This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.
Patch by Matthias Braun
llvm-svn: 363757
The goal is to improve hwasan's error reporting for stack use-after-return by
recording enough information to allow the specific variable that was accessed
to be identified based on the pointer's tag. Currently we record the PC and
lower bits of SP for each stack frame we create (which will eventually be
enough to derive the base tag used by the stack frame) but that's not enough
to determine the specific tag for each variable, which is the stack frame's
base tag XOR a value (the "tag offset") that is unique for each variable in
a function.
In IR, the tag offset is most naturally represented as part of a location
expression on the llvm.dbg.declare instruction. However, the presence of the
tag offset in the variable's actual location expression is likely to confuse
debuggers which won't know about tag offsets, and moreover the tag offset
is not required for a debugger to determine the location of the variable on
the stack, so at the DWARF level it is represented as an attribute so that
it will be ignored by debuggers that don't know about it.
Differential Revision: https://reviews.llvm.org/D63119
llvm-svn: 363635
Inter-block localization is the same as what currently happens, except now it
only runs on the entry block because that's where the problematic constants with
long live ranges come from.
The second phase is a new intra-block localization phase which attempts to
re-sink the already localized instructions further right before one of the
multiple uses.
One additional change is to also localize G_GLOBAL_VALUE as they're constants
too. However, on some targets like arm64 it takes multiple instructions to
materialize the value, so some additional heuristics with a TTI hook have been
introduced attempt to prevent code size regressions when localizing these.
Overall, these changes improve CTMark code size on arm64 by 1.2%.
Full code size results:
Program baseline new diff
------------------------------------------------------------------------------
test-suite...-typeset/consumer-typeset.test 1249984 1217216 -2.6%
test-suite...:: CTMark/ClamAV/clamscan.test 1264928 1232152 -2.6%
test-suite :: CTMark/SPASS/SPASS.test 1394092 1361316 -2.4%
test-suite...Mark/mafft/pairlocalalign.test 731320 714928 -2.2%
test-suite :: CTMark/lencod/lencod.test 1340592 1324200 -1.2%
test-suite :: CTMark/kimwitu++/kc.test 3853512 3820420 -0.9%
test-suite :: CTMark/Bullet/bullet.test 3406036 3389652 -0.5%
test-suite...ark/tramp3d-v4/tramp3d-v4.test 8017000 8016992 -0.0%
test-suite...TMark/7zip/7zip-benchmark.test 2856588 2856588 0.0%
test-suite...:: CTMark/sqlite3/sqlite3.test 765704 765704 0.0%
Geomean difference -1.2%
Differential Revision: https://reviews.llvm.org/D63303
llvm-svn: 363632
Summary: This case is related to D63405 in that we need to be propagating FMF on negates.
Reviewers: volkan, spatel, arsenm
Reviewed By: arsenm
Subscribers: wdng, javed.absar
Differential Revision: https://reviews.llvm.org/D63458
llvm-svn: 363631
Summary:
Change the way we deal with iterator invalidation in the extload combines as it
was still possible to neglect to visit a use. Even worse, it happened in the
in-tree test cases and the checks weren't good enough to detect it.
We now take a cheap copy of the use list before iterating over it. This
prevents iterator invalidation from occurring and has the nice side effect
of making the existing schedule-for-erase/schedule-for-insert mechanism
moot.
Reviewers: aditya_nandakumar
Reviewed By: aditya_nandakumar
Subscribers: rovka, kristof.beyls, javed.absar, volkan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61813
llvm-svn: 363616
Basically porting over the behaviour in AArch64ISelLowering to GISel. See
emitComparison for reference.
When we have something like this:
```
lhs = G_SUB 0, y
...
G_ICMP lhs, rhs
```
We can fold away the G_SUB and produce a cmn instead, given that we produce
the same value in NZCV.
Add a test showing that the transformation works, and also showing that we
don't perform the transformation when it's unsafe.
Also factor out the CSet emission into emitCSetForICMP.
Differential Revision: https://reviews.llvm.org/D63163
llvm-svn: 363596
This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.
This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.
Reviewers: arsenm, thegameg, qcolombet
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D60137
llvm-svn: 363533
Third time's the charm.
This was reverted in r363220 due to being suspected of an internal benchmark
regression and a test failure, none of which turned out to be caused by this.
llvm-svn: 363529
This reverts rL363474. -debug-only=isel was added to some tests that
don't specify `REQUIRES: asserts`. This causes failures on
-DLLVM_ENABLE_ASSERTIONS=off builds.
