effects, non-willreturn calls
(aka "divergence") cannot be removed and cannot be reordered relative
to other side effects. This fixes a number of bugs where
non-willreturn calls are either incorrectly dropped or moved. In
particular, it also fixes the last open problem in
https://bugs.llvm.org/show_bug.cgi?id=50511.
I performed a cursory review of all current mayHaveSideEffect()
uses, which convinced me that these are indeed the desired default
semantics. Places that do not want to consider non-willreturn as a
sideeffect generally do not want mayHaveSideEffect() semantics at
all. I identified two such cases, which are addressed by D106591
and D106742. Finally, there is a use in SCEV for which we don't
really have an appropriate API right now -- what it wants is
basically "would this be considered forward progress". I've just
spelled out the previous semantics there.
Differential Revision: https://reviews.llvm.org/D106749
Need to fix several cost-related problems. The final type may be defined
incorrectly because of to early definition (we may end up with the wider
type), the CommonCost should not be redefined in ExtractElements
cost related calculations and the shuffle of the final insertelements
vectors should be calculated as a cost of single vector permutations
+ costs of two vector permutations for other n-1 incoming vectors.
Differential Revision: https://reviews.llvm.org/D106578
isSafeToSpeculateStore() looks for a preceding store to the same
location to make sure that introducing a new store of the same
value is safe. It currently bails on intervening mayHaveSideEffect()
instructions. However, I believe just checking mayWriteToMemory()
is sufficient there -- we just need to make sure that we know which
value was stored, we don't care if we can unwind in the meantime.
While looking into this, I started having some doubts about the
correctness of the transform with regard to thread safety. While
we don't try to hoist non-simple stores, I believe we also need
to make sure that the preceding store is simple as well. Otherwise
we could introduce a spurious non-atomic write after an atomic write
-- under our memory model this would result in a subsequent undef
atomic read, even if the second write stores the same value as the
first.
Example: https://alive2.llvm.org/ce/z/q_3YAL
Differential Revision: https://reviews.llvm.org/D106742
Fixes more casts to `<FixedVectorType>` for the cases where the
instruction is a Insert/ExtractElementInst.
For fixed-width, this part of truncateToMinimalBitWidths is tested by
AArch64/type-shrinkage-insertelt.ll. I attempted to write a test case for this part
of truncateToMinimalBitWidths which uses scalable vectors, but was unable to add
one. The tests in type-shrinkage-insertelt.ll rely on scalarization to create extract
element instructions for instance, which is not possible for scalable vectors.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D106163
Need to fix several cost-related problems. The final type may be defined
incorrectly because of to early definition (we may end up with the wider
type), the CommonCost should not be redefined in ExtractElements
cost related calculations and the shuffle of the final insertelements
vectors should be calculated as a cost of single vector permutations
+ costs of two vector permutations for other n-1 incoming vectors.
Differential Revision: https://reviews.llvm.org/D106578
Instead of getting the VPValue for the stored IR values through the
current plan, use the stored value of the recipes directly.
This way, the correct VPValues are used if the store recipes have been
modified in the VPlan and the IR value is not correct any longer. This
can happen, e.g. due to D105008.
Add folds to instcombine to support the removal of select instruction when the masked_load is guaranteed to zero the same lanes, i.e. select(mask, mload(,,mask,0), 0) -> mload(,,mask,0).
Patch originally authored by @paulwalker-arm
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D106376
I have added a new FastMathFlags parameter to getArithmeticReductionCost
to indicate what type of reduction we are performing:
1. Tree-wise. This is the typical fast-math reduction that involves
continually splitting a vector up into halves and adding each
half together until we get a scalar result. This is the default
behaviour for integers, whereas for floating point we only do this
if reassociation is allowed.
2. Ordered. This now allows us to estimate the cost of performing
a strict vector reduction by treating it as a series of scalar
operations in lane order. This is the case when FP reassociation
is not permitted. For scalable vectors this is more difficult
because at compile time we do not know how many lanes there are,
and so we use the worst case maximum vscale value.
I have also fixed getTypeBasedIntrinsicInstrCost to pass in the
FastMathFlags, which meant fixing up some X86 tests where we always
assumed the vector.reduce.fadd/mul intrinsics were 'fast'.
