This fixes two use-after-frees in selectLEA64_32Addr. If matchAddress
matches an ADD with an AND as an operand, and that AND hits one of the
"heroic transforms" that folds masks and shifts, we end up with N
pointing to an SDNode that was deleted. Make sure we're done accessing
it before that.
Found by ASan with the recycling allocator changes in llvm.org/PR26808.
llvm-svn: 266130
Restrict the max length of long nops for Lakemont to 7. Experiments on MCU
benchmarks (Dhrystone, Coremark) show that this is the most optimal length.
Differential Revision: http://reviews.llvm.org/D18897
llvm-svn: 265924
Extend the existing lowering of vXi8 multiplies to support v64i8 on avx512bw targets.
I added the Lower512IntArith helper function to help with this - not sure how often this could be used in the future, but it seemed better than putting all that logic inside LowerMUL.
Differential Revision: http://reviews.llvm.org/D18937
llvm-svn: 265902
This patch adds support for decoding XOP VPPERM instruction when it represents a basic shuffle.
The mask decoding required the existing MCInstrLowering code to be updated to support binary shuffles - the implementation now matches what is done in X86InstrComments.cpp.
Differential Revision: http://reviews.llvm.org/D18441
llvm-svn: 265874
This is a cleanup patch for SSP support in LLVM. There is no functional change.
llvm.stackprotectorcheck is not needed, because SelectionDAG isn't
actually lowering it in SelectBasicBlock; rather, it adds check code in
FinishBasicBlock, ignoring the position where the intrinsic is inserted
(See FindSplitPointForStackProtector()).
llvm-svn: 265851
As discussed on D18441 - auto brief is used so we don't need /brief, we don't need to include the function name and added some missing descriptions.
llvm-svn: 265785
Re-apply r265450 which caused PR27245 and was reverted in r265559
because of a wrong generalization: the fetch_and_add->add_and_fetch
combine only works in specific, but pretty common, cases:
(icmp slt x, 0) -> (icmp sle (add x, 1), 0)
(icmp sge x, 0) -> (icmp sgt (add x, 1), 0)
(icmp sle x, 0) -> (icmp slt (sub x, 1), 0)
(icmp sgt x, 0) -> (icmp sge (sub x, 1), 0)
Original Message:
We only generate LOCKed versions of add/sub when the result is unused.
It often happens that the result is used, but only by a comparison. We
can optimize those out by reusing EFLAGS, which lets us use the proper
instructions, instead of having to fallback to LXADD.
Instead of doing this as an MI peephole (as we do for the other
non-LOCKed (really, non-MR) forms), do it in ISel. It becomes quite
tricky later.
This also makes it eventually possible to stop expanding and/or/xor
if the only user is an icmp (also see D18141).
This uses the LOCK ISD opcodes added by r262244.
Differential Revision: http://reviews.llvm.org/D17633
llvm-svn: 265636
Third time's the charm? The previous attempt (r265345) caused ASan test
failures on X86, as broken CFI caused stack traces to not work.
This version of the patch makes sure not to merge with stack adjustments
that have CFI, and to not add merged instructions' offests to the CFI
about to be generated.
This is already covered by the lit tests; I just got the expectations
wrong previously.
llvm-svn: 265623
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.
The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).
This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.
As a follow-up I'll add:
bool operator<(AtomicOrdering, AtomicOrdering) = delete;
bool operator>(AtomicOrdering, AtomicOrdering) = delete;
bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.
Reviewers: jyknight, reames
Subscribers: jyknight, llvm-commits
Differential Revision: http://reviews.llvm.org/D18775
llvm-svn: 265602
Bionic has a defined thread-local location for the stack protector
cookie. Emit a direct load instead of going through __stack_chk_guard.
llvm-svn: 265481
Some Include What You Use suggestions were used too.
Use anonymous namespaces in source files.
Differential revision: http://reviews.llvm.org/D18778
llvm-svn: 265454
We only generate LOCKed versions of add/sub when the result is unused.
It often happens that the result is used, but only by a comparison. We
can optimize those out by reusing EFLAGS, which lets us use the proper
instructions, instead of having to fallback to LXADD.
Instead of doing this as an MI peephole (as we do for the other
non-LOCKed (really, non-MR) forms), do it in ISel. It becomes quite
tricky later.
This also makes it eventually possible to stop expanding and/or/xor
if the only user is an icmp (also see D18141).
This uses the LOCK ISD opcodes added by r262244.
Differential Revision: http://reviews.llvm.org/D17633
llvm-svn: 265450
The original commit miscompiled things on 32-bit Windows, e.g. a Clang
boostrap. It turns out that mergeSPUpdates() was a bit too generous in
what it interpreted as a stack adjustment, causing the following code:
addl $12, %esp
leal -4(%ebp), %esp
To be "optimized" into simply:
addl $8, %esp
This commit tightens up mergeSPUpdates() and includes a new test
(test14 in movtopush.ll) for this situation.
llvm-svn: 265345
We can only perform a tail call to a callee that preserves all the
registers that the caller needs to preserve.
This situation happens with calling conventions like preserver_mostcc or
cxx_fast_tls. It was explicitely handled for fast_tls and failing for
preserve_most. This patch generalizes the check to any calling
convention.
Related to rdar://24207743
Differential Revision: http://reviews.llvm.org/D18680
llvm-svn: 265329
Summary:
This adds the same checks that were added in r264593 to all
target-specific passes that run after register allocation.
Reviewers: qcolombet
Subscribers: jyknight, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D18525
llvm-svn: 265313
Implemented truncstore for KNL and skylake-avx512.
Covered vectors from v2i1 to v64i1. We save the value in bits (not in bytes) - v32i1 is saved in 4 bytes.
Differential Revision: http://reviews.llvm.org/D18740
llvm-svn: 265283
Add support for lowering with the MOVMSK instruction to extract vector element signbits to a GPR.
This is an early step towards more optimal handling of vector comparison results.
Differential Revision: http://reviews.llvm.org/D18741
llvm-svn: 265266
Tidied up comments, stripped trailing whitespace, split apart nodes that aren't related.
No change in ordering although there is definitely some scope for it.
llvm-svn: 265263
Follow-up to http://reviews.llvm.org/D18566 and http://reviews.llvm.org/D18676 -
where we noticed that an intermediate splat was being generated for memsets of
non-zero chars.
That was because we told getMemsetStores() to use a 32-bit vector element type,
and it happily obliged by producing that constant using an integer multiply.
The 16-byte test that was added in D18566 is now equivalent for AVX1 and AVX2
(no splats, just a vector load), but we have PR27141 to track that splat difference.
Note that the SSE1 path is not changed in this patch. That can be a follow-up.
This patch should resolve PR27100.
llvm-svn: 265161
Follow-up to D18566 - where we noticed that an intermediate splat was being
generated for memsets of non-zero chars.
That was because we told getMemsetStores() to use a 32-bit vector element type,
and it happily obliged by producing that constant using an integer multiply.
The tests that were added in the last patch are now equivalent for AVX1 and AVX2
(no splats, just a vector load), but we have PR27141 to track that splat difference.
In the new tests, the splat via shuffling looks ok to me, but there might be some
room for improvement depending on uarch there.
Note that the SSE1/2 paths are not changed in this patch. That can be a follow-up.
This patch should resolve PR27100.
Differential Revision: http://reviews.llvm.org/D18676
llvm-svn: 265148
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.
It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.
Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.
Differential Revision: http://reviews.llvm.org/D18627
llvm-svn: 265036
David L Kreitzer