Fixes two latent bugs:
- There was no fence inserted before expanded seq_cst load (unsound on Power)
- There was only a fence release before seq_cst stores (again unsound, in particular on Power)
It is not even clear if this is correct on ARM swift processors (where release fences are
DMB ishst instead of DMB ish). This behaviour is currently preserved on ARM Swift
as it is not clear whether it is incorrect. I would love to get documentation stating
whether it is correct or not.
These two bugs were not triggered because Power is not (yet) using this pass, and these
behaviours happen to be (mostly?) working on ARM
(although they completely butchered the semantics of the llvm IR).
See:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075821.html
for an example of the problems that can be caused by the second of these bugs.
I couldn't see a way of fixing these in a completely target-independent way without
adding lots of unnecessary fences on ARM, hence the target-dependent parts of this
patch.
This patch implements the new target-dependent parts only for ARM (the default
of not doing anything is enough for AArch64), other architectures will use this
infrastructure in later patches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217076 91177308-0d34-0410-b5e6-96231b3b80d8
This is the final round of renaming. This changes tblgen to emit lower-case
function names for FastEmitInst_* and FastEmit_*, and updates all its uses
in the source code.
Reviewed by Eric
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217075 91177308-0d34-0410-b5e6-96231b3b80d8
Things got a little bit messy over the years and it is time for a little bit
spring cleaning.
This first commit is focused on the FastISel base class itself. It doxyfies all
comments, C++11fies the code where it makes sense, renames internal methods to
adhere to the coding standard, and clang-formats the files.
Reviewed by Eric
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217060 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a crash in the OpenCV test:
ImgprocWarpResizeArea/Resize.Mat/16
There is no test case for this, because this failure depends on a
specific ordering of the loads, which could easily change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217040 91177308-0d34-0410-b5e6-96231b3b80d8
This reapplies r216805 with a fix to a copy-past error, which resulted in an
incorrect register class.
Original commit message:
Select the correct register class for the various instructions that are
generated when combining instructions and constrain the registers to the
appropriate register class.
This fixes rdar://problem/18183707.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217019 91177308-0d34-0410-b5e6-96231b3b80d8
There is already target-dependent instruction selection support for Adds/Subs to
support compares and the intrinsics with overflow check. This takes advantage of
the existing infrastructure to also support Add/Sub, which allows the folding of
immediates, sign-/zero-extends, and shifts.
This fixes rdar://problem/18207316.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217007 91177308-0d34-0410-b5e6-96231b3b80d8
This uses the target-dependent selection code for shifts first, which allows us
to create better code for shifts with immediates and sign-/zero-extend folding.
Vector type are not handled yet and the code falls back to target-independent
instruction selection for these cases.
This fixes rdar://problem/17907920.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216985 91177308-0d34-0410-b5e6-96231b3b80d8
FastISel for AArch64 supports more value types than are actually legal. Use a
dedicated helper function to reflect this.
It is very similar to the isLoadStoreTypeLegal function, with the exception
that vector types are not supported yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216984 91177308-0d34-0410-b5e6-96231b3b80d8
Approved by Jim Grosbach, Lang Hames, Rafael Espindola.
This reinstates commits r215111, 215115, 215116, 215117, 215136.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216982 91177308-0d34-0410-b5e6-96231b3b80d8
The only valid lowering of atomic stores in the X86 backend was mov from
register to memory. As a result, storing an immediate required a useless copy
of the immediate in a register. Now these can be compiled as a simple mov.
Similarily, adding/and-ing/or-ing/xor-ing an
immediate to an atomic location (but through an atomic_store/atomic_load,
not a fetch_whatever intrinsic) can now make use of an 'add $imm, x(%rip)'
instead of using a register. And the same applies to inc/dec.
This second point matches the first issue identified in
http://llvm.org/bugs/show_bug.cgi?id=17281
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This change moves FastISel for AArch64 to target-dependent instruction selection
only. This change replicates the existing target-independent behavior, therefore
there are no changes to the unit tests or new tests.
Future changes will take advantage of this change and update functionality
and unit tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216955 91177308-0d34-0410-b5e6-96231b3b80d8
We duplicate ~30 lines of code to lower FABS and FNEG for x86, so this patch combines them into one function.
No functional change intended, so no additional test cases. Test-suite behavior is unchanged.
