Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`. `id` gets propagated to the ID field
in the generated StackMap section. If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.
This change brings statepoints one step closer to patchpoints. With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.
PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`. This can be made more sophisticated
later.
Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9546
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DEBUG_VALUE nodes do not take part in code generation. Ignore them when
performing KILL updates. Addresses PR23486.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237211 91177308-0d34-0410-b5e6-96231b3b80d8
We already had a method to iterate over all the incoming values of a PHI. This just changes all eligible code to use it.
Ineligible code included anything which cared about the index, or was also trying to get the i'th incoming BB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237169 91177308-0d34-0410-b5e6-96231b3b80d8
According to the documentation in StackMap section for the safepoint we should have:
"The first Location in each pair describes the base pointer for the object. The second is the derived pointer actually being relocated."
But before this change we emitted them in reverse order - derived pointer first, base pointer second.
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to use the information in the module rather than TargetOptions.
We've had and clang has used the use-soft-float attribute for some
time now so have the backends set a subtarget feature based on
a particular function now that subtargets are created based on
functions and function attributes.
For the one middle end soft float check go ahead and create
an overloadable TargetLowering::useSoftFloat function that
just checks the TargetSubtargetInfo in all cases.
Also remove the command line option that hard codes whether or
not soft-float is set by using the attribute for all of the
target specific test cases - for the generic just go ahead and
add the attribute in the one case that showed up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237079 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The original code inserted new instructions by following a
Create->Remove->ReInsert flow. This patch removes the unnecessary
Remove->ReInsert part by setting up the InsertPoint correctly at the
very beginning. This change does not introduce any functionality change.
Patch by Chen Li!
Reviewers: reames, AndyAyers, sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9687
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237070 91177308-0d34-0410-b5e6-96231b3b80d8
This is a less ambitious version of:
http://reviews.llvm.org/rL236546
because that was reverted in:
http://reviews.llvm.org/rL236600
because it caused memory corruption that wasn't related to FMF
but was actually due to making nodes with 2 operands derive from a
plain SDNode rather than a BinarySDNode.
This patch adds the minimum plumbing necessary to use IR-level
fast-math-flags (FMF) in the backend without actually using
them for anything yet. This is a follow-on to:
http://reviews.llvm.org/rL235997
...which split the existing nsw / nuw / exact flags and FMF
into their own struct.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237046 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In RewriteStatepointsForGC pass, we create a gc_relocate intrinsic for
each relocated pointer, and the gc_relocate has the same type with the
pointer. During the creation of gc_relocate intrinsic, llvm requires to
mangle its type. However, llvm does not support mangling of all possible
types. RewriteStatepointsForGC will hit an assertion failure when it
tries to create a gc_relocate for pointer to vector of pointers because
mangling for vector of pointers is not supported.
This patch changes the way RewriteStatepointsForGC pass creates
gc_relocate. For each relocated pointer, we erase the type of pointers
and create an unified gc_relocate of type i8 addrspace(1)*. Then a
bitcast is inserted to convert the gc_relocate to the correct type. In
this way, gc_relocate does not need to deal with different types of
pointers and the unsupported type mangling is no longer a problem. This
change would also ease further merge when LLVM erases types of pointers
and introduces an unified pointer type.
Some minor changes are also introduced to gc_relocate related part in
InstCombineCalls, CodeGenPrepare, and Verifier accordingly.
Patch by Chen Li!
Reviewers: reames, AndyAyers, sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9592
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The bug showed up as a compile-time assertion failure:
Assertion `NumBits >= MIN_INT_BITS && "bitwidth too small"' failed
when building msan tests on x86-64.
Prior to r236850, this bug was masked due to a bogus alignment check,
which also accidentally rejected non-byte-sized accesses. Afterwards,
an invalid ElementSizeBytes == 0 got further into the function, and
triggered the assertion failure.
It would probably be a good idea to allow it to handle merging stores
of unusual widths as well, but for now, to un-break it, I'm just
making the minimal fix.
Differential Revision: http://reviews.llvm.org/D9626
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When emitting something like 'add x, 1000' if we remat the 1000 then we should be able to
mark the vreg containing 1000 as killed. Given that we go bottom up in fast-isel, a later
use of 1000 will be higher up in the BB and won't kill it, or be impacted by the lower kill.
However, rematerialised constant expressions aren't generated bottom up. The local value save area
grows downwards. This means that if you remat 2 constant expressions which both use 1000 then the
first will kill it, then the second, which is *lower* in the BB will read a killed register.