I chose to revert instead of fixing the tests because I'm not sure
whether we should add `REQUIRES: asserts` to more tests.
llvm-svn: 363482
Current findBestLoopTop can find and move one kind of block to top, a latch block has one successor. Another common case is:
* a latch block
* it has two successors, one is loop header, another is exit
* it has more than one predecessors
If it is below one of its predecessors P, only P can fall through to it, all other predecessors need a jump to it, and another conditional jump to loop header. If it is moved before loop header, all its predecessors jump to it, then fall through to loop header. So all its predecessors except P can reduce one taken branch.
Differential Revision: https://reviews.llvm.org/D43256
llvm-svn: 363471
This is a branch opcode that takes a jump table pointer, jump table index and an
index into the table to do an indirect branch.
We pass both the table pointer and JTI to allow targets like ARM64 to more
easily use the existing jump table compression optimization without having to
walk up the block to find a paired G_JUMP_TABLE.
Differential Revision: https://reviews.llvm.org/D63159
llvm-svn: 363434
Constants, including G_GLOBAL_VALUE, are all emitted into the entry block which
lets us use the vreg def assuming it dominates all other users. However, it can
cause jumpy debug behaviour since the DebugLoc attached to these MIs are from
a user instruction that could be in a different block.
Fixes PR40887.
Differential Revision: https://reviews.llvm.org/D63286
llvm-svn: 363331
Summary:
Relate bug: https://bugs.llvm.org/show_bug.cgi?id=37472
The shrink wrapping pass prematurally restores the stack, at a point where the stack might still be accessed.
Taking an exception can cause the stack to be corrupted.
As a first approach, this patch is overly conservative, assuming that any instruction that may load or store could access
the stack.
Reviewers: dmgreen, qcolombet
Reviewed By: qcolombet
Subscribers: simpal01, efriedma, eli.friedman, javed.absar, llvm-commits, eugenis, chill, carwil, thegameg
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63152
llvm-svn: 363265
This patch uses the mechanism from D62995 to strengthen the
definitions of the reduction intrinsics by letting the scalar
result/accumulator type be overloaded from the vector element type.
For example:
; The LLVM LangRef specifies that the scalar result must equal the
; vector element type, but this is not checked/enforced by LLVM.
declare i32 @llvm.experimental.vector.reduce.or.i32.v4i32(<4 x i32> %a)
This patch changes that into:
declare i32 @llvm.experimental.vector.reduce.or.v4i32(<4 x i32> %a)
Which has the type-constraint more explicit and causes LLVM to check
the result type with the vector element type.
Reviewers: RKSimon, arsenm, rnk, greened, aemerson
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D62996
llvm-svn: 363240
We have observed some failures with internal builds with this revision.
- Performance regressions:
- llvm's SingleSource/Misc evalloop shows performance regressions (although these may be red herrings).
- Benchmarks for Abseil's SwissTable.
- Correctness:
- Failures for particular libicu tests when building the Google AppEngine SDK (for PHP).
hwennborg has already been notified, and is aware of reproducer failures.
llvm-svn: 363220
Summary:
Fix hoisting to basic block which are not legal for hoisting cause
it can be terminated by exception or it is return block.
Reviewers: john.brawn, RKSimon, MatzeB
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63148
llvm-svn: 363164
Extern global merging is good for code-size. There's definitely potential for
performance too, but there's one regression in a benchmark that needs
investigating, so that's why we enable it only when we optimise for size for
now.
Patch by Ramakota Reddy and Sjoerd Meijer.
Differential Revision: https://reviews.llvm.org/D61947
llvm-svn: 363130
This patch changes how LLVM handles the accumulator/start value
in the reduction, by never ignoring it regardless of the presence of
fast-math flags on callsites. This change introduces the following
new intrinsics to replace the existing ones:
llvm.experimental.vector.reduce.fadd -> llvm.experimental.vector.reduce.v2.fadd
llvm.experimental.vector.reduce.fmul -> llvm.experimental.vector.reduce.v2.fmul
and adds functionality to auto-upgrade existing LLVM IR and bitcode.
Reviewers: RKSimon, greened, dmgreen, nikic, simoll, aemerson
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D60261
llvm-svn: 363035
If the source is undef, then just don't do anything.
This matches SelectionDAG's behaviour in SelectionDAG.cpp.
Also add a test showing that we do the right thing here.
(irtranslator-memfunc-undef.ll)
Differential Revision: https://reviews.llvm.org/D63095
llvm-svn: 362989
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.
This re-enables it for FastISel with the corresponding fix.
This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.
FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.