Differential Revision: http://reviews.llvm.org/D5064
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216942 91177308-0d34-0410-b5e6-96231b3b80d8
Also fix a small copy-paste bug in X86ISelLowering where Chain should
have been used in place of DAG.getEntryToken().
Fixes PR20828.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216929 91177308-0d34-0410-b5e6-96231b3b80d8
This removes static initializers from the backends which generate this data, and also makes this struct match the other Tablegen generated structs in behaviour
Reviewed by Andy Trick and Chandler C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216919 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Left shift of negative integer is an undefined behavior, and
is reported by UBSan. It's ok for imm values to be negative, so we can
just replace left shifts with multiplications.
Test Plan: check-llvm test suite
Reviewers: t.p.northover
Reviewed By: t.p.northover
Subscribers: aemerson, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D5132
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216910 91177308-0d34-0410-b5e6-96231b3b80d8
r208640 was reverted because it caused a self-hosting failure on ppc64. The
underlying cause was the formation of ISD::ADD nodes with ISD::TargetConstant
operands. Because we have no patterns for 'add' taking 'timm' nodes, these are
selected as r+r add instructions (which is a miscompile). Guard against this
kind of behavior in the future by making the backend crash should this occur
(instead of silently generating invalid output).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216897 91177308-0d34-0410-b5e6-96231b3b80d8
The structures for Windows unwinding are shared across multiple platforms.
Indicate the encoding to be used for the particular target. Use this to switch
the unwind emitter instantiated by the AsmPrinter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216895 91177308-0d34-0410-b5e6-96231b3b80d8
This change will ease refactoring LowerFABS() and LowerFNEG()
since they have a lot of overlap.
Remove the creation of a floating point constant from an integer
because it's going to be used for a bitwise integer op anyway.
No change to codegen expected, but the verbose comment string
for asm output may change from float values to hex (integer),
depending on whether the constant already exists or not.
Differential Revision: http://reviews.llvm.org/D5052
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216889 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a few changes related to the Thumb2 M-class MSR instruction:
* better handling of unpredictable encodings,
* recognition of the _g and _nzcvqg variants by the asm parser only if the DSP
extension is available, preferred output of MSR APSR moves with the _<bits>
suffix for v7-M.
Patch by Petr Pavlu.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216874 91177308-0d34-0410-b5e6-96231b3b80d8
Select the correct register class for the various instructions that are
generated when combining instructions and constrain the registers to the
appropriate register class.
This fixes rdar://problem/18183707.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216805 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If a variadic function body contains a musttail call, then we copy all
of the remaining register parameters into virtual registers in the
function prologue. We track the virtual registers through the function
body, and add them as additional registers to pass to the call. Because
this is all done in virtual registers, the register allocator usually
gives us good code. If the function does a call, however, it will have
to spill and reload all argument registers (ew).
Forwarding regparms on x86_32 is not implemented because most compilers
don't support varargs in 32-bit with regparms.
Reviewers: majnemer
Subscribers: aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D5060
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216780 91177308-0d34-0410-b5e6-96231b3b80d8
We've rejected these kinds of functions since r28405 in 2006 because
it's impossible to lower the return of a callee cleanup varargs
function. However there are lots of legal ways to leave such a function
without returning, such as aborting. Today we can leave a function with
a musttail call to another function with the correct prototype, and
everything works out.
I'm removing the verifier check declaring that a normal return from such
a function is UB.
Reviewed By: nlewycky
Differential Revision: http://reviews.llvm.org/D5059
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216779 91177308-0d34-0410-b5e6-96231b3b80d8
This patch checks for DAG patterns that are an add or a sub followed by a
compare on 16 and 8 bit inputs. Since AArch64 does not support those types
natively they are legalized into 32 bit values, which means that mask operations
are inserted into the DAG to emulate overflow behaviour. In many cases those
masks do not change the result of the processing and just introduce a dependent
operation, often in the middle of a hot loop.
This patch detects the relevent DAG patterns and then tests to see if the
transforms are equivalent with and without the mask, removing the mask if
possible. The exact mechanism of this patch was discusses in
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074444.html
There is a reasonably good chance there are missed oppurtunities due to similiar
(but not identical) DAG patterns that could be funneled into this test, adding
them should be simple if we see test cases.
Tests included.
rdar://13754426
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The new solution is to not use this lowering if there are any dynamic
allocas in the current function. We know up front if there are dynamic
allocas, but we don't know if we'll need to create stack temporaries
with large alignment during lowering. Conservatively assume that we will
need such temporaries.
