This patch sets the 'KeepReg' bit for any tied and live registers during the PrescanInstruction() phase of the dependency breaking algorithm. It then checks those 'KeepReg' bits during the ScanInstruction() phase to avoid changing any tied registers. For more details, please see comments in:
http://llvm.org/bugs/show_bug.cgi?id=20020
I added two FIXME comments for code that I think can be removed by using register iterators that include self. I don't want to include those code changes with this patch, however, to keep things as small as possible.
The test case is larger than I'd like, but I don't know how to reduce it further and still produce the failing asm.
Differential Revision: http://reviews.llvm.org/D4351
llvm-svn: 212275
The PowerPC 128-bit long double data type (ppcf128 in LLVM) is in fact a
pair of two doubles, where one is considered the "high" or
more-significant part, and the other is considered the "low" or
less-significant part. When a ppcf128 value is stored in memory or a
register pair, the high part always comes first, i.e. at the lower
memory address or in the lower-numbered register, and the low part
always comes second. This is true both on big-endian and little-endian
PowerPC systems. (Similar to how with a complex number, the real part
always comes first and the imaginary part second, no matter the byte
order of the system.)
This was implemented incorrectly for little-endian systems in LLVM.
This commit fixes three related issues:
- When printing an immediate ppcf128 constant to assembler output
in emitGlobalConstantFP, emit the high part first on both big-
and little-endian systems.
- When lowering a ppcf128 type to a pair of f64 types in SelectionDAG
(which is used e.g. when generating code to load an argument into a
register pair), use correct low/high part ordering on little-endian
systems.
- In a related issue, because lowering ppcf128 into a pair of f64 must
operate differently from lowering an int128 into a pair of i64,
bitcasts between ppcf128 and int128 must not be optimized away by the
DAG combiner on little-endian systems, but must effect a word-swap.
Reviewed by Hal Finkel.
llvm-svn: 212274
This operation was classified as a binary operation in the widening
logic for some reason (clearly, untested). It is in fact a unary
operation. Add a RUN line to a test to exercise this for x86.
Note that again the vector widening strategy doesn't regress anything
and in one case removes a totally unecessary instruction that we
couldn't avoid when promoting the element type.
llvm-svn: 212257
mode.
This also runs the test in that mode which would reproduce the crash.
What I love is that *every single FIXME* in the test is addressed by
switching to widening.
llvm-svn: 212254
vector type legalization strategies in a more fine grained manner, and
change the legalization of several v1iN types and v1f32 to be widening
rather than scalarization on AArch64.
This fixes an assertion failure caused by scalarizing nodes like "v1i32
trunc v1i64". As v1i64 is legal it will fail to scalarize v1i32.
This also provides a foundation for other targets to have more granular
control over how vector types are legalized.
Patch by Hao Liu, reviewed by Tim Northover. I'm committing it to allow
some work to start taking place on top of this patch as it adds some
really important hooks to the backend that I'd like to immediately start
using. =]
http://reviews.llvm.org/D4322
llvm-svn: 212242
This includes assembler and codegen support (see the new tests in
avx512-encodings.s and avx512-shuffle.ll).
<rdar://problem/17492620>
llvm-svn: 212221
If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.
While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.
Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.
Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).
llvm-svn: 212203
This reverts commits r212189 and r212190.
While this pass was accidentally disabled (until r212073), r205437
slipped in a use of `auto` that should have been `auto&`.
This fixes PR20188.
llvm-svn: 212201
This reverts commit r212109, which reverted r212088.
However, disable the assert as it's not necessary for correctness. There are
several corner cases that the assert needed to handle better for in-order
scheduling, but none of them are incorrect scheduler behavior. The assert is
mainly there to collect good unit tests like this and ensure that the
target-independent scheduler is working as expected with the various machine
models.
llvm-svn: 212187
On targets without cmpxchg16b or cmpxchg8b, the borderline atomic
operations were slipping through the gaps.
X86AtomicExpand.cpp was delegating to ISelLowering. Generic
ISelLowering was delegating to X86ISelLowering and X86ISelLowering was
asserting. The correct behaviour is to expand to a libcall, preferably
in generic ISelLowering.
This can be achieved by X86ISelLowering deciding it doesn't want the
faff after all.
llvm-svn: 212134
The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..
rdar://problem/13496295
llvm-svn: 212119
AArch64AddressTypePromotion was doing nothing because it was using the
old semantics of `Use` and `uses()`, when it really wanted to get at the
`users()`.
llvm-svn: 212073
separate MDNode so they can be uniqued via folding set magic. To conserve
space, DIVariable nodes are still variable-length, with the last two
fields being optional.
No functional change.
http://reviews.llvm.org/D3526
llvm-svn: 212050
This patch adds support for a new builtin instruction called
__builtin_ia32_rdpmc.
Builtin '__builtin_ia32_rdpmc' is defined as a 'GCC builtin'; on X86, it can
be used to read performance monitoring counters. It takes as input the index
of the performance counter to read, and returns the value of the specified
performance counter as a 64-bit number.
Calls to this new builtin will map to instruction RDPMC.
The index in input to the builtin call is moved to register %ECX. The result
of the builtin call is the value of the specified performance counter (RDPMC
would return that quantity in registers RDX:RAX).
This patch:
- Adds builtin int_x86_rdpmc as a GCCBuiltin;
- Adds a new x86 DAG node called 'RDPMC_DAG';
- Teaches how to lower this new builtin;
- Adds an ISel pattern to select instruction RDPMC;
- Fixes the definition of instruction RDPMC adding %RAX and %RDX as
implicit definitions, and adding %ECX as implicit use;
- Adds a LLVM test to verify that the new builtin is correctly selected.
llvm-svn: 212049
lowering for v16i8.
ASan and some bots caught this bug with existing test cases. Fixing it
even fixed a miscompile with one of the test cases. I'm still a bit
suspicious of this test case as I've not taken a proper amount of time
to think about it, but the fix here is strict goodness.
llvm-svn: 211976
These show up really frequently, not the least with actual splats. =] We
lowered these quite badly before. The new code path tries to widen i8
shuffles to i16 shuffles in a splat-like way. There are still some
inefficiencies in our i16 splat logic though, so we aren't really done
here.
Also, for certain patterns (bit of a gather-and-splat) we still
generate pretty silly code, and I've left a fixme for addressing it.
However, I'm not actually worried about this code pattern as much. The
old shuffle lowering generates a 29 instruction monstrosity for it that
should execute much more slowly.
llvm-svn: 211974
lowering.
For maximum irony, I had already discovered this bug, diagnosed it, and
left FIXMEs about it in the test cases. =[ I just failed to go back over
those until after i had reduced a bootstrap miscompile down to a single
TU, stared at the assembly for an hour, and figured out the bug. Again.
Oh well.
llvm-svn: 211955
The address space of the pointer must be global (1) for these intrinsics. There must also be alignment metadata attached to the intrinsic calls, e.g.
%val = tail call i32 @llvm.nvvm.ldu.i.global.i32.p1i32(i32 addrspace(1)* %ptr), !align !0!0 = metadata !{i32 4}
llvm-svn: 211939
a bootstrap.
I managed to mis-remember how PACKUS worked on x86, and was using undef
for the high bytes instead of zero. The fix is fairly obvious.
llvm-svn: 211922
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
llvm-svn: 211920