This fix moves the replacement of registers before the emission of
copies for the live-ins.
The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).
A few tests are affected by this:
* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed
Differential Revision: https://reviews.llvm.org/D62361
llvm-svn: 362963
Incorrect Debug Variable Range was calculated while "COMPUTING LIVE DEBUG VARIABLES" stage.
Range for Debug Variable("i") computed according to current state of instructions
inside of basic block. But Register Allocator creates new instructions which were not taken
into account when Live Debug Variables computed. In the result DBG_VALUE instruction for
the "i" variable was put after these newly inserted instructions. This is incorrect.
Debug Value for the loop counter should be inserted before any loop instruction.
Differential Revision: https://reviews.llvm.org/D62650
llvm-svn: 362750
This patch is a follow up for D62018 to add lrint/llrint
support for float16.
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D62863
llvm-svn: 362700
This patch is a follow up for D61391 to add lround/llround
support for float16.
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D62861
llvm-svn: 362698
We already get support for G_ZEXTLOAD to s32 from the importer, but it can't
deal with the SUBREG_TO_REG in the pattern. Tweaking the existing manual
selection code for G_LOAD to handle an additional SUBREG_TO_REG when dealing
with G_ZEXTLOAD isn't much work.
Also add tests to check the imported pattern selections to s32 work.
llvm-svn: 362681
When looking through copies, make sure to not try to find the vreg def of a physreg.
Normally getVRegDef will return nullptr in this case, but if there happens to be
multiple defs then it will assert.
This fixes PR42129.
llvm-svn: 362666
Although we had the support in the prelegalizer combiner to generate the
G_SEXTLOAD or G_ZEXTLOAD ops, the legalizer definitions for arm64 had them as
lowering back to separate ops.
llvm-svn: 362553
Summary:
Following the cleanup in D48202, method foldBlockIntoPredecessor has the
same behavior. Replace its uses with MergeBlockIntoPredecessor.
Remove foldBlockIntoPredecessor.
Reviewers: chandlerc, dmgreen
Subscribers: jlebar, javed.absar, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62751
llvm-svn: 362538
Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.
As far as i can tell, there are no regressions here (ignoring x86-32),
all changes are either good or neutral.
This, almost surprisingly to me, fixes the motivational tests (in `shift-amount-mod.ll`)
`@reg32_lshr_by_sub_from_negated` from [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].
https://rise4fun.com/Alive/vMd3
Reviewers: RKSimon, t.p.northover, craig.topper, spatel, efriedma
Reviewed By: RKSimon
Subscribers: sdardis, javed.absar, arichardson, kristof.beyls, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62774
llvm-svn: 362488
Instead of emitting all of the test stuff for a compare when it's only used by
a select, instead, just emit the compare + select. The select will use the
value of NZCV correctly, so we don't need to emit all of the test instructions
etc.
For now, only support fp selects which use G_FCMP. Also only support condition
codes which will only require one select to represent.
Also add a test.
Differential Revision: https://reviews.llvm.org/D62695
llvm-svn: 362446
Add (opt-in) support for implicit truncation to isConstOrConstSplat, which allows us to match truncated 'all ones' cases in isBitwiseNot.
PR41020 compares against using ISD::isBuildVectorAllOnes() instead, but that predicate silently accepts any UNDEF elements in the build vector which might not be what we want in isBitwiseNot - so I've added an opt-in 'AllowUndefs' flag that is set to false by default but will allow us to enable it on individual cases where its safe.
Differential Revision: https://reviews.llvm.org/D62783
llvm-svn: 362323
I have initially added it in for test to display both
whether the binop w/ constant is sinked or hoisted.
But as it can be seen from the 'sub (sub C, %x), %y'
test, that actually conceals the issues it is supposed to test.
At least two more patterns are unhandled:
* 'add (sub C, %x), %y' - D62266
* 'sub (sub C, %x), %y'
llvm-svn: 362295
Summary:
Only vector tests are being affected here,
since subtraction by scalar constant is rewritten
as addition by negated constant.
No surprising test changes.
https://rise4fun.com/Alive/pbT
This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs.
Reviewers: RKSimon, craig.topper, spatel
Reviewed By: RKSimon
Subscribers: javed.absar, kristof.beyls, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62257
llvm-svn: 362146
Summary:
Again only vectors affected. Frustrating. Let me take a look into that..
https://rise4fun.com/Alive/AAq
This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.
Reviewers: RKSimon, craig.topper, spatel
Reviewed By: RKSimon
Subscribers: javed.absar, JDevlieghere, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62294
llvm-svn: 362145
Matt Arsenault