Reviewed By: hans
Differential Revision: http://reviews.llvm.org/D5128
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216775 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Mostly renaming the (not very explicit) variables Tmp0, .. Tmp4, and grouping
related statements together, along with a few lines of comments for the
surprising parts.
No functional change intended.
Test Plan: make check-all
Reviewers: jfb
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5088
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216768 91177308-0d34-0410-b5e6-96231b3b80d8
When we select a trunc instruction we don't emit any code if the type is already
i32 or smaller. This is because the instruction that uses the truncated value
will deal with it.
This behavior can incorrectly transfer a kill flag, which was meant for the
result of the truncate, onto the source register.
%2 = trunc i32 %1 to i16
... = ... %2 -> ... = ... vreg1 <kill>
... = ... %1 ... = ... vreg1
This commit fixes this by emitting a COPY instruction, so that the result and
source register are distinct virtual registers.
This fixes rdar://problem/18178188.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216750 91177308-0d34-0410-b5e6-96231b3b80d8
A bug in r216725 meant we tried to discover the type of a SETCC before
confirming the node actually was a SETCC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216734 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Instead of specifying the alignment as metadata which may be destroyed by
transformation passes, make the alignment the second argument to ldu/ldg
intrinsic calls.
Test Plan:
ldu-ldg.ll
ldu-i8.ll
ldu-reg-plus-offset.ll
Reviewers: eliben, meheff, jholewinski
Reviewed By: meheff, jholewinski
Subscribers: jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D5093
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216731 91177308-0d34-0410-b5e6-96231b3b80d8
In an llvm-stress generated test, we were trying to create a v0iN type and
asserting when that failed. This case could probably be handled by the
function, but not without added complexity and the situation it arises in is
sufficiently odd that there's probably no benefit anyway.
Should fix PR20775.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216725 91177308-0d34-0410-b5e6-96231b3b80d8
and forget about the previously used accumulator.
Coming up with a simple testcase is not easy, as this highly depends on
what the register allocator is doing: this issue showed up while working
with the PBQP allocator, which produced a different allocation scheme.
A testcase would need to come up with chain starting in D[0-7], then
moving to D[8-15], followed by a call to a function whose regmask
clobbers the starting accumulator in D[0-7], then another use of the chain.
Fixed some formatting, added some invariant checks while there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216721 91177308-0d34-0410-b5e6-96231b3b80d8
Added new types to Legalizer.
Fixed getSetCCResultType function
Added lowering tests.
Reviewed by Elena Demikhovsky.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216717 91177308-0d34-0410-b5e6-96231b3b80d8
This fix checks first if the instruction to be folded (e.g. sign-/zero-extend,
or shift) is in the same machine basic block as the instruction we are folding
into.
Not doing so can result in incorrect code, because the value might not be
live-out of the basic block, where the value is defined.
This fixes rdar://problem/18169495.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216700 91177308-0d34-0410-b5e6-96231b3b80d8
The AArch64 target lowering for [zs]ext of vectors is set up to handle
input simple types and expects the generic SDag path to do something reasonable
with anything that's not a simple type. The code, however, was only
checking that the result type was a simple type and assuming that
implied that the source type would also be a simple type. That's not a
valid assumption, as operations like "zext <1 x i1> %0 to <1 x i32>"
demonstrate. The fix is to simply explicitly validate the source type
as well as the result type.
PR20791
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216689 91177308-0d34-0410-b5e6-96231b3b80d8
a single early exit.
And factor the subsequent cast<> from all but one block into a single
variable.
No functionality changed.
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functionality changed.
Separating this into two functions wasn't helping. There was a decent
amount of boilerplate duplicated, and some subsequent refactorings here
will pull even more common code out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216644 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Introduce support::ulittleX_t::ref type to Support/Endian.h and use it in x86 JIT
to enforce correct endianness and fix unaligned accesses.
Test Plan: regression test suite
Reviewers: lhames
Subscribers: ributzka, llvm-commits
Differential Revision: http://reviews.llvm.org/D5011
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216631 91177308-0d34-0410-b5e6-96231b3b80d8
Currently instructions are folded very aggressively into the memory operation,
which can lead to the use of killed operands:
%vreg1<def> = ADDXri %vreg0<kill>, 2
%vreg2<def> = LDRBBui %vreg0, 2
... = ... %vreg1 ...