This is the case in the attached test where the 2 GEPs both need to generate 'add x, 6680' for the constant offset.
Note that this commit only makes kill flag generation conservative. There's nothing else obviously wrong with
the local value save area growing downwards, and in fact it needs to for handling arbitrarily complex constant expressions.
However, it would be nice if there was a solution which would let us generate more accurate kill flags, or just kill flags completely.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236922 91177308-0d34-0410-b5e6-96231b3b80d8
The code that builds the dependence graph assumes that two PseudoSourceValues
don't alias. In a tail calling function two FixedStackObjects might refer to the
same location. Worse 'immutable' fixed stack objects like function arguments are
not immutable and will be clobbered.
Change this so that a load from a FixedStackObject is not invariant in a tail
calling function and don't return a PseudoSourceValue for an instruction in tail
calling functions when building the dependence graph so that we handle function
arguments conservatively.
Fix for PR23459.
rdar://20740035
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When selecting an extract instruction, we don't actually generate code but instead work out which register we are reading, and rewrite uses of the extract def to the source register. This is done via updateValueMap,.
However, its possible that the source register we are rewriting *to* to also have uses. If those uses are after a kill of the value we are rewriting *from* then we have uses after a kill and the verifier fails.
This code checks for the case where the to register is also used, and if so it clears all kill on the from register. This is conservative, but better that always clearing kills on the from register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236897 91177308-0d34-0410-b5e6-96231b3b80d8
This changes the shape of the statepoint intrinsic from:
@llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 unused, ...call args, i32 # deopt args, ...deopt args, ...gc args)
to:
@llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 flags, ...call args, i32 # transition args, ...transition args, i32 # deopt args, ...deopt args, ...gc args)
This extension offers the backend the opportunity to insert (somewhat) arbitrary code to manage the transition from GC-aware code to code that is not GC-aware and back.
In order to support the injection of transition code, this extension wraps the STATEPOINT ISD node generated by the usual lowering lowering with two additional nodes: GC_TRANSITION_START and GC_TRANSITION_END. The transition arguments that were passed passed to the intrinsic (if any) are lowered and provided as operands to these nodes and may be used by the backend during code generation.
Eventually, the lowering of the GC_TRANSITION_{START,END} nodes should be informed by the GC strategy in use for the function containing the intrinsic call; for now, these nodes are instead replaced with no-ops.
Differential Revision: http://reviews.llvm.org/D9501
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The test here was sinking the AND here to a lower BB:
%vreg7<def> = ANDWri %vreg8, 0; GPR32common:%vreg7,%vreg8
TBNZW %vreg8<kill>, 0, <BB#1>; GPR32common:%vreg8
which meant that vreg8 was read after it was killed.
This commit changes the code from clearing kill flags on the AND to clearing flags on all registers used by the AND.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236886 91177308-0d34-0410-b5e6-96231b3b80d8
1) check whether the alignment of the memory is sufficient for the
*merged* store or load to be efficient.
Not doing so can result in some ridiculously poor code generation, if
merging creates a vector operation which must be aligned but isn't.
2) DON'T check that the alignment of each load/store is equal. If
you're merging 2 4-byte stores, the first *might* have 8-byte
alignment, but the second certainly will have 4-byte alignment. We do
want to allow those to be merged.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236850 91177308-0d34-0410-b5e6-96231b3b80d8
If we duplicate an instruction then we must also clear kill flags on any uses we rewrite.
Otherwise we might be killing a register which was used in other BBs.
For example, here the entry BB ended up with these instructions, the ADD having been tail duplicated.
%vreg24<def> = t2ADDri %vreg10<kill>, 1, pred:14, pred:%noreg, opt:%noreg; GPRnopc:%vreg24 rGPR:%vreg10
%vreg22<def> = COPY %vreg10; GPR:%vreg22 rGPR:%vreg10
The copy here is inserted after the add and so needs vreg10 to be live.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236782 91177308-0d34-0410-b5e6-96231b3b80d8
After r236617, branch probabilities are no longer guaranteed to be >= 1. This
patch makes the swich lowering code handle that correctly, without bumping the
branch weights by 1 which might cause overflow and skews the probabilities.
Covered by @zero_weight_tree in test/CodeGen/X86/switch.ll.