New tests have been added here:
Analysis/CostModel/AArch64/reduce-fadd.ll
Analysis/CostModel/AArch64/sve-intrinsics.ll
Transforms/LoopVectorize/AArch64/strict-fadd-cost.ll
Transforms/LoopVectorize/AArch64/sve-strict-fadd-cost.ll
Differential Revision: https://reviews.llvm.org/D105432
If the branch isn't `unpredictable`, and it is predicted to *not* branch
to the block we are considering speculatively executing,
then it seems counter-productive to execute the code that is predicted not to be executed.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D106650
This patch introduces a new RAII struct that will temporarily make an OpenMP
RTL function have external linkage. This is done before the attributor is
invoked to prevent it from incorrectly removing some function definitions that
we will use later. For example, if we determine all calls to one function are
dead, because it has internal linkage it can safely be removed. Later when we
try to get an instance to that function to modify the source using
`getOrCreateRuntimeFunction` we will then get an empty declaration for that
function that won't be defined anywhere. This patch prevents this from
occurring.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106707
Rather than adding methods for dropping these attributes in
various places, add a function that returns an AttrBuilder with
these attributes, which can then be used with existing methods
for dropping attributes. This is with an eye on D104641, which
also needs to drop them from returns, not just parameters.
Also be more explicit about the semantics of the method in the
documentation. Refer to UB rather than Undef, which is what this
is actually about.
Bug Fix for PR: https://llvm.org/PR47960
This patch makes sure that the fast math flag used in the 'select'
instruction is the same as the 'fabs' instruction after the transformation.
Differential Revision: https://reviews.llvm.org/D101727
In D106041, a freeze was added before the branch condition to solve the miscompilation problem of SimpleLoopUnswitch.
However, I found that the added freeze disturbed other optimizations in the following situations.
```
arg.fr = freeze(arg)
use(arg.fr)
...
use(arg)
```
It is a problem that occurred when arg and arg.fr were recognized as different values.
Therefore, changing to use arg.fr instead of arg throughout the function eliminates the above problem.
Thus, I add a function that changes all uses of arg to freeze(arg) to visitFreeze of InstCombine.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D106233
This patch introduces a pass that uses the Attributor to deduce AMDGPU specific attributes.
Reviewed By: jdoerfert, arsenm
Differential Revision: https://reviews.llvm.org/D104997
checkForAllInstructions was not handling declarations correctly.
It should have been returning false when it gets called on a declaration
The patch also fixes a test case for AAFunctionReachability for it to be able
to pass after the changes to the checkForAllinstructions.
Differential Revision: https://reviews.llvm.org/D106625
Otherwise e.g. the FoldTwoEntryPHINode() has to do a lot of legwork
to re-deduce what is the dominant block (i.e. for which block
is this branch the terminator).
The check for sinking instructions past the load + cmp sequence
currently checks for side-effects, which includes writing to memory
and unwinding. However, I don't believe we care about sinking the
instructions past an unwind (as they don't have any side-effects
themselves).
Differential Revision: https://reviews.llvm.org/D106591
Since we are using assumed information now, the logic should be refined to avoid
unncessary assertion.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106630
Deduplication in OpenMPOpt finds redundant OpenMP runtime calls and replaces them with a single call placed in the earliest safe location in the IR. When deduplication happens in a target region this patch makes sure replacement calls are put after target_init.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106556
Constfold constrained variants of operations fadd, fsub, fmul, fdiv,
frem, fma and fmuladd.
The change also sets up some means to support for removal of unused
constrained intrinsics. They are declared as accessing memory to model
interaction with floating point environment, so they were not removed,
as they have side effect. Now constrained intrinsics that have
"fpexcept.ignore" as exception behavior are removed if they have no uses.
As for intrinsics that have exception behavior other than "fpexcept.ignore",
they can be removed if it is known that they do not raise floating point
exceptions. It happens when doing constant folding, attributes of such
intrinsic are changed so that the intrinsic is not claimed as accessing
memory.
Differential Revision: https://reviews.llvm.org/D102673
A simplification callback can mean that the IR value is modified beyond
the apparent IR semantics. That is, a `i1 true` could be replaced by an
`i1 false` based on high-level domain-specific information. If a user
provides a simplification callback we will not look at the IR but
instead give up if the callback returns a nullptr.
SPMDization D102307 detects incompatible OpenMP runtime calls to abort converting a target region to SPMD mode. Calls to memory allocation/de-allocation routines kmpc_alloc_shared, kmpc_free_shared are incompatible unless they are removed by AAHeapToStack/AAHeapToShared analysis. This patch extends SPMDization detection to include AAHeapToStack/AAHeapToShared analysis results for enlarging the scope of possible SPMDized regions detected.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105634
Fixing a typo in SampleContextTracker to use debug name when debug linkage name is no present. This should only affect C programs.
Saw 0.6% perf win on Cinder which is mostly C code.
Reviewed By: wenlei, wmi
Differential Revision: https://reviews.llvm.org/D106599
This function is called when some predecessor of an empty return block
ends with a conditional branch, with both successors being empty ret blocks.
Now, because of the way SimplifyCFG works, it might happen to simplify
one of the blocks in a way that makes a conditional branch
into an unconditional one, since it's destinations are now identical,
but it might not have actually simplified said conditional branch
into an unconditional one yet.