This usually happens when the result is also used by another non-memory
instruction in the same basic block, or any instruction in another basic block.
If the computed address is used by only memory operations in the same basic
block, then it is safe to fold them. This is because all memory operations will
fold the address computation and the original computation will never be emitted.
This fixes rdar://problem/18142857.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216629 91177308-0d34-0410-b5e6-96231b3b80d8
When the address comes directly from a shift instruction then the address
computation cannot be folded into the memory instruction, because the zero
register is not available as a base register. Simplify addess needs to emit the
shift instruction and use the result as base register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216621 91177308-0d34-0410-b5e6-96231b3b80d8
Use the zero register directly when possible to avoid an unnecessary register
copy and a wasted register at -O0. This also uses integer stores to store a
positive floating-point zero. This saves us from materializing the positive zero
in a register and then storing it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216617 91177308-0d34-0410-b5e6-96231b3b80d8
Instructions like 'fxsave' and control flow instructions like 'jne'
match any operand size. The loop I added to the Intel syntax matcher
assumed that using a different size would give a different instruction.
Now it handles the case where we get the same instruction for different
memory operand sizes.
This also allows us to remove the hack we had for unsized absolute
memory operands, because we can successfully match things like 'jnz'
without reporting ambiguity. Removing this hack uncovered test case
involving 'fadd' that was ambiguous. The memory operand could have been
single or double precision.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216604 91177308-0d34-0410-b5e6-96231b3b80d8
int may not have enough bits in it, which was detected by UBSan
bootstrap (it reported left shift by a too large constant).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216579 91177308-0d34-0410-b5e6-96231b3b80d8
This teaches the AArch64 backend to deal with the operations required
to deal with the operations on v4f16 and v8f16 which are exposed by
NEON intrinsics, plus the add, sub, mul and div operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216555 91177308-0d34-0410-b5e6-96231b3b80d8
we stopped efficiently lowering sextload using the SSE41 instructions
for that operation.
This is a consequence of a bad predicate I used thinking of the memory
access needs. The code actually handles the cases where the predicate
doesn't apply, and handles them much better. =] Simple fix and a test
case added. Fixes PR20767.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216538 91177308-0d34-0410-b5e6-96231b3b80d8
This combine is essentially combining target-specific nodes back into target
independent nodes that it "knows" will be combined yet again by a target
independent DAG combine into a different set of target-independent nodes that
are legal (not custom though!) and thus "ok". This seems... deeply flawed. The
crux of the problem is that we don't combine un-legalized shuffles that are
introduced by legalizing other operations, and thus we don't see a very
profitable combine opportunity. So the backend just forces the input to that
combine to re-appear.
However, for this to work, the conditions detected to re-form the unlegalized
nodes must be *exactly* right. Previously, failing this would have caused poor
code (if you're lucky) or a crasher when we failed to select instructions.
After r215611 we would fall back into the legalizer. In some cases, this just
"fixed" the crasher by produces bad code. But in the test case added it caused
the legalizer and the dag combiner to iterate forever.
The fix is to make the alignment checking in the x86 side of things match the
alignment checking in the generic DAG combine exactly. This isn't really a
satisfying or principled fix, but it at least make the code work as intended.
It also highlights that it would be nice to detect the availability of under
aligned loads for a given type rather than bailing on this optimization. I've
left a FIXME to document this.
Original commit message for r215611 which covers the rest of the chang:
[SDAG] Fix a case where we would iteratively legalize a node during
combining by replacing it with something else but not re-process the
node afterward to remove it.
In a truly remarkable stroke of bad luck, this would (in the test case
attached) end up getting some other node combined into it without ever
getting re-processed. By adding it back on to the worklist, in addition
to deleting the dead nodes more quickly we also ensure that if it
*stops* being dead for any reason it makes it back through the
legalizer. Without this, the test case will end up failing during
instruction selection due to an and node with a type we don't have an
instruction pattern for.
It took many million runs of the shuffle fuzz tester to find this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216537 91177308-0d34-0410-b5e6-96231b3b80d8
When a shift with extension or an add with shift and extension cannot be folded
into the memory operation, then the address calculation has to be materialized
separately. While doing so the code forgot to consider a possible sign-/zero-
extension. This fix folds now also the sign-/zero-extension into the add or
shift instruction which is used to materialize the address.