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We had code such as this:
r2 = ...
t2Bcc
label1:
ldr ... r2
label2;
return r2<dead, def>
The if converter was transforming this to
r2<def> = ...
return [pred] r2<dead,def>
ldr <r2, kill>
return
which fails the machine verifier because the ldr now reads from a dead def.
The fix here detects dead defs in stepForward and passes them back to the caller in the clobbers list. The caller then clears the dead flag from the def is the value is live.
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demanded by the machine verifier.
After shrinking a live-range to its uses, it is possible to create several
smaller live-ranges. When this happens, shrinkToUses returns true and we need to
split the different components into their own live-ranges.
The problem does not reproduce on any in-tree target but Jonas Paulsson
<jonas.paulsson@ericsson.com>, who reported the problem, checked that this patch
fixes the issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236658 91177308-0d34-0410-b5e6-96231b3b80d8
If called twice in the same BB on the same constant, FastISel::fastEmit_ri_ was marking the materialized vreg as killed on each use, instead of only the last use.
Change this to only mark the last use as killed by making earlier uses check if the vreg is already used elsewhere.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236650 91177308-0d34-0410-b5e6-96231b3b80d8
Don't create names for temporary symbols when using an object streamer.
The names never make it to the output anyway. From the starting point
of r236629, my heap profile says this drops peak memory usage from 1100
MB to 1058 MB for CodeGen of `verify-uselistorder`, a savings of almost
4% on peak memory, and removes `StringMap<bool, BumpPtrAllocator...>`
from the profile entirely.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
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It's quite possible to encounter an insertvalue instruction that's more deeply
nested than the value we're looking for, but when that happens we really
mustn't compare beyond the end of the index array.
Since I couldn't see any guarantees about what comparisons std::equal makes, we
probably need to directly check the size beforehand. In practice, I suspect
most std::equal implementations would probably bail early, which would be OK.
But just in case...
rdar://20834485
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236635 91177308-0d34-0410-b5e6-96231b3b80d8
Emit the number of bytes in a `.debug_loc` entry directly. The old code
created temp labels (expensive), emitted the difference between them,
and then emitted one on each side of the relevant bytes.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`
(the optimized version of ld64's `-save-temps` when linking the
`verify-uselistorder` executable in an LTO bootstrap). I've hacked
`MCContext::Allocate()` to just call `malloc()` instead of using the
`BumpPtrAllocator` so that the heap profile is easier to read. As far
as peak memory is concerned, `MCContext::Allocate()` is equivalent to a
leak, since it only gets freed at process teardown.
In my heap profile, this patch drops memory usage of
`DwarfDebug::emitDebugLoc()` from 132.56 MB (11.4%) down to 29.86 MB
(2.7%) at peak memory. Some of that must be noise from `SmallVector`
(or other) allocations -- peak memory only dropped from 1160 MB down to
1100 MB -- but this nevertheless shaves 5% off the top.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236629 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When computing branch weights in BPI, we used to disallow branches with
weight 0. This is a minor nuisance, because a branch with weight 0 is
different to "don't have information". In the context of
instrumentation, it may mean "never executed", in the context of
sampling, it means "never or seldom executed".
In allowing 0 weight branches, I ran into issues with the switch
expansion code in selection DAG. It is currently hardwired to not handle
branches with weight 0. To maintain the current behaviour, I changed it
to use 1 when it finds 0, but perhaps the algorithm needs changes to
tolerate branches with weight zero.
Reviewers: hansw
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9533
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Summary: This patch correctly handles undef case of EXTRACT_VECTOR_ELT node where the element index is constant and not less than vector size.
Test Plan:
CodeGen for X86 test included.
Also one incorrect regression test fixed.
Reviewers: qcolombet, chandlerc, hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, llvm-commits
Differential Revision: http://reviews.llvm.org/D9250
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236584 91177308-0d34-0410-b5e6-96231b3b80d8
For accessors in the `Statepoint` class, use symbolic constants for
offsets into the argument vector instead of literals. This makes the
code intent clearer and simpler to change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236566 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We default the value argument to nullptr. The only use of the value is
in diagnosePossiblyInvalidConstraint and that seems to be resilient to
it being nullptr.
Reviewers: atrick, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9479
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Summary:
The exported class will be used in later change, in
StatepointLowering.cpp. It is still internal to SelectionDAG (not
exported via include/).
Reviewers: reames, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9478
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236554 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently this does not change anything, but change will be used in a
later change to StatepointLowering.cpp
Reviewers: reames, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9477
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236553 91177308-0d34-0410-b5e6-96231b3b80d8