So, we have to check that ourselves first,
especially now that SimplifyCFG aggressively tail-merges
all ret and resume blocks.
Even if it was an unconditional branch already,
`SimplifyCFGOpt::simplifyReturn()` doesn't call `FoldReturnIntoUncondBranch()`
by default.
The logical (select) form of and/or will now be a source of problems.
We don't really account for it's inverted form, yet it exists,
and presumably we should treat it just like non-inverted form:
https://alive2.llvm.org/ce/z/BU9AXkhttps://bugs.llvm.org/show_bug.cgi?id=51149 reports a reportedly-serious
perf regression that will hopefully be mitigated by this.
We should only add the fake lowering entry for the matrix remark if the
transpose is not lowered on its own. `MapVector::insert` is used to insert
the entry during proper lowering which does not overwrite the fake entry in
the map.
We actually had test coverage for this but the reference output code was
wrong; it was storing undef rather than the transposed column.
Also add an assert that would have caught this.
Differential Revision: https://reviews.llvm.org/D106457
D101977 added `BooleanStateWithPtrSetVector` to store pointers to a set meanwhile
tracking boolean state. One of the limitation is that it can only store pointer.
We might want it to store other types of values, such as integer for parallel
level. This patch generalizes the idea and create `BooleanStateWithSetVector`.
`BooleanStateWithPtrSetVector` therefore becomes a type alias of `BooleanStateWithSetVector`.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106149
This patch avoids computing discounts for predicated instructions when the
VF is scalable.
There is no support for vectorization of loops with division because the
vectorizer cannot guarantee that zero divisions will not happen.
This loop now does not use VF scalable
```
for (long long i = 0; i < n; i++)
if (cond[i])
a[i] /= b[i];
```
Differential Revision: https://reviews.llvm.org/D101916
The purpose of patch is to learn Loop idiom recognition pass how to recognize simple memmove patterns
in similar way like GCC: https://godbolt.org/z/fh95e83od
LoopIdiomRecognize already has machinery for memset and memcpy recognition, patch tries to extend exisiting capabilities with minimal effort.
Differential Revision: https://reviews.llvm.org/D104464
As noticed on D106352, after we've folded "(select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0))" if the inner Ptr was also a (now one use) gep we could then merge the geps, using the sum of the indices instead.
I've limited this to basic 2-op geps - a more general case further down InstCombinerImpl.visitGetElementPtrInst doesn't have the one-use limitation but only creates the add if it can be created via SimplifyAddInst.
https://alive2.llvm.org/ce/z/f8pLfD (Thanks Roman!)
Differential Revision: https://reviews.llvm.org/D106450
If we remove a non-intrinsic instruction we need to tell the (old) call
graph about it. This caused problems with some features down the line as
they allowed to removed calls more aggressively.
If we have a recursive function we could create multiple instantiations
of an SSA value, one per recursive invocation of the function. This is a
problem as we use SSA value equality in various places. The basic idea
follows from this test:
```
static int r(int c, int *a) {
int X;
return c ? r(false, &X) : a == &X;
}
int test(int c) {
return r(c, undef);
}
```
If we look through the argument `a` we will end up with `X`. Using SSA
value equality we will fold `a == &X` to true and return true even
though it should have been false because `a` and `&X` are from different
instantiations of the function.
Various tests for this have been placed in value-simplify-instances.ll
and this commit fixes them all by avoiding to produce simplified values
that could be non-unique at runtime. Thus, the result of a simplify
value call will always be unique at runtime or the original value, both
do not allow to accidentally compare two instances of a value with each
other and conclude they are equal statically (pointer equivalence) while
they are unequal at runtime.
A call that is analyzed in an optimization needs to be verified against
the name and type of the runtime function to avoid that we look at
arguments that do not exist (anymore). This can happen if the signature
was rewritten. Since we will not set RFI.Declaration if the type doesn't
match we can use it (if it's not null) to determine if the signature is
as expected.
Differential Revision: https://reviews.llvm.org/D106341
This patch strips the NoInline attribute from known OpenMP runtime functions.
This is done so that we can denote certain runtime functions as NoInline to
ensure their call sites are intact so they can be checked by OpenMPOpt. We
don't wan't this noinline attribute to remain for any functions after OpenMPOpt
has been run however.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106482
This patch adds the ability to fold `__kmpc_is_generic_main_thread_id` if we
know for a fact that it is executed by the initial thread using
AAExecutionDomain. This combined with folding `__kmpc_is_spmd_exec_mode` will
allow us to fully fold `__kmpc_is_generic_main_thread`.
Depends on D106438 D106437
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106439
Function internalization can sometimes occur in situations where we want to
keep the call sites intact. This patch adds an option to disable function
internalization and prevents the device runtime from being internalized while
creating the bitcode library.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106438
Alina Sbirlea