This fixes rdar://problem/18141718.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216511 91177308-0d34-0410-b5e6-96231b3b80d8
The existing matcher has lots of AT&T assembly dialect assumptions baked
into it. In particular, the hack for resolving the size of a memory
operand by appending the four most common suffixes doesn't work at all.
The Intel assembly dialect mnemonic table has ambiguous entries, so we
need to try matching multiple times with different operand sizes, since
that's the only way to choose different instruction variants.
This makes us more compatible with gas's implementation of Intel
assembly syntax. MSVC assumes you want byte-sized operations for the
instructions that we reject as ambiguous.
Reviewed By: grosbach
Differential Revision: http://reviews.llvm.org/D4747
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216481 91177308-0d34-0410-b5e6-96231b3b80d8
It seems on Darwin the illegal round-trip ::iterator -> MachineInstr* -> ::iterator breaks execution horribly when the iterator is not a real MachineInstr, like ::end().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216455 91177308-0d34-0410-b5e6-96231b3b80d8
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.
A create static method would be even better, but this patch is already a bit too
big.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216393 91177308-0d34-0410-b5e6-96231b3b80d8
This actually was caught by existing tests but those tests were disabled
with an XFAIL because of PR20736. While working on fixing that,
I noticed the test failure, and tracked it down to this.
We even have a really nice Clang warning that would have caught this but
it isn't enabled in LLVM! =[ I may look at enabling it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216391 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support to recognize division by uniform power of 2 and modifies the cost table to vectorize division by uniform power of 2 whenever possible.
Updates Cost model for Loop and SLP Vectorizer.The cost table is currently only updated for X86 backend.
Thanks to Hal, Andrea, Sanjay for the review. (http://reviews.llvm.org/D4971)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216371 91177308-0d34-0410-b5e6-96231b3b80d8
Adds code generation support for dcbtst (data cache prefetch for write) and
icbt (instruction cache prefetch for read - Book E cores only).
We still end up with a 'cannot select' error for the non-supported prefetch
intrinsic forms. This will be fixed in a later commit.
Fixes PR20692.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216339 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r215862 due to nightly failures. Will work on getting a
reduced test case, but I wanted to get our bots green in the meantime.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216325 91177308-0d34-0410-b5e6-96231b3b80d8
these DAG combines.
The DAG auto-CSE thing is truly terrible. Due to it, when RAUW-ing
a node with its operand, you can cause its uses to CSE to itself, which
then causes their uses to become your uses which causes them to be
picked up by the RAUW. For nodes that are determined to be "no-ops",
this is "fine". But if the RAUW is one of several steps to enact
a transformation, this causes the DAG to really silently eat an discard
nodes that you would never expect. It took days for me to actually
pinpoint a test case triggering this and a really frustrating amount of
time to even comprehend the bug because I never even thought about the
ability of RAUW to iteratively consume nodes due to CSE-ing them into
itself.
To fix this, we have to build up a brand-new chain of operations any
time we are combining across (potentially) intervening nodes. But once
the logic is added to do this, another issue surfaces: CombineTo eagerly
deletes the one node combined, *but no others*. This is... really
frustrating. If deleting it makes its operands become dead, those
operand nodes often won't go onto the worklist in the
order you would want -- they're already on it and not near the top. That
means things higher on the worklist will get combined prior to these
dead nodes being GCed out of the worklist, and if the chain is long, the
immediate users won't be enough to re-detect where the root of the chain
is that became single-use again after deleting the dead nodes. The
better way to do this is to never immediately delete nodes, and instead
to just enqueue them so we can recursively delete them. The
combined-from node is typically not on the worklist anyways by virtue of
having been popped off.... But that in turn breaks other tests that
*require* CombineTo to delete unused nodes. :: sigh ::
Fortunately, there is a better way. This whole routine should have been
returning the replacement rather than using CombineTo which is quite
hacky. Switch to that, and all the pieces fall together.
I suspect the same kind of miscompile is possible in the half-shuffle
folding code, and potentially the recursive folding code. I'll be
switching those over to a pattern more like this one for safety's sake
even though I don't immediately have any test cases for them. Note that
the only way I got a test case for this instance was with *heavily* DAG
combined 256-bit shuffle sequences generated by my fuzzer. ;]
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There's no need to do this if the user doesn't call va_start. In the
future, we're going to have thunks that forward these register
parameters with musttail calls, and they won't need these spills for
handling va_start.
Most of the test suite changes are adding va_start calls to existing
tests to keep things working.
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These pointers are really just offsets and they will always be
less than 16-bits. Using AssertZExt allows us to use computeKnownBits
to prove that these values are positive. We will use this information
in a later commit.
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instruction from ARMInstrInfo to ARMBaseInstrInfo.
That way, thumb mode can also benefit from the advanced copy optimization.
<rdar://problem/12702965>
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This (mostly) reverts commit r216119.
Somewhere during the review Reid committed r214980 which fixed this
another way, and I neglected to check that the testcase still failed
before committing.
I've left test/CodeGen/X86/aligned-variadic.ll around in case it adds
extra coverage.
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This adds the missing variable shift support for value type i8, i16, and i32.
This fixes <rdar://problem/18095685>.
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isPow2DivCheap
That name doesn't specify signed or unsigned.
Lazy as I am, I eventually read the function and variable comments. It turns out that this is strictly about signed div. But I discovered that the comments are wrong:
srl/add/sra
is not the general sequence for signed integer division by power-of-2. We need one more 'sra':
sra/srl/add/sra
That's the sequence produced in DAGCombiner. The first 'sra' may be removed when dividing by exactly '2', but that's a special case.
This patch corrects the comments, changes the name of the flag bit, and changes the name of the accessor methods.
No functional change intended.
Differential Revision: http://reviews.llvm.org/D5010
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This is mostly achieved by providing the correct register class manually,
because getRegClassFor always returns the GPR*AllRegClass for MVT::i32 and
MVT::i64.
Also cleanup the code to use the FastEmitInst_* method whenever possible. This
makes sure that the operands' register class is properly constrained. For all
the remaining cases this adds the missing constrainOperandRegClass calls for
each operand.
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This will simplify the SGPR spilling and also allow us to use
MachineFrameInfo for calculating offsets, which should be more
reliable than our custom code.
This fixes a crash in some cases where a register would be spilled
in a branch such that the VGPR defined for spilling did not dominate
all the uses when restoring.
This fixes a crash in an ocl conformance test. The test requries
register spilling and is too big to include.
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This fixes a crash in an ocl conformance test. The test requries
register spilling and is too big to include.
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We discussed the issue of generality vs. readability of the AVX512 classes
recently. I proposed this approach to try to hide and centralize the mappings
we commonly perform based on the vector type. A new class X86VectorVTInfo
captures these.
The idea is to pass an instance of this class to classes/multiclasses instead
of the corresponding ValueType. Then the class/multiclass can use its field
for things that derive from the type rather than passing all those as separate
arguments.
I modified avx512_valign to demonstrate this new approach. As you can see
instead of 7 related template parameters we now have one. The downside is
that we have to refer to fields for the derived values. I named the argument
'_' in order to make this as invisible as possible. Please let me know if you
absolutely hate this. (Also once we allow local initializations in
multiclasses we can recover the original version by assigning the fields to
local variables.)
Another possible use-case for this class is to directly map things, e.g.:
RegisterClass KRC = X86VectorVTInfo<32, i16>.KRC
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The AdvSIMD pass may produce copies that are not coalescer-friendly. The
peephole optimizer knows how to fix that as demonstrated in the test case.
<rdar://problem/12702965>
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There are two add-immediate instructions in Thumb1: tADDi8 and tADDi3. Only
the latter supports using different source and destination registers, so
whenever we materialize a new base register (at a certain offset) we'd do
so by moving the base register value to the new register and then adding in
place. This patch changes the code to use a single tADDi3 if the offset is
small enough to fit in 3 bits.
Differential Revision: http://reviews.llvm.org/D5006
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The FPv4-SP floating-point unit is generally referred to as
single-precision only, but it does have double-precision registers and
load, store and GPR<->DPR move instructions which operate on them.
This patch enables the use of these registers, the main advantage of
which is that we now comply with the AAPCS-VFP calling convention.
This partially reverts r209650, which added some AAPCS-VFP support,
but did not handle return values or alignment of double arguments in
registers.
This patch also adds tests for Thumb2 code generation for
floating-point instructions and intrinsics, which previously only
existed for ARM.
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target hook.
This patch teaches the compiler that:
rX, rY = VMOVRRD dZ
is the same as:
rX = EXTRACT_SUBREG dZ, ssub_0
rY = EXTRACT_SUBREG dZ, ssub_1
<rdar://problem/12702965>
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